Cytogenetic and dosimetric effects of 131I in patients with differentiated thyroid carcinoma: comparison between stimulation with rhTSH and thyroid hormone withdrawal treatments

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• 作者：Márcia Augusta da Silva…
• 刊名：Radiation and Environmental Biophysics
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：55
• 期：3
• 页码：317-328
• 全文大小：579 KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics
  Biophysics and Biomedical Physics
  Effects of Radiation and Radiation Protection
  Environmental Physics
  Environmental Computing and Modeling
  Ecosystems
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-2099
• 卷排序：55

文摘

A study directed to the cytogenetic and dosimetric aspects of radionuclides of medical interest is very valuable, both for an accurate evaluation of the dose received by the patients, and consequently of the genetic damage, and for the optimization of therapeutic strategies. Cytogenetic and dosimetric effects of 131I in lymphocytes of thyroidectomized differentiated thyroid cancer (DTC) patients were evaluated through chromosome aberration (CA) technique: Euthyroid patients submitted to recombinant human thyroid-stimulating hormone (rhTSH) therapy (group A) were compared with hypothyroid patients left without levothyroxine treatment (group B). CA analysis was carried out prior to and 24 h, 1 week, 1 month and 1 year after radioiodine administration (4995–7030 MBq) in both groups. An activity–response curve of 131I (0.074–0.740 MBq/mL) was elaborated, comparing dicentric chromosomes in vivo and in vitro in order to estimate the absorbed dose through Monte Carlo simulations. In general, radioiodine therapy induced a higher total CA rate in hypothyroid patients as compared to euthyroid patients. The frequencies of dicentrics obtained in DTC patients 24 h after treatment were equivalent to those induced in vitro (0.2903 ± 0.1005 MBq/mL in group A and 0.2391 ± 0.1019 MBq/mL in group B), corresponding to absorbed doses of 0.65 ± 0.23 Gy and 0.53 ± 0.23 Gy, respectively. The effect on lymphocytes of internal radiation induced by 131I therapy is minimal when based on the frequencies of CA 1 year after the treatment, maintaining a higher quality of life for DTC patients receiving rhTSH-aided therapy.Keywords131IChromosome aberrationRecombinant human thyroid-stimulating hormoneThyroid hormone withdrawalBiological dosimetryDifferentiated thyroid carcinoma