Myocardial perfusion imaging with 99mTc-DMPE in man

Area of Science:

• Nuclear Medicine
• Radiopharmaceutical Development
• Cardiovascular Imaging

Background:

• Technetium-99m DMPE (99mTc-DMPE) is a novel agent for myocardial perfusion imaging.
• Initial studies in dogs showed intense myocardial accumulation.

Purpose of the Study:

• To assess the dosimetry and clinical usefulness of 99mTc-DMPE in human subjects.
• To evaluate the efficacy of 99mTc-DMPE for myocardial perfusion imaging in humans.

Main Methods:

• Dosimetry and clinical utility assessment in four human subjects.
• Evaluation of myocardial uptake, target-to-nontarget ratios, and image quality.
• Comparison with established imaging agents like thallium-201 (201Tl).

Main Results:

• Low absorbed radiation doses were observed, with gallbladder (200 mrad/mCi) and liver (160 mrad/mCi) receiving the highest doses.
• No clinical toxicity was detected.
• Myocardial imaging was achieved, but target-to-nontarget ratios were less favorable than in dogs, and intense hepatic activity obscured the cardiac apex in two subjects.

Conclusions:

• The prototype 99mTc-DMPE is capable of myocardial perfusion imaging in humans.
• Planar myocardial images produced by 99mTc-DMPE are of inferior quality compared to 201Tl images.
• Further research is warranted to develop improved analogs addressing current clinical limitations.