Integrated models of education and service involving community-based health care for underserved populations: Tulane student-run free clinics.

OBJECTIVES: Throughout the United States numerous models of local programs, including student-run clinics, exist to address the issue of access to care. The role of these clinics in serving the local community and contributing to medical education has been documented only in limited detail, however. The purpose of this article is to describe the clinic models, patient demographics, and services provided by four student-run clinics in New Orleans. METHODS: This is a retrospective, multisite chart review study of adult patients examined at student-run clinics between January 1, 2010 and July 31, 2011. RESULTS: During a 19-month period, 859 patients collectively were seen at the clinics, for a total of 1455 visits. The most common reasons for seeking care were medication refills (21.6%) and musculoskeletal pain (12.0%). Counseling and health education were provided primarily for smoking cessation (9.0%), diabetes management (7.1%), and hypertension management (5.8%). Nearly one-fifth of patients were given a referral to primary care services. In the 2010-2011 academic year, 87.6% of preclinical medical students volunteered at ≥1 of these clinics and spent 4508 hours during 1478 shifts. CONCLUSIONS: This article highlights the role of student-run clinics in the community, the safety-net healthcare system, and medical education. Future directions include the establishment of a new clinic, fundraising, and prospective studies to further assess the impact of student-run clinics.

Rectal Hydrogel Spacer Improves Late Gastrointestinal Toxicity Compared to Rectal Balloon Immobilization After Proton Beam Radiation Therapy for Localized Prostate Cancer: A Retrospective Observational Study.

PURPOSE: Our purpose was to compare dosimetric parameters and late gastrointestinal outcomes between patients treated with proton beam therapy (PBT) for localized prostate cancer with rectal balloon immobilization versus a hydrogel rectal spacer. METHODS AND MATERIALS: Patients with localized, clinical stage T1-4 prostate adenocarcinoma were treated at a single institution using conventionally fractionated, dose-escalated PBT from 2013 to 2018. Patient-reported gastrointestinal toxicity was prospectively collected, and the incidence of rectal bleeding was retrospectively reviewed from patient records. RESULTS: One hundred ninety-two patients were treated with rectal balloon immobilization, and 75 were treated with a rectal spacer. Rectal hydrogel spacer significantly improved rectal dosimetry while maintaining excellent target coverage. The 2-year actuarial rate of grade 2+ late rectal bleeding was 19% and 3% in the rectal balloon and hydrogel spacer groups, respectively (P = .003). In univariable analysis, the probability of grade 2+ rectal bleeding was significantly correlated with increasing rectal dose. In multivariable analysis, only receipt of spacer hydrogel (hazard ratio, 0.145; P = .010) and anticoagulation use (hazard ratio, 5.019; P < .001) were significantly associated with grade 2+ bleeding. At 2-year follow-up, patient-reported Expanded Prostate Cancer Index Composite bowel quality of life composite scores were less diminished in the hydrogel spacer group (absolute mean difference, 5.5; P = .030). CONCLUSIONS: Use of rectal hydrogel spacer for prostate PBT is associated with a significantly lower incidence of clinically relevant, late rectal bleeding and lower decrement in long-term, patient-reported bowel quality of life compared with rectal balloon immobilization. Our results suggest that hydrogel spacer may improve rectal sparing compared with rectal balloon immobilization during PBT for prostate cancer.

International Survey on the Use of Complementary and Alternative Medicines for Common Toxicities of Radiation Therapy.

PURPOSE: Complementary and alternative medicines (CAMs) are widely used by patients with cancer. However, little is known about the extent to which these potential remedies are used internationally to treat the most common toxicities of radiation therapy. We report on the results of an international survey that assessed the use of CAMs. METHODS AND MATERIALS: Surveys were distributed to 1174 practicing radiation oncologists. Questions evaluated the perceptions of CAMs and specific practice patterns for the use of CAM remedies in the treatment of common radiation-induced toxicities (eg, skin, fatigue, nausea, diarrhea, and mucositis/xerostomia). The responses were compared between the groups using the χ2 test and stratified on the basis of provider location, number of years in practice, and perception of CAMs. RESULTS: A total of 114 radiation oncologists from 29 different countries completed the survey, with a balanced distribution between North American (n = 56) and non-North American (n = 58) providers. Among the responding clinicians, 63% recommended CAMs in their practice. The proportion of clinicians who recommend CAMs for radiation toxicities did not significantly vary when stratified by provider's number of years in practice (P = .23) or location (United States/Canada vs other; P = .74). Overall, providers reported that 29.4% of their patients use CAMs, and 87.7% reported that their practice encouraged or was neutral on CAM use, whereas 12.3% recommended stopping CAMs. The most common sources of patient information on CAMs were the Internet (75.4%), friends (60.5%), and family (58.8%). Clinicians reported the highest use of CAMs for radiation skin toxicity at 66.7%, followed by 48.2% for fatigue, 40.4% for nausea, and 36.8% for mucositis/xerostomia. CONCLUSIONS: Nearly two-thirds of the surveyed radiation oncologists recommend CAMs for radiation-related toxicities; however, they estimated that less than one third of patients use CAMs for this purpose. This suggests a need for further investigation and perhaps greater patient education on the roles of CAMs in treating radiation toxicities.

Analysis of Gastrointestinal Toxicity in Patients Receiving Proton Beam Therapy for Prostate Cancer: A Single-Institution Experience.

PURPOSE: We characterized both physician- and patient-reported rates of gastrointestinal (GI) toxicity in patients treated with proton beam therapy (PBT) at our institution for prostate adenocarcinoma and identified factors associated with toxicity. METHODS AND MATERIALS: We treated 192 patients with PBT between July 2013 and July 2016. Included patients had ≥1 year of follow-up. Potential preexisting clinical and treatment-related risk factors for GI toxicity were recorded. Common Terminology Criteria for Adverse Events version 4.0 was used to score toxicity. Expanded Prostate Cancer Index Composite (EPIC) bowel domain questionnaires assessed patient-reported quality of life. Associations between grade (GR) 2+ toxicity and clinical, treatment, and dosimetric factors were assessed using Cox models and corresponding hazard ratios. RESULTS: The median follow-up was 1.7 years. Most of the observed GI toxicity (>90%) was in the form of rectal bleeding (RB). GR2+ GI toxicity and RB actuarial rates specifically at 2 years were 21.3% and 20.4%, respectively. GR3 toxicity was rare, with only 1 observed RB event. No GR4/5 toxicity was seen. The EPIC bowel domain median score was 96 (range, 61-100) pretreatment, 93 (range, 41-100) at 1 year, 89 (range, 57-100) at 1.5 years, and 89 (range, 50-100) at 2 years. Anticoagulation use was the only factor selected during multivariate analysis for predicting GR2+ RB, with a resulting concordance index of 0.59 (95% confidence interval, 0.48-0.68; P = .088). Type of proton technology (pencil beam scanning vs uniform scanning) and number of fields treated per day (1 vs 2) showed no significant difference in toxicity rate. CONCLUSIONS: PBT was associated with acceptable rates of GR2+ transient GI toxicity, mostly in the form of RB, which correlated with anticoagulation use. High EPIC bowel domain quality of life was maintained in the 2 years after treatment.

Patterns of Failure After Stereotactic Radiosurgery for Recurrent High-Grade Glioma: A Single Institution Experience of 10 Years.

BACKGROUND: Stereotactic radiosurgery (SRS) is a treatment modality that is frequently used as salvage therapy for small nodular recurrent high-grade gliomas (HGG). Due to the infiltrative nature of HGG, it is unclear if this highly focused technique provides a durable local control benefit. OBJECTIVE: To determine how demographic or clinical factors influence the pattern of failure following SRS for recurrent high-grade gliomas. METHODS: We retrospectively reviewed clinical, radiographic, and follow-up information for 47 consecutive patients receiving SRS for recurrent HGG at our institution between June 2006 and July 2016. All patients initially presented with an HGG (WHO grade III and IV). Following SRS for recurrence, all patients experienced treatment failure, and we evaluated patterns of local, regional, and distant failure in relation to the SRS 50% isodose line. RESULTS: Most patients with recurrent HGG developed "in-field" treatment failure following SRS (n = 40; 85%). Higher SRS doses were associated with longer time to failure (hazards ratio = 0.80 per 1 Gy increase; 95% confidence interval 0.67-0.96; P = .016). There was a statistically significant increase in distant versus in-field failure among older patients (P = .035). This effect was independent of bevacizumab use (odds ratio = 0.54, P = 1.0). CONCLUSION: Based on our experience, the majority of treatment failures after SRS for recurrent HGG were "in-field." Older patients, however, presented with more distant failures. Our results indicate that higher SRS doses delivered to a larger area as fractioned or unfractioned regimen may prolong time to failure, especially in the older population.

MRI Radiomic Features Are Independently Associated With Overall Survival in Soft Tissue Sarcoma.

PURPOSE: Soft tissue sarcomas (STS) represent a heterogeneous group of diseases, and selection of individualized treatments remains a challenge. The goal of this study was to determine whether radiomic features extracted from magnetic resonance (MR) images are independently associated with overall survival (OS) in STS. METHODS AND MATERIALS: This study analyzed 2 independent cohorts of adult patients with stage II-III STS treated at center 1 (N = 165) and center 2 (N = 61). Thirty radiomic features were extracted from pretreatment T1-weighted contrast-enhanced MR images. Prognostic models for OS were derived on the center 1 cohort and validated on the center 2 cohort. Clinical-only (C), radiomics-only (R), and clinical and radiomics (C+R) penalized Cox models were constructed. Model performance was assessed using Harrell's concordance index. RESULTS: In the R model, tumor volume (hazard ratio [HR], 1.5) and 4 texture features (HR, 1.1-1.5) were selected. In the C+R model, both age (HR, 1.4) and grade (HR, 1.7) were selected along with 5 radiomic features. The adjusted c-indices of the 3 models ranged from 0.68 (C) to 0.74 (C+R) in the derivation cohort and 0.68 (R) to 0.78 (C+R) in the validation cohort. The radiomic features were independently associated with OS in the validation cohort after accounting for age and grade (HR, 2.4; P = .009). CONCLUSIONS: This study found that radiomic features extracted from MR images are independently associated with OS when accounting for age and tumor grade. The overall predictive performance of 3-year OS using a model based on clinical and radiomic features was replicated in an independent cohort. Optimal models using clinical and radiomic features could improve personalized selection of therapy in patients with STS.

Heart Dose and Outcomes in Radiation Treatment for Esophageal Cancer.

Purpose Studies have shown that radiation dose to the heart may be associated with worse outcomes in patients receiving chemoradiation for lung cancer. As esophageal cancer radiation treatment can result in relatively high cardiac doses, we evaluated a single-institution database of patients treated for esophageal cancer for heart dose and outcomes. Methods We retrospectively reviewed 59 patients with stage IIA-IIIB esophageal cancer treated with neoadjuvant chemoradiation to 50.4 Gy followed by esophagectomy from 2007-2015. Patient demographics and outcome data, including pathological response, local recurrence, distant metastases, and overall survival, were obtained. Mean heart dose (MHD), heart V5, V40, and V50, were calculated. Differences in patient characteristics between the three radiation therapy modalities: three-dimensional (3D) conformal radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT), and proton beam radiation therapy (PBT) were tested using non-parametric Kruskal-Wallis (K-W) analysis of variance (ANOVA). Patient characteristics and heart dosimetric parameters were screened by univariate Cox regression for an association to overall survival, and univariate predictors (p < 0.05) were then selected as inputs into a multivariate Cox regression model using stepwise backward elimination. Kaplan-Meier risk-stratified survival curves were plotted for the best univariate or multivariate Cox model variables. An exploratory subgroup univariate Cox regression was conducted in each of the treatment modalities (proton, IMRT, 3D-CRT). Results The median follow-up was 20 months. The median overall survival was 73 months. Eleven patients (20%) experienced a complete pathologic response (pCR). Only two patients (4%) experienced a local recurrence. On univariate analysis, predictors of survival were age, prior radiation, pathologic response in involved lymph nodes, and tumor length post-treatment. On a multivariate analysis, only pathologic nodal response (yN) remained significant (p = 0.007). There was no relationship between any heart dosimetric variables analyzed and any clinical outcomes. Conclusions In this retrospective review, radiation dose to the heart was not associated with inferior treatment outcomes in patients receiving trimodality therapy for esophageal cancer.

Autosegmentation of prostate anatomy for radiation treatment planning using deep decision forests of radiomic features.

Machine learning for image segmentation could provide expedited clinic workflow and better standardization of contour delineation. We evaluated a new model using deep decision forests of image features in order to contour pelvic anatomy on treatment planning CTs. 193 CT scans from one UK and two US institutions for patients undergoing radiotherapy treatment for prostate cancer from 2012-2016 were anonymized. A decision forest autosegmentation model was trained on a random selection of 94 images from Institution 1 and tested on 99 scans from Institution 1, 2, and 3. The accuracy of model contours was measured with the Dice similarity coefficient (DSC) and the median slice-wise Hausdorff distance (MSHD) using clinical contours as the ground truth reference. Two comparison studies were performed. The accuracy of the model was compared to four commercial software packages on twenty randomly-selected images. Additionally, inter-observer variability (IOV) of contours between three radiation oncology experts and the original contours was evaluated on ten randomly-selected images. The highest median values of DSC across all institutions were 0.94-0.97 for bladder (with interquartile range, or IQR, of 0.92-0.98) and 0.96-0.97 (IQR 0.94-0.97) for femurs. Good agreement was seen for prostate, with median DSC 0.75-0.76 (IQR 0.67-0.82), and rectum, with median DSC 0.71-0.82 (IQR 0.63-0.87). The lowest median scores were 0.49-0.70 for seminal vesicles (IQR 0.31-0.79). For the commercial software comparison, model-based segmentation produced higher DSC than atlas-based segmentation, with decision forests producing highest DSC for all organs of interest. For the interobserver study, variability in DSC between observers was similar to the agreement between the model and ground truth. Deep decision forests of radiomic features can generate contours of pelvic anatomy with reasonable agreement with physician contours. This method could be useful for automated treatment planning, and autosegmentation may improve efficiency and increase standardization in the clinic.

Early toxicity and patient reported quality-of-life in patients receiving proton therapy for localized prostate cancer: a single institutional review of prospectively recorded outcomes.

BACKGROUND: We report prospectively captured clinical toxicity and patient reported outcomes in a single institutional cohort of patients treated for prostate cancer with proton beam therapy (PBT). This is the largest reported series of patients treated mostly with pencil beam scanning PBT. METHODS: We reviewed 231 patients treated on an IRB approved institutional registry from 2013 to 2016; final analysis included 192 patients with > 1-year of follow-up. Toxicity incidence was prospectively captured and scored using CTCAE v4.0. International Prostate Symptoms Score (IPSS), Sexual Health Inventory for Men (SHIM) score, and Expanded Prostate Cancer Index Composite (EPIC) bowel domain questionnaires were collected at each visit. Univariate Cox regression was used to explore associations of grade 2+ toxicity with clinical, treatment, and dosimetric variables. RESULTS: Median follow-up was 1.7 years. Grade 3 toxicity was seen in 5/192 patients. No grade 4 or 5 toxicity was seen. Patient reported quality-of-life showed no change in urinary function post-radiation by IPSS scores. Median SHIM scores declined by 3.7 points at 1-year post-treatment without further decrease beyond year 1. On univariate analysis, only younger age (HR = 0.61, p = 0.022) was associated with decreased sexual toxicity. EPIC bowel domain scores declined from 96 at baseline (median) by an average of 5.4 points at 1-year post-treatment (95% CI: 2.5-8.2 points, p < 0.001), with no further decrease over time. Bowel toxicity was mostly in the form of transient rectal bleeding and was associated with anticoagulation use (HR = 3.45, p = 0.002). CONCLUSIONS: Grade 3 or higher toxicity was rare at 2-years after treatment with PBT for localized prostate cancer. Longer follow-up is needed to further characterize late toxicity and biochemical control. TRIAL REGISTRATION: NCT, NCT01255748 . Registered 1 January 2013.

A ring-based compensator IMRT system optimized for low- and middle-income countries: Design and treatment planning study.

PURPOSE: We propose a novel compensator-based IMRT system designed to provide a simple, reliable, and cost-effective adjunct technology, with the goal of expanding global access to advanced radiotherapy techniques. The system would employ easily reusable tungsten bead compensators that operate independent of a gantry (e.g., mounted in a ring around the patient). Thereby the system can be retrofitted to existing linac and cobalt teletherapy units. This study explores the quality of treatment plans from the proposed system and the dependence on associated design parameters. METHODS: We considered 60 Co-based plans as the most challenging scenario for dosimetry and benchmarked them against clinical MLC-based plans delivered on a linac. Treatment planning was performed in the Pinnacle treatment planning system with commissioning based on Monte Carlo simulations of compensated beams. 60 Co-compensator IMRT plans were generated for five patients with head-and-neck cancer and five with gynecological cancer and compared to respective IMRT plans using a 6 MV linac beam with an MLC. The dependence of dosimetric endpoints on compensator resolution, thickness, position, and number of beams was assessed. Dosimetric accuracy was validated by Monte Carlo simulations of dose distribution in a water phantom from beams with the IMRT plan compensators. RESULTS: The 60 Co-compensator plans had on average equivalent PTV coverage and somewhat inferior OAR sparing compared to the 6 MV-MLC plans, but the differences in dosimetric endpoints were clinically acceptable. Calculated treatment times for head-and-neck plans were 7.6 ± 2.0 min vs 3.9 ± 0.8 min (6 MV-MLC vs 60 Co-compensator) and for gynecological plans were 8.7 ± 3.1 min vs 4.3 ± 0.4 min. Plan quality was insensitive to most design parameters over much of the ranges studied, with no degradation found when the compensator resolution was finer than 6 mm, maximum thickness at least 2 tenth-value-layers, and more than five beams were used. Source-to-compensator distances of 53 and 63 cm resulted in very similar plan quality. Monte Carlo simulations suggest no increase in surface dose for the geometries considered here. Simulated dosimetric validation tests had median gamma pass rates of 97.6% for criteria of 3% (global)/3 mm with a 10% threshold. CONCLUSIONS: The novel ring-compensator IMRT system can produce plans of comparable quality to standard 6 MV-MLC systems. Even when 60 Co beams are used the plan quality is acceptable and treatment times are substantially reduced. 60 Co-compensator IMRT plans are adequately modeled in an existing commercial treatment planning system. These results motivate further development of this low-cost adaptable technology with translation through clinical trials and deployment to expand the reach of IMRT in low- and middle-income countries.

Neutron Radiation Therapy for Treatment of Refractory Merkel Cell Carcinoma.

We describe the first reported use of neutron radiation therapy for successful palliation of treatment refractory Merkel cell carcinoma. The patient was a 78-year-old man with Merkel cell carcinoma involving the scalp and bilateral cervical lymph nodes. The extensive coalescing scalp lesions were locally destructive, painful, and highly detrimental to his overall quality of life, and he had previously progressed through 3 courses of conventional x-ray-based radiation therapy and multiple immunotherapy regimens. We treated him with neutron radiation therapy, and he experienced a complete and durable local response with minimal toxicity. High linear energy transfer particle therapy approaches deserve consideration as a treatment option in cancers that are refractory to standard radiation therapy.

Herpes zoster and radiation therapy: what radiation oncologists need to know about diagnosing, preventing, and treating herpes zoster.

Herpes zoster, a viral disease that is characterized by a painful and blistering eruption in the skin, represents reactivation of latent varicella zoster (chickenpox) virus infection. In high-risk groups such as elderly or immunocompromised patients, the incidence of zoster can be as high as 50%. Radiation oncologists are likely to see zoster because cancer, and cancer therapy, can adversely affect immune function. A few reports suggest that radiation therapy is a risk factor for zoster, and that the skin eruption is often in or near the radiation treatment field. The diagnosis is typically made through clinical history and exam, but several tests are available to confirm the diagnosis and differentiate it from other infections or dermatitis. Effective management consists of prompt antiviral medication, acute pain control, appropriate precautions to limit transmission, and referral to specialists in certain cases. Despite appropriate therapy, up to 18% of patients can develop persistent postherpetic neuralgia, defined as pain more than 4 months after resolution of the rash. Several classes of pain medication are available to treat acute or long-term pain. Vaccination against zoster is recommended for patients aged 60 years or older, as it can reduce the incidence and severity of zoster.