Endoscopic Ultrasound Placement of Preloaded Fiducial Markers Shortens Procedure Time Compared to Back-Loaded Markers.

BACKGROUND & AIMS: Fiducial markers are inert radiopaque gold or carbon markers implanted in or near pancreatic tumor to demarcate areas for image-guided radiation therapy. Endoscopic ultrasound (EUS) pre-loaded fiducial needles (PLNs) have been developed to circumvent technical issues associated with traditional back-loaded fiducials (BLNs). We performed a randomized controlled trial to compare procedure times in patients with pancreatic adenocarcinoma undergoing EUS-guided placement of BLNs vs PLNs. METHODS: In a prospective study, 44 patients with pancreatic adenocarcinoma referred for fiducial marker placement at 2 tertiary care centers were assigned to groups that received PLNs (n = 22) or BLNs (n = 22); each group had the same proportion of patients with tumors of different locations (head or neck vs body or tail).The procedure was standardized among all endoscopists and placement of a minimum of 3 markers inside the tumor was defined as technical success. The times for procedure and fiducial placement were recorded, total number of fiducial markers used documented, and grade of procedure difficulty ranked by passing the needle or deploying the fiducials. Other recorded variables included tumor characteristics, fluoroscopy use, and the number of fiducials clearly seen by EUS and fluoroscopy. The primary aim was to compare the duration of EUS-guided fiducial insertion of BLNs vs PLNs. RESULTS: The median placement time was significantly shorter in the PLN group (9 min) than the BLN group (16 min) (P < .001). However, the 44% reduction in time did not reach pre-specified levels (≥60%). Similar results were found after stratifying by tumor location. Deployment of BLNs was easier than deployment of PLNs (P = .03). There was no significant difference between groups in technical success, number of fiducials placed, EUS or fluoroscopic visualization, or adverse events. During simulation computed tomography and image-guided radiation therapy, there was no difference between groups in visualization of fiducials, migration rate, or accuracy of placement. CONCLUSIONS: In a randomized controlled trial of 44 patients with pancreatic adenocarcinoma, we found EUS-guided placement of PLNs to require less time and produce similar results compared with BLNs. Further refinements in PLN delivery system are needed to increase the ease of deployment. Clinicaltrials.gov no: NCT02332863.

Pilot Prehabilitation Program for Patients With Esophageal Cancer During Neoadjuvant Therapy and Surgery.

BACKGROUND: Locally advanced esophageal cancer is often treated with neoadjuvant therapy followed by surgery. Many patients present with or experience clinical deconditioning during neoadjuvant therapy. Prehabilitation programs in other areas of surgery have demonstrated improved postoperative outcomes. The aims of this study were to evaluate the feasibility of a pilot prehabilitation program and determine preliminary effects on surgical and cancer-related outcomes. METHODS: A retrospective review of patients treated at a single institution with resectable esophageal cancer was performed (n = 22). Patients in the prehabilitation group received protocol-structured intervention in several clinical domains including nutrition, psychosocial support, and physical exercise. RESULTS: Clinical stage and comorbidities were well matched between groups. The structured prehabilitation program was feasible and well received by participants. Fewer patients required admission during neoadjuvant therapy in the prehabilitation group (27.3% versus 54.5%). Percentage weight loss during treatment was 3.0% in the prehabilitation group versus 4.3% in the control group. Compared with the control group, the prehabilitation group demonstrated 0.0% versus 18.2% 30-d postoperative readmission rate and 18.2% versus 27.3% 90-d postoperative readmission rate. There were no statistically significant differences between groups in regard to complications or mortality. CONCLUSIONS: The pilot prehabilitation program demonstrated feasibility of implementing a structured program for patients receiving neoadjuvant therapy for esophageal cancer. Although the small population limits evaluation of statistical significance, trends in the data suggest a potential benefit of the prehabilitation program on neoadjuvant hospital admission rates, postsurgical readmission rates, and nutritional status.

Rising Rates of Upfront Surgery in Early Locally Advanced Cervical Cancer: What Factors Predict for This Treatment Paradigm?

OBJECTIVE: In this study, we analyzed patterns of care for patients with locally advanced cervical cancer to identify predictors for upfront surgery compared with definitive chemoradiation (CRT). METHODS: The National Cancer Database was queried for patients aged 18 years or older with Federation of Gynecology and Obstetrics IB2-IIB cervical cancer. All patients underwent either upfront hysterectomy with or without postoperative radiation therapy versus definitive CRT. Logistic regression was used to assess variables associated with modality of treatment (surgery vs CRT). RESULTS: Of the 9494 patients included, 2151 (22.7%) underwent upfront surgery. Of those undergoing surgery, 380 (17.7%) had positive margins, 478 (22.2%) had positive nodes, and 458 (21.3%) had pathologic involvement of the parametrium. Under multiple logistic regression, rates of surgery significantly increased from 2004 (12.2%) to 2012 (31.2%) (odds ratio [OR] per year increase, 1.15; confidence interval [CI], 1.12-1.17; P < 0.001). Upfront surgery was more commonly performed in urban (OR, 1.21; 95% CI, 1.03-1.41; P = 0.018) and rural counties (OR, 1.79; 95% CI, 1.24-2.58; P = 0.002), for adenocarcinoma (OR, 2.14; 1.88-2.44; P < 0.001) and adenosquamous (OR, 2.69; 2.11-3.43; P < 0.001) histologies, and in patients from higher median income communities (ORs, 1.19-1.37). Upfront surgery was less common at academic centers (OR, 0.73; 95% CI, 0.58-0.93; P = 0.011). CONCLUSIONS: Rates of upfront surgery relative to definitive CRT have increased significantly over the past decade. In the setting of level 1 evidence supporting the use of definitive CRT alone for these women, the rising rates of upfront surgery raises concern for both unnecessary surgical procedures with higher rates of treatment-related morbidity and greater health care costs.

Impact of facility volume on outcomes in patients with squamous cell carcinoma of the anal canal: Analysis of the National Cancer Data Base.

BACKGROUND: Given the rarity of anal cancer and the technical aspects involved in radiation (RT) planning, the authors conducted a population-based analysis evaluating the impact of radiation oncology facility volume on overall survival (OS) in patients with squamous cell carcinoma (SCC) of the anal canal. METHODS: The National Cancer Data Base (NCDB) was queried for patients with SCC of the anal canal who underwent RT. All patients were coded as having received their entire course of RT at the NCDB reporting facility. Facility volume was categorized into tertiles (low, intermediate, and high) and was based on the number of times a facility's unique identification code appeared. RESULTS: In total, 13,550 patients were identified. Patients who received treatment at higher volume radiation oncology facilities had longer OS based on multivariate analysis (MVA) (hazard ratio, 0.81; 95% confidence interval [CI], 0.73-0.90; P < .001) and propensity score matching analysis (hazard ratio, 0.79; 95% CI, 0.69-0.91; P < .001). For patients who received treatment at low-volume, intermediate-volume, and high-volume centers, the 5-year OS rate was 70%, 72.2%, and 75.4%, respectively (P < .001). Compared with low/intermediate-volume radiation oncology centers, high-volume centers were more likely to treat patients with concurrent chemotherapy (odds ratio, 1.27; 95% CI, 1.07-1.51; P = .006) and less likely to have treatment delays leading to an RT duration of >45 days (odds ratio, 0.74; 95% CI, 0.69-0.80; P < .001). CONCLUSIONS: Treatment at higher volume radiation oncology centers appears to be associated with improved OS in patients with SCC of the anal canal. These results likely reflect the relation between physician experience and delivery of high-quality RT, which perhaps is best evident in rare tumors such as anal SCC. Cancer 2017;123:228-236. © 2016 American Cancer Society.

Adjuvant radiotherapy improves overall survival in patients with resected gastric adenocarcinoma: A National Cancer Data Base analysis.

BACKGROUND: For patients with resectable gastric adenocarcinoma, perioperative chemotherapy and adjuvant chemoradiotherapy (CRT) are considered standard options. In the current study, the authors used the National Cancer Data Base to compare overall survival (OS) between these regimens. METHODS: Patients who underwent gastrectomy for nonmetastatic gastric adenocarcinoma from 2004 through 2012 were divided into those treated with perioperative chemotherapy without RT versus those treated with adjuvant CRT. Survival was estimated and compared using univariate and multivariate models adjusted for patient and tumor characteristics, surgical margin status, and the number of lymph nodes examined. Subset analyses were performed for factors chosen a priori, and potential interactions between treatment and covariates were assessed. RESULTS: A total of 3656 eligible patients were identified, 52% of whom underwent perioperative chemotherapy and 48% of whom received postoperative CRT. The median follow-up was 47 months, and the median age of the patients was 62 years. Analysis of the entire cohort demonstrated improved OS with adjuvant RT on both univariate (median of 51 months vs 42 months; P = .013) and multivariate (hazard ratio, 0.874; 95% confidence interval, 0.790-0.967 [P = .009]) analyses. Propensity score-matched analysis also demonstrated improved OS with adjuvant RT (median of 49 months vs 39 months; P = .033). On subset analysis, a significant interaction was observed between the survival impact of adjuvant RT and surgical margins, with a greater benefit of RT noted among patients with surgical margin-positive disease (hazard ratio with RT: 0.650 vs 0.952; P for interaction <.001). CONCLUSIONS: In this National Cancer Data Base analysis, the use of adjuvant RT in addition to chemotherapy was associated with a significant OS advantage for patients with resected gastric cancer. The survival advantage observed with adjuvant CRT was most pronounced among patients with positive surgical margins. Cancer 2017;123:3402-9. © 2017 American Cancer Society.

The Multidisciplinary Approach to GI Cancer Results in Change of Diagnosis and Management of Patients. Multidisciplinary Care Impacts Diagnosis and Management of Patients.

BACKGROUND: The multidisciplinary approach to GI cancer is becoming more widespread as a result of multimodality therapy. At the University of Colorado Hospital (UCH), we utilize a formal multidisciplinary approach through specialized clinics across a variety of settings, including pancreas and biliary cancer, esophageal and gastric cancer, liver cancer and neuroendocrine tumors (NET), and colorectal cancer. Patients with these suspected diagnoses are seen in a multidisciplinary clinic. We evaluated whether implementation of disease-specific multidisciplinary programs resulted in a change in diagnosis and/or change in management for these patients. METHODS: Data from 1747 patients were prospectively collected from inception of each multidisciplinary program through December 31, 2015. Change in diagnosis was defined as a change in radiographic or endoscopic findings that resulted in a change in cancer stage or clinical diagnosis and/or a change in pathologic diagnosis. Reports of incidental findings unrelated to primary diagnosis on radiographic evaluation were also assessed, but not included in overall change in diagnosis findings. We further evaluated if patients had a change in the management of their disease compared with outside recommendations. RESULTS: Of 1747 patients evaluated, change occurred in 38 % (pancreas and biliary), 13 % (esophageal and gastric); 22 % (liver and NET), and 16 % (colorectal). Change in management for each multidisciplinary program occurred in 35 % (pancreas and biliary), 20 % (esophageal and gastric), 27 % (liver and NET), and 13 % (colorectal). CONCLUSIONS: The use of a multidisciplinary clinic to manage GI cancer has a substantial impact in change in diagnosis and/or management in more than one-third of patients evaluated.

Disparities in standard of care treatment and associated survival decrement in patients with locally advanced cervical cancer.

PURPOSE: Standard of care (SOC) treatment for locally advanced cervical cancer includes pelvic external beam radiation (EBRT) with chemotherapy and interdigitated brachytherapy. We evaluated national utilization trends and factors associated with receiving SOC therapy. MATERIALS AND METHODS: We utilized the National Cancer Database (NCDB) to identify women with locally advanced cervical cancer treated with definitive radiation or chemoradiation therapy and stratified these patients by treatment received. RESULTS: We identified 15,194 patients. Only 44.3% of patients received SOC treatment and this group had significantly improved OS. High volume centers, academic centers, comprehensive community cancer centers, private insurance, and higher income, were all associated with an increased likelihood of receiving SOC, whereas Black patients were less likely to receive SOC. We found 26.8% of patients received no radiation boost, 23.8% received an EBRT boost only, and 49.5% of patients received EBRT with brachytherapy. Although an EBRT boost was advantageous over no boost at all (HR 0.720, p<0.001), OS was superior in patients who received brachytherapy (HR 0.554, p<0.001). Patients were more likely to receive no radiotherapy boost if they had lower incomes, Medicaid, were treated at low volume centers, or were treated at non-comprehensive community cancer centers. CONCLUSIONS: SOC for locally advanced cervical cancer offers superior outcomes, yet less than half of patients receive SOC and there are disparities in which patients receive SOC treatment. No additional treatment, including sophisticated EBRT techniques including IMRT or SBRT, can make up for the survival decrement from lack of brachytherapy as a component of definitive care.

Should we customize PTV expansions for BMI? Daily cone beam computerized tomography to assess organ motion in postoperative endometrial and cervical cancer patients.

AIM: A single-institution review assessing patient characteristics contributing to daily organ motion in postoperative endometrial and cervical cancer patients treated with intensity-modulated radiotherapy (IMRT). BACKGROUND: The Radiation Therapy Oncology Group has established consensus guidelines for postoperative pelvic IMRT, recommending a 7 mm margin on all three axes of the target volume. MATERIALS AND METHODS: Daily shifts on 457 radiation setups for 18 patients were recorded in the x axis (lateral), y axis (superior-inferior) and z axis (anterior-posterior); daily positions of the planning tumor volume were referenced with the initial planning scan to quantify variations. RESULTS: Of the 457 sessions, 85 (18.6%) had plan shifts of at least 7 mm in one of the three dimensions. For obese patients (body mass index [BMI] ≥ 30), 75/306 (24.5%) sessions had plan shifts ≥7 mm. Odds of having a shift ≥7 mm in any direction was greater for obese patients under both univariate (OR 4.227, 95% CI 1.235-14.466, p = 0.021) and multivariate (OR 5.000, 95% CI 1.341-18.646, p = 0.016) analyses (MVA). Under MVA, having a BMI ≥ 30 was associated with increased odds of shifts in the anterior-posterior (1.173 mm, 95% CI 0.281-2.065, p = 0.001) and lateral (2.074 mm, 95% CI 1.284-2.864, p < 0.000) directions but not in the superior-inferior axis (0.298 mm, 95% CI -0.880 to 1.475, p = 0.619) exceeding 7 mm. CONCLUSIONS: Based on these findings, the standard planned tumor volume expansion of 7 mm is less likely to account for daily treatment changes in obese patients.

Sarcomas of the aorta: a systematic review and pooled analysis of published reports.

BACKGROUND: Aortic sarcomas are rare and aggressive tumors with a propensity for arterial embolization, disseminated metastases, and rapid clinical deterioration. Overall, little is known about the evaluation and management of this disease. METHODS: A systematic review and pooled analysis were performed from a comprehensive search of the MEDLINE database for reports of primary aortic sarcomas published in the English language. RESULTS: One hundred sixty-five cases were analyzed. The median age was 60 years, and the male:female ratio was 1.5:1. High tumor grade (87.3%), arterial embolization (46.7%), and metastatic disease at diagnosis (44.8%) were common. Typical histologies were undifferentiated (39.4%), angiosarcomatous (37%), leiomyosarcomatous (13.3%), and fibroblastic (7.3%). Management was diverse and included combinations of surgical resection (46.7%), palliative vascular surgeries (37.7%), chemotherapy (28.7%), and radiotherapy (14.7%). The median survival was 11 months, and the 1-, 3-, and 5-year survival rates were 46.7%, 17.1%, and 8.8%, respectively. On univariate analyses, metastatic disease at diagnoses, surgical resection, and chemotherapy were associated with survival. On multivariate analysis, only metastatic disease remained significant (P < 0.001). CONCLUSIONS: Aortic tumors are devastating malignancies with distinct clinical features from sarcomas at other sites. Although prognosis is poor overall, long-term survivors have been reported, and aggressive management with surgical resection and adjuvant therapy should be considered in medically suitable patients. High embolic rates suggest a potential role for prophylactic anticoagulation.

Clinical and Dosimetric Impact of 2D kV Motion Monitoring and Intervention in Liver Stereotactic Body Radiation Therapy.

Purpose: Positional errors resulting from motion are a principal challenge across all disease sites in radiation therapy. This is particularly pertinent when treating lesions in the liver with stereotactic body radiation therapy (SBRT). To achieve dose escalation and margin reduction for liver SBRT, kV real-time imaging interventions may serve as a potential solution. In this study, we report results of a retrospective cohort of liver patients treated using real-time 2D kV-image guidance SBRT with emphasis on the impact of (1) clinical workflow, (2) treatment accuracy, and (3) tumor dose. Methods and Materials: Data from 33 patients treated with 41 courses of liver SBRT were analyzed. During treatment, planar kV images orthogonal to the treatment beam were acquired to determine treatment interventions, namely treatment pauses (ie, adequacy of gating thresholds) or treatment shifts. Patients were shifted if internal markers were >3 mm, corresponding to the PTV margin used, from the expected reference condition. The frequency, duration, and nature of treatment interventions (ie, pause vs shift) were recorded, and the dosimetric impact associated with treatment shifts was estimated using a machine learning dosimetric model. Results: Of all fractions delivered, 39% required intervention, which took on average 1.9 ± 1.6 minutes and occurred more frequently in treatments lasting longer than 7 minutes. The median realignment shift was 5.7 mm in size, and the effect of these shifts on minimum tumor dose in simulated clinical scenarios ranged from 0% to 50% of prescription dose per fraction. Conclusion: Real-time kV-based imaging interventions for liver SBRT minimally affect clinical workflow and dosimetrically benefit patients. This potential solution for addressing positional errors from motion addresses concerns about target accuracy and may enable safe dose escalation and margin reduction in the context of liver SBRT.

Association of Radiotherapy Duration With Clinical Outcomes in Patients With Esophageal Cancer Treated in NRG Oncology Trials: A Secondary Analysis of NRG Oncology Randomized Clinical Trials.

Importance: For many types of epithelial malignant neoplasms that are treated with definitive radiotherapy (RT), treatment prolongation and interruptions have an adverse effect on outcomes. Objective: To analyze the association between RT duration and outcomes in patients with esophageal cancer who were treated with definitive chemoradiotherapy (CRT). Design, Setting, and Participants: This study was an unplanned, post hoc secondary analysis of 3 prospective, multi-institutional phase 3 randomized clinical trials (Radiation Therapy Oncology Group [RTOG] 8501, RTOG 9405, and RTOG 0436) of the National Cancer Institute-sponsored NRG Oncology (formerly the National Surgical Adjuvant Breast and Bowel Project, RTOG, and Gynecologic Oncology Group). Enrolled patients with nonmetastatic esophageal cancer underwent definitive CRT in the trials between 1986 and 2013, with follow-up occurring through 2014. Data analyses were conducted between March 2022 to February 2023. Exposures: Treatment groups in the trials used standard-dose RT (50 Gy) and concurrent chemotherapy. Main Outcomes and Measures: The outcomes were local-regional failure (LRF), distant failure, disease-free survival (DFS), and overall survival (OS). Multivariable models were used to examine the associations between these outcomes and both RT duration and interruptions. Radiotherapy duration was analyzed as a dichotomized variable using an X-Tile software to choose a cut point and its median value as a cut point, as well as a continuous variable. Results: The analysis included 509 patients (median [IQR] age, 64 [57-70] years; 418 males [82%]; and 376 White individuals [74%]). The median (IQR) follow-up was 4.01 (2.93-4.92) years for surviving patients. The median cut point of RT duration was 39 days or less in 271 patients (53%) vs more than 39 days in 238 patients (47%), and the X-Tile software cut point was 45 days or less in 446 patients (88%) vs more than 45 days in 63 patients (12%). Radiotherapy interruptions occurred in 207 patients (41%). Female (vs male) sex and other (vs White) race and ethnicity were associated with longer RT duration and RT interruptions. In the multivariable models, RT duration longer than 45 days was associated with inferior DFS (hazard ratio [HR], 1.34; 95% CI, 1.01-1.77; P = .04). The HR for OS was 1.33, but the results were not statistically significant (95% CI, 0.99-1.77; P = .05). Radiotherapy duration longer than 39 days (vs ≤39 days) was associated with a higher risk of LRF (HR, 1.32; 95% CI, 1.06-1.65; P = .01). As a continuous variable, RT duration (per 1 week increase) was associated with DFS failure (HR, 1.14; 95% CI, 1.01-1.28; P = .03). The HR for LRF 1.13, but the result was not statistically significant (95% CI, 0.99-1.28; P = .07). Conclusions and Relevance: Results of this study indicated that in patients with esophageal cancer receiving definitive CRT, prolonged RT duration was associated with inferior outcomes; female patients and those with other (vs White) race and ethnicity were more likely to have longer RT duration and experience RT interruptions. Radiotherapy interruptions should be minimized to optimize outcomes.

High-dose MVCT image guidance for stereotactic body radiation therapy.

PURPOSE: Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance. METHODS: Two nonstandard, high-dose imaging modes were created on a tomotherapy machine by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high-dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast-to-noise ratios (CNRs), high-contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high-dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard-dose images for comparison. RESULTS: MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high-dose modes respectively. CNR values for both low and high-contrast materials were found to increase with the square root of dose. Axial high-contrast spatial resolution was comparable for all imaging modes at 0.5 lp∕mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable. CONCLUSIONS: High-dose imaging modes are made possible on a clinical tomotherapy machine by increasing the LINAC pulse rate. Increasing the imaging dose results in increased CNRs; making it easier to distinguish the boundaries of low contrast objects. The imaging dose levels observed in this work are considered acceptable at our institution for SBRT treatments delivered in 3-5 fractions.

Practical Implementation of Emergent After-Hours Radiation Treatment Process Using Remote Treatment Planning on Optimized Diagnostic CT Scans.

The purpose of this report is to present the implementation of a process for after-hours radiation treatment (RT) utilizing remote treatment planning based on optimized diagnostic computed tomography (CT) scans for the urgent palliative treatment of inpatients. A standardized operating procedure was developed by an interprofessional panel to improve the quality of after-hours RT and minimize the risk of treatment errors. A new diagnostic CT protocol was created that could be performed after-hours on hospital scanners and would ensure a reproducible patient position and adequate field of view. An on-call structure for dosimetry staff was created utilizing remote treatment planning. The optimized CT protocol was developed in collaboration with the radiology department, and a novel order set was created in the electronic health system. The clinical workflow begins with the radiation oncologist notifying the on-call team (therapist, dosimetrist, and physicist) and obtaining an optimized diagnostic CT scan on a hospital-based scanner. The dosimetrist remotely creates a plan; the physicist checks the plan; and the patient is treated. Plans are intentionally simple (parallel opposed fields, symmetric jaws) to expedite care and reduce the risk of error. Education on the new process was provided for all relevant staff. Our process was successfully implemented with the use of an optimized CT protocol and remote treatment planning. This approach has the potential to improve the quality and safety of emergent after-hours RT by better approximating the normal process of care.

Long-Term Outcomes of NRG Oncology/RTOG 0529: A Phase 2 Evaluation of Dose-Painted Intensity Modulated Radiation Therapy in Combination With 5-Fluorouracil and Mitomycin-C for the Reduction of Acute Morbidity in Anal Canal Cancer.

PURPOSE: A multi-institutional phase 2 trial assessed long-term outcomes of dose-painted intensity modulated radiation therapy (IMRT) with 5-fluorouracil (5FU) and mitomycin-C (MMC) for anal canal cancer. METHODS AND MATERIALS: T2-4N0-3M0 anal cancers received 5FU (1000 mg/m2/d, 96-hour infusion) and MMC (10 mg/m2 bolus) on days 1 and 29 of dose-painted IMRT prescribed as follows: T2N0 = 42 Gy elective nodal and 50.4 Gy anal tumor planning target volumes, 28 fractions; T3-4N0-3 = 45Gy elective nodal, 50.4 Gy ≤3 cm and 54 Gy >3cm metastatic nodal and 54 Gy anal tumor planning target volumes, 30 fractions. Local-regional failures, distant metastases, and colostomy failures were assessed using the cumulative incidence method, and disease-free survival, overall survival, and colostomy-free survival were assessed using the Kaplan-Meier method. Late effects were scored using National Cancer Institute-Common Terminology Criteria for Adverse Events v3. RESULTS: Of 52 patients, 54% were stage II, 25% were stage IIIA, and 21% were stage IIIB. Median follow-up was 7.9 years (min-max, 0.02-9.2 years). Local-regional failure, colostomy failures, distant metastases, overall survival, disease-free survival, and colostomy-free survival at 5 years are 16% (95% confidence interval [CI], 7%-27%), 10% (95% CI, 4%-20%), 16% (95% CI, 7%-27%), 76% (95% CI, 61%-86%), 70% (95% CI, 56%-81%), and 74% (95% CI, 59%-84%); and at 8 years they are 16% (95% CI, 7%-27%), 12% (95% CI, 5%-23%), 22% (95% CI, 12%-34%), 68% (95% CI, 53%-79%), 62% (95% CI, 47%-74%) and 66% (95% CI, 51%-77%), respectively. Eight patients experienced local-regional failure, with 5 patients having persistent disease at 12 weeks. No isolated nodal failures occurred in the microscopic elective nodal volumes. Six patients required colostomy-5 for local-regional salvage and 1 for a temporary ostomy for anorectal dysfunction. Rates of late adverse events included: 28 patients (55%) with grade 2, 8 patients (16%) with grade 3, 0 patients with grade 4, and 2 patients (4%) with grade 5 events (sinus bradycardia and myelodysplasia, possibly owing to chemotherapy). Only 11 patients reported grade 1 to 3 sexual dysfunction. CONCLUSIONS: Dose-painted IMRT with 5FU/MMC for the treatment of anal canal cancer yields comparable long-term efficacy as conventional radiation cohorts. Enhanced normal tissue protection lowered rates of grade 3 and higher late effects without compromising pelvic tumor control.

Use of the Toxicity Index in Evaluating Adverse Events in Anal Cancer Trials: Analysis of RTOG 9811 and RTOG 0529.

Novel toxicity metrics that account for all adverse event (AE) grades and the frequency of may enhance toxicity reporting in clinical trials. The Toxicity Index (TI) accounts for all AE grades and frequencies for categories of interest. We evaluate the feasibility of using the TI methodology in 2 prospective anal cancer trials and to evaluate whether more conformal radiation (using Intensity Modulated Radiation Therapy) results in improved toxicity as measured by the TI. Patients enrolled on NRG/RTOG 0529 or nonconformal RT enrolled on the 5-Fluorouracil/Mitomycin arm of NRG/RTOG 9811 were compared using the TI. Patients treated on NRG/RTOG 0529 had lower median TI compared with patients treated with nonconformal RT on NRG/RTOG 9811 for combined GI/GU/Heme/Derm events (3.935 vs 3.996, P=0.014). The TI methodology is a feasible method to assess all AEs of interest and may be useful as a composite metric for future efforts aimed at treatment de-escalation or escalation.

Stereotactic body radiotherapy for colorectal liver metastases: a pooled analysis.

BACKGROUND: This study was undertaken to determine outcomes of stereotactic body radiotherapy for colorectal liver metastases in a pooled patient cohort. METHODS: Patients with colorectal liver metastases from 3 institutions were included if they had 1 to 4 lesions, received 1 to 6 fractions of stereotactic body radiotherapy, and had radiologic imaging ≥ 3 months post-treatment. Sixty-five patients with 102 lesions treated from August 2003 to May 2009 were retrospectively analyzed. A tumor control probability (TCP) model was used to estimate the 3-fraction dose required for > 90% local control after converting the schedule into biologically equivalent dose (BED), single-fraction equivalent dose, or linear quadratic model-based single-fraction dose. RESULTS: Forty-seven (72%) patients had ≥ 1 chemotherapy regimen before stereotactic body radiotherapy, and 27 (42%) patients had ≥ 2 regimens. The median follow-up was 1.2 years (range, 0.3-5.2 years). The median dose was 42 gray (Gy; range, 22-60 Gy). When evaluated separately by multivariate analysis, total dose (P = .0015), dose/fraction (P = .003), and BED (P = .004) all correlated with local control by lesion. On multivariate analysis, nonactive extrahepatic disease was associated with overall survival (OS; P = .046), and sustained local control was closely correlated (P = .06). By using single-fraction equivalent dose, BED, or linear quadratic model-based single-fraction dose in the TCP model, the estimated dose range needed for 1-year local control > 90% is 46 to 52 Gy in 3 fractions. CONCLUSIONS: Liver stereotactic body radiotherapy is well tolerated and effective for colorectal liver metastases. The strong correlation between local control and OS supports controlling hepatic disease even for heavily pretreated patients. For a 3-fraction regimen of stereotactic body radiotherapy, a prescription dose of ≥ 48 Gy should be considered, if normal tissue constraints allow.

Esophageal cancer patients undergoing external beam radiation after placement of self-expandable metal stents: is there a risk of radiation dose enhancement?

BACKGROUND: Self-expandable metal stents (SEMSs) are used for palliation of malignant dysphagia. It is not known whether dose adjustments are required when there is a stent in the radiation field. OBJECTIVE: To measure the effects of esophageal stents of various designs and materials on radiation dose to the tissue adjacent to the stent in the radiation field to determine whether there should be any dose adjustment. DESIGN: Simulated clinical protocol. SETTING: Linear accelerator radiation treatment center. PATIENTS: Solid Water phantoms were used to mimic the tissue environment of the human esophagus as well as stents of various designs and materials and controls. INTERVENTIONS: Radiation beams composed of photons (x-rays) delivered in split dosing with energies of 6, 10, and 15 million volts. MAIN OUTCOME MEASUREMENTS: Film and image-based evidence of dose enhancement; Monte Carlo calculations. RESULTS: Dose enhancement from single beams was seen only on the anterior surface, particularly in the stainless steel Z-stent (3.5%-7.8%) and the nonmetal Polyflex stent (5.5%-8.8%); less dose enhancement was seen on the anterior surface of the Alimaxx and Ultraflex nitinol stents (2%-2.5%). A negligible dose effect was seen on the posterior wall of all the stents tested. Monte Carlo calculation results were roughly similar to actual dosimeter measurements. LIMITATIONS: Simulated clinical protocol. CONCLUSIONS: This tissue-mimicking model reveals that radiation dose enhancement is a function of stent design and material, and the dose reduction is unnecessary as long as multiple fields are used.

Use of Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: Initial Results From the Pembrolizumab Arm of a Phase 2 Randomized Clinical Trial.

IMPORTANCE: Total neoadjuvant therapy (TNT) is often used to downstage locally advanced rectal cancer (LARC) and decrease locoregional relapse; however, more than one-third of patients develop recurrent metastatic disease. As such, novel combinations are needed. OBJECTIVE: To assess whether the addition of pembrolizumab during and after neoadjuvant chemoradiotherapy can lead to an improvement in the neoadjuvant rectal (NAR) score compared with treatment with FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) and chemoradiotherapy alone. DESIGN, SETTING, AND PARTICIPANTS: In this open-label, phase 2, randomized clinical trial (NRG-GI002), patients in academic and private practice settings were enrolled. Patients with stage II/III LARC with distal location (cT3-4 ≤ 5 cm from anal verge, any N), with bulky disease (any cT4 or tumor within 3 mm of mesorectal fascia), at high risk for metastatic disease (cN2), and/or who were not candidates for sphincter-sparing surgery (SSS) were stratified based on clinical tumor and nodal stages. Trial accrual opened on August 1, 2018, and ended on May 31, 2019. This intent-to-treat analysis is based on data as of August 2020. INTERVENTIONS: Patients were randomized (1:1) to neoadjuvant FOLFOX for 4 months and then underwent chemoradiotherapy (capecitabine with 50.4 Gy) with or without intravenous pembrolizumab administered at a dosage of 200 mg every 3 weeks for up to 6 doses before surgery. MAIN OUTCOMES AND MEASURES: The primary end point was the NAR score. Secondary end points included pathologic complete response (pCR) rate, SSS, disease-free survival, and overall survival. This report focuses on end points available after definitive surgery (NAR score, pCR, SSS, clinical complete response rate, margin involvement, and safety). RESULTS: A total of 185 patients (126 [68.1%] male; mean [SD] age, 55.7 [11.1] years) were randomized to the control arm (CA) (n = 95) or the pembrolizumab arm (PA) (n = 90). Of these patients, 137 were evaluable for NAR score (68 CA patients and 69 PA patients). The mean (SD) NAR score was 11.53 (12.43) for the PA patients (95% CI, 8.54-14.51) vs 14.08 (13.82) for the CA patients (95% CI, 10.74-17.43) (P = .26). The pCR rate was 31.9% in the PA vs 29.4% in the CA (P = .75). The clinical complete response rate was 13.9% in the PA vs 13.6% in the CA (P = .95). The percentage of patients who underwent SSS was 59.4% in the PA vs 71.0% in the CA (P = .15). Grade 3 to 4 adverse events were slightly increased in the PA (48.2%) vs the CA (37.3%) during chemoradiotherapy. Two deaths occurred during FOLFOX: sepsis (CA) and pneumonia (PA). No differences in radiotherapy fractions, FOLFOX, or capecitabine doses were found. CONCLUSIONS AND RELEVANCE: Pembrolizumab added to chemoradiotherapy as part of total neoadjuvant therapy was suggested to be safe; however, the NAR score difference does not support further study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02921256.

Anal Cancer in the Era of Dose Painted Intensity Modulated Radiation Therapy: Implications for Regional Nodal Therapy.

Since the initial development of 5-fluorouracil and mitomycin as a standard of care platform for definitive anal cancer chemoradiotherapy, multiple studies have evaluated the optimal chemotherapy regimen, and radiotherapy technique. Refinements in treatment technique have taken place during an era of improved diagnostic imaging, including incorporation of FDG-PET, with implications for a possible stage migration effect. This has introduced an opportunity to develop stage-specific recommendations for primary tumor, involved nodal, and elective nodal irradiation dose. Elective nodal irradiation remains standard given the low rates of elective nodal failure with current practice, although may be subject to evolving controversy for patients with early stage disease. In this review, development of the current standard of care for anal cancer chemoradiotherapy is reviewed in the context of modern staging and dose-painted radiotherapy treatment techniques.