Treatment algorithms for brainstem and thalamic cavernous malformations: a single centre experience.

Purpose: Treatment algorithms for brainstem cavernous malformations (BSCM) are still discussed controversially. The aim of our study is to provide the results of a centre with a long-standing experience in the micro-surgical resection and the radiosurgical treatment of BSCM and to elucidate how to best use the two different treatment options for the benefit of the patient. Patients an. Methods: 29 patients (female: male = 13: 16) were treated microsurgically. In 38 patients (female: male = 19:19) Gamma Knife radiosurgery (GKRS) was applied. Surgical approaches have been chosen according to the most direct approach with the lowest risk of neurological deficits. GKRS patients were treated with a Leksell Gamma Knife. Gamma Knife parameters were applied as following: median margin dose 12 Gy (6 -16 Gy), median maximum dose 24 Gy (8 - 32 Gy), median isodose line 50% (45 - 80%). Clinical data were obtained by retrospective chart review. A minimum follow up of 2 years was established and a recent follow up was evaluated for all patients resulting in a median follow up of 7.7 years (2.0 - 22.1 years). Patients were rated according to the modified Rankin scale (mRS). Results: Statistical significant differences revealed that radiosurgically treated patients harboured significantly smaller and deep seated lesions (p<0.001). Surgically treated patients more often showed intralesional or extralesional haemorrhage (p=0.002), were superficially seated but larger and presented with a significantly higher preoperative mRS score (p=0.019). In both treatment groups, patients presented with a significant better mRS score (p=0.002, p<0.001) at time of follow up compared to the mRS score prior to surgery or GKRS. Overall annual pre-operative haemorrhage rates were calculated as 3.2% among surgery patients and 2.3% among GKRS patients. The annual pre-operative re-hemorrhage rate amounted to 25.1% for surgery and 7.2% for GKRS patients in the observation period. The overall annual post-operative haemorrhage rate for GKRS patients was 1.3% at time of follow up. In the first two years after GKRS the haemorrhage rate was 2.6% but dropped to 0.6% after the first two years. The annual postoperative haemorrhage rate was 8.8% for surgically treated patients with residual lesions. Conclusion: GKRS and microsurgery are complimentary treatment options that both result in a favourable patient outcome if applied on accurately selected patients in a multidisciplinary setting. Disclosure: No significant relationships. [ABSTRACT FROM AUTHOR]