Radiosurgery for brain tumours

Editor—Brada and Cruickshank express their concerns about the lack of evidence based research in the field of radiosurgery.¹ We agree that radiosurgery replaced neurosurgical resection or fractionated radiotherapy in the treatment of certain intracranial lesions before randomised controlled trials were performed.^2–5 However, the original and continual biological basis for radiosurgery remains strong. The early pioneers in radiosurgery understood that once irradiated volumes could be reduced dramatically the need for fractionation became less important. It was also understood that large single doses of radiation were particularly damaging to late responding tissues, explaining why obliteration rates for arteriovenous malformation treated with radiosurgery were substantially higher than those seen rarely after fractionated radiotherapy. Twenty year follow up does nowexist for patients treated with radiosurgery foracoustic neuromas, arteriovenous malformations (at Karolinska Hospital⁴), and pituitary adenomas (at Massachusetts General Hospital), and the results strongly support its continued use for the future. Recent results of patient assessments for quality of life outcomes suggest that patients are more satisfied with the outcome from radiosurgery compared with other therapeutic modalities.²

It is ironic that this editorial immediately preceded the fourth congress of the International Stereotactic Radiosurgery Society. This congress was the largest ever and was attended by over 400 neurosurgeons, radiation oncologists, and physicists worldwide. The founders of the society set out more than eight years ago to create a scientifically based group of clinical investigators so that results could be presented in a critical fashion to other members. Rather than publishing a skewed view of the current state of radiosurgery, we would encourage the authors of the editorial to participate in the design of important prospective trials to address their concerns.