title: Musculoskeletal tumors: follow-up with MR imaging after treatment with surgery and radiation therapy.
abstract: Magnetic resonance (MR) imaging was used as a follow-up technique in 60 patients who underwent surgery and/or radiation therapy for primary malignant musculoskeletal tumors. MR imaging was performed on a 1.5-T imager with T1- and T2-weighted imaging sequences; MR imaging findings were confirmed by means of posttreatment surgery and histologic analysis or follow-up for at least 1 year. If a low-signal-intensity lesion was seen on T2-weighted images in a patient who had undergone radiation therapy or surgery, the patient usually did not have active tumor (sensitivity, 96%). If a high-signal-intensity lesion was seen after a patient had undergone only surgery, the patient had active tumor (six of six such cases). In patients who had undergone only radiation therapy, however, the presence of a high-signal-intensity lesion may indicate either active tumor or radiation-induced inflammatory changes. Thus, in such cases, differential diagnosis of active tumor may be difficult, if not impossible, to make from MR images.
mesh_terms: D001859:Bone Neoplasms / Q000175:diagnosis* / Q000628:therapy; D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009135:Muscular Diseases / Q000175:diagnosis* / Q000628:therapy; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000628:therapy; D013997:Time Factors