Pre‐Operative chemotherapy response assessed by contrast‐enhanced MRI can predict the prognosis of Enneking surgical margins in patients with osteosarcoma

The method used to evaluate the response of osteosarcoma to preoperative chemotherapy before specimen resection is still unclear. The purpose of this study was to identify factors that contribute to overall survival (OS) and to discuss their roles in making a decision regarding Enneking surgical margins. Patients (109) with pathologically confirmed Enneking stage IIB osteosarcoma were retrospectively analyzed. Univariate and multivariate survival analyses were performed. Patient characteristics and chemotherapy-induced contrast-enhanced MRI changes were considered as potential factors. Changes in the tumor volume and the relative necrosis ratio measured by MRI were independent risk factors predicting the OS of patients who underwent limb-salvage surgery. For those in whom the tumor volume had decreased (VolRatio