Gallium imaging in metastatic and recurrent soft-tissue sarcoma.

Fifty-six patients with metastatic or recurrent soft-tissue sarcoma were evaluated by 67Ga-citrate imaging. Prior to entry on the therapy protocol, 52/56 (93%) patients had true-positive 67Ga studies. Two of four patients with liposarcoma, one of twelve with leiomyosarcoma and one with an epithelioid sarcoma had false-negative studies; 89/105 disease sites (85%) were 67Ga positive, including 100% of pleural lesions, 94% in bone, 88% in the abdomen, 85% in soft tissue, 78% in lung parenchyma and 56% of liver metastases. There was significant association between 67Ga avidity and tumor grade with the exception of mesothelioma. No relationship was seen between 67Ga avidity and tumor cell type, disease site or lesion size. Following therapy, 67Ga correctly identified 11/12 sites of active disease in 8/9 patients. Mean pre- and post-therapy 67Ga avidity scores did not differ significantly. Gallium-67 appears to have an important role in the evaluation of patients presenting with either primary or metastatic soft-tissue sarcoma.