Histological evaluation of tumor-associated reactive zone in MRI

To determine the clinical significance of tumor-associated reactive zone in MRI, MRI findings in 29 patients with malignant musculoskeletal tumors were reviewed. Increased signal intensity on T2-weighted and Gd-DTPA enhanced T1-weighted image was presented in 22 patients. Histological examination of the resected tumor resulted in muscle atrophy (15 patients), fibrosis (8), inflammation (3), and invasion of tumor cells (7) in this area. Thirteen patients underwent preoperative chemotherapy. The size of the reactive zone increased in five, did not change in four, and decreased in four patients. Four patients with decreased reactive zone after preoperative chemotherapy had no viable tumor cells in this area. These findings suggest that reductive surgery can be performed to the patients presenting decreased tumor-associated reactive zone after preoperative chemotherapy. (author)