Rates of osteoradionecrosis in resected oral cavity cancer reconstructed with free tissue transfer in the intensity-modulated radiotherapy era.

[BACKGROUND] Resected oral cavity carcinoma defects are often reconstructed with osteocutaneous or soft-tissue free flaps, but risk of osteoradionecrosis (ORN) is unknown.

[METHODS] This retrospective study included oral cavity carcinoma treated with free-tissue reconstruction and postoperative IMRT between 2000 and 2019. Risk-regression assessed risk factors for grade ≥2 ORN.

[RESULTS] One hundred fifty-five patients (51% male, 28% current smokers, mean age 62 ± 11 years) were included. Median follow-up was 32.6 months (range, 1.0-190.6). Thirty-eight (25%) patients had fibular free flap for mandibular reconstruction, whereas 117 (76%) had soft-tissue reconstruction. Grade ≥2 ORN occurred in 14 (9.0%) patients, at a median 9.8 months (range, 2.4-61.5) after IMRT. Post-radiation teeth extraction was significantly associated with ORN. One-year and 10-year ORN rates were 5.2% and 10%, respectively.

[CONCLUSIONS] ORN risk was comparable between osteocutaneous and soft-tissue reconstruction for resected oral cavity carcinoma. Osteocutaneous flaps can be safely performed with no excess concern for mandibular ORN.