title: Preclinical evaluation of [99m]Tc-labeled doxorubicin as a potential scintigraphic probe for tumor imaging.
abstract: BACKGROUND
  The currently available radiopharmaceuticals are not specific for tumor imaging.
  
  
  OBJECTIVE
  The present study was conducted to radiolabel doxorubicin with Technetium-99m ([99m]Tc) as a scintigraphic marker of high DNA turnover/intercalation in malignant cells.
  
  
  METHODS
  Labeling was done by direct method and the developed radiotracer was subjected to quality control tests. The blood kinetics, scintigraphy of tumor-bearing mice, and biodistribution were studied after intravenous injection of about 7.4 MBq of [99m]Tc-doxorubicin. The isotime (5 minutes) anterior images were acquired at different time intervals of 1.5, 3, and 4 hours.
  
  
  RESULTS
  The labeling efficiency of [99m]Tc-doxorubicin was estimated to be more than 95%. The protein-binding efficiency was greater than 88% and in vitro stability was up to 24 hours. The biodistribution data support the clearance of the radioligand by dual (renal and hepatic) pathways. A semiquantitative data analysis of the anterior images indicated that a focal concentration of the radiotracer was seen in the tumor at 1.5 hours, which persisted in 3-hour and 4-hour images, respectively.
  
  
  CONCLUSIONS
  This scintigraphic approach, therefore, could be a powerful tool for cancer detection at early stage. The technique, however, needs further validation through animal experimentation and clinical studies.
authors.affiliation: Department of Nuclear Medicine and PET, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Pardeep
authors.initials: P
authors.lastname: Kumar
authors.forename: Baljinder
authors.initials: B
authors.lastname: Singh
authors.forename: Sarika
authors.initials: S
authors.lastname: Sharma
authors.forename: Anchal
authors.initials: A
authors.lastname: Ghai
authors.forename: Krishna
authors.initials: K
authors.lastname: Chuttani
authors.forename: Anil K
authors.initials: AK
authors.lastname: Mishra
authors.forename: Devinder
authors.initials: D
authors.lastname: Dhawan
authors.forename: Bhagwant R
authors.initials: BR
authors.lastname: Mittal
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000627:therapeutic use*; D002286:Carcinoma, Ehrlich Tumor / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D004317:Doxorubicin / Q000627:therapeutic use*; D008657:Metabolic Clearance Rate; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013667:Technetium; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
chemical_list: D000903:Antibiotics, Antineoplastic; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013667:Technetium; D004317:Doxorubicin