Hypofractionated stereotactic radiotherapy (hfSRT) after tumour resection of a single brain metastasis: report of a single-centre individualized treatment approach.

PURPOSE: Standard treatment of single brain metastases so far is tumour resection in combination with postoperative whole-brain radiotherapy or stereotactic radiosurgery. Here, we report retrospectively our first experience with postoperative hypofractionated stereotactic radiotherapy (hfSRT) to the resection cavity in order to replace upfront WBRT with respect to treatment efficacy and safety.
METHODS: Between March 2006 and October 2011, 33 patients with a single newly diagnosed intracranial metastasis were treated with hfSRT following microsurgical resection. Fractionation concepts were 10 × 4 Gy (n = 22), 7 × 5 Gy (n = 7) and 5 × 6 Gy (n = 4). Planning target volume enclosed the tumour resection cavity with a safety margin of 4 mm.
RESULTS: No patient demonstrated toxicity grade 2 or higher. Actuarial median overall survival summed up to 20.2 months, and 12-month survival was 64 %. Actuarial mean local brain control was 30.6 months, median distant brain control 12.4 months and intracranial control 8.8 months, respectively. Actuarial 1-year rates of local, distant brain and intracranial control were 71, 57 and 43 %. Salvage whole-brain radiotherapy due to recurrent brain metastases was performed in 13 patients (39 %).
CONCLUSION: Postoperative hfSRT appears to be a feasible treatment option in patients with a single newly diagnosed brain metastasis. Replacing the standard postoperative whole-brain radiotherapy necessitates compliant patients and regular MRI follow-up analysis.