Gamma knife radiosurgery for brainstem cavernous malformations

- Gamma knife radiosurgery for brainstem cavernous malformation is effective.
- The previously reported papers about the change of the rate of hemorrhage and the rate of radiation complications were summarized.
- The optimal dose directed to the lesion margin was approximately 11.0 Gy.
- Depending on the patient's condition, choosing a suitable treatment method can reduce the rates of hemorrhage and adverse effects.
- Gamma knife radio surgery is suitable for the patients who aren't willing to do operation.

ObjectiveThe goal of this retrospective study was to evaluate the efficacy and safety of gamma knife radiosurgery (GKS) for the treatment of brainstem cavernous malformations (CMs).MethodsBetween January of 2009 and December of 2014, 43 patients (20 males and 23 females) with brainstem CMs were treated at the West China Hospital, Sichuan University, Gamma Knife Center. The mean age of these patients was 41.7 years. All of the patients experienced 1 or more episodes of symptomatic bleeding (range 1-4) before undergoing GKS. The mean volume of the malformations at the time of GKS was 442.1 mm3, and the mean prescribed marginal radiation dose was 11.9 Gy. The mean follow-up period after radiosurgery was 36 months (range 12-120 months).ResultsBefore GKS, 50 hemorrhages (1.2 per patient) were observed (25.0% annual hemorrhage rate). Three hemorrhages following GKS were observed within the first 2 years (3.92% annual hemorrhage rate), and 1 hemorrhage was observed in the period after the first 2 years (1.85% annual hemorrhage rate). In this study of 43 patients, new neurological deficits developed in only 1 patient (2.32%; permanent paresthesia on the left side of the face and the right lower limb of the patient). There were no deaths in this study.ConclusionGKS is a favorable alternative treatment for brainstem CMs. Using a low marginal dose treatment might reduce the rate of hemorrhage and radiation-induced complications.