Trends in photon and proton radiotherapy populations in pediatric patients: A single institutional experience.

e13517 Background: The Children’s Hospital of Los Angeles (CHLA) offers advanced forms of photon radiation therapy to pediatric cancer patients; however, proton therapy is unavailable in Los Angeles County. This poses challenges impacted by socioeconomic factors, as it has a higher treatment cost and higher associated costs such as travel, housing, and unpaid time off work. From 2000 to 2020, we found that most of the patient population for radiation oncology at CHLA was Latino or Hispanic (53.7%), in contrast, only 15.4% of proton therapy recipients were Latino or Hispanic during this period. Our main goal was to investigate disparities between cohorts opting for proton therapy versus photon therapy. Conducting a retrospective chart review from 2000 to 2022, we built our dataset by utilizing the University of Wisconsin’s Area Deprivation Index (ADI) and analyzing socioeconomic proxies such as housing conditions and insurance status. Methods: Between 2000 and 2022, the Radiation Oncology Program at CHLA served 2,275 pediatric patients. A retrospective chart review allowed us to build a database with patient demographics, insurance information, and treatment specifics. Of these patients, 600 patients were eligible for our study as they had diagnoses eligible for proton therapy (i.e. CNS tumors, bone & soft tissue tumors, neuroblastomas, and leukemia & lymphoma). Using patient addresses, we recorded the ADI at state and national levels. Public databases aided in determining commuting distances, housing types, and square footage of patient homes. We utilized univariable and multivariable logistic regression models to investigate potential disparities between proton and photon therapy cohorts. Results: The photon cohort demonstrated a racial distribution of 52% Hispanic, 31% non-Hispanic White, 6% Black, and 11% Other, whereas the proton cohort had 14% Hispanic, 54% non-Hispanic White, 14% Black, and 18% Other (p-value: .005). Additionally, the photon cohort had a higher median ADI. Commuting distance, housing analyses, and insurance types indicated substantial variations as well. Patients receiving proton therapy were more likely to have private insurance, live in single family homes, or live in larger homes. Conclusions: Our study concludes that, at CHLA, minority patients are less likely to receive proton therapy. Photon therapy patients have higher ADI, which may indicate greater socioeconomic disadvantage. Our future direction aims to determine if these varying trends between the two cohorts can be mitigated to improve the accessibility of proton therapy.