Practical Radiation Oncology - Articles in Press

Radiotherapy following gross total resection of adult soft tissue sarcoma of the head and neck - Corrected Proof

2012-02-20

Abstract: Purpose: This study reports the outcomes of adults with soft tissue sarcoma (STS) of the head and neck following resection and postoperative radiotherapy (RT), and provides a framework for explaining the issues that radiation oncologists must understand to manage patients with this diverse group of tumors.Methods and Materials: Twenty-four patients met the following inclusion criteria of this study: age ≥19 years, head or neck primary site, STS, with the exception of rhabdomyosarcoma, Ewing, or angiosarcoma variants, and curative-attempt treatment with gross total tumor resection followed by RT.Results: All patients underwent gross total tumor resection followed by adjuvant RT at our institution during the 28-year period between June 1, 1981, and December 31, 2009. This is a mature study with a median follow-up of 11 years (range, 0.6-27 years). No patient was lost to follow-up. All recurrences were at the primary site. No patient developed an isolated regional or distant recurrence. No patient developed synchronous nodal or distant recurrences at the time of local recurrence. Half of the recurrences presented within 1 year of completing RT, but there were 2 cases where we did not detect recurrence until years 6 and 8 after RT. No recurrence was successfully salvaged. The actuarial rate of local control and relapse-free survival was 83% (95% CI [confidence interval], 63%-94%) at 5 years and 73% (95% CI, 51%-87%) at 10 years. The incidence of moderate to severe treatment complications was 4%.Conclusions: Our series documents that gross total resection followed by RT cures most patients (75%) with the most common types of STS of the head and neck. All recurrences were local, meaning near the primary site in tissue that received the full RT prescription dose. For this reason, modifying the approach to treatment of the primary tumor site is the only strategy that will meaningfully improve outcomes for this group of patients.

Salvage craniospinal irradiation with an intensity modulated radiotherapy technique for patients with disseminated neuraxis disease - Corrected Proof

Randy L. Wei, Son T. Nguyen, James N. Yang, Johannes Wolff, Anita Mahajan — 2012-02-20

Abstract: Purpose: To report the use and results of a novel intensity modulated radiotherapy (IMRT)-based technique used for salvage craniospinal irradiation (CSI) in 6 patients who developed neuraxis disease after initial high-dose conformal radiotherapy (RT) to the brain.Methods and Materials: After Institutional Review Board approval, all patients treated for disseminated leptomeningeal disease with salvage CSI using IMRT with conventional external beam radiotherapy were identified. The medical records and radiotherapy dosimetry were reviewed. Tolerance, morbidity, tumor control, and overall survival were evaluated.Results: Six patients who received IMRT-based salvage CSI were identified. The median age was 6.5 years (range 2- 34 years) at initial RT and 7.7 years (range, 3-35 years) at salvage CSI. Disease progression necessitating salvage CSI was noted at a median of 10 months (range, 1-26 months) from the initial RT. The original disease site remained well controlled in all 6 patients. The median dose of the initial RT treatment was 52 Gy (range, 30.6-60 Gy). Salvage CSI dose was 36 Gy in 20 fractions in all 6 patients. IMRT was used to treat the cranial contents excluding the previously treated area. Five pediatric patients received electron beams to spine and 1 adult patient received photon beams to spine. IMRT allowed a conformal and uniform dose distribution to the target tissue while excluding previously treated areas. Salvage CSI dose of 36 Gy, delivered using IMRT and 36 Gy using electrons or photons to the spine, proved effective in providing good control of the disease.Conclusions: This technique of salvage CSI was effective in this patient cohort for leptomeningeal dissemination occurring outside of an area of focal irradiation. The technique was well tolerated and thus far has not been associated with any significant toxicity. Salvage therapy has been effective in 4 of the 6 patients thus far.

The efficacy of external beam radiotherapy and stereotactic body radiotherapy for painful spinal metastases from renal cell carcinoma - Corrected Proof

2012-02-17

Abstract: Purpose: Palliative radiotherapy is routinely used to treat painful spinal metastases from renal cell carcinoma (RCC). Conventionally planned external beam radiotherapy (CRT) has been standard, with high-dose stereotactic body radiotherapy (SBRT) becoming increasingly common given the radioresistant nature of RCC. We compared the efficacy and durability of pain relief produced by these 2 modalities.Methods and Materials: Patients with painful spinal metastases from RCC treated from 2002-2010 were included. Response was defined similar to the Radiation Therapy Oncology Group 0631 protocol: complete response (CR) being resolution of pain without increased narcotics; partial response (PR) included patients with an incomplete reduction in pain without increased narcotics. Patients who experienced a CR or PR were coded as having pain relief, while those with persistent pain or additional narcotics requirements were coded as failures. Achievement of pain relief was analyzed using competing risk analysis with death as the competing event. Time to pain relief was plotted using cumulative incidence analysis.Results: A total of 110 patients (34 CRT; 76 SBRT) were included. Median follow-up was 4.3 months (range, 0.2-38). Median Karnofsky performance score was higher for patients treated with SBRT compared with CRT (80 vs 70; P = .0004). Overall pain response rates were 68% for CRT and 62% for SBRT, with respective CR and PR rates of 12% and 56% for CRT, and 33% and 29% for SBRT (P = .01). Median time to pain relief was 0.6 weeks for CRT versus 1.2 weeks for SBRT (P = .29). For patients who achieved pain relief (n = 79), median duration was 1.7 months for CRT versus 4.8 months for SBRT (P = .095). On univariate analysis no factors were significantly related to pain relief.Conclusions: CRT was not statistically different than SBRT for pain relief in symptomatic spine metastases from RCC and should be used as first line treatment. The appropriate use of SBRT in this population merits prospective study.

Evaluation of dose variation to normal and critical structures for lung hypofractionated stereotactic body radiation therapy - Corrected Proof

Heeteak Chung, Laurence Court, Steven H. Lin, Dhananjay Kulkarni, Peter Balter — 2012-02-16

Abstract: Purpose: To quantify the dose received by normal and critical structures during lung stereotactic body radiation therapy (SBRT) when registered to tumor or bone.Methods and Materials: Sixteen patients with lung cancer receiving a total dose of 50 Gy in 4fractions for lung SBRT were retrospectively studied. Cone-beam computed tomography (CT) was performed for all fractions, and the images obtained were registered with planning CT with respect tosoft tissue for target localization. Isocenter shifts were determined for each fraction from differences between the bony and tumor alignments; doses were then recalculated based on the new isocenters and summed over all 4 fractions to compare against the planned normal and critical tissue dose. The normal and critical structures evaluated were total and ipsilateral lung, spinal cord, and esophagus. The first data collected were isocenter coordinate shifts in all 3 Cartesian coordinates for both tumor andbony alignments. The second were the dose differences to the normal and critical structures fromthe planned and recalculated doses for alignment based on the tumor.Results: The study showed that while the maximum isocenter coordinate shifts in any direction couldbe as much as 1.60 cm, the normal and critical structure dose variations between the original plans and the simulated plans showed almost no change. The mean volume of total lung that receivedat least 20Gy difference for total lung and ipsilateral lung were 0.01% and −0.04%, respectively. For the esophagus, spinal cord, and heart the maximum and mean dose differences were 0.25 Gy and −0.04 Gy, −0.08 Gy and −0.02 Gy, and 0.02 Gy and 0.05 Gy, respectively.Conclusions: Target localization using daily cone-beam CT with soft tissue registration was appropriate for minimizing the dose to the normal and critical structures without the need to re-plan due to the changes in the tumor position. For tumors located close to a critical structure, daily cone-beam CT is recommended to determine the appropriate isocenter shifts.

Palliative radiotherapy in patients with esophageal carcinoma: A retrospective review - Corrected Proof

2012-02-13

Abstract: Purpose: Palliative radiotherapy has traditionally been used as a noninvasive means of palliating dysphagia in patients with incurable esophageal cancer. Insertion of an esophageal stent is a traditional alternative and newer treatment modalities such as brachytherapy and laser therapy are being increasingly investigated and employed. There are few large series in the literature which examine the role of short palliative radiotherapy regimens in this patient group. This retrospective review aims to demonstrate the useful role that external beam radiotherapy can have in the palliation of patients with incurable esophageal carcinoma.Methods and Materials: One hundred forty-eight patients with histologically proven esophageal cancer, who were unsuitable for radical treatment, were identified. Notes were reviewed to determine baseline characteristics, indications for radiotherapy, response to treatment, need for further intervention, time to further intervention, and survival.Results: The median age of patients who received palliative radiotherapy was 74 years (range, 31-91). Forty-nine percent of patients (n = 73) were performance status 2 or 3, 70% (n = 103) had adenocarcinoma, 58% (n = 86) had locally advanced disease, and 28% (n = 41) had metastatic disease. Ninety-three percent of patients (n = 138) complained of dysphagia prior to radiotherapy. Eighty-nine percent of patients (n = 132) received a dose of 20 Gy in 5 fractions. Only 2 patients (1%) failed to complete the prescribed course of treatment. Following radiotherapy, 75% of patients experienced an improvement in dysphagia and 25% of patients gained weight. Twenty-six percent of patients (n = 38) required subsequent insertion of an esophageal stent and a further 3% (n = 5) received retreatment with radiotherapy. The median stent (and retreatment)-free survival was 4.9 months. Median overall survival was 6.1 months.Conclusions: Despite a lack of randomized comparison to other modalities, external beam radiotherapy remains an effective, noninvasive, and generally well-tolerated means to palliate dysphagia in selected patients with incurable esophageal carcinoma.

Spot scanning proton therapy for craniopharyngioma - Corrected Proof

2012-02-13

Craniopharyngiomas are histologically benign tumors that represent the third most common pediatric brain tumor. Despite their benign appearance, craniopharyngiomas are locally invasive with a propensity for recurrence. Historically craniopharyngiomas were treated with surgery alone. However, aggressive surgical resection is frequently associated with significant sequealae including endocrinopathies. As early as 1961, groups began to report the benefits of employing more limited surgical resection followed with adjuvant radiation therapy. Radiation therapy now holds a more prominent role in the treatment of craniopharyngiomas when coupled with limited surgical resection., Understandably, fears persist over the long-term complications of irradiation in the developing brain, including cognitive dysfunction, vascular disease, and secondary malignancies. However, in counseling patients and parents the practitioner must also consider the implications of tumor recurrence and additional surgical interventions.

Contouring inguinal and femoral nodes; how much margin is needed around the vessels? - Corrected Proof

Carolyn H. Kim, Adam C. Olson, Hayeon Kim, Sushil Beriwal — 2012-02-10

Abstract: Purpose: To determine the optimal margin needed around the femoral vessels for appropriate inguinofemoral lymph node coverage and to propose guidelines defined by anatomic boundaries for clinical target volume delineation.Methods and Materials: Twenty-two patients with pelvic malignancies and involved inguinal lymph nodes treated with conformal radiation therapy were selected. Lymph nodes were considered positive if they were pathologically malignant by biopsy, had 18F-fluorodeoxyglucose avidity on positron emission tomography or measured ≥1.5 cm on computed tomographic scan. We measured distance from the center of node(s) to the edge of the nearest femoral vessel.Results: There were 52 total positive inguinal nodes among 22 patients. Relative to the femoral vessels, the location of the nodes were 51.9% anteromedial, 21.2% anterior, 11.5% anterolateral, 9.6% medial, 1.9% posterior, and 3.9% lateral. To cover ≥90% disease, the margins needed around the nearest femoral vessel were anteromedial ≥35 mm, anterior ≥23 mm, anterolateral ≥25 mm, medial ≥22 mm, posterior ≥9 mm, and ≥32 mm lateral. The corresponding anatomic boundaries were the following: laterally, medial border of the iliopsoas; medially, lateral border of adductor longus or medial end of pectineus; posteriorly, iliopsoas muscle laterally and anterior aspect of the pectineus muscle; medially and anteriorly, the anterior edge of the sartorius muscle. Most of the macroscopic nodes were medial or anteromedial to the femoral vessels. No patient had involved posterior or lateral nodes alone without positive nodes in the anterior or anteromedial positions.Conclusions: Circumferential margins around femoral vessels required to adequately cover this nodal region were >2 cm in most directions. Contouring the inguinal lymph nodes as a compartment defined by the anatomic landmarks suggested above may be more reproducible. Physicians should exercise caution in extrapolating pelvic nodal contouring guidelines to inguinal lymph nodal contouring.

Plan quality and treatment planning technique for single isocenter cranial radiosurgery with volumetric modulated arc therapy - Corrected Proof

2012-02-01

Abstract: Purpose: To demonstrate plan quality and provide a practical, systematic approach to the treatment planning technique for single isocenter cranial radiosurgery with volumetric modulated arc therapy (VMAT; RapidArc, Varian Medical systems, Palo Alto, CA).Methods and materials: Fifteen patients with 1 or more brain metastases underwent single isocenter VMAT radiosurgery. All plans were normalized to deliver 100% of the prescription dose to 99%-100% of the target volume. All targets per plan were treated to the same dose. Plans were created with dose control tuning structures surrounding targets to maximize conformity and dose gradient. Plan quality was evaluated by calculation of conformity index (CI = 100% isodose volume/target volume) and homogeneity index (HI = maximum dose/prescription dose) scores for each target and a Paddick gradient index (GI = 50% isodose volume/100% isodose volume) score for each plan.Results: The median number of targets per patient was 2 (range, 1-5). The median number of non-coplanar arcs utilized per plan was 2 (range, 1- 4). Single target plans were created with 1 or 2 non-coplanar arcs while multitarget plans utilized 2 to 4 non-coplanar arcs. Prescription doses ranged from 5-16 Gy in 1-5 fractions. The mean conformity index was 1.12 (± SD, 0.13) and the mean HI was 1.44 (± SD, 0.11) for all targets. The mean GI per plan was 3.34 (± SD, 0.42).Conclusions: We have outlined a practical approach to cranial radiosurgery treatment planning using the single isocenter VMAT platform. One or 2 arc single isocenter plans are often adequate for treatment of single targets, while 2-4 arcs may be more advantageous for multiple targets. Given the high plan quality and extreme clinical efficiency, this single isocenter VMAT approach will continue to become more prevalent for linac-based radiosurgical treatment of 1 or more intracranial targets and will likely replace multiple isocenter techniques.

Radiotherapeutic and surgical management for newly diagnosed brain metastasis(es): An American Society for Radiation Oncology evidence-based guideline - Corrected Proof

2012-02-01

Abstract: Purpose: To systematically review the evidence for the radiotherapeutic and surgical management of patients newly diagnosed with intraparenchymal brain metastases.Methods and Materials: Key clinical questions to be addressed in this evidence-based Guideline were identified. Fully published randomized controlled trials dealing with the management of newly diagnosed intraparenchymal brain metastases were searched systematically and reviewed. The U.S. Preventative Services Task Force levels of evidence were used to classify various options of management.Results: The choice of management in patients with newly diagnosed single or multiple brain metastases depends on estimated prognosis and the aims of treatment (survival, local treated lesion control, distant brain control, neurocognitive preservation).Single brain metastasis and good prognosis (expected survival 3 months or more): For a single brain metastasis larger than 3 to 4 cm and amenable to safe complete resection, whole brain radiotherapy (WBRT) and surgery (level 1) should be considered. Another alternative is surgery and radiosurgery/radiation boost to the resection cavity (level 3). For single metastasis less than 3 to 4 cm, radiosurgery alone or WBRT and radiosurgery or WBRT and surgery (all based on level 1 evidence) should be considered. Another alternative is surgery and radiosurgery or radiation boost to the resection cavity (level 3). For single brain metastasis (less than 3 to 4 cm) that is not resectable or incompletely resected, WBRT and radiosurgery, or radiosurgery alone should be considered (level 1). For nonresectable single brain metastasis (larger than 3 to 4 cm), WBRT should be considered (level 3).Multiple brain metastases and good prognosis (expected survival 3 months or more): For selected patients with multiple brain metastases (all less than 3 to 4 cm), radiosurgery alone, WBRT and radiosurgery, or WBRT alone should be considered, based on level 1 evidence. Safe resection of a brain metastasis or metastases causing significant mass effect and postoperative WBRT may also be considered (level 3).Patients with poor prognosis (expected survival less than 3 months): Patients with either single or multiple brain metastases with poor prognosis should be considered for palliative care with or without WBRT (level 3).It should be recognized, however, that there are limitations in the ability of physicians to accurately predict patient survival. Prognostic systems such as recursive partitioning analysis, and diagnosis-specific graded prognostic assessment may be helpful.Conclusions: Radiotherapeutic intervention (WBRT or radiosurgery) is associated with improved brain control. In selected patients with single brain metastasis, radiosurgery or surgery has been found to improve survival and locally treated metastasis control (compared with WBRT alone).

The role of radiation oncologists and discussion of fertility preservation in young cancer patients - Corrected Proof

Clement K. Gwede, Susan T. Vadaparampil, Sarah Hoffe, Gwendolyn P. Quinn — 2012-01-27

Abstract: Purpose: The risk of infertility increases after cancer treatment with chemotherapy, with radiotherapy, and in some cases with surgery. The goal of these secondary analyses was to examine potential differences in practice behaviors, specifically referral and discussion of fertility preservation, among oncologists (ie, surgical oncologists, medical oncologists, and radiation oncologists).Methods and Materials: Two items examining discussion and referral for fertility preservation were administered as part of a larger 53-item survey measuring oncologists’ fertility preservation knowledge, practice behaviors, and attitudes was developed and mailed to a nationally representative, stratified, random sample of US oncology care physicians.Results: There was a significant difference by oncology subspecialty in discussion of the impact of treatment on future fertility for cancer patients of childbearing age. Follow-up χ2 tests of discussion and specialty showed 82% of radiation oncologists “always/often” discussed the impact of treatment on fertility, compared with 51% for surgical oncologists. There was not a significant difference between oncology specialty and reported referrals to reproductive endocrinologist with 24% to 31% of all oncologist types reporting “rarely/never” referring patients of child-bearing age to an infertility specialist or reproductive endocrinologist.Conclusions: These findings are important particularly for radiation oncologists, who may have a unique role in communicating fertility preservation options to their patients given their opportunity for multiple patient encounters. As such, there is a notable opportunity for further research into the reasons why and how to implement provider education about fertility preservation to improve quality of life and quality care for patients of reproductive potential.

Variation in external beam treatment plan quality: An inter-institutional study of planners and planning systems - Corrected Proof

2012-01-11

Abstract: Purpose: This study quantifies variation in radiation treatment plan quality for plans generated by a population of treatment planners given very specific plan objectives.Methods and Materials: A “Plan Quality Metric” (PQM) with 14 submetrics, each with a unique value function, was defined for a prostate treatment plan, serving as specific goals of a hypothetical “virtual physician.” The exact PQM logic was distributed to a population of treatment planners (to remove ambiguity of plan goals or plan assessment methodology) as was a predefined computed tomographic image set and anatomic structure set (to remove anatomy delineation as a variable). Treatment planners used their clinical treatment planning system (TPS) to generate their best plan based on the specified goals and submitted their results for analysis.Results: One hundred forty datasets were received and 125 plans accepted and analyzed. There was wide variability in treatment plan quality (defined as the ability of the planners and plans to meet the specified goals) quantified by the PQM. Despite the variability, the resulting PQM distributions showed no statistically significant difference between TPS employed, modality (intensity modulated radiation therapy versus arc), or education and certification status of the planner. The PQM results showed negligible correlation to number of beam angles, total monitor units, years of experience of the planner, or planner confidence.Conclusions: The ability of the treatment planners to meet the specified plan objectives (as quantified by the PQM) exhibited no statistical dependence on technologic parameters (TPS, modality, plan complexity), nor was the plan quality statistically different based on planner demographics (years of experience, confidence, certification, and education). Therefore, the wide variation in plan quality could be attributed to a general “planner skill” category that would lend itself to processes of continual improvement where best practices could be derived and disseminated to improve the mean quality and minimize the variation in any population of treatment planners.

Novel setup techniques for radiation treatment of severely obese patients with cervical cancer - Corrected Proof

Alexander C Whitley, Brendan M. Prendergast, Robert Y. Kim — 2012-01-09

The prevalence of overweight (body mass index [BMI] > 25 kg/m2) and obesity (BMI >30 kg/m2) in the United States currently exceeds two-thirds of the adult population. Obesity and severe obesity (BMI > 40 kg/m2) may impact the management of early-stage cervical cancer, where surgical resection is often the preferred treatment. Due to medical comorbidities and surgical risks, these patients are often not considered surgical candidates, and definitive radiation or chemoradiation may be the only curative option.

Screening colonoscopy before prostate cancer treatment can detect colorectal cancers in asymptomatic patients and reduce the rate of complications after brachytherapy - Corrected Proof

2012-01-06

Abstract: Purpose: To investigate the incidence of undiagnosed, asymptomatic synchronous colorectal cancer (CRC) by using screening colonoscopy before brachytherapy, and to compare the subsequent rates of CRC and rectal toxicity in this screened population with those rates in unscreened patients after brachytherapy.Methods and Materials: Patient, disease, and treatment characteristics, including history of colonoscopy and CR malignancy, were extracted from the medical records of all men who had undergone brachytherapy as monotherapy for low- or intermediate-risk prostate cancer at a single tertiary cancer care center between January 2000 and December 2009. The frequency of biopsy or polypectomy at screening colonoscopy, incidence of CR malignancy before and after prostate cancer diagnosis, and rate of brachytherapy toxicity including rectal bleeding were compared between men who had had screening colonoscopy before brachytherapy and men who had not.Results: Of the 451 men identified, 268 had undergone screening colonoscopy during the 36 months before brachytherapy and 183 had not. Of the 268 men who had had screening colonoscopy, 117 (44%) underwent biopsy or polypectomy, and 6 (3.2%) were found to have asymptomatic CRC. After brachytherapy, CRC was diagnosed in 3 (1.6%) of the 183 men who had not had screening colonoscopy before treatment versus 0 of the 268 men who had had screening colonoscopy (P = 0.035). Rectal toxicity was more common and more severe among men who had not undergone screening colonoscopy compared with those who had had screening colonoscopy before brachytherapy (14% vs 6%, P = 0.003). More unscreened patients (18% vs 5%) underwent postbrachytherapy colonoscopy (P < 0.001), with the potential of subjecting the irradiated rectum to biopsy.Conclusions: More than 3% of men with newly diagnosed prostate cancer in this study presented with undiagnosed, asymptomatic CRC, and the rate of postbrachytherapy rectal complications was higher among unscreened than among screened patients. We recommend screening colonoscopy for men who have not had CRC screening within the 3 years preceding prostate cancer diagnosis before radiation therapy to avoid unnecessary rectal biopsies and the associated risk of major complications.

Radiotherapy for hilar or mediastinal lymph node metastases after definitive treatment with stereotactic body radiotherapy or surgery for stage I non-small cell lung cancer - Corrected Proof

2012-01-03

Abstract: Purpose: Management of regional lymph node (LN) recurrence is an important issue in definitive treatment of non-small cell lung cancer (NSCLC). We evaluated clinical outcomes of conventional radiotherapy for hilar or mediastinal LN metastases developing after stereotactic body radiotherapy (SBRT) or surgery for stage I NSCLC.Methods and Materials: Between 2004 and 2008, 26 patients with hilar or mediastinal LN metastases without local recurrence and distant metastasis after SBRT (n = 14) or surgery (n = 12) were treated with conventional radiotherapy. Twelve of the 14 post-SBRT patients (86%) were judged medically inoperable at the time of SBRT. All patients were treated to the hilum and mediastinum with conventional daily fractions of 2.0 Gy (n = 25) or 2.4 Gy (n = 1). The median total dose for treating metastatic LN was 60 Gy (range, 54-66 Gy) for the post-SBRT patients and 65 Gy (range, 60-66 Gy) for the post-surgery patients. Only 1 of the 14 post-SBRT patients and 8 of the 12 post-surgery patients received chemotherapy.Results: For all 26 patients, the overall and cause-specific survival rates at 3 years from radiation for LN metastases were 36% and 51%, respectively (14% and 39%, respectively, for the 14 post-SBRT patients and both 64% for the 12 post-surgery patients). Three of the SBRT patients were alive at 35 to 43 months with (n = 2) or without (n = 1) further recurrence, and 4 of the post-surgery patients were alive at 36 to 62 months with (n = 2) or without (n = 2) further recurrence. The incidence of ≥grade 2 pulmonary toxicity was 49% at 1 year (53% for post-SBRT patients and 44% for post-surgery patients). A grade 5 pulmonary toxicity was observed in 1 of the post-SBRT patients.Conclusions: Conventional radiotherapy could successfully salvage LN relapses after SBRT as well as after surgery in 7 of 26 patients. Radiotherapy in this setting appears reasonably well tolerated.

Can trained volunteers provide psychosocial support to patients undergoing radiotherapy? The perspective of patients and volunteers - Corrected Proof

2011-12-26

Abstract: Purpose: Clinic-based psychosocial interventions, including volunteer-based ones, may be a cost-efficient and acceptable means of integrating psychosocial support into cancer care during radiotherapy. The present study evaluated a new psychosocial volunteer support program in a large radiotherapy clinic.Methods and Materials: Patients were asked to complete a demographic and satisfaction with care questionnaire. Clinic volunteers were asked to report their interactions with patients on shift logs.Results: Of the 182 participating patients, 93 (51%) recalled meeting a volunteer in the clinic, with the 2 most common support types provided being the following: “listening and caring,” and “information on services.” Analysis of 224 volunteers' shift logs indicated that almost all interactions (94%) were initiated by the volunteers, and almost half (47%) involved the patients' companions in the clinic. The most common support type documented was “information and navigation” (71%), followed by “emotional” (47%), “diversional” (21%), and “physical/practical” (17%) support.Conclusions: Trained volunteers can effectively provide clinic-based psychosocial support and information to a high proportion of radiotherapy patients. These findings demonstrate that volunteer support is a feasible means of meeting the psychosocial needs of patients with cancer attending outpatient radiotherapy clinics, who may not require or want professional psychosocial support.

The impact of class III (morbid) obesity on heterotopic ossification outcomes - Corrected Proof

2011-12-21

Abstract: Purpose: Obesity is associated with a chronic low inflammatory process that may act as common soil for the pathogenesis of obesity-related comorbidities including heterotopic ossification (HO). The purpose of this study is to compare the incidence of HO between patients with body mass index (BMI) <40 versus ≥40 after operative treatment of displaced acetabular fractures followed by radiation therapy (RT) ± indomethacin.Methods and Materials: This is a single institution retrospective chart review of 419 patients. All patients with well-documented BMI underwent operative treatment followed by RT ± indomethacin. All patients received 700 cGy to the soft tissues around the proximal femur and acetabulum without bone shielding. All RT were given postoperatively within 72 hours. The patients were divided into 2 groups: Group (A) BMI < 40 and Group (B) BMI ≥40. HO was assessed with X-ray. BMI was used as a surrogate measure to test the risk of HO despite prophylaxis.Results: The incidence of HO among all patients is 21% (89 of 419), while among those in group A (BMI <40), 68 of 374 patients developed HO (18%); in the morbidly obese group (BMI ≥40) 21of 45 patients developed HO (47%). The difference between the rates of HO in the 2 groups was 29%; the χ2 test showed a significant difference between the 2 BMI groups (P < .001 at α = 0.05).Conclusions: There is a higher incidence of HO among the morbidly obese patients despite RT ± indomethacin. RT doses for HO prophylaxis in morbidly obese patients need to be reassessed; also, understanding the signaling pathways in target tissues in obese patients at which adipokines control metabolism may reveal novel therapies. Higher radiation doses ± indomethacin may need to be considered and optimally evaluated in the context of a prospective, randomized clinical trial.

Planning comparison of intensity modulated radiation therapy delivered with 2 tangential fields versus 3-dimensional conformal radiotherapy for cardiac sparing in women with left-sided breast cancer - Corrected Proof

Neil K. Taunk, Robert G. Prosnitz — 2011-12-15

Abstract: Purpose: In women with unfavorable thoracic anatomy undergoing left breast radiation therapy (RT) after breast-conserving surgery, a significant volume of the heart may receive high-dose radiation, which has been shown previously to be associated with increased late cardiac morbidity and mortality. Use of intensity modulated radiation therapy (IMRT) has been proposed to reduce cardiac dose in these patients. We compared cardiac exposure from IMRT delivered from 2 opposed fields and 3-dimensional conformal radiation therapy (3DCRT) plans employing simple heart blocks.Methods and Materials: Fourteen patients with left-sided breast cancer treated with breast-conserving surgery and RT were identified to have unfavorable cardiac anatomy, defined as maximum heart depth (MHD) ≥1.0 cm within the unblocked opposed tangential fields. 3DCRT plans utilized dynamic wedges, segments, and custom heart blocks designed by the treating physician. Tangent IMRT plans were optimized to reduce cardiac dose while maintaining planning target volume (PTV) coverage equal to that achieved with the 3DCRT plan. We generated tangential field plans with complete heart block (CHB) or no heart block (NHB) for comparison. Plans were normalized to deliver 46 Gy to the PTV. Dose to the heart, PTV, and lumpectomy cavity were compared.Results: Mean MHD was 1.44 cm (1.0-1.86 cm). There was no significant difference in PTV receiving >95% of the prescription dose between 3DCRT and IMRT, as intended. Mean V30 to the heart was 0% for CHB plans, 1.7% for 3DCRT plans, 1.8% for IMRT plans, and 3.3% for NHB plans, respectively. There was no significant difference in heart V30 for 3DCRT and IMRT plans (P = .8). IMRT plans delivered 256 total monitor units compared with 201 in 3DCRT plans (P < .01).Conclusions: Inverse-planned tangent IMRT does not reduce high-dose radiation to the heart compared with 3DCRT, incorporating a simple heart block in women with left-sided cancer and unfavorable cardiac anatomy when PTV coverage was equalized for both plans. In select patients with early-stage breast cancer and unfavorable thoracic anatomy, 3DCRT with heart block may be sufficient to adequately protect the heart from high-dose radiation.

Preservation of adrenal function after successful stereotactic body radiation therapy of metastatic renal cell carcinoma involving the remaining contralateral adrenal gland - Corrected Proof

2011-12-12

Renal cell carcinoma (RCC) metastases have been reported in almost every organ. The most common involved organs are the lungs, liver, kidneys, bones, and brain. Autopsy series have reported RCC adrenal metastases rates ranging from 7% to 19%. Contralateral adrenal involvement is rare. In one study the incidence was 2.5%. In addition contralateral adrenal metastases from RCC can present late, even after 23 years from primary tumor resection. Such unusual delay in presentation, infrequent occurrence, and confusing clinical presentation can lead to misdiagnosis, delayed diagnosis, or failure to treat promptly.

Stereotactic body radiation therapy and 3-dimensional conformal radiotherapy for stage I non-small cell lung cancer: A pooled analysis of biological equivalent dose and local control - Corrected Proof

2011-12-05

Abstract: Purpose: To determine the relationship between tumor control probability (TCP) and biological effective dose (BED) for radiation therapy in medically inoperable stage I non-small cell lung cancer (NSCLC).Methods and Materials: Forty-two studies on 3-dimensional conformal radiation therapy (3D-CRT) and SBRT for stage I NSCLC were reviewed for tumor control (TC), defined as crude local control ≥ 2 years, as a function of BED. For each dose-fractionation schedule, BED was calculated at isocenter using the linear quadratic (LQ) and universal survival curve (USC) models. A scatter plot of TC versus BED was generated and fitted to the standard TCP equation for both models.Results: A total of 2696 patients were included in this study (SBRT: 1640; 3D-CRT: 1056). Daily fraction size was 1.2-4 Gy (total dose: 48-102.9) with 3D-CRT and 6-26 (total dose: 20-66) with SBRT. Median BED was 118.6 Gy (range, 68.5-320.3) and 95.6 Gy (range, 46.1-178.1) for the LQ and USC models, respectively. According to the LQ model, BED to achieve 50% TC (TCD50) was 61 Gy (95% confidence interval, 50.2-71.1). TCP as a function of BED was sigmoidal, with TCP ≥ 90% achieved with BED ≥ 159 Gy and 124 Gy for the LQ and USC models, respectively.Conclusions: Dose-escalation beyond a BED 159 by LQ model likely translates into clinically insignificant gain in TCP but may result in clinically significant toxicity. When delivered with SBRT, BED of 159 Gy corresponds to a total dose of 53 Gy in 3 fractions at the isocenter.

Neoadjuvant chemoradiation followed by interstitial prostate brachytherapy for synchronous prostate and rectal cancer - Corrected Proof

Haoming Qiu, Joseph M. Herman, Nita Ahuja, Theodore L. DeWeese, Danny Y. Song — 2011-12-02

Abstract: Purpose: To describe outcomes with the use of neoadjuvant pelvic chemoradiation followed by prostate interstitial brachytherapy for the treatment of synchronous prostate and rectal cancers.Methods and Materials: An Internal Review Board approved retrospective review was undertaken of 4 patients with synchronous prostate and rectal cancer treated between 2006 and 2008. Patients underwent pelvic chemoradiation followed by prostate brachytherapy, then low anterior resection of the rectum with diverting loop ileostomy and adjuvant chemotherapy. Follow-up evaluation included imaging and laboratory analysis of cancer markers in addition to routine interval history and physical examination.Results: At 38-62 months postdiagnosis (24-53 months post-treatment), 6 of 8 cancers remained without evidence of relapse. One patient had rising carcinoembryonic antigen levels but no clinically evident rectal cancer relapse; another developed bony metastasis of his high-risk prostate cancer. Three patients experienced grade 1-2 treatment-related toxicity; one patient had grade 3 gastrointestinal toxicity from radiation and surgery, which precluded his receiving adjuvant chemotherapy and ileostomy reversal.Conclusions: Chemoradiation followed by prostate brachytherapy, surgery, and adjuvant chemotherapy may be utilized to manage patients with synchronous prostate and rectal cancers.

Continuous localization technologies for radiotherapy delivery: Report of the American Society for Radiation Oncology Emerging Technology Committee - Corrected Proof

2011-11-21

An active arena for technological advancement in radiation oncology treatment delivery has focused on the motion inherent in target structures and normal organs. With the advances over the last decade (and more so within the last few years), in intensity modulated radiation therapy (IMRT), stereotactic radiosurgery (SRS)/radiotherapy and stereotactic body radiotherapy (SBRT), and image-guided radiation therapy, it has become critical to position patients in the treatment positions precisely and reproducibly. To address these localization issues, devices have been developed that may be implanted in the organ or volume of interest and tracked during and between treatments

De-intensification of treatment for human papilloma virus associated oropharyngeal squamous cell carcinoma: A discussion of current approaches - Corrected Proof

Sagar C. Patel, Trevor Hackman, David Neil Hayes, Bhishamjit S. Chera — 2011-11-18

The chemoradiotherapy (CRT) regimen for most oropharyngeal squamous cell carcinoma (OPSCC) is 70 Gy with concurrent cisplatin 100 mg/m2 × 3 cycles. Possibly less intensive chemotherapy, radiation therapy (RT), or surgery may be just as effective in HPV-associated OPSCC. Herein we report on a human papilloma virus (HPV)-associated OPSCC patient who obtained a pathologic complete response after receiving an incomplete course of CRT and discuss the current approaches for de-intensified treatment.

Angiosarcoma of the breast following breast conservation therapy: A case report and review of the literature - Corrected Proof

Sudha B. Mahalingam, Sarah McDonough — 2011-11-17

Breast conservation for early-stage breast cancer has become the standard of care in the last 2 decades. As part of breast conservation therapy (BCT), whole breast irradiation following lumpectomy is increasingly used, with many women surviving long term after treatment. Radiation-induced tumors typically occur after a latent period of several years. Sarcomas comprise 12% of these radiation-induced tumors. Among these, fibrosarcomas and chondrosarcomas have been described. Angiosarcomas, however, are rare, comprising only 1% of all soft tissue sarcomas; because they are malignant tumors arising from the vascular endothelium, more commonly they involve skin and subcutaneous tissues. Only 8% of angiosarcomas occur in the breast; of these, primary sarcomas are extremely rare. The first case of secondary angiosarcoma of the breast following breast conservation therapy was described in 1987; since then, 221 cases have been reported world wide. Few of these cases of secondary angiosarcomas have been reported following postmastectomy chest wall radiation therapy. We describe in this report the clinical course of a patient who developed angiosarcoma of the irradiated breast 8 years following BCT.

Current clinical coverage of Radiation Therapy Oncology Group-defined target volumes for postmastectomy radiation therapy - Corrected Proof

2011-11-16

Abstract: Purpose: The Radiation Therapy Oncology Group (RTOG) has published consensus guidelines for contouring relevant anatomy for postmastectomy radiation therapy (RT). How these contours relate to current treatment practices is unknown. We analyzed the dose-volume histograms (DVHs) for these contours using current clinical practice at University of Texas MD Anderson Cancer Center and compared them with the proposed treatment plans to treat RTOG-defined targets to full dose.Methods and Materials: We retrospectively analyzed treatment plans for 20 consecutive women treated with postmastectomy RT for which the treatment targets were the chest wall (CW), level III axilla (Ax3), supraclavicular (SCV), and internal mammary (IM) nodes. The RTOG consensus definitions were used to contour the following anatomic structures: CW; level I, II, and III axillary nodes (Ax1, Ax2, Ax3); SCV; IM; and heart (H). DVHs for these contours and the ipsilateral lung were generated from clinically designed treatment that had actually been delivered to each patient. For comparison regarding dose to normal tissue, new treatment plans were generated with the goal of covering 95% of the anatomic contours to 45 Gy.Results: The prescribed dose was 50 Gy in each case. The mean percent of volumes that received 45 Gy (V45) for the RTOG guideline-based contours were CW 74%, Ax1 84%, Ax2 88%, Ax3 96%, SCV 84%, and IM 80%. Mean heart V10 values were 11% for treatment of left-sided tumors and 6% for right-sided tumors. Mean ipsilateral lung V20 values were 28% for left-sided tumors and 34% for right-sided tumors. For the contour-based plans, mean V45 values were CW 94%, Ax1 95%, Ax2 97%, Ax3 98%, SCV 98%, and IM 85%. Mean heart V10 values were 14% for treatment of left-sided tumors and 12% for right-sided tumors. Mean ipsilateral lung V20 values were 32% for left-sided tumors and 45% for right-sided tumors.Conclusions: Clinically derived treatment plans, which have proven efficacy and are the current standard, cover 74% to 96% of the anatomy-based RTOG consensus volumes to the prescription dose. This discrepancy should be considered if treatment planning protocol guidelines are designed to incorporate these new definitions.

Three-dimensional visualization and dosimetry of stranded source migration following prostate seed implant - Corrected Proof

Sarah Daniel, Cyrus Rabbani, Amr Aref, Roy Taylor, Divya Patel, Paul J. Chuba — 2011-11-09

Abstract: Purpose: Computed tomographic (CT) imaging was used to determine the displacement of stranded seeds between day 0 and day 30 following prostate seed implants. Post-plan dosimetry was used to assess the dosimetric consequence of strand displacement.Methods and Materials: Between March 2006 and December 2009, 86 prostate seed implant patients had day 0 and day 30 post-plan CT imaging. Migrated strands were first identified by inspection of day 0 and day 30 scans. The exact distance of displacement was measured using 3-dimensional fusion software. Post-plan dosimetric analysis was performed using CMS software.Results: Of the 1550 strands placed, 23 strands exhibited substantial movement and these displacements occurred in 21 of the 86 cases. The measured distance of strand movement ranged from 0.31 cm to 3.44 cm, with mean displacement of 2.75 cm. Of the displaced strands, 15 strands moved away from the implant center while 8 strands moved toward the implant center. A comparison of changes in dosimetric parameters between day 0 and day 30 revealed expected increases in D90 related to resolution of prostate edema. When cases of strand displacement were compared with cases without displacement, there were no differences in D90 or V100 at day 0. At day 30, however, statistically significant decreases in D90 (96.8% vs 89.5%; P = .0061) and V100 (85.9% vs 82.2%; P = .046) were noted for cases with strand displacement. When the data were analyzed by looking at the change in dosimetric parameters over time for each individual case (eg, comparing the difference in D90 from day 0 to day 30 per patient) there was a trend toward decrease in D90 with displacement of the strands but this did not achieve statistical significance (P = .09).Conclusions: Stranded seeds show unexpected spatial instability in the craniocaudal dimension. Strand displacement may occur in approximately 1.5% of stranded sources placed and about 25% of cases. One may expect mean decreases in D90 and V100 of about 7% and 3%, respectively, among cases exhibiting strand migration in the first month following seed implant. Resolution of prostate edema during the same time period accounts for an approximately 30% increase in D90 and V100.

Determination of internal target volume using selective phases of a 4-dimensional computed tomography scan - Corrected Proof

2011-10-31

Abstract: Purpose: Internal target volume (ITV) is frequently determined by contouring of gross tumor volumes (GTV) on 10 phases of a 4-dimensional computed tomography (4DCT) study set for lung cancer radiotherapy. This study aimed to investigate the possibility of generating ITV by using selective phases of a 4DCT scan.Methods and Materials: The 4DCT scans of 20 patients with lung cancer were included in this study. GTVs were contoured on 10 phases in Focal4D (CMS, St Louis, MO). Different ITVs were derived by encompassing volumes of contours from selective phases. ITV10 was the combination of GTVs on all of the 10 phases and served as the gold standard volume. All of the other ITVs were smaller and within ITV10. The ratios of the volumes of these ITVs to ITV10 were calculated and used as a criterion to determine the similarity of different ITVs to ITV10. ITV2 represented the ITV derived by using end-inhalation and end-exhalation (0% + 50%). ITV3E was derived from contouring the 3 phases at end-inhalation, mid-exhalation, and end-exhalation (0% + 20% + 50%). ITV3I was derived from contouring the 3 phases at end-inhalation, mid-inhalation, and end-exhalation (0% + 70% + 50%). ITV4 was derived by contouring the 4 phases at end-inhalation, mid-inhalation, end-exhalation, and mid-exhalation (0% + 20% + 50% + 70%). ITV6E was derived from contouring the 6 consecutive phases during exhalation (0% + 10% + 20% + 30% + 40% + 50%). ITV6I was derived from contouring the 6 consecutive phases during inhalation (50% + 60% + 70% + 80% + 90% + 0%). The volumes of ITVs were calculated and compared.Results: ITV6I showed excellent agreement with ITV10 (volume ratio ITV6I/ITV10 = 0.975). ITV4 and ITV6E showed good agreement with ITV10 (ITV6E/ITV10 = 0.939, ITV4/ITV10 = 0.944). The volume ratios ITV3I/ITV10 and ITV3E/ITV10 were 0.927 and 0.906, respectively. ITV2 did not agree well with ITV10 (ITV2/ITV10 = 0.888).Conclusions: Contouring all phases during inhalation provides a good estimate of the ITV. However, the ITV may be underestimated if only contouring on 2 extreme phases.

Nelfinavir treatment of adenoid cystic carcinoma: A case report - Corrected Proof

2011-10-28

Adenoid cystic carcinoma (ACC) accounts for about 1% of all head and neck cancers and most commonly arises from the major and minor salivary glands, but may also develop in other sites. Complete resection with negative margins, the recommended surgical treatment, is commonly compromised by extensive perineural spread. Anatomic constraints such as extension to or through the skull base may also preclude meaningful resection, in which case the standard postoperative radiation therapy may serve as primary therapy instead. Despite displaying an indolent behavior, ACC is highly lethal. Disease-free survival at 5 years is around 50% and decreases to 30% to 40% at 15 years. Management options for recurrence are usually limited by the location and extent of the cancer (which is often metastatic), precluding further surgery or reirradation. Systemic treatment has been limited to toxic chemotherapy regimens with low efficacy. As a result, management of recurrent disease warrants further investigation.

Presumed early-stage lung cancer treated with stereotactic body radiation therapy in a medically inoperable patient with multiple connective tissue disorders - Corrected Proof

Michelle A. Stinauer, Brian D. Kavanagh, John D. Mitchell — 2011-10-20

Patients with medically inoperable early stage non-small cell lung cancer are now routinely offered definitive treatment with stereotactic body radiation therapy (SBRT), which achieves excellent local control and provides a 3-year survival on the order of 60%, with less than 5% chance of severe toxicity. However, the same medical comorbidities that make patients inoperable, such as diabetes and hypertension, are also thought to increase the risk of toxicity from radiation therapy. In general the comorbidities that may predispose patients to greater toxicity involve microvascular pathology. Connective tissue disorders (CTDs), including scleroderma, systemic lupus erythematous (SLE), dermatomyositis, polymyositis, rheumatoid arthritis, Sjögren’s syndrome, and mixed CTDs, have traditionally been considered a relative contraindication to radiation therapy since the effects on normal tissues could possibly be severe.

Assessing the risk of inadvertent radiation exposure of pregnant patients during radiation therapy planning and treatment in British Columbia - Corrected Proof

2011-10-10

Abstract: Purpose: To explore health care professionals' perceptions of, and experience with, the risk of inadvertent radiation exposure to pregnant patients in radiation therapy (RT) departments.Methods and Materials: The survey was distributed to 342 health care professionals working in RT departments in British Columbia (BC), including radiation therapists, medical physicists, radiation oncologists, and radiation oncology residents.Results: There were 119 responses, 65% of who were radiation therapists. Respondents' mean duration of experience was 13.9 years (range, 1-25), over which time the BC Cancer Agency has delivered at least one course of RT to an estimated 16,000 women under the age of 50. Of the responses, 11.6% indicated that they had ever, in their training or career, encountered a situation where RT was inadvertently given to a pregnant patient. Upon reviewing anonymous comments, at least 7 discrete incidents were described. Fifty-two percent of radiation oncologists never, or only occasionally, remembered to discuss the risk of RT in pregnancy; 53% did not believe there were signs posted in their cancer center warning patients or reminding staff of this risk. Furthermore, 61% did not know if there was any patient education material designed for this purpose. Establishment of a checklist to screen for potentially fertile females prior to RT was felt to be a useful intervention by 49% of respondents.Conclusions: There is a risk of RT exposure to pregnant patients. Procedures and policies to prevent inadvertent irradiation of pregnant patients appear to be inadequate in BC. Provincial policies should be introduced to help reduce the risk of inadvertent RT of pregnant patients.

The remarkably distensible stomach: Case report highlighting the implications of gastric filling on radiation treatment planning for gastric lymphoma - Corrected Proof

2011-10-03

Radiation therapy plays a prominent role in the management of gastric lymphomas, as it does in nodal and other extranodal lymphomas. The development of 3-dimensional treatment planning along with conformal radiation techniques such as intensity modulated radiation therapy (IMRT) have allowed for the accurate treatment of gastric lymphomas while minimizing risks to nearby normal tissue structures.

A 2-year review of recent Nuclear Regulatory Commission events: What errors occur in the modern brachytherapy era? - Corrected Proof

Susan Richardson — 2011-09-30

Abstract: Purpose: To perform a retrospective analysis of recently reported brachytherapy errors to the Nuclear Regulatory Commission and to compare with historical trends.Methods: All events reported in the 2-year period from January 1, 2009 to December 31, 2010 were categorized and analyzed. The 4 main areas of dose delivery were Gamma Knife radiosurgery, therapeutic radiopharmaceutical administration, high-dose-rate brachytherapy, and low-dose-rate brachytherapy. The different types of errors were wrong site, wrong dose, unintended exposure, lost or leaking source, or other. The causes of events were specified as the following: communication errors, equipment malfunction, human error, lack of training, or miscellaneous.Results: One hundred and forty-seven events were found in the 2-year period. This error reporting rate far surpasses previous reports. The greatest number of events reported was for low-dose-rate brachytherapy, and the most common cause of error was human error. Wrong dose was the error that occurred most often, followed by wrong site.Conclusions: Very simple treatment errors, such as wrong patient, or wrong side of patient treated, are still occurring. Newer, complex deliveries such as high-dose-rate partial breast irradiation and low-dose-rate prostate brachytherapy also had a large number of events reported in this sampling. This report can help institutions establish needs for quality assessment and quality control processes.

Low rate of clinician-scored gynecomastia induced by 6 months of combined androgen blockade in a randomized trial: Implications for prophylactic breast irradiation - Corrected Proof

2011-09-28

Abstract: Purpose: To determine the incidence and predictors of clinician-scored gynecomastia induced by 6 months of combined androgen blockade (CAB) in a randomized trial.Methods: We studied 94 men with intermediate or high-risk prostate cancer randomized to radiation plus 6 months of neoadjuvant CAB consisting of a gonadotropin-releasing hormone agonist and antiandrogen (flutamide). Patients were assessed for breast symptoms monthly as per protocol. Patients reporting breast tenderness or enlargement were then examined shirtless.Results: Median age at entry was 72.1 years. While 52 patients (55.3%) reported either breast tenderness or enlargement, only 9 patients (9.6%) were scored as having gynecomastia when examined shirtless by a single clinician. Four patients received radiation for self-reported breast tenderness or enlargement without clinician-scored gynecomastia. If these 4 had not been radiated, the total incidence of clinician-scored gynecomastia may have been as high as 13 of 94 (13.8%). No patient variable, such as age, body-mass index, and Adult Comorbidity Evaluation-27 score, or discontinuation of the antiandrogen, was associated with the development of gynecomastia.Conclusions: While many patients self-reported breast tenderness or enlargement with short-course CAB, the incidence of breast enlargement noticeable to an examiner when the patient was shirtless was less than 15%, which is much lower than the 60% to 80% rates typically reported with antiandrogen monotherapy. Given that the long-term risks of prophylactic breast irradiation are not well characterized, these data suggest that prophylactic breast irradiation may not be as necessary in men receiving short-course CAB.

Dosimetric evaluation of a “virtual” image-guidance alternative to explicit 6 degree of freedom robotic couch correction - Corrected Proof

2011-09-26

Abstract: Purpose: Clinical evaluation of a “virtual” methodology for providing 6 degrees of freedom (6DOF) patient set-up corrections and comparison to corrections facilitated by a 6DOF robotic couch.Methods: A total of 55 weekly in-room image-guidance computed tomographic (CT) scans were acquired using a CT-on-rails for 11 pelvic and head and neck cancer patients treated at our facility. Fusion of the CT-of-the-day to the simulation CT allowed prototype virtual 6DOF correction software to calculate the translations, single couch yaw, and beam-specific gantry and collimator rotations necessary to effectively reproduce the same corrections as a 6DOF robotic couch. These corrections were then used to modify the original treatment plan beam geometry and this modified plan geometry was applied to the CT-of-the-day to evaluate the dosimetric effects of the virtual correction method. This virtual correction dosimetry was compared with calculated geometric and dosimetric results for an explicit 6DOF robotic couch correction methodology.Results: A (2%, 2mm) gamma analysis comparing dose distributions created using the virtual corrections to those from explicit corrections showed that an average of 95.1% of all points had a gamma of 1 or less, with a standard deviation of 3.4%. For a total of 470 dosimetric metrics (ie, maximum and mean dose statistics for all relevant structures) compared for all 55 image-guidance sessions, the average dose difference for these metrics between the plans employing the virtual corrections and the explicit corrections was −0.12% with a standard deviation of 0.82%; 97.9% of all metrics were within 2%.Conclusions: Results showed that the virtual corrections yielded dosimetric distributions that were essentially equivalent to those obtained when 6DOF robotic corrections were used, and that always outperformed the most commonly employed clinical approach of 3 translations only. This suggests that for the patient datasets studied here, highly effective image-guidance corrections can be made without the use of a robotic couch.

Evaluation of variability in seroma delineation between clinical specialist radiation therapist and radiation oncologist for adjuvant breast irradiation - Corrected Proof

2011-09-21

Abstract: Purpose: Breast cancer is managed by a multidisciplinary team with a goal for the timely provision of high quality care. Given radiation oncologist (RO) time constraints, an opportunity arises for task delegation of breast seroma target delineation to an advanced practice clinical specialist radiation therapist (CSRT) with clinical and technical expertise to facilitate treatment planning. To explore this further, we quantitatively evaluated the variability in post-surgical seroma delineation between the CSRT and ROs.Methods: Specialized site specific training was provided to the CSRT, who, with 7 ROs, independently contoured the seroma and graded its clarity, using the cavity visualization score (CVS), for 20 patients with clinical stage Tis-2N0 breast tumors. The conformity indices were analyzed for all possible pairs of delineations. The estimated “true” seroma contour was derived from the RO contours using the simultaneous truth and performance level estimation algorithm. Generalized kappa coefficient and center of mass metrics were used to examine the performance level of the CSRT in seroma delineations.Results: The CVS of the CSRT correlated well with the mean RO-group CVS, (Spearman ρ = 0.87, P < .05). The mean seroma conformity index for the RO group was 0.61 and 0.65 for the CSRT; a strong correlation was observed between the RO and CSRT conformity indices (Spearman ρ = 0.95, P < .05). Almost perfect agreement levels were observed between the CSRT contours and the STAPLE RO consensus contours, with an overall kappa statistic of 0.81 (P < .0001). The average center of mass shift between the CSRT and RO consensus contour was 1.69 ± 1.13 mm.Conclusions: Following specialized education and training, the CSRT delineated seroma targets clinically comparable with those of the radiation oncologists in women with early breast tumors suitable for accelerated partial breast or whole breast radiotherapy following lumpectomy. This study provides support for potential task delegation of breast seroma delineation to the CSRT in our current multidisciplinary environment. Further study is needed to assess the impact of this role expansion on radiotherapy system efficiency.

Visualization of a variety of possible dosimetric outcomes in radiation therapy using dose-volume histogram bands - Corrected Proof

Alexei Trofimov, Jan Unkelbach, Thomas F. DeLaney, Thomas Bortfeld — 2011-09-12

Abstract: Purpose: Dose-volume histograms (DVH) are the most common tool used in the appraisal of the quality of a clinical treatment plan. However, when delivery uncertainties are present, the DVH may not always accurately describe the dose distribution actually delivered to the patient. We present a method, based on DVH formalism, to visualize the variability in the expected dosimetric outcome of a treatment plan.Methods: For a case of chordoma of the cervical spine, we compared 2 intensity modulated proton therapy plans. Treatment plan A was optimized based on dosimetric objectives alone (ie, desired target coverage, normal tissue tolerance). Plan B was created employing a published probabilistic optimization method that considered the uncertainties in patient setup and proton range in tissue. Dose distributions and DVH for both plans were calculated for the nominal delivery scenario, as well as for scenarios representing deviations from the nominal setup, and a systematic error in the estimate of range in tissue. The histograms from various scenarios were combined to create DVH bands to illustrate possible deviations from the nominal plan for the expected magnitude of setup and range errors.Results: In the nominal scenario, the DVH from plan A showed superior dose coverage, higher dose homogeneity within the target, and improved sparing of the adjacent critical structure. However, when the dose distributions and DVH from plans A and B were recalculated for different error scenarios (eg, proton range underestimation by 3 mm), the plan quality, reflected by DVH, deteriorated significantly for plan A, while plan B was only minimally affected. In the DVH-band representation, plan A produced wider bands, reflecting its higher vulnerability to delivery errors, and uncertainty in the dosimetric outcome.Conclusions: The results illustrate that comparison of DVH for the nominal scenario alone does not provide any information about the relative sensitivity of dosimetric outcome to delivery uncertainties. Thus, such comparison may be misleading and may result in the selection of an inferior plan for delivery to a patient. A better-informed decision can be made if additional information about possible dosimetric variability is presented; for example, in the form of DVH bands.

Correlation of long-term pulmonary injury with radiation dose distribution in childhood cancer survivors - Corrected Proof

2011-08-29

Advances in cancer treatment have resulted in almost 80 percent of children surviving at least 5 years after cancer diagnosis. Childhood cancer survivors are 8.6 times more likely to die from pulmonary complications when compared with the general population. Pneumonitis and pulmonary fibrosis are known sequelae of pulmonary radiation therapy (XRT) during childhood. In many instances, the presentation may be subclinical, apparent only on incidental chest radiographs or pulmonary function tests. Pulmonary injury may first become apparent shortly after XRT or it may appear years later.

Efficacy of fiducial marker-based image-guided radiation therapy in prostate tomotherapy and potential dose coverage improvement using a patient positioning optimization method - Corrected Proof

Ning J. Yue, Akshar N. Patel, Bruce G. Haffty, Sung Kim — 2011-08-29

Abstract: Purpose: To evaluate the dose coverage efficacy of fiducial marker-based prostate tomotherapy and a positioning correction optimization technique for the improvement of suboptimal dose distributions.Methods: Three gold fiducial markers were implanted in prostate glands for patients who were to receive prostate tomotherapy. TomoTherapy megavoltage computed tomographies (MVCTs; TomoTherapy, Madison, WI) were routinely acquired at treatment and were registered to corresponding planning CTs based on the markers to correct for interfractional positioning deviations using translational table movements. The prostate glands and seminal vesicles were delineated on the MVCTs acquired for 10 patients at different treatment fractions and the treatment dose coverage was computed with the marker-based correction taken into account. The treatment dose coverage was compared with the corresponding plan to evaluate the efficacy of the marker-based image-guided radiation therapy (IGRT) approach. Separately, a hill-climbing optimization algorithm was used to optimize the positioning by maximizing a dose-based objective function. During the optimization, the dose was constantly recomputed with the translational correction until an optimized dose coverage was reached. This optimized dose coverage was compared with the marker-based dose coverage to evaluate dosimetric improvement for treatments in which suboptimal dose distributions were observed after the marker-based corrections.Results: Suboptimal dose coverage of prostate glands and seminal vesicles were observed in about 8 and 6 of a total 75 fractions, respectively, after the marker-based IGRT positioning corrections. Six of the 10 patients experienced 1 or more factions of suboptimal prostate gland coverage and 2 of the 10 patients experienced 1 or more fractions of suboptimal seminal vesicle dose coverage. Utilization of the proposed positioning correction optimization method led to satisfactory dose coverage of both prostate glands and seminal vesicles for all 10 patients.Conclusions: Given the planning target volume margin size specified in the current study, the fiducial marker-based IGRT approach may not be completely adequate to achieve desired dose coverage of the target volumes at every fraction. Due to relatively poor image quality of MVCTs, additional investigations may be required to confirm the finding. The proposed positioning correction optimization method is shown to effectively improve the observed suboptimal dose coverage of the target volumes.

Postmastectomy chest wall radiotherapy with single low-energy electron beam: An assessment of outcome and prognostic factors - Corrected Proof

2011-08-26

Abstract: Purpose: This study aimed to evaluate the outcome of patients who had received postmastectomy chest wall radiotherapy using a single electron beam, and to identify the relevant factors that influenced prognosis.Methods: The medical records of patients with breast cancer treated with postmastectomy radiotherapy from January 2000 to December 2004 were retrospectively analyzed (n = 328). Two hundred seventy-one (82.6%) patients were staged as (tumor-nodes-metastasis [TNM]) T3-4, any N, M0; or T1-2, N2-3, M0, and 57 (17.4%) patients were staged as T1-2, N1, M0. All patients received chest wall radiation with a 6-10 MeV electron beam. In addition, 327 patients (99.7%) received supraclavicular node radiation, 67 (20.4%) axillary radiation, and 35 (10.7%) internal mammary chain (IMC) radiation. Chemotherapy with anthracycline and taxane was given to 323 patients (98.5%). Of patients with positive hormone receptor, 183 (82.8%) received hormone therapy and 8 patients with negative and 3 patients with unknown hormone receptor received hormone therapy. Locoregional recurrence (LRR), distant metastasis (DM), and overall survival (OS) were calculated using the Kaplan-Meier method, and the differences assessed by log-rank test.Results: The median follow-up time was 78 months (range, 5-123 months) for patients who remained alive. The 5-year LRR, DM, disease-free survival and OS rates were 5.9%, 26.2%, 72.5%, and 83.1%, respectively. LRR occurred in 1 or more sites in 21 patients. The 5-year recurrence rates in the chest wall, supraclavicular node, axilla, and internal mammary chain were 1.9%, 2.3%, 2.9%, and 0%, respectively. In multivariate analysis, hormone therapy was the only independent favorable prognostic factor for LRR (P = .017). LRR was significantly associated with DM and OS. The 5-year DM rate was 82.9% and 22.7% (P < .0001) and the 5-year OS rate was 52.8% and 84.7% (P < .0001) for patients with or without LRR. The treatment-related toxicity was low, with the incidence of symptomatic pneumonitis being 0.3%.Conclusions: Breast cancer patients can be treated with postmastectomy single electron beam radiotherapy with excellent local control and low toxicity.

Baroreflex failure following radiotherapy for head and neck cancer: A case study - Corrected Proof

Andrew Farach, Rajeev Fernando, Modushudan Bhattacharjee, Francisco Fuentes — 2011-08-08

The baroreflex functions via carotid stretch receptors to maintain optimal perfusion pressures. Disruption of this reflex, in the chronic phase, presents insidiously and is characterized by severe labile blood pressure (BP). This condition is commonly referred to as the syndrome of baroreflex failure (BRF). BRF is an important clinical problem that may develop following radiation therapy (RT) or other treatments for head and neck cancer. It is important for radiation oncologists to be aware of this diagnosis as they are often in the best position to diagnose BRF early in its development. The purpose of this paper is to discuss the presenting signs and symptoms, diagnostic work-up, treatment, and possible causes of BRF to aid in the diagnosis of this rare condition. Herein we report a case of BRF following RT for head and neck (H-N) cancer and provide a critical review of the currently published literature discussing this association.

Six sigma tools for a patient safety-oriented, quality-checklist driven radiation medicine department - Corrected Proof

Ajay Kapur, Louis Potters — 2011-08-08

Abstract: Introduction: The purpose of this work was to develop and implement six sigma practices toward the enhancement of patient safety in an electronic, quality checklist-driven, multicenter, paperless radiation medicine department.Methods and Materials: A quality checklist process map (QPM), stratified into consultation through treatment-completion stages was incorporated into an oncology information systems platform. A cross-functional quality management team conducted quality-function-deployment and define-measure-analyze-improve-control (DMAIC) six sigma exercises with a focus on patient safety. QPM procedures were Pareto-sorted in order of decreasing patient safety risk with failure mode and effects analysis (FMEA). Quantitative metrics for a grouped set of highest risk procedures were established. These included procedural delays, associated standard deviations and six sigma Z scores. Baseline performance of the QPM was established over the previous year of usage. Data-driven analysis led to simplification, standardization, and refinement of the QPM with standard deviation, slip-day reduction, and Z-score enhancement goals. A no-fly policy (NFP) for patient safety was introduced at the improve-control DMAIC phase, with a process map interlock imposed on treatment initiation in the event of FMEA-identified high-risk tasks being delayed or not completed. The NFP was introduced in a pilot phase with specific stopping rules and the same metrics used for performance assessments. A custom root-cause analysis database was deployed to monitor patient safety events.Results: Relative to the baseline period, average slip days and standard deviations for the risk-enhanced QPM procedures improved by over threefold factors in the NFP period. The Z scores improved by approximately 20%. A trend for proactive delays instead of reactive hard stops was observed with no adverse effects of the NFP. The number of computed potential no-fly delays per month dropped from 60 to 20 over a total of 520 cases. The fraction of computed potential no-fly cases that were delayed in NFP compliance rose from 28% to 45%. Proactive delays rose to 80% of all delayed cases. For potential no-fly cases, event reporting rose from 18% to 50%, while for actually delayed cases, event reporting rose from 65% to 100%.Conclusions: With complex technologies, resource-compromised staff, and pressures to hasten treatment initiation, the use of the six sigma driven process interlocks may mitigate potential patient safety risks as demonstrated in this study.

Intact performance of a cochlear implant following radiotherapy in a child with acute lymphoblastic leukemia - Corrected Proof

2011-08-08

Cochlear implants, via direct electrical stimulation of the auditory nerve, allow the restoration of hearing and speech recognition in both adults and children having sensorineural deafness. These devices typically contain both external components (speech processor, microphone, transmitter) and internal components (including the cochlear stimulator and electrode array), which are surgically placed under the skin behind the ear and in the cochlea. According to the National Institute on Deafness and other Communications Disorders, by June 2010, over 188,000 individuals worldwide had received cochlear implants, including approximately 41,500 adults and 25,500 children in the US. Given the important role of radiotherapy (RT) in the multidisciplinary management of various malignancies, the tolerance of cochlear implants to therapeutic doses of radiation is an important consideration. In this work, we present a case of a pediatric patient with leukemia found to have sensorineural deafness, who then received a cochlear implant and subsequently received RT to the whole brain. Literature regarding RT in the setting of a cochlear implant and the importance of early childhood implantation for language-speech development is reviewed.

Evaluation of predictive variables in locally advanced pancreatic adenocarcinoma patients receiving definitive chemoradiation - Corrected Proof

2011-08-04

Abstract: Purpose: To analyze a single-center experience with locally advanced pancreatic cancer (LAPC) patients treated with chemoradiation (CRT) and to evaluate predictive variables of outcome.Methods and Materials: LAPC patients at our institution between 1997 and 2009 were identified (n = 109). Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier analysis. Cox proportional hazard models were used to evaluate predictive factors for survival. Patterns of failure were characterized, and associations between local progression and distant metastasis were explored.Results: Median OS was 12.1 months (2.5-34.7 months) and median PFS was 6.7 months (1.1-34.7 months). Poor prognostic factors for OS include Karnofsky performance status ≤80 (P = .0062), treatment interruption (P = .0474), and locally progressive disease at time of first post-therapy imaging (P = .0078). Karnofsky performance status ≤80 (P = .0128), pretreatment CA19-9 >1000 U/mL (P = .0224), and treatment interruption (P = .0009) were poor prognostic factors for PFS. Both local progression (36%) and distant failure (62%) were common. Local progression was associated with a higher incidence of metastasis (P < .0001) and decreased time to metastasis (P < .0001).Conclusions: LAPC patients who suffer local progression following definitive CRT may experience inferior OS and increased risk of metastasis, warranting efforts to improve control of local disease. However, patients with poor pretreatment performance status, elevated CA19-9 levels, and treatment interruptions may experience poor outcomes despite aggressive management with CRT, and may optimally be treated with induction chemotherapy or supportive care. Novel therapies aimed at controlling both local and systemic progression are needed for patients with LAPC.

Video surface image guidance for external beam partial breast irradiation - Corrected Proof

2011-08-01

Abstract: Objective: Accelerated partial breast irradiation is an emerging treatment option for early stage breast cancer. With accelerated partial breast irradiation, patient setup, and target registration accuracy is vital. The current study compared various methods for isocenter placement accuracy.Methods and Materials: Twenty-three patients treated on an institutional-approved partial breast irradiation protocol were monitored at each treatment fraction. All patients included in this study underwent clip placement at the time of surgery. Patients underwent computed tomographic simulation and surface contours were used to reconstruct a reference surface map. At the treatment machine, patients were initially positioned by laser alignment to tattoos. Orthogonal kilovoltage imaging of the chest wall, followed by video surface mapping of the breast, was performed. This video surface map was matched to the reference surface map to adjust the couch position. Verification orthogonal chest wall imaging and video surface mapping was again performed. The accuracy of setup by laser, orthogonal imaging of the chest wall, and surface alignment was retrospectively compared using the centroid clip position as the reference standard. The impact of setup error by surface alignment and by orthogonal kilovoltage imaging on planning target volume coverage was then calculated.Results: Laser-based positioning resulted in a residual setup error of 3.9 ± 3.7 mm, 4.6 ± 3.9 mm, and 4.3 ± 4.5 mm in the posterior-anterior (P-A), inferior-superior (I-S), and left-right (L-R) directions, respectively, using clips as the reference standard. Setup based on bony anatomy with orthogonal imaging resulted in residual setup error of 3.2 ± 2.9 (P-A), 4.2 ± 3.5 (I-S), and 4.7 ± 5.3 mm (L-R). Setup with video surface mapping resulted in a residual setup error of 1.9 ± 2.2, 1.8 ± 1.9, and 1.8 ± 2.1 mm in the P-A, I-S, and L-R directions, respectively. Vector spatial deviation was 8.8 ± 4.2, 8.3 ± 3.8, and 4.0 ± 2.3 mm with laser, chest wall on board imaging, and video surface mapping based setup, respectively. Setup by video surface mapping resulted in improved dosimetric coverage of the planning target volume when compared with orthogonal imaging of the chest wall (V100 96.0% ± 0.1% vs 89.3% ± 0.2%; V95 99.7% ± 0.01% vs 98.6% ± 0.01%, P < .05).Conclusions: Video surface mapping of the breast is a more accurate method for isocenter placement in comparison to conventional laser-based alignment or orthogonal kilovoltage imaging of the chest wall.

Radiation-induced sarcoma following radiation prophylaxis of heterotopic ossification - Corrected Proof

2011-07-22

Heterotopic ossification (HO) is defined as the abnormal formation of mature, lamellar bone in soft tissues, often containing bone marrow. Heterotopic ossification was first identified in 1883 by Riedel, a German physician. It was later described as “paraosteoarthropathy” by French physicians Dejerine and Ceillier based on their observations of patients with traumatic paraplegia in World War I.