MR imaging for detection of local recurrence of osseous Ewing sarcoma

This paper reports on the value of MR imaging in diagnosing recurrence of primary Ewing sarcoma and to compare its accuracy with that of radiography, CT, and skeletal scintigraphy. The authors retrospectively reviewed imaging studies of 8 consecutive patients obtained at the time of clinically suspected local recurrence of osseous Ewing sarcoma. All patients underwent MR imaging with T1- and T2-weigthed sequences, 7 underwent plan radiography, 7 underwent CT, and 8 underwent Tc-99m MDP bone scanning. Imaging diagnosis of relapse was based on changes in osseous or soft-tissue components of the tumor and on a decrease in T2-weighted marrow signal. Local recurrence was identified in 7/8 MR images, 4/7 CT scans, and 2/8 bone scans. In 1 patient, recurrence was diagnosed only on plain radiographs. All 8 relapses were identified by a combination of radiography and T2-weighted MR imaging. Two of 8 recurrent tumors would have been missed without MR imaging