Imaging tissue hypoxia: clinical and pre-clinical experience with 123IAZA

The molecular mechanisms that underline the selective binding of iodazomycin arabinoside, IAZA, and related nitromidazoles are reviewed as a basis for interpretation of preclinical and clinical data for hypoxic binding of radioiodinated IAZA. Clinical data are presented for 123IAZA uptake in a number of pathologies including metastatic tumours, peripheral vascular disease in diabetes, muscle stress and rheumatoid arthritis. The results of studies to determine the influence of tumour type on uptake of 123 I-IAZA in patients with a variety of deep-seated solid tumours will be presented. Correlations of hypoxia-dependent binding with 99mTc-HMPAO perfusion images will be reviewed and early correlations of uptake to treatment response in cancer will be presented. Unusual features of 123I-IAZA biodistribution will also be discussed together with detailed pharmacokinetic and radiation dosimetry data for '2123I- IAZA in normal volunteers