Mandibular osteoradionecrosis: clinical behaviour and diagnostic aspects

Area of Science:

• Oncology
• Radiotherapy
• Oral and Maxillofacial Surgery

Background:

• Osteoradionecrosis (ORN) of the mandible is a serious complication following radiotherapy for head and neck cancers.
• Existing definitions of ORN often lack comprehensive criteria, leading to classification challenges.
• A clear staging system is needed to accurately describe and manage mandibular ORN.

Purpose of the Study:

• To retrospectively analyze patients with mandibular osteoradionecrosis (ORN) post-radiotherapy.
• To define and characterize distinct stages of mandibular ORN.
• To propose a revised definition for ORN, excluding tumor recurrence.

Main Methods:

• Retrospective study of 73 patients treated with radiotherapy (50-130 Gy) including the mandible.
• Analysis of clinical and radiological data to establish four distinct stages of ORN.
• Inclusion of imaging techniques for verification of exposed radionecrotic bone.

Main Results:

• Four stages of mandibular ORN were defined: Stage 0 (mucosal defects), Stage I (radiological necrosis, intact mucosa), Stage II (radiographic findings, denuded bone), Stage III (exposed bone, fistulas, infection).
• Clinical features, characteristics, and outcomes for each stage were described.
• Current ORN definitions were found to be incomplete, particularly regarding mucosal defects and bone exposure.

Conclusions:

• A novel four-stage classification system for mandibular osteoradionecrosis (ORN) has been established.
• The proposed ORN definition emphasizes radiological evidence of bone necrosis within the radiation field, excluding tumor recurrence.
• This revised classification aims to improve the accuracy and clinical utility in managing ORN.