[Radiosurgery in the treatment of brain cavernomas. Experience with 17 lesions treated in 15 patients]

The aim of this study is to assess the efficiency of radiosurgery (RS) in the treatment of brain cavernomas. The series included intra-axial 17 lesions in 15 patients, 10 women and 5 men. Eleven were infratentorial lesions (brain stem and cerebellum) and 6 supratentorial (thalamus, hippocampus, brain cortex and paraventricular region). Fifteen lesions bled once or twice. Two lesions revealed by focal epilepsy displayed a rim of hemosiderin on MRI. RS was performed for all 17 lesions. The risk of morbidity was considered too high for surgery in 13 patients and 2 patients wished to be treated by RS. RS was delivered by a 6 MeV linear accelerator with a conic collimators device. Stereotactic localization and dosimetry were carried out with STP system 3.O (Fischer-Liebinger TM, Germany). Doses ranged between 16 and 23 Gy, the lower doses being delivered to brain stem lesions. All the lesions received a single fraction isocentric radiation. Lesion volumes ranged between 0.7 and 4.7 cm(3). Twelve lesions disappeared on MRI, the volume reduced (50-80%) in 3 lesions, and did not change in 2 lesions. Volume reduction was significant (P<0.01, P<0.001). In the follow up, 4 patients experienced bleeding, 1 of them died. Edema diagnosed in 2 patients at 3 and 13 months was treated by corticosteroids. The risk of hemorrhage without treatment in this group of patients was estimated about 34.45% a year. Hemorrhage incidence observed after RS was 7.17% (significant with P<0.01, P<0.001). At the end of follow up, 12 patients were symptom-free, 2 had sequels from bleeding, 1 patient died. Radiosurgery is an efficient treatment of cavernomas leading to a total disappearance of 70% of the lesions and significantly reducing the risk of new hemorrhages.