Neoadjuvant fractionated stereotactic radiotherapy followed by piecemeal resection of brain metastasis: a case series of 20 patients

Background The safety and effectiveness of neoadjuvant fractionated stereotactic radiotherapy (FSRT) before piecemeal resection of brain metastasis (BM) remains unknown. Methods We retrospectively reviewed 20 consecutive patients with BM who underwent neoadjuvant FSRT followed by piecemeal resection between July 2019 and March 2021. The prescribed dose regimens were as follows: 30 Gy (n = 11) or 35 Gy (n = 9) in five fractions. Results The mean follow-up duration was 7.8 months (range 2.2-22.3). The median age was 67 years (range 51-79). Fourteen patients were male. All patients were symptomatic. All tumors were located in the supratentorial compartment. The median maximum diameter and volume were 3.7 cm (range 2.6-4.9) and 17.6 cm(3) (range 5.6-49.7), respectively. The median time from the end of FSRT to resection was 4 days (range 1-7). Nausea (CTCAE Grade 2) occurred in one patient and simple partial seizures (Grade 2) in two patients during radiation therapy. Gross total removal was performed in seventeen patients and sub-total removal in three patients. Postoperative complications were deterioration of paresis in two patients. Local recurrence was found in one patient (5.0%) who underwent sub-total resection at 2 months after craniotomy. Distant recurrence was found in six patients (30.0%) at a median of 6.9 months. Leptomeningeal disease recurrence was found in one patient (5.0%) at 3 months. No radiation necrosis developed. Conclusions Neoadjuvant FSRT appears to be a safe and effective approach for patients with BM requiring piecemeal resection. A multi-institutional prospective trial is needed.