Comparison of treatment results between 3- and 2-stage Gamma Knife radiosurgery for large brain metastases: a retrospective multi-institutional study

Abstract

OBJECTIVE In order to obtain better local tumor control for large (i.e., > 3 cm in diameter or > 10 cm in volume) brain metastases (BMs), 3-stage and 2-stage Gamma Knife surgery (GKS) procedures, rather than a palliative dose of stereotactic radiosurgery, have been proposed. Here, authors conducted a retrospective multi-institutional study to compare treatment results between 3-stage and 2-stage GKS for large BMs. METHODS This retrospective multi-institutional study involved 335 patients from 19 Gamma Knife facilities in Japan. Major inclusion criteria were 1) newly diagnosed BMs, 2) largest tumor volume of 10.0-33.5 cm, 3) cumulative intracranial tumor volume ≤ 50 cm, 4) no leptomeningeal dissemination, 5) no more than 10 tumors, and 6) Karnofsky Performance Status 70% or better. Prescription doses were restricted to between 9.0 and 11.0 Gy in 3-stage GKS and between 11.8 and 14.2 Gy in 2-stage GKS. The total treatment interval had to be within 6 weeks, with at least 12 days between procedures. There were 114 cases in the 3-stage group and 221 in the 2-stage group. Because of the disproportion in patient numbers and the pre-GKS clinical factors between these two GKS groups, a case-matched study was performed using the propensity score matching method. Ultimately, 212 patients (106 from each group) were selected for the case-matched study. Overall survival, tumor progression, neurological death, and radiation-related adverse events were analyzed. RESULTS In the case-matched cohort, post-GKS median survival time tended to be longer in the 3-stage group (15.9 months) than in the 2-stage group (11.7 months), but the difference was not statistically significant (p = 0.65). The cumulative incidences of tumor progression (21.6% vs 16.7% at 1 year, p = 0.31), neurological death (5.1% vs 6.0% at 1 year, p = 0.58), or serious radiation-related adverse events (3.0% vs 4.0% at 1 year, p = 0.49) did not differ significantly. CONCLUSIONS This retrospective multi-institutional study showed no differences between 3-stage and 2-stage GKS in terms of overall survival, tumor progression, neurological death, and radiation-related adverse events. Both 3-stage and 2-stage GKS performed according to the aforementioned protocols are good treatment options in selected patients with large BMs.

Comparison between stereotactic radiosurgery and whole‑brain radiotherapy for 10‑20 brain metastases from non‑small cell lung cancer

“…Due to the lack of relevant data, pulmonologists or neurosurgeons help patients make informed decisions to select their treatment modality depending on the patients' preference. For patients with relatively larger lesion (≥10 cm 3 ) who are not candidate for surgery, the two-session SRS would be offered as an option (14). For patients with the desire for home care, SRS would also be an option because SRS is a one-day treatment while WBRT takes over 2 weeks.…”

Gamma Knife Radiosurgery for Treatment of Brain Metastases during the COVID-19 Outbreak

“…Between the two stages, a biopsy of the cecal lesion, detected by abdomen CT scan, was performed and histopathologic diagnosis of colon adenocarcinoma was made. We chose to treat a cluster of 9 patients, whose greater lesion exceeded 10 cm 3 , with 2-stage modality GKRS (12 Gy to total volume in two sessions, 4 weeks apart) rather than palliative GKRS to minimize tumour recurrence and radiation necrosis [12]. Five of these patients underwent the second stage of their treatment in the time span described in this article (see Fig.…”

Radiosurgery for Patients with More Than Ten Brain Metastases

“…At present, SRS and SRT are considered key treatments for metastatic brain tumors [1,2,3]. Several patients with fewer than 5 or 10 brain metastases have been successfully treated using radiosurgery [2].…”

“…With the aid of stereotactic radiosurgery (SRS), current studies have demonstrated that the presence of fewer than five brain metastasis is associated with excellent tumor control. Moreover, a few reports have concluded that radiosurgery for fewer than 10 brain metastases is not inferior to radiosurgery for fewer than five brain metastases in terms of tumor control [1,2]. However, the treatment of more than 10 brain metastases seems to be more difficult and challenging.…”