SFRT alleviates symptoms associated with bulky advanced cancer: a retrospective single-center cohort analysis.

OBJECTIVE/BACKGROUND: To evaluate the impact of Spatially Fractionated Radiation Therapy (SFRT) on symptomatic relief and survival outcomes in patients with large-volume tumors. METHODS: A total of 60 cancer patients who received SFRT between February 2023 and May 2025 were analyzed in this retrospective study. Collected data comprised demographic characteristics, as well as follow-up information on symptomatic response, best overall response, survival duration, and treatment-related adverse events. RESULTS: By the end of the median follow-up duration of 15.8 months (3.8-30.8 months), 91.7% (55/60) of patients showed symptomatic relief. Follow-up imaging was available for 51 patients, showing tumor regression in 45 cases (6 showed increased volume after treatment). According to RECIST 1.1 criteria, 17 patients achieved Partial response (PR), 32 had Stable disease (SD), and 2 experienced Progressive disease (PD). The Overall response rate (ORR) was 33.3%, and the Disease control rate (DCR) was 96.1%. The median Overall survival (OS) was 7.6 months (95% CI: 4.3-10.9). Univariate analysis identified that a Biologically effective dose at the Vertex (BED-Vertex) ≥ 88 Gy was significantly associated with treatment response (P = 0.020). All adverse events were mild to moderate in severity, no grade 3 or higher toxicities were observed. CONCLUSION: SFRT appeared to be effective with limited toxicities for bulky tumors. BED-Vertex is a significant predictor of response in univariate analysis, suggesting that a strategy of safe BED escalation could enhance palliative efficacy.