Efficacy of Gamma Knife Radiosurgery for Recurrent High-Grade Gliomas with Limited Tumor Volume

Abstract

Objective: This study aims to determine whether gamma knife radiosurgery (GKR) improves survival in patients with recurrent highgrade gliomas.

Methods: Twenty nine patients with recurrent high-grade glioma underwent 38 GKR. The male-to-female ratio was 10 : 19, and the median age was 53.8 years (range, 20-75). GKR was performed in 11 cases of recurrent anaplastic oligodendrogliomas, five anaplastic astrocytomas, and 22 glioblastomas. The median prescription dose was 16 Gy (range, 10-24), and the median target volume was 7.0 mL (range, 1.1-15.7). Of the 29 patients, 13 (44.8%) received concurrent chemotherapy. We retrospectively analyzed the progression-free survival (PFS) and overall survival (OS) after GKR depending on the Eastern Cooperative Oncology Group (ECOG) performance status (PS), pathology, concurrent chemotherapy, radiation dose, and target tumor volume.

Results: Starting from when the patients underwent GKR, the median PFS and OS were 5.0 months (range, 1.1-28.1) and 13.0 months (range, 1.1-75.1), respectively. On univariate analysis, the median PFS was significantly long in patients with anaplastic oligodendroglioma, ECOG PS 1, and target tumor volume less than 10 mL (p<0.05). Meanwhile, on multivariate analysis, patients with ECOG PS 1 and target tumor volume less than 10 mL showed improved PFS (p=0.043 and p=0.007, respectively). The median OS was significantly increased in patients with ECOG PS 1 and tumor volume less than 10 mL on univariate and multivariate analyses (p<0.05).

Conclusion: GKR could be an additional treatment option in recurrent high-grade glioma, particularly in patients with good PS and limited tumor volume.

Keywords: Gamma knife radiosurgery; Glioma; Recurrence; Tumor volume.

Fig. 1.

Kaplan-Meier curve related to progression-free survival. A : Median PFS was significantly longer in patients with anaplastic oligodendroglioma than in those with glioblastoma (p=0.001). B : Survival of patients with ECOG PS 1 was statistically significantly different compared to those with ECOG PS 3 (p=0.024). C : Survival of patients with tumor volume less than 10 mL was statistically significantly different compared to those with tumor volume over 10 mL (p=0.008). AO : anaplastic oligodendroglioma, AA : anaplastic astrocytoma, GM : glioblastoma; PFS : progression-free survival, ECOG : the Eastern Cooperative Oncology Group, PS : performance status.

Fig. 2.

A : Kaplan-Meier curve related with overall survival. Patients with ECOG PS 1 and 2 had better OS compared to those with ECOG PS 3 (p=0.000 and 0.042, respectively). B : Patients with tumor volume less than 10 mL had better OS compared to those with tumor volume over 10 mL (p=0.002). ECOG : the Eastern Cooperative Oncology Group, PS : performance status, OS : overall survival.

Fig. 3.

GKR for recurred glioblastoma. A : Brain MRI showed the recurred homogenous enhanced lesion on the parietal lobe. B : Methionine-PET image showed a hot uptake lesion. C : GKR was performed for this lesion. The tumor volume was 2.05 mL, and the marginal radiation dose was 18 Gy with 50% isodose. D : Follow-up brain MRI after 24 months showed a decreased enhancing lesion without any neurologic symptoms. GKR : gamma knife radiosurgery, MRI : magnetic resonance images, PET : positron emission tomography.

Fig. 4.

GKR for recurred anaplastic oligodendroglioma. A : Brain MRI showed a non-enhancing lesion adjacent to the right frontal horn. B : Methionine-PET image showed a hot uptake lesion. C : GKR was performed. The tumor volume was 2.0 mL, and the marginal radiation dose was 18 Gy with 50% isodose. D : Follow-up brain MRI after 11.3 months showed a stable enhancing lesion without any neurologic symptoms. GKR : gamma knife radiosurgery, MRI : magnetic resonance images, PET : positron emission tomography.