Irradiated bone and its management.

Abstract

There are two undeniable attributes of radiotherapy: its value in controlling head and neck malignancies and the progressive damage it inflicts on all treated tissues. It is fortunate that over the past decade, we have developed techniques and treatments that counteract, at least in part, the negative effects of radiotherapy on bone. Some of these measures are purely preventive and must be employed before or during radiation therapy to be successful. They include limiting the total radiation dose to less than 7000 Rads, appropriately shielding structures that do not require radiation, sparing one or more major salivary glands to minimize xerostomia, limiting fraction dosages to less than 200 Rads, obtaining pre-radiation dental evaluations, and performing dental extractions before radiotherapy begins. Additionally, treatments have been devised to prevent ORN following radiotherapy. They consist of patient participation in aggressive dental maintenance programs, oral fluoride treatments, and the use of preextraction hyperbaric oxygen when unhealthy teeth need to be removed. Should radiation-induced complications develop in spite of these efforts, treatments have been developed that effectively deal with ORN, namely, hyperbaric oxygen (the Marx protocol) and prolonged courses of intravenous antibiotics. Finally, when ORN results in mandibular loss and deformity, these defects can be effectively reconstructed with either corticocancellous particulate bone grafts or microvascular osseous tissue transfers, depending on the clinical situation. Much can be done to prevent and treat radiation-induced complications involving bone, and it remains the responsibility of the head and neck surgeon to make sure that these measures are utilized. When all priorities in treating ORN are considered, differentiating a radiation-induced wound healing problem from a delayed tumor recurrence remains paramount. This differentiation should always be the first step in the treatment of any radiation-induced wound.