Nomogram for Predicting Osteoradionecrosis After Fibula Free Flap for Mandibular Reconstruction

Area of Science:

• Oral and Maxillofacial Surgery
• Radiation Oncology
• Biostatistics

Background:

• Osteoradionecrosis (ORN) is a serious complication after radiotherapy (RT), especially following mandibular reconstruction using fibula free flaps.
• Accurate risk prediction for ORN is currently limited due to insufficient data.

Purpose of the Study:

• To develop and validate a predictive nomogram for osteoradionecrosis (ORN) in patients undergoing mandibular reconstruction with fibula free flaps.
• To provide a tool for individualized risk assessment to aid clinical decision-making.

Main Methods:

• A multicenter retrospective study included 294 patients who received fibula free flap reconstruction and adjuvant RT.
• Logistic regression with stepwise backward selection was used to develop the nomogram, which was validated using 10-fold cross-validation.

Main Results:

• Osteoradionecrosis (ORN) occurred in 9.9% of the patient cohort.
• The final predictive model included eight variables, demonstrating excellent discrimination (AUC = 0.94) and good calibration (mean absolute error = 0.017).
• The model achieved a sensitivity of 1.0, specificity of 0.80, and overall accuracy of 0.82 at an optimal classification threshold of 0.30.

Conclusions:

• This study presents the first nomogram specifically designed to predict ORN risk after fibula free flap mandibular reconstruction.
• The nomogram offers a personalized risk estimate, facilitating individualized clinical decisions and optimizing pre- and postoperative planning.
• Prospective validation of this predictive tool is recommended for further confirmation.