title: Interventional therapy for human breast cancer in nude mice with 131I gelatin microspheres (¹³¹I-GMSs) following intratumoral injection.
abstract: BACKGROUND
  The aim of this study was to investigate the effects of 131I gelatin microspheres (131I-GMS) on human breast cancer cells (MCF-7) in nude mice and the biodistribution of 131I-GMSs following intratumoral injections.
  
  
  METHODS
  A total of 20 tumor-bearing mice were divided into a treatment group and control group and received intratumoral injections of 2.5 mci 131I-GMSs and nonradioactive GMSs, respectively. Tumor size was measured once per week. Another 16 mice received intratumoral injections of 0.4 mci 131I-GMSs and were subjected to single photon emission computed tomography (SPECT) scans and tissue radioactivity concentration measurements on day 1, 4, 8 and 16 postinjection. The 20 tumor-bearing mice received intratumoral injections of 0.4 mci [131I] sodium iodide solution and were subjected to SPECT scans and intratumoral radioactivity measurements at 1, 6, 24, 48 and 72 h postinjection. The tumors were collected for histological examination.
  
  
  RESULTS
  The average tumor volume in the 131I-GMSs group on post-treatment day 21 decreased to 86.82 ± 63.6%, while it increased to 893.37 ± 158.12% in the control group (P < 0.01 vs. the 131I-GMSs group). 131I-GMSs provided much higher intratumoral retention of radioactivity, resulting in 19.93 ± 5.24% of the injected radioactivity after 16 days, whereas the control group retained only 1.83 ± 0.46% of the injected radioactivity within the tumors at 1 h postinjection.
  
  
  CONCLUSIONS
  131I-GMSs suppressed the growth of MCF-7 in nude mice and provided sustained intratumoral radioactivity retention. The results suggest the potential of 131I-GMSs for clinical applications in radiotherapy for breast cancer.
authors: Chuan-Chao
authors: CC
authors: Li
authors: Jun-Lin
authors: JL
authors: Chi
authors: Yu
authors: Y
authors: Ma
authors: Jian-Hong
authors: JH
authors: Li
authors: Department of General Surgery, West China Hospital of Sichuan University, Chengdu (610041), China. xiachqin@163.com.
authors: Chuan-Qin
authors: CQ
authors: Xia
authors: Lin
authors: L
authors: Li
authors: Zhuo
authors: Z
authors: Chen
authors: Xiao-Li
authors: XL
authors: Chen
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D005780:Gelatin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006801:Humans; D015552:Injections, Intralesional; D007457:Iodine Radioisotopes / Q000008:administration & dosage* / Q000493:pharmacokinetics; D061986:MCF-7 Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008863:Microspheres; D019275:Radiopharmaceuticals / Q000008:administration & dosage* / Q000493:pharmacokinetics; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon; D047368:Tumor Burden
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D005780:Gelatin