Sun-Yung Bak1, X Sharon Qi2, James A Kelly3, Sherri Alexander4, Yunro Chung5, Samvel Gyurdzhyan6, Lauren L Patton7, Steve P Lee8. 1. Clinical Assistant Professor, Department of Prosthodontics, University of North Carolina School of Dentistry, Chapel Hill, NC, USA. Electronic address: Sybakdds@email.unc.edu. 2. Assistant Professor, Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, USA. 3. Assistant Professor, Mayo Clinic College of Medicine, Mayo Clinic; Consultant, Division of Prosthetic and Esthetic Dentistry, Department of Dental Specialties, Mayo Clinic, Rochester, MN, USA. 4. Dosimetrist, Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, USA. 5. Department of Biostatistics, University of North Carolina Gillings School of Global Public Health, Chapel Hill, NC, USA. 6. Quality Assurance Research Technician, Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, USA. 7. Professor and Chair, Department of Dental Ecology, University of North Carolina School of Dentistry, Chapel Hill, NC, USA. 8. Professor, Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, USA.
Abstract
OBJECTIVES: Dosimetric distribution of intensity-modulated radiotherapy (IMRT) to tooth-bearing areas for common head and neck (H&N) cancer sites were analyzed to facilitate minimization of osteoradionecrosis (ORN) risk through preradiation dental treatment planning. STUDY DESIGN: Fifty-four patients received IMRT with prescribed doses ranging from 6000 centigrays (cGy) (adjuvant) to 6930 cGy (primary) to treat base of tongue (BOT), tonsil, larynx, nasopharynx, and hypopharynx cancers. The average maximal radiation dose delivered was recorded in tooth-bearing areas (anteriors, premolars, and first, second, and third molars) of the maxilla and mandible. RESULTS: All tooth-bearing areas in laryngeal cancer cases received less than 2500 cGy. Maxillary and mandibular molar regions for BOT, tonsil, and hypopharynx cancers received 5000 cGy or higher. In nasopharynx cancers, maxillary teeth received higher doses than mandibular teeth. CONCLUSIONS: Among 5 H&N subsites, mandibular molar regions for BOT, tonsil, and hypopharynx cancers received higher IMRT doses on average, posing the greatest ORN risk.
OBJECTIVES: Dosimetric distribution of intensity-modulated radiotherapy (IMRT) to tooth-bearing areas for common head and neck (H&N) cancer sites were analyzed to facilitate minimization of osteoradionecrosis (ORN) risk through preradiation dental treatment planning. STUDY DESIGN: Fifty-four patients received IMRT with prescribed doses ranging from 6000 centigrays (cGy) (adjuvant) to 6930 cGy (primary) to treat base of tongue (BOT), tonsil, larynx, nasopharynx, and hypopharynx cancers. The average maximal radiation dose delivered was recorded in tooth-bearing areas (anteriors, premolars, and first, second, and third molars) of the maxilla and mandible. RESULTS: All tooth-bearing areas in laryngeal cancer cases received less than 2500 cGy. Maxillary and mandibular molar regions for BOT, tonsil, and hypopharynx cancers received 5000 cGy or higher. In nasopharynx cancers, maxillary teeth received higher doses than mandibular teeth. CONCLUSIONS: Among 5 H&N subsites, mandibular molar regions for BOT, tonsil, and hypopharynx cancers received higher IMRT doses on average, posing the greatest ORN risk.