Normal tissue reactions and complications following high-energy neutron beam therapy. II: Complication rates adjusted for censoring.

Abstract

A dose response analysis was performed on patients at risk for significant radiation injuries following neutron radiotherapy. Complication rates were calculated at various dose intervals using a maximum likelihood method that is formally equivalent to the product limit estimator of survival. The variance of each complication rate was used to weight a logistic regression on log dose. The treatment sites that were analyzed were head and neck, pelvis, thorax, and pancreas. Except for osteomyelitis of the mandible, complications of all types were considered collectively at each site and dose increment since there were too few complications to determine dose response functions for individual types of injuries. The head and neck was observed to be the site with the highest tolerance to radiation whereas the thorax was the most sensitive site.