KEY POINTS
- The ESTRO SBRT Focus Group systematically reviewed curative single-fraction SBRT for primary lung, liver, pancreatic, prostate and kidney tumors, covering literature published from 2008 through November 2025.
- Evidence is strongest for peripheral early-stage NSCLC. Six core studies included 627 patients receiving approximately 20–34 Gy in one fraction, with reported 2-year local control of 78–97% and overall survival of 73–84%. Randomized phase II data found no significant efficacy or safety disadvantage versus fractionated SBRT.
- Single-fraction lung SBRT should remain focused on appropriately selected peripheral T1–T2 tumors away from critical structures. Central and ultra-central disease remains controversial, and multi-fraction regimens are preferred near the proximal bronchial tree.
- Pancreatic evidence remains much less reassuring. Across eight studies and 406 patients, median prescription was approximately 25 Gy ×1, with 1-year local control often 84–100%, but late grade ≥3 gastrointestinal toxicity ranged from 2.3% to 12.3%, including ulceration, bleeding, stenosis and perforation.
- Prostate data come from three prospective phase II studies totaling 105 patients, most with intermediate-risk disease and approximately 19–24 Gy ×1. Five-year biochemical relapse-free survival reached 88% in ONE-SHOT, but patient numbers remain modest and GU toxicity requires continued surveillance.
- Primary renal cancer has one of the most mature single-fraction datasets. Across 14 publications involving 482 patients, 25–26 Gy was commonly used; IROCK reported 94% 5-year local control, while pooled FASTRACK data showed approximately 98% 5-year local control and cancer-specific survival.
- Liver evidence remains comparatively sparse and heterogeneous, with limited primary-tumor-specific data and concerns about hepatic toxicity. Across all sites, single-fraction treatment demands particularly rigorous immobilization, IGRT and intrafraction motion management because there is no opportunity to correct systematic delivery errors across later fractions.
CLINICAL TAKEAWAY
Single-fraction SBRT is no longer a purely experimental concept, but the evidence is highly site-dependent. Peripheral lung and selected renal tumors have the strongest support; prostate remains promising, while pancreatic and other upper-GI applications require substantially greater caution because a single high-dose error or OAR exposure cannot be diluted across fractions.