Systematic review and meta-analysis of stereotactic reirradiation for in-field lung cancer recurrence after stereotactic ablative radiotherapy

Systematic review and meta-analysis of 12 studies (197 patients) evaluated stereotactic reirradiation for in-field lung cancer recurrence after definiitve stereotactic ablative radiotherapy (SABR). All patients received two courses of SABR, with a median total dose of 50 Gy in five fractions. Pooled 1- and 2- year local control (LC) rates were 78.2% (95% CI 66-87) and 68.0% (55-79). Patients receiving a cumulative biologically effective dose (BED) ≥ 200 Gy had significantly higher LC rates. Pooled median overall survival (7 studies) was 26.3 months (95% CI 25..4-27.1). Median OS did not significantly differ between high and low BED groups (32.6 versus 21.4%; p=0.11). Toxicities were minimal, with a pooled incidence of ≥ grade 2 pneumonitis of 6.4%, and only 0.10% reporting grade ≥3 toxicity. The authors conclude that salvage in-fiel reirradiation with SABR achieves high local control and low toxicity.