The clinical analysis of Gamma knife radiosurgery for meningeal hemangiopericytomas

Abstract

Objective The aim was to assess the clinical effects of gamma knife radiosurgery (GKS)in the comprehensive treatment of meningeal hemangiopericytomas(M-HPC).Method Between December 1994 and December 2006,22 patients with 58 postoperative recurrent M-HPC underwent GKS at the Gamma Knife Center of Beijing Neurosurgical Institute(BNI).Of these 22 patients,13 patients were males and 9 patients were females.The mean volume of these tumors was 5.4 cm3(ranged from 0.1 to 37.2 cm3).The mean tumor margin dose was 13.5 Gy(ranged from 10.0 to 20.0 Gy).The mean tumor central dose was 28.2 Gy(ranged from 21.8 to 35.0 Gy).The mean prescription isodose line was 48.4% (ranged from 30.0%to 70.0%).Results The mean period of follow-up was 26.0 months(ranged from 5 to 90 months).Of these 22 patients,intracranial metastases developed in 7 patients,extracranial metastases in 3 patients.Four patients died.The mean life expectancy of these 22 patients was 67.7 months ( ranged from 7 to 192 months).Of these 58 target tumors,radiological follow-up showed that 25 tumors(43.1%)disappeared,13 tumors(22.4%)shrinked,14 tumors(24.1%)remained stable,and 6 tumors (10.3%)enlarged.The overall tumor control rate was 89.7%.Conclusions GKS provided an effective and safe adjunct management for postoperative small to moderate sized M-HPC.Neither GKS nor WBRT seems to protect against future recurrence and metastasis.More clinical materials have demonstrated that the treatment principle should be altered with the development of GKS for recurrent M-HPC. Key words: Gamma knife; Radiosurgery; Meningeal hemangiopericytoma