Measurement of PDT-Induced Hypoxia in Dunning Prostate Tumors by Iodine-123-Iodoazomycin Arabinoside

Photodynamic therapy (PDT) is known to produce vascular damage in solid tumors resulting in secondary ischemia and tumor cell death from hypoxia. The oxygenation status of both non-treated and PDT-treated Dunning R3327-AT prostate tumors growing in Fischer X Copenhagen rats was investigated with the novel hypoxic marker, 123 I-iodoazomycin arabinoside (IAZA). Both qualitative and quantitative data from planar scintigraphy of anesthetized tumor-bearing rats showed increased retention of 123 I-IAZA in tumors treated with PDT. Tumor perfusion in the same tumors was measured with 99m Tc-hexamethylpropyleneamine oxime (HM-PAO)