title: Radiosensitivity of human normal and tumoral thyroid cells using fluorescence in situ hybridization and clonogenic survival assay.
abstract: OBJECTIVE
  By using cell survival as a reference, we evaluated the radiosensitivity of human normal and tumoral thyroid cells using of radiation-induced translocations.
  
  
  METHODS
  Tissue samples were obtained from patients undergoing thyroidectomy. Cell cultures were established, irradiated with 60Co, and metaphases painted using commercial whole-chromosome 4 hybridization probe and pancentromeric probe. The clonogenic survival was assessed by conventional colony forming assay.
  
  
  RESULTS
  After irradiation, normal cultured thyroid cells yielded a higher number of translocations than cultures derived from adenomas or thyroid carcinoma. The colony forming assay demonstrated, by way of the mean inactivation dose, a higher survival of thyroid carcinoma and adenoma cells than of normal thyroid cells. This difference between tumoral and nontumoral cells is significant in each method (p = 0.0001), and cannot be explained by apoptosis in irradiated malignant cells. Correlation of the results obtained by both methods is shown by comparing the survival fraction at 2 Gy (SF2) and the percentage of chromosome 4 translocations at 2 Gy.
  
  
  CONCLUSIONS
  These results indicate that the yield of radiation-induced translocations serves as a good and rapid prediction of the intrinsic radiosensitivity of thyroid cells, and that this test could be applied to other tumors.
authors.affiliation: Service de Médecine Nucléaire, Institut Gustave-Roussy, Villejuif, France.
authors.forename: A
authors.initials: A
authors.lastname: Gaussen
authors.forename: J D
authors.initials: JD
authors.lastname: Legal
authors.forename: N
authors.initials: N
authors.lastname: Beron-Gaillard
authors.forename: A
authors.initials: A
authors.lastname: Laplanche
authors.forename: J P
authors.initials: JP
authors.lastname: Travagli
authors.forename: B
authors.initials: B
authors.lastname: Caillou
authors.forename: C
authors.initials: C
authors.lastname: Parmentier
mesh_terms: D000236:Adenoma / Q000235:genetics / Q000473:pathology*; D002277:Carcinoma / Q000235:genetics / Q000473:pathology*; D002470:Cell Survival; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D011836:Radiation Tolerance; D011853:Radiobiology; D013961:Thyroid Gland / Q000166:cytology / Q000528:radiation effects*; D013964:Thyroid Neoplasms / Q000235:genetics / Q000473:pathology*; D014407:Tumor Cells, Cultured / Q000528:radiation effects