2374 - Domain-Specific Quality-of-Life Outcomes in GI Malignancies: A Comparative Analysis of SBRT, PBT and IMRT

Purpose/Objective(s): Radiation therapy (RT) is critical to the management of gastrointestinal (GI) malignancies. Questions around quality of life (QOL) often arise when selecting a modality for the delivery of RT. This study aims to assess domain-specific QOL changes in patients treated with stereotactic body radiation therapy (SBRT), proton beam therapy (PBT), and intensity-modulated radiation therapy (IMRT) to guide individualized clinical decision making.

Materials/Methods: This retrospective study consisted of 108 patients who underwent RT for a GI malignancy between February 2019 and June 2024 at a single institution. The analysis included 45 (42%) patients with pancreatic cancer, 18 (17%) with colorectal cancer, 27 (25%) with esophageal cancer, and 18 (17%) with hepatobiliary cancer. Patients prospectively completed Functional Assessment of Cancer Therapy (FACT) questionnaires at baseline (T0), end of RT (T1), and 3 months post-RT (T2), and were included if they completed surveys at at least T0 and T1. Surveys generated FACT-G scores and subscores of physical, functional, social, and emotional well-being (PWB, FWB, SWB, EWB). Statistical analysis included Friedman tests for overall QOL differences across timepoints, followed by Wilcoxon signed-rank tests for post-hoc pairwise comparisons. Sub-analysis of patients whose QOL decreased from T0 to T1 was performed to elucidate the role of RT modality in declining QoL.

Results: 108 patients were included, with 51 (47%) receiving PBT, 27 (25%) SBRT, 24 (22%) IMRT, and 6 (6%) 3D-CRT. Compliance for all three timepoints was 38%. A statistically significant difference in PWB across timepoints was observed (?² = 14.69, p = 0.0006). PWB significantly increased from T0 to T1 (p = 0.0018) and significantly declined from T1 to T2 (p = 0.0006), with no significant difference between T0 and T2 (p = 0.3331). In contrast, SWB, EWB, FWB, and overall FACT-G scores did not demonstrate statistically significant changes over time.

There were no statistically significant differences in QoL outcomes across RT modalities from T0 to T1. However, on sub-analysis, SBRT was associated with the smallest decline in PWB (mean change = -1.20) from baseline to T1. SBRT was also associated with the smallest decrease in FWB (-1.10), while PBT (-1.50) and IMRT (-1.80) produced stronger declines. IMRT had the most pronounced negative impact (-1.80) on SWB, while PBT exhibited the least negative effect (-0.30). IMRT patients experienced the greatest increase (+3.10) in EWB, followed by PBT (+2.50), while SBRT showed the smallest positive change (+0.50).

Conclusion: During treatment for GI cancer, SBRT resulted in the lowest decline in PWB and FWB, PBT resulted in the lowest decline in SWB, and IMRT resulted in the highest increase in EWB. While this study is limited in sample size, modality-specific differences in patient reported QOL warrant further study to help guide treatment decision making.