Retrospective review of Osteoradionecrosis cases treated with virtual surgical planning following review of received irradiation dose to the mandible

Abstract

Osteoradionecrosis of the mandible represents a cohort of patients that are notoriously difficult to treat. Complications are commonplace following free tissue transfer reconstructive surgery, including non-osseous union at the osteotomy site.We retrospectively reviewed a cohort of patients that were treated with fibula free tissue transfer reconstruction utilising virtual surgical planning. It was possible to deform previously delivered radiation dosimetry data onto the virtual mandible and superimpose the osteotomy site. This enabled the delivered radiation dose at the osteotomy site to be determined, plus the volume of mandible remaining that had received above 50Gy of irradiation.Two out of the four patients with appropriate follow up demonstrated evidence of bony consolidation at the osteotomy site between the native mandible and the composite fibula reconstruction. On retrospective review of the dosimetry mapping, one patient's resection margins were performed in areas of the mandible with a received irradiation dose of less than 50Gy. The second patient had a received dose of just over 50Gy at the resection margin, with only 0.1 cm [3] of affected mandible remaining at the osteotomy site.Two patients demonstrated a non-osseous union at a resection margin through an area of the mandible that received an irradiation dose way in excess of 50Gy, with one patient demonstrating a high volume of retained mandible receiving a radiation dose in excess of 50Gy.In this known cohort of difficult to manage patients, any technique that aids in the reduction of complications is a welcome addition.