Decision analysis of the treatment of AVMs with radiosurgery.

Decision analysis uses a tree-like diagram to describe treatment outcomes, the likelihood and value of which are obtained from the literature. A personal computer program entitled 'D-Tree' was used to compare radiosurgery to both microsurgery and nonoperative management of cerebral arteriovenous malformations (AVMs). The results indicated that radiosurgery is the treatment of choice for all AVMs up to 3 cm in diameter, not just those considered inoperable. Sensitivity analysis, to show the effect on treatment preference of a range of assumptions concerning outcome probabilities and values, suggested that for microsurgery to provide more years of life expectancy than radiosurgery, the obliteration rate of radiosurgery should be less than 60%. If the radiosurgical obliteration rate is 85%, then microsurgery must have a zero mortality and morbidity rate to equal the results of radiosurgery.