Ability to Propose Optimal Prosthetic Rehabilitation can be Improved by Discussion between the Dentist and Radiation Oncologist Regarding Upstream Dosimetry.

OBJECTIVE: Improvement of dental rehabilitation for patients who have undergone radiation therapy requires knowledge of the dose in the maxillary and mandible bones. MATERIALS AND METHODS: Forty-three patients with head and neck cancers underwent evaluation for dental rehabilitation before radiation treatment dosimetry. The delivered dose to the maxilla and mandible was determined. From the dose data in the literature, three levels of risk of implant failure were defined. According to the delivered doses, the authors calculated the percentage of patients who could be fully rehabilitated with an implant, as proposed by the dentist before radiation planning. RESULTS: Before dosimetry calculation, all of the completely edentulous arches and 94 partially edentulous (PESs) sextants could be optimally rehabilitated. After dose calculation, among the 14 arches of 7 patients who were completely edentulous, according to the mean and maximal delivered doses, 11 arches (78.6%) and 7 arches (50%) could receive an optimal prosthesis, respectively. For the three patients, who were PESs but with one arch that was completely edentulous, according to the mean and maximal delivered doses, one arch for each dose condition could receive an optimal prosthesis. Among the 94 PESs sextants, according to the mean and maximal delivered doses, 41 (43.6%) and 24 (25.5%) sextants could receive an optimal prosthesis, respectively. CONCLUSION: By determining the sites of implantation before dosimetry, the radiation oncologist could shield specified areas, potentially improving the possibilities for dental rehabilitation. The dialogue between the dentist and the radiation oncologist can improve the possibilities for implants and decrease the risk of unsafe implantation.

Maxillary and mandible contouring in patients with a head and neck area irradiation.

PURPOSE: Dental care is crucial after irradiation of the head and neck. This care may include dental restoration, extractions, and prosthetic implantation or prosthesis adjustment. To perform these procedures safely, dentists need to know the delivered radiation dose delivered to the relevant part of the mandible and/or maxilla. We propose a simple, fast, and useful contouring technique to aid accurate recording of radiation therapy dose to the mandible and maxilla. METHODS AND MATERIALS: The maxilla and mandible of 2 patients, 1 dentate and 1 edentulous, have been contoured on computed tomography planning scans. The jaw has been divided into sextants (3 segments in both the mandible and maxilla) using bony landmarks. RESULTS: We have developed a contouring atlas to aid radiation oncologists in delineating the maxilla and mandible allowing accurate recording of dose to each sextant and meaningful communication with their dental colleagues. CONCLUSION: Delineation of the maxilla and mandible is important if we are to improve communication between radiation oncologists and dentists regarding radiation and risk to these structures. Our method should not increase the time to delineate the organs at risk and target volumes in the head and neck area and could improve the safety of subsequent dental treatments.