In Vivo Image and Biodistribution of $^{123}I$-15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid (BMIPP) in Liposarcoma Bearing Nude Mice

Purpose: -labeled fatty acids have been used in the evaluation of regional myocardial energy metabolism. This study aimed to evaluate the usefulness of -BMIPP as a liposarcoma-imaging agent. Materials and Methods: We compared in vitro uptakes between liposarcoma(SW872) and glioma(9L) cell lines, and examined biodistribution and in vivo images of -BMIPP in liposarcoma-bearing nude mice. Cold-BMIPP was labeled with as catalyst. After purification by Sep-pak, radiochemical purity was determined by TLC. We compared cellular uptake between glioma and liposarcoma after incubation of 5, 10, 15, 30, 60, 120, and 180 mins with culture medium containing -BMIPP. The difference in biodistribution was determined between non-feeding (water only) group for 18 hr and feeding group in normal mice (n=6/group) at 0.5, 2, and 24 hr. In liposarcoma-hearing nude mice model, liposarcoma, SW872, ceil lines were injected subcutaneously into the felt thigh of nude mice. The biodistribution of -BMIPP was evaluated at 0.5, 2, and 24 hr (n:5 / group) and in vivo Image of -BMIPP was obtained with gamma camera at 2 and 24 hr in liposarcoma-hearing nude mice. Results: Radiolabeling yield and radiochemical purity were 95% and above 99%, respectively. SW872 cell line showed more increased uptake than 9L with 1.5 times at 180 mins. The clearance of -BMIPP in various tissues was more delayed in the non-feeding group than in the feeding group, especially at delayed time (24 hr) in normal mice, and the major excreting organ was the gastrointestinal tract. In liposarcoma-bearing nude mice, tumor/blood ratio of -BMIPP was 0.94, 0.75, and 1.38 and tumor/muscle ratio was 0.66, 1.53, and 1.11 at 0.5, 2, and 24hr, respectively. -BMIPP was selectively localized in liposarcoma at 24 hr image. Conclusions: These results suggest that -BMIPP can be used as a liposarcoma-imaging agent.