Referral Patterns and Treatment Delays in Medulloblastoma: A Large Academic Proton Center Experience

The Relationship Between Travel Distance for Treatment and Outcomes in Patients Undergoing Radiation Therapy: A Systematic Review

Purpose

Although recent technological advances in radiation therapy have significantly improved treatment outcomes, the global distribution of radiation therapy is unbalanced, making access especially challenging for patients in rural or low-resource settings because of travel burden. This systematic review aimed to explore the impact of geographic distance to treatment facilities on survival, as well as other treatment outcomes, among patients undergoing radiation therapy.

Methods and Materials

A search of four databases (PubMed, Embase, CINAHL, and Web of Science) was performed. Studies were included if they were primary literature, published between May 2000 and May 2023, and reported the travel distances for patients undergoing radiation therapy for malignant conditions and its influence on survival outcomes. Studies were excluded if they did not report primary outcomes, were published before 2000, or were non-English.

Results

After review, 23 studies were included. Most studies were conducted in the United States, with cervical cancer being the most frequently studied disease site. Data suggested that travel distances vary significantly, with patients often traveling a median distance of 20 miles to radiation therapy. Among the studies, 5 reported a negative impact on overall survival, often associating greater travel with nonadherence to recommended care. Other survival metrics, including progression-free survival and all-cause mortality, were also assessed, demonstrating similar variability in relation to travel distance. Conversely, seven studies found no significant impact on overall survival, and four suggested a positive impact on overall survival, with improved outcomes at centers with higher case volumes. Some data also revealed an inverse correlation between travel distance and the likelihood of receiving guideline-concordant radiation therapy.

Conclusions

The impact of travel distance on radiation therapy outcomes is varied. Our findings underscore the challenges posed by travel in accessing radiation therapy and the disparities affecting particular patient demographic groups. Additional studies are needed to thoroughly assess the impacts of geographic disparities and to identify effective measures to address these challenges.

Distance Traveled by Patients Globally to Access Radiation Therapy: A Systematic Review

PURPOSE

This study aimed to systematically review the literature on the travel patterns of patients seeking radiation therapy globally. It examined the distance patients travel for radiation therapy as well as secondary outcomes, including travel time.

METHODS AND MATERIALS

A comprehensive search of 4 databases was conducted from June 2022 to August 2022. Studies were included in the review if they were observational, retrospective, randomized/nonrandomized, published between June 2000 and June 2022, and if they reported on the global distance traveled for radiation therapy in the treatment of malignant or benign disease. Studies were excluded if they did not report travel distance or were not written in English.

RESULTS

Of the 168 studies, most were conducted in North America (76.3%), with 90.7% based in the United States. Radiation therapy studies for treating patients with breast cancer were the most common (26.6%), while external beam radiation therapy was the most prevalent treatment modality (16.6%). Forty-six studies reported the mean distance traveled for radiation therapy, with the shortest being 4.8 miles in the United States and the longest being 276.5 miles in Iran. It was observed that patients outside of the United States traveled greater distances than those living within the United States. Geographic location, urban versus rural residence, and patient population characteristics affected the distance patients traveled for radiation therapy.

CONCLUSIONS

This systematic review provides the most extensive summary to date of the travel patterns of patients seeking radiation therapy globally. The results suggest that various factors may contribute to the variability in travel distance patterns, including treatment center location, patient residence, and treatment modality. Overall, the study highlights the need for more research to explore these factors and to develop effective strategies for improving radiation therapy access and reducing travel burden.

PIPER adult comfort: an open-source full body human body model for seating comfort assessment and its validation under static loading conditions

Introduction: In this paper we introduce an adult-sized FE full-body HBM for seating comfort assessments and present its validation in different static seating conditions in terms of pressure distribution and contact forces. Methods: We morphed the PIPER Child model into a male adult-sized model with the help of different target sources including his body surface scans, and spinal and pelvic bone surfaces and an open sourced full body skeleton. We also introduced soft tissue sliding under the ischial tuberosities (ITs). The initial model was adapted for seating applications with low modulus soft tissue material property and mesh refinements for buttock regions, etc. We compared the contact forces and pressure-related parameters simulated using the adult HBM with those obtained experimentally from the person whose data was used for the model development. Four seat configurations, with the seat pan angle varying from 0° to 15° and seat-to-back angle fixed at 100°, were tested. Results: The adult HBM could correctly simulate the contact forces on the backrest, seat pan, and foot support with an average error of less than 22.3 N and 15.5 N in the horizontal and vertical directions, which is small considering the body weight (785 N). In terms of contact area, peak, and mean pressure, the simulation matched well with the experiment for the seat pan. With soft tissue sliding, higher soft tissue compression was obtained in agreement with the observations from recent MRI studies. Discussion: The present adult model could be used as a reference using a morphing tool as proposed in PIPER. The model will be published openly online as part of the PIPER open-source project (www.PIPER-project.org) to facilitate its reuse and improvement as well as its specific adaptation for different applications.

Health Care Transition for Adolescents and Young Adults With Pediatric-Onset Liver Disease and Transplantation: A Position Paper by the North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition

Advances in medical therapies and liver transplantation have resulted in a greater number of pediatric patients reaching young adulthood. However, there is an increased risk for medical complications and morbidity surrounding transfer from pediatric to adult hepatology and transplant services. Health care transition (HCT) is the process of moving from a child/family-centered model of care to an adult or patient-centered model of health care. Successful HCT requires a partnership between pediatric and adult providers across all disciplines resulting in a transition process that does not end at the time of transfer but continues throughout early adulthood. Joint consensus guidelines in collaboration with the American Society of Transplantation are presented to facilitate the adoption of a structured, multidisciplinary approach to transition planning utilizing The Six Core Elements of Health Care Transition TM for use by both pediatric and adult specialists. This paper provides guidance and seeks support for the implementation of an HCT program which spans across both pediatric and adult hepatology and transplant centers.

Factors Associated With Travel Distance in the Receipt of Proton Breast Radiation Therapy

Introduction

Proton radiation therapy (PBT) may reduce cardiac doses in breast cancer treatment. Limited availability of proton facilities could require significant travel distances. This study assessed factors associated with travel distances for breast PBT.

Materials and Methods

Patients receiving breast PBT at the University of Pennsylvania from 2010 to 2021 were identified. Demographic, cancer, and treatment characteristics were summarized. Straight-line travel distances from the department to patients' addresses were calculated using BatchGeo. Median and mean travel distances were reported. Given non-normality of distribution of travel distances, Wilcoxon rank sum or Kruskal-Wallis test was used to determine whether travel distances differed by race, clinical trial participation, disease laterality, recurrence, and prior radiation.

Results

Of 1 male and 284 female patients, 67.8% were White and 21.7% Black. Median travel distance was 13.5 miles with interquartile range of 6.1 to 24.8 miles, and mean travel distance was 13.5 miles with standard deviation of 261.4 miles. 81.1% of patients traveled less than 30 and 6.0% more than 100 miles. Black patients' travel distances were significantly shorter than White patients' and non-Black or non-White patients' travel distances (median = 4.5, 16.5, and 11.3 miles, respectively; P < .0001). Patients not on clinical trials traveled more those on clinical trials (median = 14.7 and 10.2 miles, respectively; P = .032). There was no difference found between travel distances of patients with left-sided versus right-sided versus bilateral disease (P = .175), with versus without recurrent disease (P = .057), or with versus without prior radiation (P = .23).

Conclusion

This study described travel distances and demographic and clinicopathologic characteristics of patients receiving breast PBT at the University of Pennsylvania. Black patients traveled less than White and non-Black or non-White patients and comprised a small portion of the cohort, suggesting barriers to travel and PBT. Patients did not travel further to receive PBT for left-sided or recurrent disease.

Predictors of Time to Definitive Surgery and Survival in Merkel Cell Carcinoma: Analysis of National Cancer Database

BACKGROUND

Effects of delays in treatment for Merkel cell carcinoma (MCC) are not yet fully understood.

OBJECTIVES

To determine the effect of time to treatment initiation (TTI) on mortality in MCC and predictors of TTI itself.

METHODS

Retrospective cohort analysis of the National Cancer Database (NCDB) for cases of MCC from 2004-2016, excluding individuals with Stage IV MCC as surgery is not the preferred treatment for this group.

RESULTS

A total of 12,157 patients (average age:74.4 years, SD:10.9) were included in the study, 7,491(61.6%) were male and 4,666 (38.4%) were female. Risk of higher TTI was seen in Blacks (odds ratio [OR]:1.7, 95% CI:1.2,2.6) and elderly individuals over 70 years (OR:1.7, 95% CI:1.2,2.5). On Kaplan-Meier survival analysis, individuals with TTI <30 days had a significantly longer overall survival than those with TTI >120 days (6.1 vs. 4.8 years, p=0.0002). However, after controlling for clinical and tumor factors in Cox multivariable analysis, no difference in survival was noted for TTI <30 days and TTI >120 days (Hazard Ratio [HR]:0.9, 95% CI:0.8,1.1). Worse outcomes were also associated with increasing age (HR:2.0, 95% CI:1.7,2.5), male sex (HR:1.2, 95% CI:1.2-1.3), higher CDCC (HR:1.4, 95% CI:1.3,1.5), lack of radiation therapy (HR:0.8, 95% CI:0.8-0.9), lack of private insurance (HR:0.7, 95% CI:0.6-1.0), and surgical technique other than Mohs or WLE (HR:1.2, 95% CI:1.2-1.3).

CONCLUSIONS

Although TTI is a useful prognostic metric in isolated survival analysis, its utility declines when controlling for other factors. Age, radiotherapy, type of surgery performed, co-morbidities, tumor size, and lymph node involvement may be important predictors of survival.

A Decision Support Tool to Optimize Selection of Head and Neck Cancer Patients for Proton Therapy

Simple Summary

A decision support tool was developed to select head and neck cancer patients for proton therapy. The tool uses delineation data to predict expected toxicity risk reduction with proton therapy and can be used before a treatment plan is created. The positive predictive value of the tool is >90%. This tool significantly reduces delays in commencing treatment and avoid redundant photon vs. proton treatment plan comparison.

Abstract

Selection of head and neck cancer (HNC) patients for proton therapy (PT) using plan comparison (VMAT vs. IMPT) for each patient is labor-intensive. Our aim was to develop a decision support tool to identify patients with high probability to qualify for PT, at a very early stage (immediately after delineation) to avoid delay in treatment initiation. A total of 151 HNC patients were included, of which 106 (70%) patients qualified for PT. Linear regression models for individual OARs were created to predict the D_mean to the OARs for VMAT and IMPT plans. The predictors were OAR volume percentages overlapping with target volumes. Then, actual and predicted plan comparison decisions were compared. Actual and predicted OAR D_mean (VMAT R² = 0.953, IMPT R² = 0.975) and NTCP values (VMAT R² = 0.986, IMPT R² = 0.992) were highly correlated. The sensitivity, specificity, PPV and NPV of the decision support tool were 64%, 87%, 92% and 51%, respectively. The expected toxicity reduction with IMPT can be predicted using only the delineation data. The probability of qualifying for PT is >90% when the tool indicates a positive outcome for PT. This tool will contribute significantly to a more effective selection of HNC patients for PT at a much earlier stage, reducing treatment delay.