2024 ACP Annual Session

Incidence of Osteoradionecrosis and Dosimetric Distribution Utilization in Treatment Planning
for Head and Neck Cancer Patients: A Literature Review
Doyub Lee DDS, Akshay Parmar BDS, DDS, MDSc, FACP, Mijin Choi DDS, MS, MBA, FACP

Jonathan and Maxine Ferencz Advanced Education Program in Prosthodontics New York University College of Dentistry

Introduction

Radiotherapy plays a critical role in managing various malignancies, particularly in the head and neck region. However, one of the significant complications associated with radiotherapy is osteoradionecrosis (ORN), a condition characterized by the necrosis of bone tissue in irradiated areas.1 The teeth, soft tissue, salivary glands, and muscles can be affected by the side effects or complications of ORN.2,3

Both radiologists and prosthodontists can employ various strategies to minimize radiation exposure to areas surrounding the target region during radiotherapy by employing high-precision radiotherapy techniques and intraoral protective devices, as outlined below:

High-Precision Radiotherapy Techniques:

• Radiologists use techniques like Intensity-Modulated Radiation Therapy (IMRT), Volumetric Modulated Arc Therapy (VMAT), and Stereotactic Body Radiation Therapy (SBRT) to target radiation precisely at tumors while minimizing damage to healthy tissues.4

Intraoral Protective Devices:

• Prosthodontists can fabricate intraoral devices, including lead protective stents, tongue depressing devices, and positioning devices, to provide additional protection for non-targeted areas during radiotherapy.5

In addition to efforts to minimize radiation exposure to healthy tissues, factors such as the risk of osteoradionecrosis (ORN) post-radiotherapy and the timing of dental extractions must be carefully planned to reduce ORN risk without compromising oncological outcomes. Dosimetry involves mapping and calculating radiation doses to evaluate the prescribed dose delivered to regions surrounding the tumor site after radiotherapy.6

To Develop Dosimetry:

• Computerized treatment plans utilize axial CT scans to contour the mandible, maxilla, and teeth.14

• Cumulative doses for each jaw sextant are calculated to create dose-volume histograms, which facilitate the determination of mean and maximum radiation doses for each jaw sextant—anterior teeth, left and right premolars, and left and right molars.14

By assessing the risk of osteoradionecrosis (ORN) after tooth extraction post-radiotherapy and using dosimetric contouring to map radiation doses to specific jaw regions, clinicians can create a precise treatment plan, even for patients who have received a total radiation dose exceeding 60 Gy. Additionally, a thorough understanding of dosimetric distribution for different types of head and neck cancers will assist clinicians in making informed decisions during treatment planning.

2024 ACP Annual Session

Incidence of Osteoradionecrosis and Dosimetric Distribution Utilization in Treatment Planning for Head and Neck Cancer Patients

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