Search

Purpose: The aim of this work was to report the effect of mismatch repair (MMR) status on outcomes of patients with stage I-II endometrioid endometrial adenocarcinoma (EEC) who receive adjuvant radiation therapy., Methods and Materials: This is a multi-institutional retrospective cohort study across 11 institutions in North America. Patients with known MMR status and stage I-II EEC status postsurgical staging were included. Overall survival (OS) and recurrence-free survival (RFS) rates were estimated via the Kaplan-Meier method. Univariable and multivariable analyses were performed via Cox proportional hazard models for RFS and OS. Statistical analyses were conducted using SPSS version 27., Results: In total, 744 patients with a median age at diagnosis of 65 years (IQR, 58-71) were included. Most patients were White (69.4%) and had Federation of Obstetrics and Gynecology 2009 stage I (84%) and Federation of Obstetrics and Gynecology grade 1 to 2 (73%). MMR deficiency was reported in 234 patients (31.5%), whereas 510 patients (68.5%) had preserved MMR. External beam radiation therapy with or without vaginal brachytherapy was delivered to 186 patients (25%), whereas 558 patients (75%) received vaginal brachytherapy alone. At a median follow-up of 43.5 months, the estimated crude OS and RFS rates for the entire cohort were 92.5% and 84%, respectively. MMR status was significantly correlated with RFS. RFS was inferior for MMR deficiency compared with preserved MMR (74.3% vs 88.6%, P < .001). However, no difference in OS was seen (90.8% vs 93.2%, P = .5). On multivariable analysis, MMR deficiency status was associated with worse RFS (hazard ratio, 1.86; P = .001) but not OS., Conclusions: MMR status was independently associated with RFS but not OS in patients with early-stage EEC who were treated with adjuvant radiation therapy. These findings suggest that differential approaches to surveillance and/or treatment based on MMR status could be warranted., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Lymphovascular space invasion (LVSI) predicts for higher rates of recurrence and increased mortality in endometrial cancer. Using 3-tier LVSI scoring, a PORTEC-1 and -2 trials analysis demonstrated that substantial LVSI was associated with worse locoregional (LR-DFS) and distant metastasis disease-free survival (DM-DFS), and these patients possibly benefited from external beam radiation therapy (EBRT). Furthermore, LVSI is a predictor for lymph node (LN) involvement, but the significance of substantial LVSI is unknown in patients with a pathologically negative LN assessment. We aimed to evaluate clinical outcomes of these patients in relation to the 3-tier LVSI scoring system., Methods and Materials: We performed a single-institutional retrospective review of patients with stage I endometrioid-type endometrial cancer who underwent surgical staging with pathologically negative LN evaluation from 2017 to 2019 with 3-tier LVSI scoring (none, focal, or substantial). Clinical outcomes (LR-DFS, DM-DFS, and overall survival) were analyzed using the Kaplan-Meier method., Results: A total of 335 patients with pathologically LN-negative stage I endometrioid-type endometrial carcinoma were identified. Substantial LVSI was present in 17.6% of patients; 39.7% of patients received adjuvant vaginal brachytherapy and 6.9% of patients received EBRT. Adjuvant radiation treatment varied by LVSI status. In patients with focal LVSI, 81.0% received vaginal brachytherapy. Among patients with substantial LVSI, 57.9% received vaginal brachytherapy alone, and 31.6% of patients received EBRT. The 2-year LR-DFS rates were 92.5%, 98.0%, and 91.4% for no LVSI, focal LVSI, and substantial LVSI, respectively. The 2-year DM-DFS rates were 95.5%, 93.3%, and 93.8% for no LVSI, focal LVSI, and substantial LVSI, respectively., Conclusions: In our institutional study, patients with pathologically LN-negative stage I endometrial cancer with substantial LVSI had similar rates of LR-DFS and DM-DFS compared with patients with none or focal LVSI. These findings highlight the need for multi-institutional studies to validate the prognostic value of substantial LVSI in this patient population., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: Representatives from the Gynecologic Groupe European de Curietherapie-European Society for Radiation Therapy and Oncology (GYN GEC-ESTRO), the American Brachytherapy Society (ABS), and the Canadian Brachytherapy Group (CBG) met to develop international consensus recommendations for target definitions for image-guided adaptive brachytherapy for vaginal recurrences of endometrial or cervical cancer., Methods and Materials: Seventeen radiation oncologists and 2 medical physicists participated. Before an in-person meeting each participant anonymously contoured 3 recurrent endometrial/cervical cancer cases. Participants contoured the residual gross primary tumor volume (GTV-T res ), a high-risk clinical target volume (CTV-T HR ), and an intermediate-risk clinical target volume (CTV-T IR ), on T2-weighted magnetic resonance images (MRIs). All contours were drawn using Falcon EduCase. Contours were reviewed at an in-person meeting during which a consensus document was created defining agreed-upon target definitions (Trial 1). After establishing these definitions, the group was sent one of the cases again (recurrent cervical cancer vaginal recurrence) and asked to contour the targets again (Trial 2). The Computerized Environment for Radiation Research (CERR) software (The Mathworks, Natwick, MA) was used to analyze the contours. Kappa statistics were generated to assess level of agreement between contours. A conformity index (CI), defined as the ratio between the intersection and union volume of a given pair of contours, was calculated. A simultaneous truth and performance level estimation (STAPLE) contour was created for the CTV-T HR and CTV-T IR for the postmeeting case., Results: Consensus definitions for GTV-T res , CTV-T HR , and CTV-T IR were established. Kappa statistics (Trial 1/Trial 2) for GTV-T res , CTV-T HR , and CTV-T IR were 0.536/0.583, 0.575/0.743 and 0.522/0.707. Kappa statistics for Trial 2 for the CTV-T HR and CTV-T IR showed "substantial" agreement while the GTV-T res remained at moderate agreement., Conclusions: This consensus provides recommendations to facilitate future collaborations for MRI-guided adaptive brachytherapy target definitions in endometrial/cervical vaginal recurrences., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Owing to conflicting prospective data, controversy exists regarding prophylactic cranial irradiation (PCI) in extensive-stage small cell lung cancer (ES-SCLC). We evaluated the cost-effectiveness of PCI versus magnetic resonance imaging (MRI) surveillance for patients with ES-SCLC based on currently available evidence and in the context of the proposed Centers for Medicare & Medicaid Services alternative payment model., Methods and Materials: A Markov state transition model was constructed to perform a cost-effectiveness analysis comparing MRI surveillance alone with PCI for ES-SCLC. Clinical parameters were obtained from clinical trial data, and cost data were based on 2019 Medicare reimbursement. Strategies were compared using the incremental cost-effectiveness ratio (ICER) with effectiveness in quality-adjusted life years (QALYs) and evaluated with a willingness-to-pay threshold of $100,000 per QALY gained. One-way and probabilistic sensitivity analyses were performed to consider model uncertainty., Results: In the base-case scenario, PCI was not cost-effective in this model, with an ICER of $168,456 per QALY gained compared with MRI surveillance alone, assuming that overall survival was 10 months for MRI surveillance alone and 12.5 months for PCI. One-way sensitivity analysis showed that results were most sensitive to the variation of overall survival and cognitive decline rates between the 2 groups. In a scenario analysis in which all patients received hippocampal-avoidance PCI, the model results became nearly cost-effective with PCI., Conclusions: PCI was not found to be cost-effective within this model compared with MRI surveillance alone, owing to the neurocognition decline effect of PCI based on available evidence. Hippocampal-avoidance PCI may be a potential cost-effective strategy for ES-SCLC, with confirmation expected after an ongoing prospective clinical trial (The Southwest Oncolology Group MRI Brain Surveillance Alone Versus MRI Surveillance And Prophylactic Cranial Irradiation [MAVERICK]), which includes assessments of cognitive function., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Definitive, nonsurgical management of gynecologic malignancies involves external beam radiation therapy (EBRT) and/or brachytherapy (BT). Summation of the cumulative dose is critical to assess the total biologic effective dose to targets and organs at risk. Cumulative dose calculation from EBRT and BT can be performed with or without image registration (IR) and biologic dose summation. Among these dose summation strategies, linear addition of dose-volume histogram (DVH) parameters without IR is the global standard for composite dose reporting. This approach stems from an era without image guidance and simple external beam and brachytherapy treatment approaches. With technological advances, EBRT and high-dose-rate BT have evolved to allow for volume-based treatment planning and delivery. Modern conformal therapeutic radiation involves volumetric or intensity modulated EBRT, capable of simultaneously treating multiple targets at different specified dose levels. Therefore, given the complexity of modern radiation treatment, the linear addition of DVH parameters from EBRT and high-dose-rate BT is challenging to represent the combined dose distribution. Deformable image registration (DIR) between EBRT and image guided brachytherapy (IGBT) data sets may provide a more nuanced calculation of multimodal dose accumulation. However, DIR is still nascent in this regard, and needs further development for accuracy and efficiency for clinical use. Biologic dose summation can combine physical dose maps from EBRT and each IGBT fraction, thereby generating a composite DVH from the biologic effective dose. However, accurate radiobiologic parameters are tissue-dependent and not well characterized. A combination of voxel-based DIR and biologic weighted dose maps may be the best approximation of dose accumulation but remains invalidated. The purpose of this report is to review dose summation strategies for EBRT and BT, including conventional equivalent dose in 2-Gy fractions dose summation without image registration, physical dose summation using 3-dimensional rigid IR and DIR, and biologic dose summation. We also provide general clinical workflows for IGBT with a focus on cervical cancer., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: Our purpose was to evaluate the effect of sequence and type of adjuvant therapy for patients with stage IIIC endometrial carcinoma (EC) on outcomes., Methods and Materials: In a multi-institutional retrospective cohort study, patients with stage IIIC EC who had surgical staging and received both adjuvant chemotherapy and radiation therapy (RT) were included. Adjuvant treatment regimens were classified as adjuvant chemotherapy followed by sequential RT (upfront chemo), which was predominant sequence; RT with concurrent chemotherapy followed by chemotherapy (concurrent); systemic chemotherapy before and after RT (sandwich); adjuvant RT followed by chemotherapy (upfront RT); or chemotherapy concurrent with vaginal cuff brachytherapy alone (chemo-brachy). Overall survival (OS) and recurrence-free survival (RFS) rates were estimated by the Kaplan-Meier method., Results: A total of 686 eligible patients were included with a median follow-up of 45.3 months. The estimated 5-year OS and RFS rates were 74% and 66%, respectively. The sequence and type of adjuvant therapy were not correlated with OS or RFS (adjusted P = .68 and .84, respectively). On multivariate analysis, black race, nonendometrioid histology, grade 3 tumor, stage IIIC2, and presence of adnexal and cervical involvement were associated with worse OS and RFS (all P < .05). Regardless of the sequence of treatment, the most common site of first recurrence was distant metastasis (20.1%). Vaginal only, pelvic only, and paraortic lymph node (PALN) recurrences occurred in 11 (1.6%),15 (2.2 %), and 43 (6.3 %) patients, respectively. Brachytherapy alone was associated with a higher rate of PALN recurrence (15%) compared with external beam radiation therapy (5%) P < .0001., Conclusions: The sequence and type of combined adjuvant therapy did not affect OS or RFS rates. Brachytherapy alone was associated with a higher rate of PALN recurrence, emphasizing the role of nodal radiation for stage IIIC EC. The vast proportion of recurrences were distant despite systemic chemotherapy, highlighting the need for novel regimens., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: Accurate target definition is critical for the appropriate application of radiation therapy. In 2008, the Radiation Therapy Oncology Group (RTOG) published an international collaborative atlas to define the clinical target volume (CTV) for intensity modulated pelvic radiation therapy in the postoperative treatment of endometrial and cervical cancer. The current project is an updated consensus of CTV definitions, with removal of all references to bony landmarks and inclusion of the para-aortic and inferior obturator nodal regions., Methods and Materials: An international consensus guideline working group discussed modifications of the current atlas and areas of controversy. A document was prepared to assist in contouring definitions. A sample case abdominopelvic computed tomographic image was made available, on which experts contoured targets. Targets were analyzed for consistency of delineation using an expectation-maximization algorithm for simultaneous truth and performance level estimation with kappa statistics as a measure of agreement between observers., Results: Sixteen participants provided 13 sets of contours. Participants were asked to provide separate contours of the following areas: vaginal cuff, obturator, internal iliac, external iliac, presacral, common iliac, and para-aortic regions. There was substantial agreement for the common iliac region (sensitivity 0.71, specificity 0.981, kappa 0.64), moderate agreement in the external iliac, para-aortic, internal iliac and vaginal cuff regions (sensitivity 0.66, 0.74, 0.62, 0.59; specificity 0.989, 0.966, 0.986, 0.976; kappa 0.60, 0.58, 0.52, 0.47, respectively), and fair agreement in the presacral and obturator regions (sensitivity 0.55, 0.35; specificity 0.986, 0.988; kappa 0.36, 0.21, respectively). A 95% agreement contour was smoothed and a final contour atlas was produced according to consensus., Conclusions: Agreement among the participants was most consistent in the common iliac region and least in the presacral and obturator nodal regions. The consensus volumes formed the basis of the updated NRG/RTOG Oncology postoperative atlas. Continued patterns of recurrence research are encouraged to refine these volumes., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Immunotherapy using immune checkpoint blockade has revolutionized the treatment of many types of cancer. Radiation therapy (RT)-particularly when delivered at high doses using newer techniques-may be capable of generating systemic antitumor effects when combined with immunotherapy in breast cancer. These systemic effects might be due to the local immune-priming effects of RT resulting in the expansion and circulation of effector immune cells to distant sites. Although this concept merits further exploration, several challenges need to be overcome. One is an understanding of how the heterogeneity of breast cancers may relate to tumor immunogenicity. Another concerns the need to develop knowledge and expertise in delivery, sequencing, and timing of RT with immunotherapy. Clinical trials addressing these issues are under way. We here review and discuss the particular opportunities and issues regarding this topic, including the design of informative clinical and translational studies., (Published by Elsevier Inc.)

Purpose: We sought to characterize temporal trends of radiation oncology resident-reported external beam radiation therapy (EBRT) case experience with respect to various disease sites, including trends in stereotactic radiosurgery and stereotactic body radiation therapy cases., Methods and Materials: Summarized, deidentified case logs for graduating radiation oncology residents between 2007 and 2018 were obtained from the Accreditation Council for Graduate Medical Education national summary data report. Mean number of cumulative cases and standard deviations per graduating resident by year were evaluated. Cases were subdivided into 12 disease-site categories using the Accreditation Council for Graduate Medical Education classification. Analysis of variance was used to determine significant differences, and strength of association was evaluated using Pearson correlation., Results: The number of graduating residents per year increased by 66% from 114 in 2007 to 189 in 2018 (P < .001, r = 0.88). The overall mean number of EBRT cases per graduating resident decreased by 13.2% from 521.9 in 2007 to 478.5 in 2018, with a decrease in the ratio of nonmetastatic to metastatic cases per graduating resident. There was significant variation among the disease categories analyzed; however, the largest proportionate decreases were seen in hematologic, lung, and genitourinary malignancies. Stereotactic radiosurgery volume per graduating resident increased from an average of 27.9 cases in 2007 to 50.3 in 2018 (P < .001, r = 0.96). Stereotactic body radiation therapy volume per graduating resident increased as well, from a mean of 6 cases in 2007 to 55.6 cases in 2018 (P < .001, r = 0.99)., Conclusions: We report a longitudinal summary of resident-reported experience in EBRT cases. These findings have implications for future efforts to optimize residency training programs and requirements., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Multifocal pattern of regression after neoadjuvant chemotherapy has been identified as a risk factor for ipsilateral breast tumor recurrence (IBTR). We aimed to determine the significance of multifocal regression as a predictor of IBTR after neoadjuvant chemotherapy and breast conservation therapy in the modern era., Methods and Materials: We retrospectively reviewed 346 patients treated between November 2009 and June 2017. Pattern of regression was categorized as pathologic complete response (pCR), unifocal (tumor present as a cohesive mass), limited multifocal (single cells or clusters of cells concentrated in 1 portion of the fibrotic area), or diffuse multifocal (cells spread over entire fibrotic area). IBTR was defined as new ipsilateral invasive or noninvasive breast tumor after breast conservation therapy. Predictive factors were analyzed using Cox regression., Results: Incidence of multifocal regression was 25.7% for the overall cohort and 12.2% for estrogen receptor (ER) negative/progesterone receptor (PR) negative/human epidermal growth factor receptor 2 (HER2) positive, 17.5% for triple-negative, 36.9% for ER+ or PR+/HER2-, and 38.5% for triple-positive (P < .001). With a median follow-up of 41.1 months, 4-year IBTR-free survival after pCR or unifocal regression versus multifocal regression was 94.1% versus 90.9% (P = .411). Pattern of regression (P = .010; compared to pCR, hazard ratio [HR] of 11.2 for diffuse multifocal regression, 1.65 for limited multifocal regression, and 3.81 for unifocal regression), phenotype (P = .001; compared to ER+ or PR+/HER2-, HR of 30.67 for ER-/PR-/HER2+, 25.30 for triple-negative, and 1.60 for triple-positive), and lack of nodal pCR (P = .004; HR of 3.78) predicted for IBTR on multivariate Cox regression. On multivariate subset analysis, pattern of regression and lymphovascular space invasion predicted for IBTR in hormone receptor-negative patients, but pattern of regression was not associated with IBTR for hormone receptor-positive patients., Conclusions: Multifocal regression, hormone receptor-negative phenotype, and lack of nodal pCR predict for increased risk of IBTR after neoadjuvant chemotherapy. Although more common in hormone receptor-positive disease, multifocal regression was associated with worse outcome only in hormone receptor-negative patients., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: There is limited long-term data on outcome and side effects of Cs-131 prostate brachytherapy and minimal patient-reported data on rectal bleeding with any isotope. We aimed to describe the incidence, prevalence, and predictors of late patient-reported rectal bleeding after Cs-131 brachytherapy., Methods and Materials: We reviewed a prospectively collected database of 620 men treated with Cs-131 prostate brachytherapy. Of 620 patients, 390 (62.9%) received brachytherapy as monotherapy; the remainder received combination therapy with external beam radiation therapy (EBRT). Patients were administered Expanded Prostate Cancer Index Composite questionnaires preoperatively and postoperatively at each follow-up visit. The primary outcome was late rectal bleeding, defined as rectal bleeding reported at the 6-month follow-up or later. Clinically significant rectal bleeding was defined as occurring more than "rarely," and clinically significant bother from rectal bleeding was defined as considering bleeding more than a "very small problem." Univariate and multivariate Cox regression were performed to identify factors predictive for rectal bleeding., Results: With a median follow-up time of 48 months, the cumulative incidence of clinically significant late rectal bleeding was 12.4%, with 15.2% reporting clinically significant bother from bleeding. At the time of last follow-up, the prevalence of clinically significant rectal bleeding and bother were 4.0% and 4.7%, respectively. On univariate analysis, acute clinically significant rectal bleeding, defined as occurring within the first 6 months (P = .001) and combination therapy with EBRT (P = .001) predicted for clinically significant late rectal bleeding. On multivariate analysis, both EBRT (P = .001; hazard ratio, 2.50; 95% confidence interval, 1.58-3.94) and acute rectal bleeding (P < .001; hazard ratio, 3.11; 95% confidence interval, 1.75-5.53) remained significant predictors for late rectal bleeding., Conclusions: Prostate brachytherapy with Cs-131 is well tolerated in the long term. Although the incidence of clinically significant patient-reported late rectal bleeding was 12.4%, the prevalence at last follow-up was only 4.0%, suggesting that this problem tends to resolve., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Recent Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology guidelines recommend that the dose to 90% (D90) of the high-risk clinical target volume (HRCTV) in cervical cancer be at least 85 Gy, with higher doses for poor response to radiation therapy., Methods and Materials: A retrospective review of brachytherapy delivered at a single institution was evaluated for dosimetry and outcomes. Significance of tumor parameters on local control was evaluated with Kaplan-Meier and univariable and multivariable Cox regression analysis. Correlations were determined with a linear regression model., Results: A total of 239 women underwent high-dose-rate brachytherapy for cervical cancer between 2007 and 2018 with evaluable dosimetry. Median follow-up was 28.6 months. The median prescribed dose was 27.5 Gy in 5 fractions, with a median HRCTV D90 of 83.9 Gy (range, 81.9-85.7 Gy), HRCTV volume of 31 cm 3 (range, 14.9-121.9 cm 3 ), and treatment time of 51 days (range, 36-83 days). Local control for the entire cohort at 5 years was 90.8%. Local control was worse with adenocarcinomas, HRCTV >40 cm 3 at brachytherapy, requirement for a higher brachytherapy dose, and treatment >51 days. On multivariable analysis, local control was worse with adenocarcinoma (hazard ratio, 4.141; 95% confidence interval, 1.498-11.444; P = .006) and HRCTV >40 cm 3 (hazard ratio, 3.640; 95% confidence interval, 1.316-10.069; P = .013). HRCTV EQD2 D90 > 85 Gy did not statistically improve outcomes for any subset. The 2-year progression-free survival for HRCTV >40 cm 3 was 66.2% versus 84.1% if ≤40 cm 3  (P < .001). Overall survival was predicted by HRCTV and overall treatment time in multivariable analysis. For women with HRCTV ≤40 cm 3 , overall survival at 2 years was 90.4% versus 68.5% if >40 cm 3  (P < .001)., Conclusion: Local control was excellent with magnetic resonance imaging-based planning in the entire cohort of patients. A poor response to external beam radiation (larger HRCTV) and adenocarcinoma histology predicted for worse local control despite association with higher brachytherapy prescription. Women with these risk factors face higher rates of extrapelvic progression and poorer overall survival., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Vulvar squamous cell carcinoma (VSCC) is a relatively rare malignancy. Human papillomavirus has been implicated as a causative factor for a subset of these patients. The purpose of this study was to evaluate whether p16-positivity (a human papillomavirus surrogate) predicts for better response rates in women who undergo surgery followed by adjuvant radiation therapy (RT)., Methods and Materials: We retrospectively analyzed data from women with VSCC who were treated with adjuvant RT. p16-Positivity was defined as diffuse strong immunoreactivity within the tumor. Time to event outcomes was performed with Kaplan-Meier and cumulative incidence methodologies., Results: Thirty-nine women were identified. Ten had positive results for p16 (p16+), and 29 had negative results (p16-). The median follow-up was 25.7 months. The median age at diagnosis was 59 years for women with p16+ tumors and 74 years for women with p16- tumors (P = .022). The distribution of stage did not differ by p16 status. The indications for adjuvant RT were close/positive margins in 19 women, positive nodes in 9 women, and both in 11 women. There were 21 recurrences: 15 vulvar, 3 isolated nodal, 2 synchronous vulvar/nodal, and 1 distant metastasis. In-field relapse rates at 3 years were lower in p16+ patients (32.5%) than in p16- patients (59.1%, P = .072). This trend was also observed in progression-free survival (P = .062). A p16+ status and a lower International Federation of Gynecology and Obstetrics stage were associated with fewer in-field relapses and improved progression-free survival in multivariable analyses. The p16 status was not a predictor of overall survival., Conclusions: p16-Positivity appears to be a prognostic factor for in-field relapse rates in patients with VSCC appropriately treated with adjuvant RT., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: Underutilization of hypofractionated whole-breast irradiation (HF-WBI) in large-breasted women may be partially explained by concerns about dose heterogeneity. Although modern planning may mitigate this issue, validated dosimetric guidelines are lacking. Our clinical pathway mandates hypofractionation, guided by institutional dosimetric criteria for plan evaluation. We examined acute radiation dermatitis rates with HF-WBI in large-breasted patients when our guidelines are followed and evaluated factors predictive for dermatitis., Methods and Materials: Patients with whole-breast clinical target volumes (WB-CTV) of ≥1000 cm 3 treated with HF-WBI were reviewed. WB-CTV V105, V107, and V110 were assessed. Our guidelines recommend limiting V105 to <10% to 15% and V110 to 0%. The highest grade of acute dermatitis was recorded. Potential clinical and dosimetric predictors of dermatitis were analyzed using logistic regression., Results: From 2012 to 2017, 505 breasts in 502 patients were treated with HF-WBI. The median WB-CTV was 1261.3 cm 3 (interquartile range [IQR], 1115.3-1510.0). Most plans (99%) delivered 42.56 Gy in 16 fractions. A cavity boost of 10 Gy in 4 fractions was delivered in 99% of plans. Electrons were used in 69% of boost plans. Three-dimensional field-in-field technique was used in 68% of plans and inverse-planned intensity modulated radiation therapy in 32%. The median WB-CTV V105 was 9.7% (IQR, 5.6%-13.3%); the median WB-CTV V107 was 0.8% (IQR, 0.0%-2.5%). The WB-CTV V110 was 0% in 97.4% of plans (median, 0.0%; IQR, 0.0%-0.0%). Grade 1, 2, and 3 dermatitis rates were 55.0%, 40.8%, and 3.4%, respectively. On multivariate analysis, age >64 years (P = .016; odds ratio [OR] 4.0; 95% confidence interval [CI], 1.3-12.3), WB-CTV >1500 cm 3  (P = .006; OR, 4.3; 95% CI, 1.5-12.3), body mass index ≥34 (P = .044; OR, 3.9; 95% CI, 1.0-14.5), and WB-CTV V105 >10% (P = .011; OR, 5.3; 95% CI, 1.5-19.3) predicted for grade 3 dermatitis., Conclusions: With our institutional dosimetric guidelines, grade 3 dermatitis rates with HF-WBI in large-breasted women was <5%. WB-CTV V105 should be optimized to <10% to keep grade 3 dermatitis rates <2%., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: To investigate the correlation between positron emission tomography/computed tomography (PET/CT) response and outcome in the era of magnetic resonance imaging (MRI)-based planning and to assess whether the addition of diffusion-weighted MRI (DW-MRI) could more accurately classify treatment response and prognosis., Methods and Materials: A retrospective chart review identified 244 consecutive patients with International Federation of Gynecology and Obstetrics stage IB1-IVA cervical cancer treated with concurrent chemoradiation, including high-dose-rate image-based brachytherapy, between 2007 and 2016. Image-based brachytherapy was delivered with 5 intracavitary/interstitial fractions, each 5 to 6 Gy per fraction., Results: An complete response on posttreatment PET/CT (PET-CR) was discovered in 50 of 244 patients (20%) at a median interval of 3.3 months (range, 2.1-7.7 months) after treatment. After a median follow-up of 27 months, 2-year overall survival was 83% in all patients. Metabolic response significantly impacted 2-year overall survival (94% complete response on posttreatment PET/ CT vs 62.4% PET-IR, P < .001). Of those with a PET-IR, 16 of 50 patients (32%) suffered a local recurrence. A total of 27 of 50 patients with a PET-IR underwent DW-MRI; 11 of 27 posttreatment DW-MRI scans (40%) were interpreted as positive by central review (median apparent diffusion coefficient of 0.973 × 10 -3  mm 2 /s). Of the DW-MRI-positive patients, 9 of 11 (81.8%) suffered a histologically confirmed local recurrence, and 2 of 11 patients are without evidence of disease. Additionally, 16 of 27 DW-MRI studies were interpreted as negative, and 2 of 16 (12.5%) of these patients suffered a local recurrence. Diffusion-weighted MRI findings significantly impacted 2-year overall survival (83% negative DW-MRI vs 36% positive DW-MRI, P = .049)., Conclusion: Incomplete PET/CT response was documented in 20% of patients after image-based brachytherapy for locally advanced cervical cancer. Integration of DW-MRI helped accurately identify patients at risk for persistent disease and worse long-term outcome. The value of DW-MRI requires further validation in a large prospective dataset as this modality may allow earlier evaluation and salvage treatment in those with PET-IR., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: We evaluated the use of brachytherapy (BT) in addition to external beam radiation therapy (EBRT) and the resulting effect on survival in patients with cervical cancer after hysterectomy with positive surgical margins., Methods and Materials: Patients with cervical cancer diagnosed from 2004 to 2015 who underwent hysterectomy followed by adjuvant EBRT were identified using the National Cancer Database. Only patients with positive surgical margins were included for analysis. Logistic regression was used to evaluate predictors of BT use and for propensity score matching. Survival was compared between patients receiving EBRT alone and those receiving EBRT combined with BT for adjuvant treatment. Survival analysis using log-rank test and Cox proportional hazards modeling was performed in the overall and propensity score-matched cohorts., Results: We identified 1719 patients who underwent hysterectomy with positive surgical margins followed by adjuvant radiation therapy, of whom 778 (45.3%) received additional BT. Predictors of increased receipt of BT included age >55 years, private rather than government insurance, radiation treatment duration ≥7 weeks, EBRT dose ≥4500 cGy, and time between radiation and surgery ≤9 weeks. With a median follow-up of 3.8 years, 3-year overall survival was 79.4% in patients receiving BT compared with 71.9% in patients receiving EBRT alone (log-rank P < .001). On multivariate analysis, EBRT and BT were associated with significantly improved survival (hazard ratio 0.77; 95% confidence interval 0.64-0.92; P = .003) compared with EBRT alone. The survival benefit of combining EBRT and BT persisted on propensity score-matched analysis (log-rank P = .005)., Conclusions: In women with positive margins after hysterectomy for cervical cancer, the combination of EBRT and BT showed significantly improved overall survival compared with EBRT alone. However, only 45.3% of patients in our cohort received BT., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: Google is the most popular search engine in the United States, and patients are increasingly relying on online webpages to seek information about individual physicians. This study aims to characterize what patients find when they search for radiation oncologists online., Methods and Materials: The Centers for Medicare and Medicaid Services (CMS) Physician Comparable Downloadable File was used to identify all Medicare-participating radiation oncologists in the United States and Puerto Rico. Each radiation oncologist was characterized by medical school education, year of graduation, city of practice, gender, and affiliation with an academic institution. Using a custom Google-based search engine, up to the top 10 search results for each physician were extracted and categorized as relating to: (1) physician, hospital, or health care system; (2) third-party; (3) social media; (4) academic journal articles; or (5) other., Results: Among all health care providers in the United States within CMS, 4443 self-identified as being radiation oncologists and yielded 40,764 search results. Of those, 1161 (26.1%) and 3282 (73.9%) were classified as academic and nonacademic radiation oncologists, respectively. At least 1 search result was obtained for 4398 physicians (99.0%). Physician, hospital, and health care-controlled websites (16,006; 39.3%) and third-party websites (10,494; 25.7%) were the 2 most often observed domain types. Social media platforms accounted for 2729 (6.7%) hits, and peer-reviewed academic journal websites accounted for 1397 (3.4%) results. About 6.8% and 6.7% of the top 10 links were social media websites for academic and nonacademic radiation oncologists, respectively., Conclusions: Most radiation oncologists lack self-controlled online content when patients search within the first page of Google search results. With the strong presence of third-party websites and lack of social media, opportunities exist for radiation oncologists to increase their online presence to improve patient-provider communication and better the image of the overall field. We discuss strategies to improve online visibility., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: To evaluate long-term patient-reported quality of life (QOL) scores in men with prostate cancer treated at our institution with 131 Cs prostate brachytherapy., Methods and Materials: Patients treated more than 4 years ago with 131 Cs (n=290) were asked to fill out an Expanded Prostate Cancer Index Composite (EPIC) QOL questionnaire and American Urological Association Symptom Score (AUASS) survey, before treatment and at each follow-up appointment. We compared patients' EPIC and AUA scores at baseline with scores at a last follow-up of at least 4 years after treatment using the Wilcoxon signed-rank test., Results: At a median last follow-up of 5.5 years after treatment with 131 Cs prostate brachytherapy there were no clinically significant changes in the EPIC or AUA scores from baseline. There was statistical worsening in the EPIC urinary incontinence subscore. Subset analyses revealed improved QOL outcomes in patients who received external beam radiation therapy or α-blocker therapy, whereas androgen deprivation therapy was not associated with differences in QOL change., Conclusions: Our results demonstrate minimal long-term changes in urinary or bowel patient-reported QOL with 131 Cs prostate brachytherapy. These findings suggest that patients treated with this isotope are able to recover and then maintain their baseline QOL in the long term., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: Worse treatment outcomes can be expected with prolongation of the overall treatment time (OTT) during definitive chemoradiation therapy (CRT) for cervical cancer. In the adjuvant setting, data on the relative importance of the OTT and the importance of RT and chemotherapy synchronization are scarce. Using the National Cancer Database, we evaluated the effect of these treatment variables on overall survival in the adjuvant CRT setting., Methods and Materials: The present analysis included nonmetastatic cervical cancer patients undergoing hysterectomy followed by adjuvant CRT. The proportional hazard model was used to estimate the effect of prognostic factors (age, comorbidity, race, tumor size, tumor grade, tumor histologic type, number of high-risk pathologic factors) and time-related variables (surgery to RT start interval [SR], OTT [RT start to end dates], package time [from diagnosis date to CRT end date] and optimum CRT synchronization [whether chemotherapy and RT start dates coincided]) on survival., Results: Of 3051 patients, 60% finished RT within 7 weeks and 85% received optimum CRT. Among other factors, univariate analysis identified longer OTT (hazards ratio [HR] 1.33; P<.001), longer SR (HR 1.17; P=.05), and nonoptimum CRT timing (HR 1.21; P=.04) as poor prognosticators. Of these factors, SR (HR 1.20; P=.04) and OTT (HR 1.21; P=.002) retained significance on multivariate analysis. An OTT >7 weeks remained a significant factor even after propensity score matching (P=.04)., Conclusions: The results of our analysis suggest that prolongation of the adjuvant CRT duration >7 weeks is associated with poor survival and SR of <8 weeks should be attempted whenever clinically feasible., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: Positive surgical margins after radical vulvectomy for vulvar cancer portend a high risk for local relapse, which may be challenging to salvage. We assessed the impact of adjuvant radiation therapy (aRT) on overall survival (OS) and the dose-response relationship using the National Cancer Data Base., Methods and Materials: Patients with vulvar squamous cell carcinoma who underwent initial extirpative surgery with positive margins from 1998 to 2012 were included. Factors associated with aRT and specific dose levels were analyzed using logistic regression. Log-rank and multivariable Cox proportional hazards modeling were used for OS analysis., Results: We identified 3075 patients with a median age of 66 years (range, 22-90 years); the median follow-up time was 36.4 months (interquartile range [IQR] 15.4-71.0 months). Stage IA/B disease represented 41.2% of the cohort. Sixty-three percent underwent lymph node assessment, with a 45% positivity rate. In total, 1035 patients (35.3%) received aRT, with a median dose of 54.0 Gy (IQR 48.6-60.0 Gy). The 3-year OS improved from 58.5% to 67.4% with aRT (P<.001). On multivariable analysis, age, Charlson-Deyo score ≥1, stage ≥II, tumors ≥4 cm, no aRT, and adverse nodal characteristics led to inferior survival. Dose of aRT was positively associated with OS as a continuous variable on univariate analysis (P<.001). The unadjusted 3-year OS for dose subsets 30.0 to 45.0 Gy, 45.1 to 53.9 Gy, 54.0 to 59.9 Gy, and ≥60 Gy was 54.3%, 55.7%, 70.1%, and 65.3%, respectively (P<.001). Multivariable analysis using a 4-month conditional landmark revealed that the greatest mortality reduction occurred in cumulative doses ≥54 Gy: 45.1 to 53.9 Gy (hazard ratio [HR] 0.94, P=.373), 54.0 to 59.9 Gy (HR 0.75, P=.024), ≥60 Gy (HR 0.71, P=.015). No survival benefit was seen with ≥60 Gy compared with 54.0 to 59.9 Gy (HR 0.95, P=.779)., Conclusions: Patients with vulvar squamous cell carcinoma and positive surgical margins derive an OS benefit from aRT with a seemingly optimal dose in the range of 54.0 to 59.9 Gy., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: To conduct a cost-effectiveness analysis to determine whether stereotactic body radiation therapy (SBRT) is a cost-effective therapy compared with radiofrequency ablation (RFA) for patients with unresectable colorectal cancer (CRC) liver metastases., Methods and Materials: A cost-effectiveness analysis was conducted using a Markov model and 1-month cycle over a lifetime horizon. Transition probabilities, quality of life utilities, and costs associated with SBRT and RFA were captured in the model on the basis of a comprehensive literature review and Medicare reimbursements in 2014. Strategies were compared using the incremental cost-effectiveness ratio, with effectiveness measured in quality-adjusted life years (QALYs). To account for model uncertainty, 1-way and probabilistic sensitivity analyses were performed. Strategies were evaluated with a willingness-to-pay threshold of $100,000 per QALY gained., Results: In base case analysis, treatment costs for 3 fractions of SBRT and 1 RFA procedure were $13,000 and $4397, respectively. Median survival was assumed the same for both strategies (25 months). The SBRT costs $8202 more than RFA while gaining 0.05 QALYs, resulting in an incremental cost-effectiveness ratio of $164,660 per QALY gained. In 1-way sensitivity analyses, results were most sensitive to variation of median survival from both treatments. Stereotactic body radiation therapy was economically reasonable if better survival was presumed (>1 month gain) or if used for large tumors (>4 cm)., Conclusions: If equal survival is assumed, SBRT is not cost-effective compared with RFA for inoperable colorectal liver metastases. However, if better local control leads to small survival gains with SBRT, this strategy becomes cost-effective. Ideally, these results should be confirmed with prospective comparative data., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to develop a radiation therapy (RT) contouring atlas and recommendations for women with postoperative and locally advanced vulvar carcinoma., Methods and Materials: An international committee of 35 expert gynecologic radiation oncologists completed a survey of the treatment of vulvar carcinoma. An initial set of recommendations for contouring was discussed and generated by consensus. Two cases, 1 locally advanced and 1 postoperative, were contoured by 14 physicians. Contours were compared and analyzed using an expectation-maximization algorithm for simultaneous truth and performance level estimation (STAPLE), and a 95% confidence interval contour was developed. The level of agreement among contours was assessed using a kappa statistic. STAPLE contours underwent full committee editing to generate the final atlas consensus contours., Results: Analysis of the 14 contours showed substantial agreement, with kappa statistics of 0.69 and 0.64 for cases 1 and 2, respectively. There was high specificity for both cases (≥99%) and only moderate sensitivity of 71.3% and 64.9% for cases 1 and 2, respectively. Expert review and discussion generated consensus recommendations for contouring target volumes and treatment for postoperative and locally advanced vulvar cancer., Conclusions: These consensus recommendations for contouring and treatment of vulvar cancer identified areas of complexity and controversy. Given the lack of clinical research evidence in vulvar cancer radiation therapy, the committee advocates a conservative and consistent approach using standardized recommendations., Competing Interests: All other authors report no conflicts of interest., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: This is the first National Resident Matching Program analysis evaluating historical patterns of international medical graduates (IMGs) in radiation oncology (RO) and providing comparison with American (MD) medical graduates (AMGs), osteopathic students (DOs), unfilled positions, and other specialties., Methods and Materials: National Resident Matching Program data for IMGs were available from 2003 to 2015, with limited data for other specialty matches. The following RO-specific figures were obtained per year: total positions available; total matched positions; number of unfilled positions; and number of IMG, AMG, and DO matches. In addition, the number of IMG matches and total matched positions were obtained for 19 other specialties. Fisher exact tests and χ(2) tests were considered significant at α <.05., Results: From 2010 to 2015, 0.8% of RO matches were IMGs, a decline from 2.4% in 2003 to 2009 (P=.006). Proportions of DO matches during these intervals increased by 40% (from 1.0% to 1.4%), significantly lower than IMGs for 2003 to 2009 (P=.03) but not 2010 to 2015 (P=.26). From 2003 to 2015, the percentage of IMG matches, at 1.5%, was significantly lower than the percentage of unfilled seats, at 3.5% (P<.001). In comparison with other specialties (2003-2015), RO had the fewest IMG matches (1.5%), followed by otolaryngology (1.9%) and orthopedics (2.2%); specialties with the highest IMG proportions were internal medicine (37.1%), family medicine (35.7%), and neurology (31.1%)., Conclusions: Presently, IMGs represent <1% of RO matches, the lowest among major specialties. There are several speculative factors associated with this low proportion. There are significantly more unfilled positions than those filled by IMGs; programs at risk of not matching could weigh the advantages and disadvantages of interviewing IMGs., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: To analyze, in the setting of stage I seminoma, the factors affecting adjuvant treatment decisions and resulting survival outcomes, using a national dataset., Methods and Materials: We identified 33,094 stage I seminoma patients after orchiectomy from 1998 to 2012 from the National Cancer Data Base. Factors affecting treatment selection (active surveillance [AS] vs adjuvant treatment [AT]) were identified using a parsimonious multivariate logistic regression model. Propensity scores for treatment decision were generated and incorporated into a multivariate Cox regression analysis of overall survival. This process was then repeated within the AT cohort for factors predictive for chemotherapy [CT] versus radiation therapy [RT]., Results: Only 33% of patients received AS, and 65% received AT (89% RT and 11% CT). From 1998 to 2012 the proportion receiving AS increased from 23% to 60%, whereas RT utilization decreased from 73% to 21%, and CT utilization increased from 2% to 17%. Utilization of low-dose RT increased from 1.5% in 1999 to 34% in 2012. There was a small absolute overall survival advantage to AT over AS at 10 years (95.0% vs 93.4%, propensity adjusted hazard ratio 0.58, P<.0005)., Conclusions: There has been a significant increase in use of AS for stage I seminoma, influenced by both sociodemogrpahic and clinicopathologic factors. Between AT options, there has been significant increase in use of CT, mirrored by a decline in use of RT. Although overall survival remains high for all 3 treatment strategies, AT seems to be associated with a small absolute survival advantage over AS up to 10 years out from diagnosis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Radiation oncology has always been deeply rooted in modeling, from the early days of isoeffect curves to the contemporary Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) initiative. In recent years, medical modeling for both prognostic and therapeutic purposes has exploded thanks to increasing availability of electronic data and genomics. One promising direction that medical modeling is moving toward is adopting the same machine learning methods used by companies such as Google and Facebook to combat disease. Broadly defined, machine learning is a branch of computer science that deals with making predictions from complex data through statistical models. These methods serve to uncover patterns in data and are actively used in areas such as speech recognition, handwriting recognition, face recognition, "spam" filtering (junk email), and targeted advertising. Although multiple radiation oncology research groups have shown the value of applied machine learning (ML), clinical adoption has been slow due to the high barrier to understanding these complex models by clinicians. Here, we present a review of the use of ML to predict radiation therapy outcomes from the clinician's point of view with the hope that it lowers the "barrier to entry" for those without formal training in ML. We begin by describing 7 principles that one should consider when evaluating (or creating) an ML model in radiation oncology. We next introduce 3 popular ML methods--logistic regression (LR), support vector machine (SVM), and artificial neural network (ANN)--and critique 3 seminal papers in the context of these principles. Although current studies are in exploratory stages, the overall methodology has progressively matured, and the field is ready for larger-scale further investigation., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: Hypofractionated whole-breast irradiation (HF-WBI) remains underutilized in the United States despite support by multiple clinical trials. We evaluated the success of iterative modifications of our breast cancer clinical pathway on the adoption of HF-WBI in a large, integrated radiation oncology network., Methods and Materials: The breast clinical pathway was modified in January 2011 (Amendment 1) to recommend HF-WBI as the first option for women ≥70 of age with stages 0 to IIA, while maintaining conventional fractionation (CF) as a pathway-concordant secondary option. In January 2013 (Amendment 2), the pathway's HF-WBI recommendation was extended to women ≥50 years of age. In January 2014 (Amendment 3), the pathway mandated HF-WBI as the only pathway-concordant option in women ≥50 years of age, and all pathway-discordant plans were subject to peer review and justification. Women ≥50 years of age with ductal carcinoma in situ or invasive breast cancer who underwent breast conserving surgery and adjuvant WBI were included in this analysis., Results: We identified 5112 patients from 2009 to 2014 who met inclusion criteria. From 2009 to 2012, the overall HF-WBI use rate was 8.3%. Following Amendments 2 and 3 (2013 and 2014, respectively), HF-WBI use significantly increased to 21.8% (17.3% in the community, 39.7% at academic sites) and 76.7% (75.5% in the community, 81.4% at academic sites), respectively (P<.001). Compared to 2009 to 2012, the relative risk of using HF-WBI was 7.9 (95% confidence interval: 7.1-8.6, P<.001) and 10.7 (95% CI: 10.3-11.0, P<.001), respectively, after Amendments 2 and 3, respectively. Age ≥70 and treatment at an academic site increased the likelihood of receiving HF-WBI in 2009 to 2012 and following Amendment 2 (P<.001)., Conclusions: This study demonstrates the transformative effect of a clinical pathway on patterns of care for breast radiation therapy. Although our initial HF-WBI use rate was low (8%-22%) and consistent with national rates, the clinical pathway approach dramatically increased adoption rate to >75%. In contrast to passive guidelines, clinical pathways serve as active tools to promote current best practices., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: Mantle cell lymphoma (MCL) is a rare, albeit aggressive subset of non-Hodgkin lymphoma, resulting in varied treatment approaches. Given the paucity of data defining the optimal management for early-stage MCL, we conducted an analysis using the National Cancer Data Base (NCDB) to identify practice patterns and outcomes., Methods and Materials: The NCDB was queried for patients with stage I to II MCL diagnosed from 1998 to 2012 receiving chemotherapy (CT) or radiation therapy (RT), or both (CT+RT). Univariate and multivariable analyses for factors associated with treatment selection were completed using logistic regression. Propensity scores with inverse probability treatment weighting (IPTW) were calculated based on the conditional probability of receiving CT+RT. The log-rank test and Cox proportional hazards modeling with IPTW adjustment were conducted for the survival analyses., Results: In total, 2539 patients were identified. The key characteristics were as follows: 69% were male, 71% were aged ≥60 years, 28% had extranodal involvement, and 51% had stage I disease. Of the 2539 patients, 70% underwent CT, 11% underwent RT, and 19% underwent CT+RT. The use of CT+RT decreased from 23.1% to 14.1% in 1998 to 2002 and 2010 to 2012 (P<.001). CT+RT usage was lower for patients with the following characteristics: age ≥60 years, female sex, stage II disease, and the presence of B symptoms. With a median follow-up period of 42.8 months, the unadjusted 3-year overall survival estimates for patients receiving CT, RT, or CT+RT were 67.8%, 72.4%, and 79.8%, respectively (P<.001). After correcting for indication bias through IPTW-adjusted modeling, CT+RT reduced the risk of overall mortality compared with monotherapy (hazard ratio 0.65, P=.029)., Conclusions: Although uncommon, patients with stage I-II MCL can have favorable outcomes. Despite a continued decline in the usage of consolidative RT, combined modality therapy improves survival in this cohort compared with monotherapy., (Copyright © 2015 Elsevier Inc. All rights reserved.)