title: [Therapy of malignant ascites in vivo by 211At-labelled microspheres].
abstract: OBJECTIVE
  Determination of the biological effect of the alpha emitter (211)At on cellular level as well as the assessment of dosimetric data in a tumour model in vivo.
  
  
  METHODS
  Transplantation of malignant ascitic cells in mice intraperitoneally and estimation of tumour characteristics (doubling time of the cells, mean survival of the animals following an i.p. application of a defined tumour cell number). (211)At labelled human serum albumin microspheres B-20 (MSP) of varying activity were injected into tumour bearing mice intraperitoneally. The effectiveness of the therapy was evaluated by means of determination of the duration of cell cycle arrest as well as the microscopic analysis of the rate of abnormal mitotic cells due to radiation induced damage. Furthermore, dose dependence of survival was evaluated.
  
  
  RESULTS
  Three days following the intraperitoneally application of 8 x 10(6) tumour cells, 50-600 kBq (211)At-MSP were applied into the abdominal cavity. Considering the volume of ascites at this time and the administered activity, dose calculations were performed. An activity of 50 kBq caused a dose of 0.84 Gy. The increase of radiation induced effect on ascitic tumour cells was correlated with the dose. Between the duration of the cell cycle arrest and the administered activity, a directly proportional correlation was found. The mean survival of non-treated animals was 16.9 +/- 3.7 days. The prolongation of the survival was proportional to the activity administered. Using a dosage of 10 Gy, five animals out of 16 survived.
  
  
  CONCLUSIONS
  Therapy of malignant ascitic cells using (211)At-MSP was effective in vivo. For tumour therapy, the (211)At represents a highly effective alternative to usually applied beta emitters.
authors.affiliation: Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum, Dresden.
authors.forename: J
authors.initials: J
authors.lastname: Bredow
authors.forename: M
authors.initials: M
authors.lastname: Kretzschmar
authors.forename: G
authors.initials: G
authors.lastname: Wunderlich
authors.forename: W
authors.initials: W
authors.lastname: Dörr
authors.forename: T
authors.initials: T
authors.lastname: Pohl
authors.forename: W-G
authors.initials: WG
authors.lastname: Franke
authors.forename: J
authors.initials: J
authors.lastname: Kotzerke
mesh_terms: D000818:Animals; D001246:Astatine / Q000008:administration & dosage / Q000627:therapeutic use*; D002286:Carcinoma, Ehrlich Tumor / Q000532:radiotherapy*; D004195:Disease Models, Animal; D004307:Dose-Response Relationship, Radiation; D004337:Drug Carriers; D005260:Female; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D008863:Microspheres; D012709:Serum Albumin
chemical_list: D004337:Drug Carriers; D012709:Serum Albumin; D001246:Astatine