title: Distribution of the anticancer drugs doxorubicin, mitoxantrone and topotecan in tumors and normal tissues.
abstract: OBJECTIVE
  Pharmacokinetic analyses estimate the mean concentration of drug within a given tissue as a function of time, but do not give information about the spatial distribution of drugs within that tissue. Here, we compare the time-dependent spatial distribution of three anticancer drugs within tumors, heart, kidney, liver and brain.
  
  
  METHODS
  Mice bearing various xenografts were treated with doxorubicin, mitoxantrone or topotecan. At various times after injection, tumors and samples of heart, kidney, liver and brain were excised.
  
  
  RESULTS
  Within solid tumors, the distribution of doxorubicin, mitoxantrone and topotecan was limited to perivascular regions at 10 min after administration and the distance from blood vessels at which drug intensity fell to half was ~25-75 μm. Although drug distribution improved after 3 and 24 h, there remained a significant decrease in drug fluorescence with increasing distance from tumor blood vessels. Drug distribution was relatively uniform in the heart, kidney and liver with substantially greater perivascular drug uptake than in tumors. There was significantly higher total drug fluorescence in the liver than in tumors after 10 min, 3 and 24 h. Little to no drug fluorescence was observed in the brain.
  
  
  CONCLUSIONS
  There are marked differences in the spatial distributions of three anticancer drugs within tumor tissue and normal tissues over time, with greater exposure to most normal tissues and limited drug distribution to many cells in tumors. Studies of the spatial distribution of drugs are required to complement pharmacokinetic data in order to better understand and predict drug effects and toxicities.
authors.affiliation: Department of Medical Biophysics, Princess Margaret Cancer Centre and University of Toronto, Toronto, Canada.
authors.forename: Krupa J
authors.initials: KJ
authors.lastname: Patel
authors.forename: Olivier
authors.initials: O
authors.lastname: Trédan
authors.forename: Ian F
authors.initials: IF
authors.lastname: Tannock
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics; D000970:Antineoplastic Agents / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D045744:Cell Line, Tumor; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D004317:Doxorubicin / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D008942:Mitoxantrone / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D009369:Neoplasms / Q000098:blood supply* / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D014018:Tissue Distribution; D059004:Topoisomerase I Inhibitors / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics; D019772:Topotecan / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D059004:Topoisomerase I Inhibitors; D019772:Topotecan; D004317:Doxorubicin; D008942:Mitoxantrone