Gamma knife radiosurgery for skull base chondrosarcoma

Objective To assess outcomes after gamma knife radiosurgery for chondrosarcomas of the skull base.Methods Six patients (one female and five male) with skull base chondrosarcomas were reviewed who underwent gamma knife treatment between 2007 and 2013.The mean patient age was 45.6 years (range 28-65 years).All patients were diagnosed as chondrosarcoma by histological confirmation.All patients had no radiation therapy experience.The mean tumor volume was 16.8 cm(range 4.7-62.4 cm) and mean/median margin dose was 13.3/13.5 Gy (range 10-14 Gy),and the mean/median tumor maximum dose was 29.1/28.6 Gy(range 26-31 Gy).The mean/median followed up time was 29.3/27.0 months (range 6-51 months).Results One paitent who was diagnosisd as mesenchymal chondrosareoma dead at 15 months after gamma knife treatment because of tumor progression at 27 months,one patient underwent repeat gamma knife treatment,and the tumor progression free until now.Other 4 patient keep tumor progression free.No symptomatic adverse radiation effects occurred.Conclusion Stereotactic radiosurgery provide a benefit to patients as a adjuvant therapy for skull base chondrosarcoma. Key words: Stereotactic radiosurgery;  Gamma knife;  Chondrosarcoma;  Radiation therapy