Dosimetric distribution to tooth-bearing areas in intensity-modulated radiation therapy for head and neck cancer: a pilot study

Sun-Yung Bak; X Sharon Qi; James A Kelly; Sherri Alexander; Yunro Chung; Samvel Gyurdzhyan; Lauren L Patton; Steve P Lee

doi:10.1016/j.oooo.2015.10.007

Dosimetric distribution to tooth-bearing areas in intensity-modulated radiation therapy for head and neck cancer: a pilot study

Oral Surg Oral Med Oral Pathol Oral Radiol. 2016 Jan;121(1):43-8. doi: 10.1016/j.oooo.2015.10.007. Epub 2015 Oct 23.

Authors

Sun-Yung Bak¹, X Sharon Qi², James A Kelly³, Sherri Alexander⁴, Yunro Chung⁵, Samvel Gyurdzhyan⁶, Lauren L Patton⁷, Steve P Lee⁸

Affiliations

¹ Clinical Assistant Professor, Department of Prosthodontics, University of North Carolina School of Dentistry, Chapel Hill, NC, USA. Electronic address: [email protected].
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.

PMID: 26679359
DOI: 10.1016/j.oooo.2015.10.007

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.

MeSH terms

Adult
Aged
Aged, 80 and over
Female
Head and Neck Neoplasms / radiotherapy*
Humans
Male
Mandible / radiation effects*
Maxilla / radiation effects*
Middle Aged
Osteoradionecrosis / etiology*
Pilot Projects
Radiotherapy Dosage
Radiotherapy, Intensity-Modulated*
Retrospective Studies
Risk Factors
Tooth / radiation effects*