Preclinical Evaluation of (68)Ga-MAA from Commercial Available (99m)Tc-MAA Kit

(99m)Tc-Macroaggregated Albumin ((99m)Tc-MAA) has been used as a perfusion agent. This study described development of the (68)Ga-MAA via commercially available kits from Pars-Isotopes Company as a (99m)Tc-MAA kit. (68)Ge/(68)Ga generator was eluted with suprapure HCl (0.6 M, 6 mL) in 0.5 mL fractions. The two fractions with the highest (68)GaCl(3) activity were generally used for labeling purposes. After labeling, the final product was centrifuged 2 times to purify the solution. Five rats were sacrificed at each exact time interval (from 15 min to 2 h post injection) and the percentage of injected dose per gram (%ID/g) of each organ was measured by direct counting from 11 harvested organs of rats. The RTLC showed that labeling yields before centrifuges were 90% and 95% for Pars-Isotopes and GE kits, respectively and after centrifuges, they became 100%. The microscopic size examination showed a shift in the particle sizes post centrifuges and the biodistribution data revealed the efficiency and benefits of centrifuges in terms of preventing the of liver and bone marrow uptakes especially for Pars-Isotopes kits. Our results showed that after centrifuges of the final product, the lung uptakes increased from 89% to more than 97% of %ID/g after 5 min post injections. The whole procedure took less than 25 min from elution to the final product. Since (99m)Tc-MAA remained longer than (68)Ga-MAA in the lung and (68)Ga-MAA showed better image qualities, using (68)Ga-MAA is recommended.