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Background: Although intensity-modulated radiation therapy (IMRT) is considered the standard of care for the treatment of squamous cell carcinoma of the anus (SCCA), few large series have reported oncologic outcomes and toxicities. In this retrospective report, we aim to describe outcomes and toxicities after IMRT-based chemoradiation (CRT) for the treatment of SCCA, evaluate the impact of dose escalation (>54 Gy), and compare concurrent fluoropyrimidine in combination with either mitomycin or with cisplatin as chemosensitizers., Methods: Patients treated at The University of Texas MD Anderson Cancer Center between January 1, 2003 and December 31, 2018 with IMRT-based CRT were included. Median time to locoregional recurrence, time to colostomy, and overall survival were estimated using the Kaplan-Meier method., Results: A total of 428 patients were included; median follow-up was 4.4 years. Three hundred and thirty-four patients (78.0%) were treated with concurrent cisplatin and fluoropyrimidine, and 160 (37.4%) with >54 Gy. Two- and 5-year freedom from locoregional failure, freedom from colostomy failure, and overall survival were 86.5% and 81.2%, respectively, 90.0% and 88.3%, respectively, and 93.6% and 85.8%, respectively. Neither dose escalation nor mitomycin-based concurrent chemotherapy resulted in improved outcomes. Mitomycin-based concurrent chemotherapy was associated with in approximately 2.5 times increased grade 3 or greater acute toxicity. Radiation dose >54 Gy was associated with approximately 2.6 times increased Grade 3 or greater chronic toxicity., Conclusions: Our results suggest IMRT-based CRT with concurrent fluoropyrimidine and cisplatin is a safe and feasible option for patient with SCCA and may cause less acute toxicity. The role for radiation dose escalation is unclear and requires further study., (© The Author(s) 2022. Published by Oxford University Press.)

Over the past 2 decades, major technical advances in radiation therapy planning and delivery have made it possible to deliver higher doses to select high-risk volumes. This has helped to expand the role of radiation therapy in the treatment of gastrointestinal malignancies. Whereas dose escalation was previously limited by the radiosensitivity of normal tissues within and adjacent to the gastrointestinal tract, advances in target delineation, patient immobilization, treatment planning, and image-guided treatment delivery have greatly improved the therapeutic ratio. More conformal radiation modalities can offer further dose optimization to target volumes while sparing normal tissue from toxicity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Radiation therapy plays an integral role in the management of head and neck cancers (HNCs). While most HNC patients have historically been treated with photon-based radiation techniques such as intensity modulated radiation therapy (IMRT), there is a growing awareness of the potential clinical benefits of proton therapy over IMRT in the definitive, postoperative and reirradiation settings given the unique physical properties of protons. Intensity modulated proton therapy (IMPT), also known as "pencil beam proton therapy," is a sophisticated mode of proton therapy that is analogous to IMRT and an active area of investigation in cancer care. Multifield optimization IMPT allows for high quality plans that can target superficially located HNCs as well as large neck volumes while significantly reducing integral doses. Several dosimetric studies have demonstrated the superiority of IMPT over IMRT to improve dose sparing of nearby organs such as the larynx, salivary glands, and esophagus. Evidence of the clinical translation of these dosimetric advantages has been demonstrated with documented toxicity reductions (such as decreased feeding tube dependency) after IMPT for patients with HNCs. While there are relative challenges to IMPT planning that exist today such as particle range uncertainties and high sensitivity to anatomical changes, ongoing investigations in image-guidance techniques and robust optimization methods are promising. A systematic approach towards utilizing IMPT and additional prospective studies are necessary in order to more accurately estimate the clinical benefit of IMPT over IMRT and passive proton therapy on a case-by-case basis for patients with sub-site specific HNCs., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: In this study, we sought to examine the variation in intensity modulated radiation therapy (IMRT) use among radiation oncology providers., Methods and Materials: The Medicare Physician and Other Supplier Public Use File was queried for radiation oncologists practicing during 2014. Healthcare Common Procedural Coding System code 77301 was designated as IMRT planning with metrics including number of total IMRT plans, rate of IMRT utilization, and number of IMRT plans per distinct beneficiary., Results: Of 2759 radiation oncologists, the median number of total IMRT plans was 26 (mean, 33.4; standard deviation, 26.2; range, 11-321) with a median IMRT utilization rate of 36% (mean, 43%; standard deviation, 25%; range, 4% to 100%) and a median number of IMRT plans per beneficiary of 1.02 (mean, 1.07; range, 1.00-3.73). On multivariable analysis, increased IMRT utilization was associated with male sex, academic practice, technical fee billing, freestanding practice, practice in a county with 21 or more radiation oncologists, and practice in the southern United States (P < .05). The top 1% of users (28 providers) billed a mean 181 IMRT plans with an IMRT utilization rate of 66% and 1.52 IMRT plans per beneficiary. Of these 28 providers, 24 had billed technical fees, 25 practiced in freestanding clinics, and 20 practiced in the South., Conclusions: Technical fee billing, freestanding practice, male sex, and location in the South were associated with increased IMRT use. A small group of outliers shared several common demographic and practice-based characteristics., (Copyright © 2018 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.)

A potential advantage of intensity-modulated proton therapy (IMPT) over intensity-modulated (photon) radiation therapy (IMRT) in the treatment of oropharyngeal carcinoma (OPC) is lower radiation dose to several critical structures involved in the development of nausea and vomiting, mucositis, and dysphagia. The purpose of this study was to quantify doses to critical structures for patients with OPC treated with IMPT and compare those with doses on IMRT plans generated for the same patients and with a matched cohort of patients actually treated with IMRT. In this study, 25 patients newly diagnosed with OPC were treated with IMPT between 2011 and 2012. Comparison IMRT plans were generated for these patients and for additional IMRT-treated controls extracted from a database of patients with OPC treated between 2000 and 2009. Cases were matched based on the following criteria, in order: unilateral vs bilateral therapy, tonsil vs base of tongue primary, T-category, N-category, concurrent chemotherapy, induction chemotherapy, smoking status, sex, and age. Results showed that the mean doses to the anterior and posterior oral cavity, hard palate, larynx, mandible, and esophagus were significantly lower with IMPT than with IMRT comparison plans generated for the same cohort, as were doses to several central nervous system structures involved in the nausea and vomiting response. Similar differences were found when comparing dose to organs at risks (OARs) between the IMPT cohort and the case-matched IMRT cohort. In conclusion, these findings suggest that patients with OPC treated with IMPT may experience fewer and less severe side effects during therapy. This may be the result of decreased beam path toxicities with IMPT due to lower doses to several dysphagia, odynophagia, and nausea and vomiting-associated OARs. Further study is needed to evaluate differences in long-term disease control and chronic toxicity between patients with OPC treated with IMPT in comparison to those treated with IMRT., (Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.)

Background: Owing to its physical properties, intensity-modulated proton therapy (IMPT) used for patients with oropharyngeal carcinoma has the ability to reduce the dose to organs at risk compared to intensity-modulated radiotherapy (IMRT) while maintaining adequate tumor coverage. Our aim was to compare the clinical outcomes of these two treatment modalities., Methods: We performed a 1:2 matching of IMPT to IMRT patients. Our study cohort consisted of IMPT patients from a prospective quality of life study and consecutive IMRT patients treated at a single institution during the period 2010-2014. Patients were matched on unilateral/bilateral treatment, disease site, human papillomavirus status, T and N status, smoking status, and receipt of concomitant chemotherapy. Survival analyzes were performed using a Cox model and binary toxicity endpoints using a logistic regression analysis., Results: Fifty IMPT and 100 IMRT patients were included. The median follow-up time was 32months. There were no imbalances in patient/tumor characteristics except for age (mean age 56.8years for IMRT patients and 61.1years for IMPT patients, p-value=0.010). Statistically significant differences were not observed in overall survival (hazard ratio (HR)=0.55; 95% confidence interval (CI): 0.12-2.50, p-value=0.44) or in progression-free survival (HR=1.02; 95% CI: 0.41-2.54; p-value=0.96). The age-adjusted odds ratio (OR) for the presence of a gastrostomy (G)-tube during treatment for IMPT vs IMRT were OR=0.53; 95% CI: 0.24-1.15; p-value=0.11 and OR=0.43; 95% CI: 0.16-1.17; p-value=0.10 at 3months after treatment. When considering the pre-planned composite endpoint of grade 3 weight loss or G-tube presence, the ORs were OR=0.44; 95% CI: 0.19-1.0; p-value=0.05 at 3months after treatment and OR=0.23; 95% CI: 0.07-0.73; p-value=0.01 at 1year after treatment., Conclusion: Our results suggest that IMPT is associated with reduced rates of feeding tube dependency and severe weight loss without jeopardizing outcome. Prospective multicenter randomized trials are needed to validate such findings., (Copyright © 2016 The Author(s). Published by Elsevier Ireland Ltd.. All rights reserved.)

Proton beam radiation has been used for cancer treatment since the 1950s, but recent increasing interest in this form of therapy and the construction of hospital-based and clinic-based facilities for its delivery have greatly increased both the number of patients and the variety of tumors being treated with proton therapy. The mass of proton particles and their unique physical properties (ie, the Bragg peak) allow proton therapy to spare normal tissues distal to the tumor target from incidental irradiation. Initial observations show that proton therapy is particularly useful for treating tumors in challenging locations close to nontarget critical structures. Specifically, improvements in local control outcomes for patients with chordoma, chonodrosarcoma, and tumors in the sinonasal regions have been reported in series using proton. Improved local control and survival outcomes for patients with cancer of the head and neck region have also been seen with the advent of improvements in better imaging and multimodality therapy comprising surgery, radiation therapy, and chemotherapy. However, aggressive local therapy in the proximity of critical normal structures to tumors in the head and neck region may produce debilitating early and late toxic effects. Great interest has been expressed in evaluating whether proton therapy can improve outcomes, especially early and late toxicity, when used in the treatment of head and neck malignancies. This review summarizes the progress made to date in addressing this question., (Copyright © 2014. Published by Elsevier Inc.)