Highlights
- •Patients treated for differentiated thyroid cancer with different activities.
- •Significant differences in the fractional uptake and effective half-life.
- •No significant differences in the remnant time-integrated activity.
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 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.
Keywords
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References
- The SNMMI practice guideline for therapy of thyroid disease with 131I 3.0.J Nucl Med. 2012; 53: 1633-1651
- Guidelines for radioiodine therapy of differentiated thyroid cancer.Eur J Nucl Med Mol Imaging. 2008; 35: 1941-1959
- Radioiodine treatment after surgery for differentiated thyroid cancer: a reasonable option.Eur J Nucl Med Mol Imaging. 2017; 44: 918-925
- Management of thyroid cancer and related nodular disease.Springer-Verlag, London2006
- Radioiodine therapy for well-differentiated thyroid cancer: a quantitative dosimetric evaluation for remnant thyroid ablation after surgery.J Nucl Med. 1994; 35: 1944-1950
- Statistical and radiobiological analysis of the so-called thyroid stunning.EJNMMI Res. 2015; 5: 67https://doi.org/10.1186/s13550-015-0144-9
- Self-stunning in thyroid ablation: evidence from comparative studies of diagnostic 131I and 123I.Eur J Nucl Med. 2002; 29: 783-788https://doi.org/10.1007/s00259-002-0785-6
- The so-called stunning of thyroid.J Nucl Med. 2006; 47: 1406-1412
- TNM classification of malignant tumors.7th ed. Wiley-Blackwell, New York2009
International Atomic Energy Agency. Release of patients after radionuclide therapy. Safety Report Series No. 63, IAEA. Vienna. 2009.
Rasband WS, ImageJ, U. S. National Institutes of Health, Bethesda, Maryland, USA, https://imagej.nih.gov/ij/, 1997-2016.
- Whole-remnant and maximum-voxel SPECT/CT dosimetry in 131I-NaI treatments of differentiated thyroid cancer.Med Phys. 2016; 43: 5279-5287
- A dose-effect correlation for radioiodine ablation in differentiated thyroid cancer.Eur J Nucl Med Mol Imaging. 2010; 37: 270-275
- Impact of 131I diagnostic activities on the biokinetics of thyroid remnants.J Nucl Med. 2004; 45: 619-625
- Optimized 124I PET dosimetry protocol for radioiodine therapy of differentiated thyroid cancer.J Nucl Med. 2008; 49: 1017-1023
- 124I PET/CT in patients with differentiated thyroid cancer: clinical and quantitative image analysis.Thyroid. 2016; 26: 441-448
R Core Team (2014). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.URL http://www.R-project.org/. 2014.
- Thyroid disease in adults.Springer-Verlag, Berlin Heidelberg2011
- Iodine biokinetics and dosimetry in radioiodine therapy of thyroid cancer: procedures and results of a prospective international controlled study of ablation after rhTSH or hormone withdrawal.J Nucl Med. 2006; 47: 648-654
- Radiation-dose assessment in radioiodine therapy—doseresponse relationships in differentiated thyroid-carcinoma using quantitative scanning and PET.Radiother Oncol. 1993; 28: 16-26
- Relation between effective radiation dose and outcome of radioiodine therapy for thyroid cancer.N Engl J Med. 1983; 309: 937-941
- Radioiodine-131 therapy for well-differentiated thyroid cancer–a quantitative radiation dosimetric approach: outcome and validation in 85 patients.J Nucl Med. 1992; 33: 1132-1136
- MIRD pamphlet No. 24: guidelines for quantitative 131I SPECT in dosimetry applications.J NucI Med. 2013; 12: 2182-2188
- 131I activity for remnant ablation in patients with differentiated thyroid cancer: a systematic review.J Clin Endocrin Metab. 2007; 92: 28-38
- Low vs. high radioiodine activity to ablate the thyroid after thyroidectomy for cancer: a randomized study.PLoS ONE. 2008; 3e1885https://doi.org/10.1371/journal.pone.0001885
- Ablation with low-dose radioiodine and thyrotropin alfa in thyroid cancer.N Engl J Med. 2012; 366: 1674-1685
- Post-surgical thyroid ablation with low or high radioiodine activities results in similar outcomes in intermediate risk differentiated thyroid cancer patients.Eur J Endocrinol. 2013; 169: 23-29
- Low- or high-dose radioiodine remnant ablation for differentiated thyroid carcinoma: a meta-analysis.J Clin Endocrinol Metab. 2013; 98: 1353-1360
- High versus low radioiodine activity in patients with differentiated thyroid cancer: a meta-analysis.Acta Oncol. 2013; 52: 1055-1061
- Dose-response relationship in differentiated thyroid cancer patients undergoing radioiodine treatment assessed by means of 124I PET/CT.J Nucl Med. 2016; 57: 1027-1032
Article info
Publication history
Published online: August 29, 2019
Accepted:
August 23,
2019
Received in revised form:
August 21,
2019
Received:
April 3,
2019
Identification
Copyright
© 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
