Tumour localization with radionuclides of indium

Indium-113m and indium-111 radionuclides have been used in tumour localization efforts. A successful use of 113Insup(m)-labelled compounds in the localization of tumours by direct uptake has been the use of the -DTPA chelate in brain tumour investigations. It appears to localize by the simple rapid mechanism of diffusion, which is compatible with the short half-life of the radionuclide. The clinical reliability of 113Insup(m)-DTPA in brain tumour diagnosis has been reported to be about the same as that of 99Tcsup(m)-pertechnetate. 111In-chloride, by direct administration or pre-bound to autologous serum, is the form of 111In most intensively studied in tumour uptake investigations. It has shown excellent uptake in certain animal tumour systems. Its use in general tumour scanning has been limited. In comparative studies, 67Ga-citrate has seemed to be superior as a general tumour-scanning agent. However, the use of 111In-chloride as a brain-scanning agent and for tumours in the head and neck region, in doses of 3-5 mCi, seems to warrant further investigation. (author)