KEY POINTS
- This PRISMA-guided systematic review included 113 studies published between 2006 and 2023, representing 18,038 patients treated with SBRT for early-stage NSCLC.
- Only 68% of studies restricted local-control assessment to the treated primary tumor. Another 32% incorporated same-lobe, ipsilateral-lung, or regional nodal failures, while 15% did not specify the anatomical site evaluated.
- Primary tumor control was assessed using 12 different criteria, including CT or PET findings, RECIST, variable growth thresholds, serial enlargement, surveillance intervals, and histopathological confirmation.
- Documented tumor growth was required in only 30% of studies, serial growth over at least 6 months in 25%, and biopsy confirmation in only one study.
- Reporting became more treatment-site-specific over time: 95.7% of studies published from 2021 to 2023 limited local-control evaluations to the treated primary tumor.
CLINICAL TAKEAWAY
Local control after lung SBRT should be restricted to progression within the treated primary tumor, with same-lobe, ipsilateral-lung, and nodal failures reported separately. This systematic review makes a strong case for standardized outcome reporting, but it does not validate a single imaging definition and was limited to criteria documented in published studies.