Radiopharmaceutical considerations for using Tc-99m MAA in lung transplant patients

To elucidate radiopharmaceutical considerations for using technetium Tc-99m albumin aggregated (Tc-99m MAA) in lung transplant patients and to establish an appropriate routine dose and preparation procedure.

Tertiary care academic hospital during May 2007 to May 2009.

Nuclear pharmacist working in nuclear medicine department.

Radiopharmaceutical considerations deemed important for the use of Tc-99m MAA in lung transplant patients included radioactivity dose, particulate dose, rate of the radiolabeling reaction (preparation time), and final radiochemical purity. Evaluation of our initial 12-month experience, published literature, and professional practice guidelines provided the basis for establishing an appropriate dose and preparation procedure of Tc-99m MAA for use in lung transplant patients.

Radiochemical purity at typical incubation times and image quality in subsequent lung transplant patients imaged during the next 12 months.

Based on considerations of radioactivity dose, particulate dose, rate of the radiolabeling reaction (preparation time), and final radiochemical purity, a routine dose consisting of 3 mCi (111 MBq) and 100,000 particles of Tc-99m MAA for planar perfusion lung imaging of adult lung transplant patients was established as reasonable and appropriate. MAA kits were prepared with a more reasonable amount of Tc-99m and yielded high radiochemical purity values in typical incubation times. Images have continued to be of high diagnostic quality.

Tc-99m MAA used for lung transplant imaging can be readily prepared with high radiochemical purity to provide a dose of 3 mCi (111 GBq)/100,000 particles, which provides images of high diagnostic quality.