RADIOPHARMACEUTICALS FOR IMAGING OF HYPOXIC TUMORS: A REVIEW

Abstract

Radiopharmaceuticals are drugs containing a radionuclide and are used routinely in nuclear medicine for the diagnosis and therapy of various diseases. The mechanism of localization of the radiopharmaceutical in different organs provides the clue for designing of the agent meant for a specific organ or pathway. Various agent like F-18, Cu-64/67, I-123, and Tc-99m are used as imaging of hypoxic tumors. Of these, F-18-fluoromisonidazole and I-123-iodoazomycin arabinoside (IAZA) have been most widely studied clinically. Non-nitro-containing bioreductive complexes, such as the Cu-60/62/64 thiosemicarbazone ATSM and Tc-99m butylene amineoxime (BnAO or HL91), have also been evaluated. In particular, I-123-IAZA and Cu-60-ATSM have shown correlation with response to radiotherapy in preliminary clinical studies. However, more preclinical studies comparing imaging with validated invasive methods and clinical studies with outcome measures are required. Nuclear medicine is poised to play an important role in optimizing the therapy of patients with hypoxic tumors. The present review is concern with the various radiopharmaceuticals used for imaging of hypoxia.