The Headline: Definitive lung radiotherapy can be safely and effectively delivered in a single treatment.
The Study: A planned RTOG phase 3 trial comparing single-fraction (34 Gy) versus 3-fraction (60 Gy, or 54 Gy with heterogeneous planning) ablative radiotherapy for inoperable peripheral early-stage lung cancer was never activated. So investigators turned to their prospective institutional registry identifying 1107 patients treated from 2003–2025: 685 single-fraction and 422 three-fraction. Median overall survival was essentially identical (44 vs 44 months), as was overall survival rate at 3 years (58% vs 58%) and 5 years (38% vs 41%). Five-year local failure (4.5% vs 3.0%) and distant failure (21% vs 24%) were also similar. Grade 3+ events were uncommon (2.7% overall), with no difference by fractionation; each cohort had one grade 5 pneumonitis event.
TBL: In this large single-institution experience, one-fraction 34-Gy SBRT produced outcomes remarkably similar to 3-fraction treatment. | Videtic, ASTRO 2026
The Study: A planned RTOG phase 3 trial comparing single-fraction (34 Gy) versus 3-fraction (60 Gy, or 54 Gy with heterogeneous planning) ablative radiotherapy for inoperable peripheral early-stage lung cancer was never activated. So investigators turned to their prospective institutional registry identifying 1107 patients treated from 2003–2025: 685 single-fraction and 422 three-fraction. Median overall survival was essentially identical (44 vs 44 months), as was overall survival rate at 3 years (58% vs 58%) and 5 years (38% vs 41%). Five-year local failure (4.5% vs 3.0%) and distant failure (21% vs 24%) were also similar. Grade 3+ events were uncommon (2.7% overall), with no difference by fractionation; each cohort had one grade 5 pneumonitis event.
TBL: In this large single-institution experience, one-fraction 34-Gy SBRT produced outcomes remarkably similar to 3-fraction treatment. | Videtic, ASTRO 2026