Analysis of activity uptake, effective half-life and time-integrated activity for low- and high-risk papillary thyroid cancer patients treated with 1.11 GBq and 3.7 GBq of 131I-NaI respectively
(2019) In Physica Medica 65. p.143-149- Abstract
Purpose: To analyse the activity uptakes, effective half-lives and time-integrated activities, of relevance for remnant dosimetry, for patients treated for papillary thyroid cancer (PTC) with a different amount of activity of 131I-NaI. Methods: Fifty patients were included. Of those, 18 patients had low-risk PTC and were treated with 1.11 GBq of 131I-NaI (Group 1), and 32 patients had high-risk PTC and were treated with 3.7 GBq (Group 2). Radioiodine was administered after total thyroidectomy and rhTSH stimulation. Two SPECT/CT scans were performed for each patient to determine the remnant activities and effective half-lives. Results: Significantly higher values (p < 0.05) were obtained for Group 1 for the... (More)
Purpose: To analyse the activity uptakes, effective half-lives and time-integrated activities, of relevance for remnant dosimetry, for patients treated for papillary thyroid cancer (PTC) with a different amount of activity of 131I-NaI. Methods: Fifty patients were included. Of those, 18 patients had low-risk PTC and were treated with 1.11 GBq of 131I-NaI (Group 1), and 32 patients had high-risk PTC and were treated with 3.7 GBq (Group 2). Radioiodine was administered after total thyroidectomy and rhTSH stimulation. Two SPECT/CT scans were performed for each patient to determine the remnant activities and effective half-lives. Results: Significantly higher values (p < 0.05) were obtained for Group 1 for the remnant activity at 7 d (medians 1.4 MBq vs 0.27 MBq), the remnant activity per administered activity at 2 d (0.35% vs 0.09%) and at 7 d (0.13% vs 0.007%), and the effective half-life (93 h vs 40 h). Likewise, the time-integrated activity coefficient was significantly higher for Group 1. The time-integrated activity did not differ significantly between the two groups (p > 0.05). Conclusions: We found a significant difference in the remnant activity per administered activity, the rate of washout from thyroid remnants, and the time-integrated activity coefficient between low-risk PTC patients treated with 1.11 GBq and high-risk PTC patients treated with 3.7 GBq. On the contrary, there was no such difference in the time-integrated activity. If remnant masses were also not statistically different (reasonable assumption for this monocentric study) no difference in time-integrated activity would imply no difference in remnant absorbed dose, of relevance for treatment efficacy and the risks of stochastic effects.
(Less)
- author
- Mínguez, Pablo ; Rodeño, Emilia ; Genollá, José ; Domínguez, Maite ; Expósito, Amaia and Sjögreen Gleisner, Katarina LU
- organization
- publishing date
- 2019
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- I-NaI activity, Differentiated thyroid carcinoma, Dosimetry, Pharmacokinetics, Thyroid remnants
- in
- Physica Medica
- volume
- 65
- pages
- 7 pages
- publisher
- ISTITUTI EDITORIALI E POLGRAFICI INTERNAZIONALI
- external identifiers
-
- pmid:31473501
- scopus:85071388964
- ISSN
- 1120-1797
- DOI
- 10.1016/j.ejmp.2019.08.017
- language
- English
- LU publication?
- yes
- id
- 5e29319b-15b8-4586-a249-b28d9900dce7
- date added to LUP
- 2019-09-09 14:52:07
- date last changed
- 2024-04-30 20:30:33
@article{5e29319b-15b8-4586-a249-b28d9900dce7,
abstract = {{<p>Purpose: To analyse the activity uptakes, effective half-lives and time-integrated activities, of relevance for remnant dosimetry, for patients treated for papillary thyroid cancer (PTC) with a different amount of activity of <sup>131</sup>I-NaI. Methods: Fifty patients were included. Of those, 18 patients had low-risk PTC and were treated with 1.11 GBq of <sup>131</sup>I-NaI (Group 1), and 32 patients had high-risk PTC and were treated with 3.7 GBq (Group 2). Radioiodine was administered after total thyroidectomy and rhTSH stimulation. Two SPECT/CT scans were performed for each patient to determine the remnant activities and effective half-lives. Results: Significantly higher values (p < 0.05) were obtained for Group 1 for the remnant activity at 7 d (medians 1.4 MBq vs 0.27 MBq), the remnant activity per administered activity at 2 d (0.35% vs 0.09%) and at 7 d (0.13% vs 0.007%), and the effective half-life (93 h vs 40 h). Likewise, the time-integrated activity coefficient was significantly higher for Group 1. The time-integrated activity did not differ significantly between the two groups (p > 0.05). Conclusions: We found a significant difference in the remnant activity per administered activity, the rate of washout from thyroid remnants, and the time-integrated activity coefficient between low-risk PTC patients treated with 1.11 GBq and high-risk PTC patients treated with 3.7 GBq. On the contrary, there was no such difference in the time-integrated activity. If remnant masses were also not statistically different (reasonable assumption for this monocentric study) no difference in time-integrated activity would imply no difference in remnant absorbed dose, of relevance for treatment efficacy and the risks of stochastic effects.</p>}},
author = {{Mínguez, Pablo and Rodeño, Emilia and Genollá, José and Domínguez, Maite and Expósito, Amaia and Sjögreen Gleisner, Katarina}},
issn = {{1120-1797}},
keywords = {{I-NaI activity; Differentiated thyroid carcinoma; Dosimetry; Pharmacokinetics; Thyroid remnants}},
language = {{eng}},
pages = {{143--149}},
publisher = {{ISTITUTI EDITORIALI E POLGRAFICI INTERNAZIONALI}},
series = {{Physica Medica}},
title = {{Analysis of activity uptake, effective half-life and time-integrated activity for low- and high-risk papillary thyroid cancer patients treated with 1.11 GBq and 3.7 GBq of <sup>131</sup>I-NaI respectively}},
url = {{http://dx.doi.org/10.1016/j.ejmp.2019.08.017}},
doi = {{10.1016/j.ejmp.2019.08.017}},
volume = {{65}},
year = {{2019}},
}