RTAD-12 THE SAFETY AND FEASIBILITY OF ACCELERATED CONSOLIDATIVE STEREOTACTIC RADIOSURGERY WITHIN TWO WEEKS OF BRAIN METASTASES RESECTION - AN INSTITUTIONAL EXPERIENCE

Abstract

The optimal timing of consolidative radiotherapy after surgical resection of brain metastases remains controversial. Postoperative treatment is often delayed for wound healing concerns. We reviewed our experience with 146 patients who received accelerated stereotactic radiosurgery (SRS) within 1 - 14 days of brain metastases resection. This early group was compared against 50 patients who received standard-timing consolidative SRS between 15 - 30 days postoperatively. Baseline demographic characteristics were comparable between the groups. Primary cancer types were similarly distributed, except for breast cancer, which was more prevalent in the standard group (early 7.5% vs standard 16.0%, p = 0.08). Cerebellar metastases were more common in the standard group (13.5% vs 28.8%, p = 0.01). Hypofractionated regimens (2, 3, or 5 fractions) were employed in both cohorts (7.7% vs 15.1%, p = 0.10). The early group had a significantly smaller mean preoperative tumor volume (15.0 vs 21.8 cm³, p = 0.003) and a smaller mean postoperative cavity prescription isodose volume (26.2 vs 34.7 cm³, p = 0.04). In contrast, postoperative cavity volume, number of additional lesions treated during the same SRS session, total treatment and total prescription isodose volumes were similar between the two groups. The early group had a significantly longer postoperative length of stay (5.2 vs 3.0 days, p = 0.001). Our institutional practice is to apply 10Gy constraint to the surgical wound during SRS planning. The 10 Gy limit was maintained in 97.3% vs 93.5% of patients. There were no statistically significant differences in wound-healing complications (3.4% vs 2.0%), local recurrence (12.4% vs 20.0%), or rates of radiation necrosis (14.7% vs 17.1%). In conclusion, accelerated postoperative SRS can be well tolerated, with no observed increase in wound-healing complications or radiation necrosis. Early completion of consolidative radiation treatment may facilitate more rapid return to systemic therapy and should be considered when possible.