Analysis of Residence Time, Effective Half-Life, and Internal Dosimetry Before Radioiodine Therapy.

Autor: Oliveira CV; Federal Institute of Education, Science, and Technology of Santa Catarina, Florianópolis, Santa Catarina, Brazil., Camozzato TSC; Federal Institute of Education, Science, and Technology of Santa Catarina, Florianópolis, Santa Catarina, Brazil tatiane@ifsc.edu.br., Dorow PF; Federal Institute of Education, Science, and Technology of Santa Catarina, Florianópolis, Santa Catarina, Brazil., Pasqueta J; Federal Institute of Education, Science, and Technology of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
Jazyk: angličtina
Zdroj: Journal of nuclear medicine technology [J Nucl Med Technol] 2022 Sep; Vol. 50 (3), pp. 233-239. Date of Electronic Publication: 2022 Jun 14.
DOI: 10.2967/jnmt.121.263502
Abstrakt: Radioiodine therapy has been widely used for ablation of remnant tissue after surgical treatment of differentiated thyroid carcinoma (DTC). Internal dosimetry provides a new approach to choosing the administered activity-an approach that considers the distribution and retention of 131 I individually per patient. This study used clinical techniques of internal dosimetry to assess the accumulated activity, internal bone marrow dosimetry, and effective half-life in patients undergoing treatment for DTC. Methods: This was a quantitative, retrospective study analyzing diagnostic documents and images. The internal dosimetry method calculated the dose absorbed by the bone marrow per administered activity of 131 I. Calculation of the absorbed dose took into account the accumulated activity, which was obtained through measurements of whole-body images acquired at 4 intervals over 5 d. Results: The median dose absorbed by the bone marrow per administered activity was 0.117 mGy/MBq (range, 0.043-0.152 mGy/MBq). The median whole-body residence time was 22.0 h (range, 12.6-39.4 h). The median effective half-life was 15.6 h (range, 7.6-28.2 h). Conclusion: Internal dosimetry provides information relevant to safe dose limits for DTC radioiodine therapy, especially in advanced cases of the disease for which greater activities may be necessary.
(© 2022 by the Society of Nuclear Medicine and Molecular Imaging.)
Databáze: MEDLINE