Radiotherapy by particle beams (hadrontherapy) of intracranial tumours: a survey on pathology

A review of the principal contributions of radio-therapy of brain tumours by beam particles is carried out. Neutrons, protons and light ions are considered along with their pros and cons in relation to types and locations of brain tumours. A particular emphasis is given to the pathologic studies of their effects directly o n tumours and on the normal nervous tissue, considering mainly the relevant action mechanisms of the radiation types and the requirements of the clinical therapeutic strategies. For comparison the main features of the pathologic effects of radiotherapy by photons are described. From the review it emerges that the new modality of radiation by protons and light ions, because of their peculiar physical characteristics, may represent a new way of destroying the tumour and sparing normal nervous tissue, especially when deeply located and irregularly shaped tumours are concerned. More neuropathological studies are needed in order to better understand the potentiality of the new treatment of modalities.