title: Comparative dosimetric evaluation of nanotargeted (188)Re-(DXR)-liposome for internal radiotherapy.
abstract: A dosimetric analysis was performed to evaluate nanoliposomes as carriers of radionuclides ((188)Re-liposomes) and radiochemotherapeutic drugs [(188)Re-doxorubicin (DXR)-liposomes] in internal radiotherapy for colon carcinoma, as evaluated in mice.
  
  
  METHODS
  Pharmacokinetic data for (188)Re-N, N-bis (2-mercaptoethyl)-N',N'-diethylethylenediamine (BMEDA), (188)Re-liposome, and (188)Re-DXR-liposome were obtained for the estimation of absorbed doses in tumors and normal organs. Two colon carcinoma mouse models were employed: subcutaneous growing solid tumor and malignant ascites pervading tumor models. Radiation-dose estimates for normal tissues and tumors were calculated by using the OLINDA/EXM program. An evaluation of a recommended maximum administered activity (MAA) for the nanotargeted drugs was also made.
  
  
  RESULTS
  Mean absorbed doses derived from (188)Re-liposome and (188)Re-DXR-liposome in normal tissues were generally similar to those from (188)Re-BMEDA in intraperitoneal and intravenous administration. Tissue-absorbed dose in the liver was 0.24-0.40 and 0.17-0.26 (mGy/MBq) and in red marrow was 0.033-0.050 and 0.038-0.046 (mGy/MBq), respectively, for (188)Re-liposome and (188)Re-DXR-liposome. Tumor-absorbed doses for the nanotargeted (188)Re-liposome and (188)Re-DXR-liposome were higher than those of (188)Re-BMEDA for both routes of administration (4-26-fold). Dose to red marrow defined the recommended MAA.
  
  
  CONCLUSIONS
  Our results suggest that radionuclide and chemoradiotherapeutic passive targeting delivery, using nanoliposomes as the carrier, is feasible and promising in systemic-targeted radionuclide therapy.
authors.affiliation: Institute of Nuclear Energy Research, Taoyuan, Taiwan, Republic of China.
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Chang
authors.forename: Michael G
authors.initials: MG
authors.lastname: Stabin
authors.forename: Ya-Jen
authors.initials: YJ
authors.lastname: Chang
authors.forename: Liang-Cheng
authors.initials: LC
authors.lastname: Chen
authors.forename: Min-Hua
authors.initials: MH
authors.lastname: Chen
authors.forename: Tsui-Jung
authors.initials: TJ
authors.lastname: Chang
authors.forename: Te-Wei
authors.initials: TW
authors.lastname: Lee
authors.forename: Gann
authors.initials: G
authors.lastname: Ting
mesh_terms: D000818:Animals; D001201:Ascites / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D004317:Doxorubicin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D036103:Nanotechnology; D011092:Polyethylene Glycols / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D012211:Rhenium / Q000737:chemistry*; D014018:Tissue Distribution
chemical_list: D019275:Radiopharmaceuticals; C506643:liposomal doxorubicin; D011092:Polyethylene Glycols; D012211:Rhenium; D004317:Doxorubicin