Journal Article

Improving methodology of radiosurgery for posterior fossa cavernomas: higher volume, lower dose

Bollet, Marc, Birladeanu, Andrei, Bouilhol, Gauthier, Scher, Nathaniel, Sopanda, Lucian, Mandonnet, Emmanuel, Abbritti, Rosaria, Nataf, François, Mulier, Guillaume, Guey, Stéphanie, Froelich, Sébastien, Passeri, Thibault, Adle-Biassette, Homa, Lambert, Jérôme, Bernat, Anne-Laure

2025

Overview

Cavernous malformations (CM) of the brain are vascular abnormalities that carry a risk of bleeding, posing significant neurological and life-threatening challenges, particularly in posterior fossa. The efficacy of radiosurgery for cavernomas still remains a matter of debate, largely due to technical and statistical limitations. In this study, we present a series of posterior fossa cavernomas treated using CyberKnife radiosurgery, employing an innovative approach that integrates both technical and statistical advancements. Patients and methods We conducted a prospective series involving 35 posterior fossa cavernomas in 33 patients treated with low-dose radiosurgery protocols (12 Gy in a single fraction or 18 Gy in 3 fractions). Compared to previously published series, our approach targeted a larger treatment volume, encompassing the entire hemosiderin ring surrounding the cavernoma. Radiosurgery was indicated for cases of hemorrhage or progressive neurological deficits in anatomically challenging, nonsurgical areas. The statistical analysis was designed to address the unknown onset time of cavernoma prior to radiosurgery, enabling a more accurate calculation of the hemorrhage incidence rate before treatment. Follow-up evaluations, including clinical assessments and MRI, were conducted at 3-6-9-12-18-24 months and subsequently on an annual basis. Results With a mean follow-up duration of 26 months, exceeding the previously described latency period, and a median [IQR] follow-up of 13 months [8.7-30.4] which represents approximately half the latency period, only one patient experienced a recurrence of hemorrhage, occurring 20 months post-treatment and remaining asymptomatic. No patients exhibited radio-induced parenchymal changes or clinical deterioration following radiosurgery. Conclusions These preliminary results support the strategy of increasing the target volume while reducing the radiation dose for cavernous malformations. We further recommend incorporating sensitivity analyses to evaluate the robustness of results, particularly in the context of uncertainties surrounding the time of onset of cavernomas.

• Publisher: Springer Vienna,Springer Nature B.V
• Subject: Adolescent / Adult / Aged / Female / Hemangioma, Cavernous, Central Nervous System - radiotherapy / Hemangioma, Cavernous, Central Nervous System - surgery / Hemorrhage / Humans / Infratentorial Neoplasms - radiotherapy / Infratentorial Neoplasms - surgery / Interventional Radiology / Latency / Magnetic Resonance Imaging / Male / Medicine / Medicine & Public Health / Middle Aged / Minimally Invasive Surgery / Neurological diseases / Neurology / Neuroradiology / Neurosurgery / Patients / Prospective Studies / Radiosurgery / Radiosurgery - methods / Radiotherapy Dosage / Sensitivity analysis / Statistical analysis / Statistics / Surgical Orthopedics / Treatment Outcome / Young Adult