The role of 99mTc(V)-DMSA scan as compared to 99mTc-MDP and CT scans in imaging the primary tumor and metastases of osteosarcoma.

The oncophilic complex of technetium-99m labeled pentavalent dimercaptosuccinic acid (99mTc(V)-DMSA) has been successfully used for the detection of primary and metastatic medullary thyroid cancer and for imaging various soft tissue tumors like lung, brain and prostate cancer. In this article, the role of 99mTc(V)-DMSA in the diagnosis of the primary tumor and metastases of osteosarcoma patients as compared to the 99mTc-MDP scan and the CT scan was studied. Twenty-eight patients with bone disease were referred to the Nuclear Medicine Department of Saint Savas Oncology Hospital in Athens from the Orthopedics Department of the same Hospital. From them, 18 (Group A) had osteosarcoma, 7 (Group B) osteomyelitis and 3 (Group C) bone fractures. The final diagnosis was made after fine needle aspiration biopsy. All patients were subjected to the 99mTc(V)-DMSA scan, the standard bone scan (99mTc-MDP) and CT scan. Group A patients showed a selective uptake of 99mTc(V)-DMSA in the primary tumor region. No abnormal 99mTc(V)-DMSA uptake was observed in the patients of Groups B and C. The 99mTc(V)-DMSA scan was found to be superior to the 99mTc-MDP and the CT scans in identifying metastases of osteosarcoma. Sensitivity was 100%, 86% and 98% respectively.