Gamma Knife Radiosurgery for Remnant or Recurred Craniopharyngiomas

Abstract

Objective：The authors assess the long term effectiveness of gamma knife radiosurgery(GKS) for remnant or recurred craniopharyngiomas on tumor control and possibly set proper radiation dose for tumor control with utmost preservation of the adjacent structures.

Methods : Sixteen GKS were done in 14 patients with recurred or remnant craniopharyngiomas after surgery. Mean follow up duration was 44.2 months (range 11.3~123.6 months). Follow up MR imagings were analyzed.

Results : Mean tumor volume was 3.6cm3 (range 0.6~18cm3) and mean margin dose was 12.2Gy (range 8~22.4Gy). Tumor control was achieved in 87.5% (14 of 16 tumors) which were either solid or cystic in nature. Dose to optic apparatus was mean 7.9Gy and no radiation related complications were observed.

Conclusion : GKS seems to be effective treatment modality for craniopharyngiomas regardless of nature of tumor whether it is cystic or solid. Dose of 8 to 8.5Gy may be sufficient to achieve long term tumor control for remnant or recurred craniopharyngiomas.