La radiochirurgie dans le traitement des cavernomes. Expérience de 17 lésions traitées chez 15 patients

Abstract

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.