Biological dosimetry and Bayesian analysis of chromosomal damage in thyroid cancer patients.
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.
Serna
Alfredo
A
Medical Physics and Radiation Protection, Hospital Virgen de la Arrixaca, El Palmar, Murcia, Spain.
Alcaraz
Miguel
M
Navarro
Jose Luis
JL
Acevedo
Cristina
C
Vicente
Vicente
V
Canteras
Manuel
M
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*
D007457:Iodine Radioisotopes