Effects of SFRT on quality of life in patients with bulky advanced cancer: A retrospective single-center cohort analysis.

Abstract

e24058 Background: Bulky tumors remain a major therapeutic challenge in modern oncology. Spatially Fractionated Radiation Therapy (SFRT) is an emerging technique shows great potential. We therefore conducted a retrospective review of two-year data from our center, aimed to evaluate the impact of SFRT on quality of life and survival outcomes in patients with bulky tumors. Methods: 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: A total of 60 patients were included, with a median age of 66 years (26–88). Among them, 38 (63.3%) were male and 22 (36.7%) were female. Patients with 14 primary tumor types were included, and irradiation targeted 10 distinct anatomical sites. The most common clinical symptoms were pain (41, 68.3%), dyspnea (13, 21.7%), tenesmus and hematochezia (2 each, 3.3%), intestinal obstruction (1, 1.7%), and portal hypertension (1, 1.7%). The median pretreatment tumor diameter was 83.55 mm (36.43–2240.50), and median tumor volume was 288.20 cm³ (33.04–2209.73). 18 patients were treated with lattice radiotherapy (LRT) and 42 with Stereotactic Centralized Ablative Radiation Therapy (SCART) technique. The median BED was 88.8 Gy ( 40-195). All patients underwent SFRT with daily cone-beam CT (CBCT) guidance. Within 2–4 weeks after radiotherapy, 91.7% (55/60) of patients showed symptomatic relief, including pain improvement in 92.7% (38/41), resolution of dyspnea in 100% (13/13), cessation of bleeding in 100% (2/2), relief of tenesmus in 100% (2/2), and no improvement in intestinal obstruction or portal hypertension (0/1 each). 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), 33 had stable disease (SD), and 1 experienced progressive disease (PD). The overall response rate (ORR) was 33.3%, and the disease control rate (DCR) was 98.0%. A BED ≥ 88 Gy was identified as an independent predictor of treatment response in both univariate and multivariate analyses (P = 0.024). With a median follow-up of 15.8 months, 36 of 60 patients had died by September 17, 2025. The median overall survival (OS) was 7.6 months (95% CI: 4.3-10.9). All adverse events were mild to moderate in severity. No grade 3 or higher toxicities were observed. Conclusions: SFRT allows for localized high-dose irradiation in large-volume tumors, demonstrating favorable tolerability, promising symptom relief (correlating with quality of life improvement), and encouraging local control. A strategy of safe BED escalation could enhance palliative efficacy.