A prospective study comparing 99mTc-MIBI and 99mTc-MDP with 99mTc-DTPA for lung ventilation scintigraphy in pulmonary thromboembolism

Objective The aim of the study was to assess the efficacy of technetium 99m-methyl diphosphonate (Tc-99m-MDP) and technetium 99m-methoxyisobutylisonitrile (Tc-99m-MIBI) as radioaerosol alternatives to technetium 99m-diethylenetriaminepentacetate (Tc-99m-DTPA) in the evaluation of pulmonary thromboembolism, as the direct consequence of the possible outcome could be cost saving. Patients and methods Patients referred to our institution from August 2015 to July 2017 for a ventilation-perfusion scan who fulfilled the inclusion criteria were enrolled into the study as participants. Each ventilation agent was used to ventilate 43 participants, making a total of 129 participants in the study. Images were assessed for quality and alveolar clearance qualitatively and semiquantitatively correspondingly by a nuclear medicine physician blinded to the agent used. Results Tc-99m-MIBI had higher count rates than Tc-99m-DTPA and Tc-99m-MDP, with a statistically significant difference when compared with Tc-99m-DTPA (P=0.021). Tc-99m-MIBI clearly showed slower alveolar clearance when compared with the clearance of Tc-99m-DTPA (P <= 0.0001) and Tc-99m-MDP (P <= 0.001). In terms of image quality, Tc-99m-MIBI generally had better quality images as compared with the other two radioaerosols, with a statistically significant difference when compared with Tc-99m-DTPA (P=0.001). Conclusion Tc-99m-MIBI had superior image quality and slower alveolar clearance when compared with Tc-99m-DTPA. Alongside Tc-99m-MDP, these agents can replace Tc-99m-DTPA whenever clinically and economically applicable.