Thyroid Uptake and Effective Half-Life of Radioiodine in Thyroid Cancer Patients at Radioiodine Therapy and Follow-Up Whole-Body Scintigraphy Either in Hypothyroidism or Under rhTSH

6606 Background: In thyroid cancer patients, follow-up is designed to detect recurrent disease and consists of neck- ultrasonography (US), thyroglobulin measurement (Tg) and radioiodine whole body scan (WBS). Recent guidelines have restricted the use of WBS to suspicious cases. To insure diagnostic accuracy, follow-up control requires TSH stimulation, either with thyroid hormone withdrawal (THW) or rhTSH, which have demonstrated similar diagnostic accuracy. THW induces significant morbidity associated with hypothyroidism, leading to a decrease in patient quality of life and ability to work, whereas rhTSH is an innovative costly drug that avoids such patient burden. A societal cost-utility analysis was conducted to compare 4 follow-up strategies, combining a method of stimulation (rhTSH or THW) and a testing protocol (US+Tg+WBS or US+Tg alone). Methods: A Markov model was built to describe the follow-up of thyroid cancer patients first treated by thyroidectomy and radioiodine ablation, over 5 years. Estimates for diagnostic accuracy values and recurrence rate were extracted from a French multicenter randomized trial. Costs were computed from the perspective of the society, including medical resources consumed (hospitalisation, rhTSH, tests, treatment of recurrence). The model also incorporated the benefits of rhTSH in terms of quality of life (utility scores derived from SF36) and the reduction in duration and overall cost of sick leave. Results: Among the 753 patients included, 13 patients presented recurrence. rhTSH stimulation resulted in a higher utility score (0.802 vs. 0.637) over the period of stimulation and a reduction of 1083 € of absenteeism costs in active patients. As compared to the THW+Tg+US+WBS strategy, the incremental cost-utility ratios (ICER) showed economic dominance for the rhTSH strategies with ratios of −16,876 and −19,297 €/QALY with and without WBS respectively. The ICER for the strategy THW+US+Tg reached 29,333 €/QALY, as compared to THW+Tg+US+WBS strategy. Conclusions: the recommended strategy combining Tg determination and US after rhTSH stimulation appears the most cost-effective in the follow-up of thyroid cancer patients, as it is the strategy the less costly and associated with improved patient quality of life. No significant financial relationships to disclose.

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The significance of clinic-diagnostic factors in the course of estimation of side exposure of differentiated thyroid cancer patients after radioiodine therapy

Radiation and Risk Bulletin of the National Radiation and Epidemiological Registry ◽

10.21870/0131-3878-2021-30-2-101-112 ◽

2021 ◽

Vol 30 (2) ◽

pp. 101-112

Author(s):

I.K. Khvostunov ◽

◽

V.V. Krylov ◽

A.A. Rodichev ◽

N.N. Shepel ◽

...

Keyword(s):

Thyroid Cancer ◽

Cancer Patients ◽

Chromosomal Aberrations ◽

Radionuclide Therapy ◽

Time Course ◽

Differentiated Thyroid Cancer ◽

Radioiodine Therapy ◽

Individual Characteristics ◽

Internal Exposure ◽

Whole Body

The radioiodine therapy is the most well-known branch of radionuclide therapy. The therapy composed of thyroidectomy and iodine-131 radiopharmaceutical is the “gold standard” for treat-ment of differentiated thyroid cancer patients (DTC). Given metastases in lymph nodes such therapy is absolutely exclusive treatment mode. At the same time, despite the targeted effect of radioiodine on pathological foci a side internal exposure of healthy organs and tissues is noted in the course of radioiodine therapy. Therefore, a reliable assessment of the side exposure is nec-essary taking into account the individual characteristics of patients considering that the side dose varies significantly from patient to patient. For this reason, the identification of significance of personal clinic-diagnostic factors determined the side whole body exposure is the vital and im-portant task. In this aspect, the cytogenetic examination of DTC patients by means of the analysis of chromosomal aberrations in peripheral blood lymphocytes is the goal of essential importance. The certain types of chromosomal aberrations are specific radiation markers that unequivocally indicate radiation exposure. Using the frequency of radiation markers the side absorbed dose can be reliably estimated. In the present work, the statistical analysis of the significance of vari-ous clinic-diagnostic factors in relation to the induction of radiation markers in the blood lympho-cytes was performed. For that end the results of the cytogenetic examination of the group com-prised of 38 DTC patients have been used. The examined patients underwent a course of radio-iodine therapy in the department of radionuclide therapy of the A.F. Tsyb MRRC, Obninsk. The slide preparation and cytogenetic analysis were carried out in the laboratory of radiation cytoge-netic of the same Center. The performed analysis of the correlation matrix with respect to the dependence of the increased frequency of stable and unstable markers resulted from a one-time course of radioiodine therapy showed no meaningfulness at the level R>0.3 for all the studied factors. For the absolute value of the frequency of radiation markers, both before and after radioiodine therapy, the meaningful relationship was found at the level R>0.7 for unsta-ble and at the level R>0.8 for stable markers with a total administered activity of radioiodine dur-ing all the previous courses of radioiodine therapy.

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Radioiodine treatment of feline hyperthyroidism in Germany

Nuklearmedizin ◽

10.1055/s-0038-1625296 ◽

2002 ◽

Vol 41 (06) ◽

pp. 245-251 ◽

Cited By ~ 3

Author(s):

M. Knietsch ◽

T. Spillmann ◽

E.-G. Grünbaum ◽

R. Bauer ◽

M. Puille

Keyword(s):

Radiation Exposure ◽

Radiation Protection ◽

Thyroid Function ◽

Radioiodine Therapy ◽

Whole Body ◽

Radioiodine Treatment ◽

Normal Thyroid ◽

Normal Thyroid Function ◽

Body Activity ◽

Thyroid Uptake

SummaryAim: Establishment of radioiodine treatment of feline hyperthyroidism in veterinary routine in accordance with German radiation protection regulations. Patients and methods: 35 cats with proven hyperthyroidism were treated with 131I in a special ward. Thyroid uptake and effective halflife were determined using gammacamera dosimetry. Patients were released when measured whole body activity was below the limit defined in the German “Strahlenschutzverordnung”. Results: 17/20 cats treated with 150 MBq radioiodine and 15/15 cats treated with 250 MBq had normal thyroid function after therapy, normal values for FT3 and FT4 were reached after two and normal TSH levels after three weeks. In 14 cats normal thyroid function was confirmed by controls 3-6 months later. Thyroidal iodine uptake was 24 ± 10%, effective halflife 2.5 ± 0.7 days. Whole body activity <1 MBq was reached 13 ± 4 days after application of 131I. Radiation exposure of cat owners was estimated as 1.97 Sv/MBq for adults. Conclusion: Radioiodine therapy of feline hyper-thyroidism is highly effective and safe. It can easily be performed in accordance with German radiation protection regulations, although this requires hospitalisation for approximately two weeks. Practical considerations on radiation exposure of cat owners do not justify this long interval. Regulations for the veterinary use of radioactive substances similar to existing regulations for medical use in humans are higly desirable.

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Faculty Opinions recommendation of 131I effective half-life and dosimetry in thyroid cancer patients.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1141858.598949 ◽

2009 ◽

Author(s):

Furio Pacini ◽

Stefania Marchisotta

Keyword(s):

Thyroid Cancer ◽

Cancer Patients ◽

Half Life

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Malignant Struma Ovarii with Concurrent Thyroid Cancer: Outcomes during and after Pregnancy

European Thyroid Journal ◽

10.1159/000512735 ◽

2021 ◽

pp. 1-5

Author(s):

Sara Donato ◽

Helder Simões ◽

Valeriano Leite

Keyword(s):

Thyroid Cancer ◽

Thyroid Tissue ◽

Pelvic Mass ◽

Pregnant Patient ◽

Whole Body ◽

Ovarian Teratoma ◽

Struma Ovarii ◽

Pelvic Mri ◽

Biochemical Evidence

Introduction: Struma ovarii (SO) is a rare ovarian teratoma characterized by the presence of thyroid tissue in more than 50% of the tumor. Malignant transformation is rare and the most common associated malignancy is papillary thyroid carcinoma (PTC). Pregnancy may represent a stimulus to differentiated thyroid cancer (DTC) growth in patients with known structural or biochemical evidence of disease, but data about malignant SO evolution during pregnancy are rare. We present the first reported case of a pregnant patient with malignant SO and biochemical evidence of disease. Case Presentation: A previously healthy 35-year-old female diagnosed with a suspicious left pelvic mass on routine ultrasound was submitted to laparoscopic oophorectomy which revealed a malignant SO with areas of PTC. A 15-mm thyroid nodule (Bethesda V in the fine-needle aspiration cytology) was detected by palpation and total thyroidectomy was performed. Histology revealed a 15 mm follicular variant of PTC (T1bNxMx). Subsequently, she received 100 mCi of radioactive iodine therapy (RAIT) with the whole-body scan showing only moderate neck uptake. Her suppressed thyroglobulin (Tg) before RAI was 1.1 ng/mL. She maintained biochemical evidence of disease, with serum Tg levels of 7.6 ng/mL. She got pregnant 14 months after RAIT, and during pregnancy, Tg increased to 21.5 ng/mL. After delivery, Tg decreased to 14 ng/mL but, 6 months later, rose again and reached 31.9 ng/mL on the last follow-up visit. TSH was always suppressed during follow-up. At the time of SO diagnosis, a chest computed tomography scan showed 4 bilateral lung micronodules in the upper lobes which were nonspecific, and 9 months after diagnosis, a pelvic MRI revealed a suspicious cystic nodule located on the oophorectomy bed. These lung and pelvic nodules remained stable during follow-up. Neck ultrasonography, abdominal MRI, and fluorodeoxyglucose-positron emission tomography showed no suspicious lesions. Discussion/Conclusion: As for DTC, pregnancy seems to represent a stimulus to malignant SO growth. This can be caused by the high levels of estrogen during pregnancy that may bind to receptors in malignant cells and/or by the high levels of hCG which is known to stimulate TSH receptors.

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Personalized management of differentiated thyroid cancer in real life – practical guidance from a multidisciplinary panel of experts

Endocrine ◽

10.1007/s12020-020-02418-x ◽

2020 ◽

Vol 70 (2) ◽

pp. 280-291

Author(s):

Alfredo Campennì ◽

Daniele Barbaro ◽

Marco Guzzo ◽

Francesca Capoccetti ◽

Luca Giovanella

Keyword(s):

Nuclear Medicine ◽

Thyroid Cancer ◽

Clinical Practice ◽

Molecular Imaging ◽

Routine Clinical Practice ◽

Whole Body ◽

Neck Ultrasound ◽

Long Term Follow Up

Abstract Purpose The standard of care for differentiated thyroid carcinoma (DTC) includes surgery, risk-adapted postoperative radioiodine therapy (RaIT), individualized thyroid hormone therapy, and follow-up for detection of patients with persistent or recurrent disease. In 2019, the nine Martinique Principles for managing thyroid cancer were developed by the American Thyroid Association, European Association of Nuclear Medicine, Society of Nuclear Medicine and Molecular Imaging, and European Thyroid Association. In this review, we present our clinical practice recommendations with regard to implementing these principles in the diagnosis, treatment, and long-term follow-up of patients with DTC. Methods A multidisciplinary panel of five thyroid cancer experts addressed the implementation of the Martinique Principles in routine clinical practice based on clinical experience and evidence from the literature. Results We provide a suggested approach for the assessment and diagnosis of DTC in routine clinical practice, including the use of neck ultrasound, measurement of serum thyroid-stimulating hormone and calcitonin, fine-needle aspiration, cytology, and molecular imaging. Recommendations for the use of surgery (lobectomy vs. total thyroidectomy) and postoperative RaIT are also provided. Long-term follow-up with neck ultrasound and measurement of serum anti-thyroglobulin antibody and basal/stimulated thyroglobulin is standard, with 123/131I radioiodine diagnostic whole-body scans and 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography suggested in selected patients. Management of metastatic DTC should involve a multidisciplinary team. Conclusions In routine clinical practice, the Martinique Principles should be implemented in order to optimize clinical management/outcomes of patients with DTC.

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