Improving methodology of radiosurgery for posterior fossa cavernomas: higher volume, lower dose
François Nataf1,2, Nathaniel Scher3, Marc Bollet3
1Department of Neurosurgery, Lariboisière Hospital, Paris, France. francois.nataf@aphp.fr.
Acta Neurochirurgica
|February 1, 2025
Summary
CyberKnife radiosurgery for posterior fossa cavernomas shows promise. Expanding the treatment volume and lowering radiation dose resulted in a single hemorrhage recurrence in 35 patients, with no adverse effects.
Area of Science:
- Neurosurgery
- Radiation Oncology
- Vascular Neurology
Background:
- Brain cavernous malformations (CM) pose bleeding risks, especially in the posterior fossa.
- Radiosurgery's effectiveness for CM is debated due to technical and statistical challenges.
Purpose of the Study:
- To evaluate CyberKnife radiosurgery for posterior fossa cavernomas using an innovative technical and statistical approach.
- To assess the safety and efficacy of low-dose radiosurgery with expanded target volumes.
Main Methods:
- Prospective study of 35 posterior fossa cavernomas in 33 patients treated with low-dose radiosurgery (12 Gy single fraction or 18 Gy in 3 fractions).
- Treatment volume encompassed the entire hemosiderin ring.
- Statistical analysis accounted for unknown cavernoma onset time to accurately calculate pre-treatment hemorrhage rates.
Main Results:
- Mean follow-up of 26 months; median 13 months.
- Only one patient (2.8%) experienced hemorrhage recurrence 20 months post-treatment, remaining asymptomatic.
- No radio-induced parenchymal changes or clinical deterioration observed.
Conclusions:
- Preliminary results support increased target volume and reduced radiation dose for CM radiosurgery.
- Sensitivity analyses are recommended to address uncertainties in cavernoma onset time.
