BACKGROUND: Postoperative routine radioiodine (RAI) treatment is currently debated for patients with low-risk differentiated thyroid carcinoma (DTC) patients. If performed, a low 131I activity (i.e., 1 to 2 GBq) is recommended with the aim to ablate thyroid remnant and facilitate subsequent follow-up by thyroglobulin measurement. The purpose of this study was to evaluate the relationship between postsurgical technetium-99m (99mTc)-pertechnetate scintigraphy and the rate of successful remnant ablation after low activity radioiodine ablation in patients with DTC. METHODS: Enrolled were 193 patients with low risk DTC who underwent total thyroidectomy and RAI ablation with a fixed 1.1 GBq activity of 131I. 99mTc-pertechnetate scans were done and thyrotropin stimulated thyroglobulin (sTg) levels measured just before ablation. Ablation effectiveness was assessed 6 to 12 months later by sTg measurement, neck ultrasound and diagnostic whole body scan. RESULTS: A negative 99mTc-perthecnetate scans was the best predictor of successful ablation (P<0.001) followed by preablative sTg levels <0.8 ng/mL (P=0.008) and 99mTc-pertechnetate uptake rate values <0.9% (P=0.065). Neither sex nor age of the patient at the time of ablation or tumor histology and size showed a significant association with the rate of successful ablation. CONCLUSION: The 99mTc-pertechnetate scintigraphy is a simple and feasible tool to predict effectiveness of low activity 131I thyroid to ablate thyroid remnants in patients with DTC.
Follow-Up Studies ; Humans ; Neck ; Radionuclide Imaging ; Sodium Pertechnetate Tc 99m ; Thyroglobulin ; Thyroid Gland ; Thyroid Neoplasms ; Thyroidectomy ; Thyrotropin ; Ultrasonography ; Whole Body Imaging

The foundations of nuclear medicine in Vietnam were established from 1970. Until now, after 48 years of development, in Vietnam, we have some basic equipment including 31 SPECT, 4 SPECT/CT machines, 11 PET/CT scanners, five cyclotrons, and one nuclear reactor.Many nuclearmedicine techniques in diagnosis and treatment have been routinely performed at provincial and central level health facilities such as tumor scintigraphy, thyroid scintigraphy, bone scintigraphy, kidney scintigraphy, cardiac scintigraphy, and radio-isotope therapy with I-131 and P-32. Selective internal radiation therapy with Y-90 microsphere and I-125 radioactive seed implantation has been also successfully applied in some big hospitals. However, there are still many difficulties for Vietnam as the lack of new widely used radioisotopes such as Ga-67, Cu-64, Samarium-153, and Lutetium-177 and the lack of nuclear medicine specialists. In the future, we are putting our efforts on the applications of new isotopes in diagnosis and treatment of cancers (theranostic) like Ga-68-DOTATATE, Lutetium-177-DOTATATE, Ga-68-PSMA, and Lutetium-177-PSMA, equipping modern nuclear medicine diagnostic tools, strengthening the human resources training in nuclear medicine. At the same time, we are trying our best to strengthen the cooperation with international nuclear medicine societies in over the world.
Cyclotrons ; Diagnosis ; Foundations ; Health Facilities ; Humans ; Isotopes ; Kidney ; Microspheres ; Nuclear Medicine ; Positron-Emission Tomography and Computed Tomography ; Radioisotopes ; Radionuclide Imaging ; Specialization ; Theranostic Nanomedicine ; Thyroid Gland ; Tomography, Emission-Computed, Single-Photon ; Vietnam

Single-photon emission computed tomography/computed tomography (SPECT/CT) is an already established nuclear imaging modality. Co-registration of functional information (SPECT) with anatomical images (CT) paved the way to the wider application of SPECT. Recent advancements in quantitative SPECT/CT have made it possible to incorporate quantitative parameters, such as standardized uptake value (SUV) or %injected dose (%ID), in gamma camera imaging. This is indeed a paradigm shift in gamma camera imaging from qualitative to quantitative evaluation. In fact, such quantitative approaches of nuclear imaging have only been accomplished for positron emission tomography (PET) technology. Attenuation correction, scatter correction, and resolution recovery are the three main features that enabled quantitative SPECT/CT. Further technical improvements are being achieved for partial-volume correction, motion correction, and dead-time correction. The reported clinical applications for quantitative SPECT/CT are mainly related to Tc-99m-labeled radiopharmaceuticals: Tc-99m diphosphonate for bone/joint diseases, Tc-99m pertechnetate for thyroid function, and Tc-99m diethylenetriaminepentaacetic acid for measurement of glomerular filtration rate. Dosimetry before trans-arterial radio-embolization is also a promising application for Tc-99m macro-aggregated albumin. In this review, clinical applications of Tc-99m quantitative SPECT/CT will be discussed.
Evaluation Studies as Topic ; Gamma Cameras ; Glomerular Filtration Rate ; Positron-Emission Tomography ; Radionuclide Imaging ; Radiopharmaceuticals ; Sodium Pertechnetate Tc 99m ; Thyroid Gland ; Tomography, Emission-Computed, Single-Photon

Planar scintigraphy using Tc-99mpertechnetate is useful for snapshot evaluation of hot thyroid nodules, which are pathologically follicular adenoma and seldom, if ever, malignant. The autonomy of the hot nodules has been demonstrated by the presence of thyroid-stimulating hormone-dependent extra-nodular thyroid tissue besides the hot nodules. Here, we present two cases of hot thyroid nodules in patients who underwent quantitative single-photon emission computed tomography/computed tomography (SPECT/CT). In addition to the nodules, contralateral normal thyroid parenchyma was evaluated based on standardized uptake values. One patient had a traditional follicular adenoma suppressing other thyroid tissue, whereas the other patient seemed to have a nodule erupting from underlying hyperfunctioning, not suppressed, thyroid tissue. This novel approach using quantitative SPECT/CT unveils a new pathology of hot thyroid nodule that does not suppress, but coincides with hyperfunctioning thyroid tissue.
Adenoma ; Humans ; Pathology ; Radionuclide Imaging ; Sodium Pertechnetate Tc 99m ; Thyroid Gland ; Thyroid Nodule

Viral infections are known to be a predisposing factor for subacute (De Quervain's) thyroiditis. In this report, we document a novel case of thyroiditis, with an atypical presentation, following an influenza B infection. A 13-year-old previously healthy female visited the outpatient clinic complaining of right neck pain. She had been diagnosed with an influenza B infection at a local clinic 3 weeks earlier. All laboratory tests were normal. A thyroid ultrasound showed an ill-defined hypoechoic mass (1.0×0.5×1.5 cm) in the right lower thyroid, and scintigraphy of the thyroid with Technetium-99m (99m-Tc) demonstrated the normal uptake of the radiotracer. Fine-needle aspiration from the nodule showed the presence of a few neutrophils. To the best of our knowledge, this is the first case of atypical thyroiditis associated with an influenza B infection described in the literature. Influenza B infection should be considered as a possible cause of atypical thyroiditis.
Adolescent ; Ambulatory Care Facilities ; Biopsy, Fine-Needle ; Causality ; Female ; Humans ; Influenza, Human* ; Neck Pain ; Neutrophils ; Radionuclide Imaging ; Thyroid Gland* ; Thyroiditis* ; Ultrasonography

PURPOSE: Parathyroid adenoma detection with dual-phase (99m)Tc-sestamibi (MIBI) scintigraphy depends on differential MIBI washout from thyroid. However, autoimmune thyroid disease (AITD) may cause MIBI to be retained in the thyroid gland and reduce parathyroid detection.We evaluated the impact of AITD on MIBI thyroid retention and additional benefit of SPECT/CT in these patients.METHODS: Dual phase planar MIBI and SPECT/CT was performed on 82 patients. SPECT/CTwas performed immediatelyafter delayed planar scan. Thyroid density (Hounsfield unit, CT-HU) and size were measured on CT component of SPECT/CT. MIBI uptake in early scans and retention in delayed scans were visually graded and correlated with clinical factors and CT findings. Finally, planar and SPECT/CT findings were compared for parathyroid lesion visualization according to thyroid MIBI retention.RESULTS: In early scan, multivariate analysis showed only thyroid size predicted early uptake. In delayed scan, multivariate analysis showed higher visual grade in early scan, lower CTHU or AITD were significant predictors for delayed thyroid parenchymal retention. Overall, ten more parathyroid lesions were visualized on SPECT/CT compared to planar scans (57 vs. 47, p = 0.002). SPECT/CT was especially more useful in patients with thyroidal MIBI retention, as eight out of the ten additional lesions detected were found in patients with thyroid MIBI retention.CONCLUSION: AITD is an important factor for MIBI thyroid parenchymal retention on delayed scans, and may impede parathyroid lesion detection. Patients with MIBI retention in the thyroid parenchyma on delayed scans are likely to benefit from an additional SPECT/CT.
Humans ; Multivariate Analysis ; Parathyroid Neoplasms ; Radionuclide Imaging ; Thyroid Diseases ; Thyroid Gland

PURPOSE: Although Sjögren's syndrome (SS) is the most common disease causing xerostomia, autoimmune thyroid diseases can also affect the salivary glands. The aim of our study was to estimate the prevalence of thyroid diseases (TD) in subjects with symptoms of xerostomia and evaluate the efficacy of salivary gland scintigraphy (SGS) in the detection of TD in patients with SS and without SS.METHODS: We retrospectively reviewed the SGS findings of 173 subjects (men:women, 29:144) with symptoms of xerostomia. Ejection fractions (EF) in the parotid and submandibular glands were calculated. Thyroid disease was diagnosed on the basis of the results of the visual assessment of tracer uptake in the thyroid gland on SGS images as well as serological thyroid function tests.RESULTS: Based on the American-European Criteria, 94 patients were diagnosed with SS. Hashimoto's thyroiditis was diagnosed in 63 patients, subacute thyroiditis in 23, subclinical hypothyroidism in five, and Graves' disease in one. There were significant differences in the EF values of the parotid and submandibular glands between patients with TD and those with undetermined diagnoses.CONCLUSIONS: More than half of patients with xerostomia exhibited TD. Thyroid assessment by SGS is feasible, and SGS appears to be useful for the patients with xerostomia caused by TD. SGS may be the first imaging modality capable of evaluating both salivary gland function and thyroid gland status in patients with xerostomia. This strategy would make the requirement for additional workup for thyroid disease.
Diagnosis ; Graves Disease ; Humans ; Hypothyroidism ; Prevalence ; Radionuclide Imaging ; Retrospective Studies ; Salivary Glands ; Submandibular Gland ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland ; Thyroiditis ; Thyroiditis, Subacute ; Xerostomia

Single-photon emission computed tomography with integrated computed tomography (SPECT/CT) systems has been applied in a wide range of clinical circumstances, and differentiated thyroid cancer (DTC) is one of the most important indications of SPECT/CT imaging. In the treatment of DTC, SPECT/CT images have been reported to have many advantages over conventional planar whole-body scintigraphy based on its precise localization and characterization of abnormal foci of radioactive iodine (RAI) accumulation, influencing the staging, risk stratification, and clinical management as well as reader confidence. On the other hand, SPECT/CT has limitations including additional radiation exposure from the CT component, additional imaging time, and cost-related issues. Each SPECT/CT image acquired at different time points throughout the management of DTC may have a different clinical meaning and significance. This review article addresses the clinical usefulness of RAI SPECT/CT images acquired during the pre-ablation period, post-therapy period, and long-term follow-up period, respectively.
Follow-Up Studies ; Hand ; Iodine ; Radiation Exposure ; Radionuclide Imaging ; Thyroid Gland ; Thyroid Neoplasms ; Tomography, Emission-Computed

We report a case of a 74-year-old woman who was incidentally found to have a single thyroid nodule. Laboratory evaluation showed undetectable serum thyroid stimulating hormone and elevated free thyroxine levels. (99m)Tc thyroid scan showed a hyperfunctioning autonomous nodule in a right lobe of the thyroid. Thyroid ultrasonography showed a 2.2 cm sized nonhomogeneous spiculated nodule with microcalcification, and which was identical with the hyperfunctioning nodule confirmed in thyroid scan by (99m)Tc single photon emission computed tomography/computed tomography. Fine needle aspiration was done, and cytology reported as suspicious of malignancy. The patient underwent total thyroidectomy with central neck dissection, and pathology was consistent with papillary thyroid carcinoma. This case report demonstrates that diagnosis of a hyperfunctioning autonomous thyroid nodule does not preclude the possibility of thyroid cancer. Clinicians should consider further evaluation such as ultrasonography and fine needle aspiration in patients with hyperfunctioning autonomous nodules.
Aged ; Biopsy, Fine-Needle ; Diagnosis ; Female ; Humans ; Hyperthyroidism* ; Neck Dissection ; Pathology ; Radionuclide Imaging ; Thyroid Gland* ; Thyroid Neoplasms* ; Thyroid Nodule ; Thyroidectomy ; Thyrotropin ; Thyroxine ; Ultrasonography

BACKGROUND AND OBJECTIVES: Autoimmune thyroiditis (AIT) is a form of thyroiditis associated with autoimmune antibodies. Few studies have measured thyroid volume in Asians. This study was undertaken to determine the distribution of thyroid volume and to explore possible correlations between thyroid volume and other factors in a Korean cohort. MATERIALS AND METHODS: Two hundred eleven patients who underwent (99m)Tc-pertechnetate thyroid scintigraphy between 2009 and 2011 were recruited and their thyroid volume was measured. AIT was defined as having thyroperoxidase antibody (TPOAb) and/or thyroglobulin antibody (TgAb) positivity and TRAb negativity, regardless of thyroid function. RESULTS: The mean thyroid volume was 32.1 mL in AIT patients. The distribution of thyroid volume was normal after log transformation. Thyroid volume was larger in patients with both autoantibodies than in patients with only one antibody (p<0.001). The first quartile of patients grouped according to thyroid volume were older (52.1 years, p=0.037) than the patients in other quartile groups. Thyroid volume correlated independently with TPOAb titer, and TgAb titer adjusted for other factors in a multivariate analysis. CONCLUSION: Thyroid volume in Korean AIT patients had an unimodal distribution and correlated with autoantibody titer.
Antibodies ; Asian Continental Ancestry Group ; Autoantibodies ; Cohort Studies ; Humans ; Multivariate Analysis ; Radionuclide Imaging* ; Thyroglobulin ; Thyroid Gland* ; Thyroiditis ; Thyroiditis, Autoimmune*