Feasibility of collecting physician- and patient-reported adverse events and symptom burden in adolescents and young adults with cancer undergoing radiation therapy.

419 Background: Adolescents and young adults (AYAs), defined as patients (pts) aged 15–39, experience unique physical and psychosocial side effects from cancer treatment as compared to older adults. Discrepancies between physician- and pt-reported toxicities may lead to underrecognition and undertreatment of adverse events (AEs) during radiation therapy (RT). Implementing physician- and pt-reported outcome surveys may improve AE detection and symptom management in AYAs. Herein, we describe preliminary pt characteristics and survey response rates from our automated, electronic, low burden, low resource prospective study assessing physician- vs. pt-reported outcomes. Methods: AYAs receiving RT between March 2024–April 2025 were screened for participation. Exclusion criteria included inability to independently complete PROs and RT dose < 10 Gy. AEs were assessed using Patient Reported Outcome-Common Terminology Criteria for Adverse Events (PRO-CTCAE; pt) and CTCAE (physician) tools. Surveys were delivered electronically via email or text message, with four fully automated electronic reminders sent out to patients per survey and one sent to physicians. The primary endpoint was agreement between physician- and pt-reported AEs across five domains (nausea, vomiting, radiation dermatitis, tumor pain, fatigue, anxiety, and depression) at the final weekly RT visit. Secondary endpoints included agreement at earlier visits and association of AE disagreement with co-variates, including sociodemographic, clinical, and treatment-related factors. Results: Of 101 consented pts, 68% were female; median age was 31 years (range 17–39). Most pts were Caucasian (73%), followed by Hispanic/Latino (25%), Asian (14%), or Black (12%). The most prevalent cancer types included breast (31%), sarcoma (20%), central nervous system (16%), and hematologic (10%). Patient clinical stages were stage I (13%), II (21%), III (31%), and IV (36%). Most pts received curative-intent RT (90%), with a median dose of 50 Gy (range: 12–70) in a median number of 22.5 fractions (range: 1–44); 70% received concurrent chemotherapy. Of 101 pts initiating RT, 73% of pts and 65% of physicians completed baseline PRO-CTCAE and CTCAE surveys, respectively. Response rates across the 6 weekly RT appointments ranged from 64–79% and 56–76% for patients and physicians, respectively (see Table). Conclusions: PRO and physician electronic reporting offers a low-resource, low-burden, and feasible approach for capturing AEs in real time, with potential to improve symptom management in AYAs receiving RT. Weekly #1n=98 Weekly #2n=84 Weekly #3n=79 Weekly #4n=63 Weekly #5n=45 Weekly #6n=27 Patient 75(76.5%) 62(73.8%) 62(78.5%) 47(74.6%) 29(64.4%) 18(66.7%) Physician 74(75.5%) 55(65.5%) 60(75.9%) 36(57.1%) 25(55.6%) 16(59.3%)