title: Biological dosimetry and Bayesian analysis of chromosomal damage in thyroid cancer patients.
abstract: Chromosomal damage was investigated in lymphocytes of thyroid cancer patients after radioiodine treatment. An assay on micronuclei (MN) in binucleated cells was performed in blood samples of 25 patients 3 d after (131)I (3.7 GBq) was given. Statistical analysis does not show overdispersion of the MN distribution, thus considering the exposure to blood as being homogeneous (p < 0.05). A dose-protraction factor (G) of 0.1 was considered into the calculation of the blood dose to take into account the effect of the duration of exposure. The total MN count is a sum of the background distribution and the Poisson distribution induced by radiation exposure. A Bayesian approach was used to avoid inconsistencies when the total count was close to or lower than the background level. Estimated blood dose after 3 d of exposure was 0.73 Gy (0.197 mGy/MBq). The usefulness of the Bayesian method in analysing chromosomal damage when the count is low has been determined.
authors.affiliation: Medical Physics and Radiation Protection, Hospital Virgen de la Arrixaca, El Palmar, Murcia, Spain.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Serna
authors.forename: Miguel
authors.initials: M
authors.lastname: Alcaraz
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Navarro
authors.forename: Cristina
authors.initials: C
authors.lastname: Acevedo
authors.forename: Vicente
authors.initials: V
authors.lastname: Vicente
authors.forename: Manuel
authors.initials: M
authors.lastname: Canteras
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000235:genetics / Q000532:radiotherapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D001499:Bayes Theorem; D018276:Carcinoma, Medullary / Q000235:genetics / Q000532:radiotherapy; D002291:Carcinoma, Papillary / Q000235:genetics / Q000532:radiotherapy; D002478:Cells, Cultured; D002648:Child; D002869:Chromosome Aberrations / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008214:Lymphocytes / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D011874:Radiometry / Q000295:instrumentation*; D012062:Relative Biological Effectiveness; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000532:radiotherapy*
chemical_list: D007457:Iodine Radioisotopes