T1-201 chloride scintigraphy for bone tumors and soft part sarcomas

The author investigated T1-201 chloride as a tumor scanning agent of both tumors and soft part sarcomas. Six bone tumors (2 with Ewing sarcoma, 3 with osteosarcoma and 1 with giant cell tumor) and 3 soft part sarcoma (1 with liposarcoma and 2 with malignant fibrous histiocytoma (MFH)) were examined. All but one MFH were untreated primary cases. The diagnosis was determined from biopsy specimen. One patient with Ewing sarcoma had bone metastases. All cases were subsequently received chemotherpeutic agents. Surgery or local irradiation were also used in treatment. T1-201 scintigraphy were performed with intravenous administration of 2 mCi of T1-201 chloride before initiation of therapy. In addition, follow-up examinations were done in 4 patients (2 with Ewing sarcoma and 2 with osteosarcoma) to study the effect of chemotherapy on T1-201 uptake by the tumor. Tc-99m bone scans were available for comparison in 6 tumor. Ga-67 citrate scans were also examined for the 3 soft part sarcomas. The untreated tumors even in the metastatic lesions of Ewing sarcoma were distinctly visualized with T1-201 in all cases. The distribution of T1-201 in the tumors was sometimes different from that of Tc-99m and similar to that of Ga-67. Of 3 out ofmore » the 4 follow-up patients, the post-therapy scan showed reduction in T1-201 uptake more markedly than Tc-99m uptake during effective chemotherapy. The other one patient had not responded to the treatment so that the scan showed no changes in T1-201 uptake. These findings indicate that the tumor imaging with T1-201 is useful in the diagnosis of these malignant tumors and may be of value in assessing the response of bone tumors to chemotherapy.« less