The irreversibility of radiation-induced fibrosis: fact or folklore? Clinical Oncology

摘要

As the number of long-term cancer survivors increases, late complications of therapy will become an increasingly important concern to both patients and physicians. In administering radiation therapy, the physician typically has attempted to prevent complications primarily by limiting the irradiated dose and volume. Unfortunately, the relationship between radiation dose, volume of tissue irradiated, development of complications, and tumor control is complex and not precisely defined for most normal tissues and malignancies. Unlike medical oncology, there are few formal prospective studies in radiation oncology designed to establish the maximum-tolerated dose for a particular tumor or normal tissue. Commonly accepted normal tissue tolerance doses of radiation, for the most part, have been derived empirically, often with little supporting data.2 Although these estimates may be reasonably generalized, there remains considerable individual variation in radiation sensitivity. Recently, however, much progresshas been made toward better elucidating the molecular mechanisms underlying radiation injury.