The use of tumor-to-tongue thickness ratio to predict the need for microvascular flap reconstruction following glossectomy in carcinoma tongue

Background: Microvascular flap reconstruction (MFR) of medium–large tongue defects following ablative surgery is the standard of care. The decision for MFR is often made prior to surgery or intraoperatively depending on the extent of the defect and the volume of remnant tongue. However, there exists no objective technique to predict this requirement preoperatively. This knowledge is crucial for counseling and planning. We aimed to identify an objective magnetic resonance imaging (MRI) measurement tool to predict the need for MFR of tongue tumors. Materials and Methods: This was a retrospective analysis of patients undergoing surgery (with or without reconstruction) for squamous cell carcinoma of the tongue. Patients had a preoperative MRI as part of their assessment. As per our institution protocol, the decision for the requirement of MFR was made by a consensus of two experienced reconstructive surgeons intraoperatively. This decision was correlated with the ratio of tumor volume to the total tongue volume (tv) as observed in the MRI. Results: A total of 47 patients were identified. Twenty-eight patients underwent reconstruction, while 19 did not. The ratio of tumor thickness to tongue thickness (Tt/tt) was calculated, and a cutoff of >0.395 (sensitivity 89.3% and specificity 89.5%) was found to significantly correlate with the decision for MFR (P < 0.001). The volume of a tumor to total tv ratio was calculated from the data of 22 cases, and a cutoff of >4.2 (sensitivity 83.3 and specificity 90) was found to be correlated significantly with the decision for MFR (P < 0.001). Conclusion: Tt/tt ratio is a useful tool to determine the need for MFR of tongue tumor excision defects in the preoperative setting and can help guide counseling.