Osteoradionecrosis of the Mandible Resulting from External Megavoltage Radiation Therapy

The NSD and TDF concepts were used to evaluate the tumor and mandibular radiation dose levels of 13 patients with and 63 without osteoradionecrosis of the mandible following a curative course of megavoltage irradiation for carcinomas of the tonsillar region. The midplane tumor doses were from 1,600 to 2,100 RET (TDF 85–135); the mandibular doses ranged from 1,700 to 3,000 RET (TDF 102–223). The 13 patients with osteoradionecrosis received mandibular doses from 2,000 to 2,900 RET (TDF 126–212). The authors discuss the treatment factors contributing to the high mandibular dose and the role of this dose in the development of mandibular osteoradionecrosis.