title: Biologic dosimetry of 188Re-HDD/lipiodol versus 131I-lipiodol therapy in patients with hepatocellular carcinoma.
abstract: One approach to treatment of primary hepatocellular carcinoma (HCC) is intraarterial injection of (131)I-lipiodol. Although clinical results have been positive, the therapy can be improved by using (188)Re instead of (131)I as the radionuclide. (188)Re is a high-energy beta-emitter, has a shorter half-life than (131)I, and has only low-intensity gamma-rays in its decay. The present study compared the cytotoxic effect of the radionuclide therapy in HCC patients treated with (131)I-lipiodol and (188)Re-4-hexadecyl 2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol (HDD)/lipiodol. To this end, dicentric chromosomes (DCs) were scored in metaphase spreads of peripheral blood cultures. The equivalent total-body dose was deduced from the DC yields using an in vitro dose-response curve.
  
  
  METHODS
  Twenty (131)I-lipiodol treatments and 11 (188)Re-HDD/lipiodol treatments were performed on, respectively, 16 and 7 patients with inoperable HCC. Patients received a mean activity of 1.89 GBq of (131)I-lipiodol or 3.56 GBq of (188)Re-HDD/lipiodol into the liver artery by catheterization. For each patient, a blood sample was taken during the week before therapy. A blood sample was also taken 7 and 14 d after administration for the patients treated with (131)I-lipiodol and 1 or 2 d after administration for the patients treated with (188)Re-HDD/lipiodol.
  
  
  RESULTS
  The mean DC yield of (188)Re-HDD/lipiodol therapy (0.087 DCs per cell) was significantly lower than that of (131)I-lipiodol therapy (0.144 DCs per cell) for the administered activities. Corresponding equivalent total-body doses were 1.04 Gy for (188)Re-HDD/lipiodol and 1.46 Gy for (131)I-lipiodol. Data analysis showed that, in comparison with (131)I-lipidol, (188)Re-HDD/lipiodol yielded a smaller cytotoxic effect and a lower radiation exposure for an expected higher tumor-killing effect.
  
  
  CONCLUSIONS
  (188)Re is a valuable alternative for (131)I in the treatment of HCC with radiolabeled lipiodol, and a dose escalation study for (188)Re-HDD/lipiodol therapy is warranted.
authors.affiliation: Department of Anatomy, Embryology, Histology, and Medical Physics, Ghent University, Gent, Belgium. kim.deruyck@UGent.be
authors.forename: Kim
authors.initials: K
authors.lastname: De Ruyck
authors.forename: Bieke
authors.initials: B
authors.lastname: Lambert
authors.forename: Klaus
authors.initials: K
authors.lastname: Bacher
authors.forename: Filip
authors.initials: F
authors.lastname: Gemmel
authors.forename: Filip
authors.initials: F
authors.lastname: De Vos
authors.forename: Anne
authors.initials: A
authors.lastname: Vral
authors.forename: Leo
authors.initials: L
authors.lastname: de Ridder
authors.forename: Rudi A
authors.initials: RA
authors.lastname: Dierckx
authors.forename: Hubert
authors.initials: H
authors.lastname: Thierens
mesh_terms: D000328:Adult; D000368:Aged; D001822:Body Burden; D006528:Carcinoma, Hepatocellular / Q000097:blood* / Q000235:genetics* / Q000473:pathology / Q000532:radiotherapy; D002869:Chromosome Aberrations / Q000528:radiation effects; D002875:Chromosomes / Q000528:radiation effects; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D007459:Iodized Oil / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D008113:Liver Neoplasms / Q000097:blood* / Q000235:genetics* / Q000378:metabolism / Q000532:radiotherapy; D008214:Lymphocytes / Q000473:pathology* / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology; D011868:Radioisotopes / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use; D011874:Radiometry / Q000379:methods; D012062:Relative Biological Effectiveness; D012211:Rhenium / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D014915:Whole-Body Counting
chemical_list: D007457:Iodine Radioisotopes; D011868:Radioisotopes; D012211:Rhenium; D007459:Iodized Oil