111-In-labelled bleomycin; clinical experience as a diagnostic agent in tumours of the thorax and abdomen.

The potential value of indium-labelled bleomycin as a diagnostic scanning agent has been investigated in patients with a variety of malignant neoplasms involving the thorax, abdomen or pelvis. Sixty-five patients were scanned on 72 occasions, the optimum time to perform the examination being 72 hours after the intravenous injection of 2 mCi 111-In chelated to 2 mg bleomycin. Tumour uptake was visualized in 53 out of 62 scans in which tumour was present, but the extent of tumour was underestimated in seven cases, and over-estimated in five others. The latter were mostly due to uptake in infective lesions. These results indicate that the situations in which indium bleomycin is most likely to provide clinically relevant information are the distinction between recurrent tumour and post-radiotherapy changes in the thorax and pelvis, the diagnosis of recurrent carcinoma within the pelvis, and the distinction between bony metastases from carcinoma of the prostate and Paget's disease. Further clinical trials are necessary to assess these situations.