Radiosurgery for symptomatic cavernous malformations Long-term results of our institute and all over Japan Yoshihisa Kida Yoshi1, Toshinori Hasegawa2, Takenori Katoh31Aichi Prefecture, Japan 2Komaki, Japan 3Komaki City Hospital Keywords: cavernous malformation, radiosurgery, gamma knife, outcome, hemorrhage
Cavernous malformation gamma knife radiosurgery is performed in selected patients.
Long-term results of radiosurgery to cavernous malformations(CMs) are reported, and compared with the symptomatic cases treated with surgery or followed up conservatively.
152 patients were studied.
There are 152 cases of symptomatic CMs, either by hemorrhage, neurological deficits or by epilepsy, which were treated with gamma knife(A). There are another 13 cases with surgical resection (B), and 33 cases with conservative treatment(C) as symptomatic controls.
Majority of lesions in Group (A) are located in eloquent areas like brainstem or basal ganglia, followed by lobar and cerebellar lesions. With the mean maximum and marginal dose of 26.4 and 14.9 Gy respectively, 30% of them showed a shrinkage and the others were unchanged in the mean follow-up of 55.4 months. Hemorrhage rate after radiosurgery are far decreased to 3.2%/year/case, which is almost one tenth of the one during 5 years before gamma knife (31.8%). Hemorrhage rate showed 8% in the first year, then apparently decreased to less than 5% subsequently and finally reached near to 0% in the 7th year. Convulsive seizures associated with CM either disappeared or decreased in almost 70% of patients, who were treated with gamma knife. In cases of surgical resection, they had a similar hemorrhage rate to Group (A) . In contrast, the hemorrhage rate in Group (C) was 7.6 %/year/case during 62 months of mean follow-up, which is more than double than Group A.>
This was a retrospective review.
The purposes of radiosurgery for symptomatic CMs are not to totally irradicate the lesions, but to successfully control the symptomatic events. Because of markedly decreased rate of hemorrhage with acceptable rate of complications, radiosurgery for cavernous malformation is warranted and advisable, especially for CMs in brainstem and basal ganglia with less than 15Gy at the margins. However, suprotentorial CMs associated with intractable seizures can be treated with surgery, since the effects of radiosurgery are not consitent.
Moreover, a higher marginal dose more than 18Gy, which may cause adverse effects more often, is required to successfully control seizures. In this report, the results of radiosurgery from many institutes in Japan were collected and compared with ours. Project Roles:
Y. Kida Yoshi (), T. Hasegawa (), T. Katoh ()