The Absolute Effect / Evidence / FASTRACK II
Renal Cell Carcinoma · Radiation Oncology · Localized Primary RCC
FASTRACK II
Clinical question
Can stereotactic ablative body radiotherapy provide effective definitive local control for primary RCC in patients unsuitable for surgery?
Trial context
Population
70 patients with biopsy-confirmed primary RCC who were medically inoperable, high surgical risk or declined surgery
Intervention
Definitive SABR: 26 Gy single fraction for ≤4 cm tumours or 42 Gy in 3 fractions for >4–10 cm tumours
Key endpoint
12-month local control
Time horizon / follow-up
12 months
Absolute Effect
What changes for patients?
FASTRACK II achieved 100% local control at 12 months in 70 treated patients, exceeding the prespecified 90% target. Median follow-up in the primary publication was 43 months. Grade 3 toxicity occurred in fewer than 10% of patients and there were no grade 4–5 events. This was a single-arm phase II study, so no comparative NNT can be assigned.
NNT: Not applicable; single-arm phase II
Treatment burden / harm
Grade 3 treatment-related toxicity
NNH: Not applicable; single-arm study
Relative effect
Local control: 100% at 12 months
Primary endpoint met; prespecified threshold was 90%
Clinical interpretation
FASTRACK II supports high local control with SABR for selected medically inoperable primary RCC, but it is not randomized evidence against surgery or surveillance.
Primary publication
- Siva S, et al. Lancet Oncol. 2024;25:308–316.
- Primary publication / source