Effect of mandibular titanium reconstructive plates on radiation dose

Area of Science:

• Biomedical Engineering
• Radiation Oncology
• Oral and Maxillofacial Surgery

Background:

• Mandibular reconstruction often involves titanium alloy plates, but their impact on radiation-tissue interactions is not well-understood.
• Photon beam radiation therapy may be altered by metallic implants used in oncologic surgery.
• Understanding these interactions is crucial for accurate radiation dose delivery in head and neck cancer patients.

Purpose of the Study:

• To evaluate the effect of a titanium alloy plate on radiation dose distribution in a human mandible model.
• To assess radiation dose changes at the bone/titanium and bone/soft tissue interfaces.

Main Methods:

• An ex vivo adult male human head and neck model was utilized.
• A 2.4 mm medical-grade titanium alloy plate was fixed to the mandible.
• The mandible was irradiated with 6 MV photon beams, with and without the plate, and doses were measured using thermoluminescent dosimeters.

Main Results:

• The presence of the titanium alloy plate resulted in a +2.1% dose increase on the buccal aspect and +3.0% on the lingual aspect.
• These observed differences in radiation dose were not statistically significant (P > 0.05).
• No significant alteration in radiation dose was detected anterior or posterior to the mandible.

Conclusions:

• Titanium alloy plates and screws used for mandibular reconstruction do not significantly influence radiation doses in adjacent tissues.
• The findings suggest that current radiation protocols may not require modification due to the presence of these implants.