title: Monte Carlo single-cell dosimetry of I-131, I-125 and I-123 for targeted radioimmunotherapy of B-cell lymphoma.
abstract: OBJECTIVE
  To study the dosimetric characteristics of a non-internalizing and an internalizing monoclonal antibody (MAb) labeled with (131)I, (125)I or (123)I, which targets a typical lymphoma B-cell.
  
  
  METHODS
  Using our hybrid Monte Carlo (MC) code which combines detailed- and condensed-history electron track simulation we carry out transport calculations of Auger and beta electrons for different intracellular distributions of radioactivity.
  
  
  RESULTS
  Assuming permanent retention of the MAb in cells, (125)I gave the highest absorbed dose and (123)I the highest absorbed dose rate. Under the more realistic scenario of biologic excretion from the cells, (123)I resulted in the highest absorbed dose and absorbed dose rate.
  
  
  CONCLUSIONS
  The present dosimetric analysis shows that biological half-life, subcellular localization, and the proper account of low-energy electrons is critical in assessing the energy deposition inside the targeted cells from the three iodide radioisotopes examined. From a dosimetric point of view and under the present approximations (123)I might be superior to the other two radioiodides in the treatment of microscopic disease in B-cell lymphoma patients.
authors.affiliation: Medical Physics Laboratory, University of Ioannina Medical School, Ioannina, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Bousis
authors.forename: Dimitris
authors.initials: D
authors.lastname: Emfietzoglou
authors.forename: Hooshang
authors.initials: H
authors.lastname: Nikjoo
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism / Q000528:radiation effects; D007457:Iodine Radioisotopes / Q000378:metabolism / Q000627:therapeutic use; D016393:Lymphoma, B-Cell / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D009010:Monte Carlo Method; D021381:Protein Transport; D016499:Radioimmunotherapy / Q000379:methods*; D011874:Radiometry
chemical_list: D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes