Potential improvement of three dimension treatment planning and proton beams in fractionated radiotherapy of large cerebral arteriovenous malformations.

The treatment of large cerebral arteriovenous malformations is a surgical challenge, especially for deep seated brain locations. Furthermore, these lesions are unfit for radiosurgical approaches due to a high risk of complications secondary to high radiation doses to large brain volumes. Fractionated precision radiotherapy can potentially deliver high, uniform, target-contoured dose distributions optimizing the dose reduction to the critical surrounding brain. The results of a study are presented in such a way that dose distributions achievable with proton beams are compared to those with 10 MV x-rays; and the potential improvements with protons evaluated, relying heavily on dose-volume histograms to examine the coverage of the lesion as well as the dose to the normal brain, brain-stem, and optic chiasm.