Gamma knife for tumors involving orbit

Objective To investigate the outcomes of gamma knife treatment of patients with tumors involving orbit. Methods From 1995 to 2008, 35 patients with tumors involving orbit were treated by Leksell Gamma Knife in our center. 25 patients ( 16 meningiomas, 3 meningeal hemangiopericytomas, 2 schwannomas, 2 adenoid cystic carcinomas of the lacrimal gland, 1 metastatic tumor and 1 angiofibroma)were followed - up. MRI ( 1.5T PHILIPS or 3. 0T GE ) with 2 - mm thick slice was performed to acquire images for targeting tumors and Kula or GammaPlan was used. The mean tumor volume was 2.91 cm3 (0.17～ 19.50 cm3 ). The median marginal dose was 12. 4 Gy (8 ～ 15 Gy) and the median center dose was 26. 7 Gy ( 16 ～ 32 Gy) . Result After a mean follow - up of 30. 4 months ( 1 - 62 months) for 25 patients,tumor control was confirmed in 23(92％ ) patients. 6(24％ ) patients got symptoms relieved and 13(52％)stable. Transient symptoms development was observed in 5 ( 20％ ) patients. Of the 2 patients with tumor progression, 1 patient had to undergo another operation due to developed exophthalmos. Conclusions Gamma knife may be an effective treatment option for small or residual tumors involving orbit. Key words: Stereotactic radiosurgery;  Gamma knife;  Orbit;  Tumors