Thyroid imaging agents: a comparison of I-123 and Tc-99m pertechnetate.

Sixteen patients with nonsuppressible solitary hot thyroid lesions (SHTL) identified on T3 suppression images using Tc-99m sodium pertechnetate were studied over a period of 5 years. Of the 16 patients, 7 (44%) had papillary adenocarcinoma (PAC) and 9 (56%) had follicular adenoma (FA). Of the 7 patients with PAC, 3 were toxic and 4 nontoxic. Of the 9 patients with FA, 2 were toxic and 7 nontoxic. The Tl-201 chloride thyroid scans were useful in locating SHTL and revealing extranodular thyroid tissue. The echography was sensitive to visualization of the nodule structures. However, there were no significant differences between the clinical findings, radionuclide images, and echograms between for PAC and FA. All patients with PAC were treated by partial thyroidectomy and there were neither regional nor distant metastasis in any of them. In conclusion, our study provided the following extremely interesting result: SHTL in the present series have a higher incidence of malignancy than previously reported autonomously functioning thyroid lesions (AFTL). Histological examination is necessary for the diagnosis and management of SHTL and surgical treatment should be considered.

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“…The I-123 thyroid scans were also performed on 3 patients (Pt. 6,9,16). These images showed warm lesions similar to those on the Tc-99m scans.…”

Section: Resultsmentioning

confidence: 54%

Thyroid carcinoma m solitary hot thyroid lesions on Tc-99m sodium pertechnetate scans

et al. 1989

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“…Both 123 I (half-life [T 1/2 ] 5 13.13 h) and 131 I (T 1/2 5 8.02 d) are true iodine imaging radiotracers but have longer half-lives than required for a diagnostic study, which result in an unnecessarily high dose of irradiation to patients and staff. 99m Tc-pertechnetate (T 1/2 5 6 h) has found use as a radioiodine analog in thyroid diseases (7,8) and has suitable properties for SPECT. Nevertheless, SPECT has limited resolution and sensitivity, especially in detection of small metastases and low-volume diseases.…”

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confidence: 99%

Synthesis of ¹⁸F-Tetrafluoroborate via Radiofluorination of Boron Trifluoride and Evaluation in a Murine C6-Glioma Tumor Model

et al. 2016

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“…The discrepant results can be explained by the differences in kinetics and metabolism of I-131 and Tc-99m-O 4 -as well as possibly changes in the thyrocytes on molecular level (changes in NIS expression, defects in iodine integration in organic compounds) [19]. Tc-99m-O 4 -uptake reaches a peak after approximately 20 minutes, after which it decreases.…”

Section: Discussion Of Resultsmentioning

confidence: 95%

“…In the Tc-99m-O 4 -scintigram, the activity in the vessels and in the soft tissue of the neck is recorded as well as the activity in the thyrocytes. The varying kinetics of I-131 and Tc-99m-O 4 -and different molecular changes appear to have an in luence on the uptake in the autonomous thyroid areas [6,[19][20][21].…”

Section: Discussion Of Resultsmentioning

confidence: 99%

New Approach for Analysing the Discrepancy of Pretherapeutic Tc-99m and Intra-therapeutic I-131 uptake in Scintigraphies of Thyroid Autonomies using a Parametric 3D Analysis Programs

Zuhayra¹

2017

J Radiol Oncol

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Introduction: Radioiodine therapy is a standard procedure in thyroid autonomy treatment. Discrepancies in the visual comparisons of the scintigraphies prepared for this purpose using Tc-99m-O 4 -and I-131 have been known for years. In this study a new method is used to calculate and perform a quantitative comparison of both uptakes using subtraction analysis and 3D imaging. The results and their causes are discussed together with practice-relevant conclusions for better clinical results. Material and Methods:The new method was used in 38 patients with thyroid autonomies for the subtraction analysis of standardized pretherapeutic and intratherapeutic scintigraphies. The parametric distribution of activity was calculated absolutely and as a percentage and displayed three-dimensionally. These results were compared with the visual assessment of the different scintigraphies by the experts. Inclusion criteria were pretherapeutic and intratherapeutic hyperthyroidism without medication affecting the thyroid. The time difference between acquiring the scintigraphies was 28 days maximum.Results: Activity distribution was visually discrepant in 39.5% of cases. 60.5% displayed comparable uptake. The calculated values showed reversed results after applying the new method. The results using our method show a higher rate of calculated discrepancies compared with visual analysis. Conclusion: Accurate functional imaging of the thyroid is next to further aspects very important inestablishing the diagnosis and deciding about the therapy activity for thyroid treatment. In combination with clinical symptoms and laboratory values, Tc-99m-O 4 -scintigram can be used for an orientated, preliminary assessment of functional disorders of the thyroid. But because of the higher rate of found discrepancies, the solely use of Tc-99m-O 4 -scintigram is not always capable for exact and reliable diagnosis. The known reason for this is most probably due to the different biokinetics of both radiopharmaceuticals, which can be imaged more sensitively with this method. Consequently, a scintigram should be performed in the pretherapeutic radioiodine uptake test. Despite higher costs and radiation exposure, alternatively, pretherapeutic use of other diagnostic iodine isotopes like I-123 or -124 should be discussed, because they could overcome the limitation of the different biokinetics. Following this approach the preliminary assessment using Tc-99m-O 4 -scintigraphy can be precised and double checked to improve diagnostic confi dence and treatment results for a better outcome of the patients.

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Thyroid imaging agents: a comparison of I-123 and Tc-99m pertechnetate.

Cited by 40 publications

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Thyroid carcinoma m solitary hot thyroid lesions on Tc-99m sodium pertechnetate scans

Thyroid carcinoma m solitary hot thyroid lesions on Tc-99m sodium pertechnetate scans

Synthesis of ¹⁸F-Tetrafluoroborate via Radiofluorination of Boron Trifluoride and Evaluation in a Murine C6-Glioma Tumor Model

New Approach for Analysing the Discrepancy of Pretherapeutic Tc-99m and Intra-therapeutic I-131 uptake in Scintigraphies of Thyroid Autonomies using a Parametric 3D Analysis Programs

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Thyroid imaging agents: a comparison of I-123 and Tc-99m pertechnetate.

Cited by 40 publications

References 0 publications

Thyroid carcinoma m solitary hot thyroid lesions on Tc-99m sodium pertechnetate scans

Thyroid carcinoma m solitary hot thyroid lesions on Tc-99m sodium pertechnetate scans

Synthesis of 18F-Tetrafluoroborate via Radiofluorination of Boron Trifluoride and Evaluation in a Murine C6-Glioma Tumor Model

New Approach for Analysing the Discrepancy of Pretherapeutic Tc-99m and Intra-therapeutic I-131 uptake in Scintigraphies of Thyroid Autonomies using a Parametric 3D Analysis Programs

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Synthesis of ¹⁸F-Tetrafluoroborate via Radiofluorination of Boron Trifluoride and Evaluation in a Murine C6-Glioma Tumor Model