TY - JOUR T1 - Lipiodol Solution of <sup>188</sup>Re-HDD as a New Therapeutic Agent for Transhepatic Arterial Embolization in Liver Cancer: Preclinical Study in a Rabbit Liver Cancer Model JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 2033 LP - 2038 VL - 44 IS - 12 AU - Jin Chul Paeng AU - Jae Min Jeong AU - Chang Jin Yoon AU - Yun-Sang Lee AU - Young-Ger Suh AU - Jin Wook Chung AU - Jae Hyung Park AU - June-Key Chung AU - Miwon Son AU - Myung Chul Lee Y1 - 2003/12/01 UR - http://jnm.snmjournals.org/content/44/12/2033.abstract N2 - It has been reported that lipiodol solution of 188Re-labeled 2,2,9,9-tetramethyl-4,7-diaza-1,10-decanedithiol (TDD), an N2S2 derivative, shows excellent targeting of liver cancer after transhepatic arterial embolization (TAE). However, its tumor retention is not high enough to treat liver cancer. Therefore, a new form of TDD, 4-hexadecyl-TDD (HDD), was developed to improve tumor retention by introducing a long alkyl chain. In this study, we compared the tumor retention properties of 188Re-HDD/lipiodol and 188Re-TDD/lipiodol, using a rabbit liver cancer model, and performed dosimetry using the results. Methods: The VX2 cancer cell line was implanted into the livers of 7 rabbits. TAE was performed on 3 rabbits with 188Re-TDD/lipiodol and on 4 rabbits with 188Re-HDD/lipiodol, and conjugated anterior and posterior planar scans were obtained at 1, 2, 6, 24, and 48 h after TAE. From these images, tumor retention was calculated and compared between 188Re-TDD and 188Re-HDD. Afterward, the required dose of radioactivity and the radiation dosimetry for exposure of major organs were calculated using MIRDOSE3.1 software. Results: The residence times of radioactivity in the liver were 10.2 ± 1.0 h in the 188Re-TDD group and 17.6 ± 0.8 h in the 188Re-HDD group (P = 0.034). The required radioactivity for 100 Gy of irradiation to 2.64- to 5.27-cm tumors was 142–1,070 MBq of 188Re-HDD in the rabbit model. The radiation exposures for the major organs were within the tolerable range, and the S-value for the whole body (effective dose equivalent) was calculated to be 0.209 mSv/MBq. Conclusion: Introduction of a long alkyl chain significantly improved the tumor retention of 188Re-HDD/lipiodol, compared with that of 188Re-TDD/lipiodol. Moreover, the required radioactivity for humans and the radiation exposure were within the feasible range for clinical application. ER -