Introduction: No clear consensus exists as to the optimal timing for conducting whole body scintigraphy (WBS) after radioactive iodine (RAI) therapy for differentiated thyroid carcinoma. Objective: This study aimed to compare the utility of early versus delayed post-therapy WBS in identifying residual lesions and metastases. Methods A systematic review of existing literature was done, yielding 6 observational studies relevant to the subject. Meta-analyses were done comparing lesion detecting rates of early (3-4 days post-RAI) and delayed (7-11 days post-RAI) post-therapy WBS for thyroid remnants and metastases in the lymph nodes, lungs, and bone using a random-effects model with odds ratios (OR) and 95% confidence intervals (CIs). A subgroup analysis was also done relating to the type of collimator used in imaging.
Iodine-131 ; Thyroid Neoplasms ; Iodine Radioisotopes ; Radionuclide Imaging

imaging results and to compare the findings with those obtained using technetium-99m sestamibi (MIBI) scintigraphy and neck ultrasonography (US).MATERIALS AND METHODS: Images of 105 patients with hyperparathyroidism who underwent FCH PET/CT, dual-phase MIBI parathyroid scintigraphy (median interval: 42 days), and neck US were retrospectively analyzed. The gold standard was histopathological findings for 81 patients who underwent parathyroidectomy and clinical follow-up findings in the remaining 24 patients. Sensitivities, positive predictive values (PPVs), and accuracies were calculated for all imaging modalities.RESULTS: Among the 81 patients who underwent parathyroidectomy, either parathyroid adenoma (n = 64), hyperplasia (n = 9), neoplasia (n = 4), or both parathyroid adenoma and hyperplasia (n = 1) were detected, except 3 patients who did not show HPT. Of the 24 (23%) patients who were followed-up without operation, 22 (92%) showed persistent hyperparathyroidism. FCH PET/CT showed significantly higher sensitivity than MIBI scintigraphy and US in detection of HPT (p < 0.01). Sensitivity, PPV, and accuracy of FCH PET/CT were 94.1% (95/101), 97.9% (95/97), and 92.4% (97/105), respectively. The corresponding values for MIBI scintigraphy and US were 45.1% (46/102), 97.9% (46/47), and 45.7% (48/105) and 44.1% (45/102), 93.8% (45/48), and 42.9% (45/105), respectively. Among the 35 patients showing negative MIBI scintigraphy and neck US findings, 30 (86%) showed positive results on FCH PET/CT. FCH PET/CT could demonstrate ectopic locations of HPT in 11 patients whereas MIBI and US showed positive findings in only 6 and 3 patients, respectively.CONCLUSION: FCH PET/CT is an effective imaging modality for detection of HPT with the highest sensitivity among the available imaging techniques. Therefore, FCH PET/CT can be recommended especially for patients who show negative or inconclusive results on conventional imaging.]]>
Electrons ; Follow-Up Studies ; Humans ; Hyperparathyroidism ; Hyperplasia ; Neck ; Parathyroid Hormone ; Parathyroid Neoplasms ; Parathyroidectomy ; Positron-Emission Tomography ; Positron-Emission Tomography and Computed Tomography ; Radionuclide Imaging ; Retrospective Studies ; Ultrasonography

Fibrous dysplasia (FD) is a non-malignant bone tumor that typically behaves as a slow and indolent growing mass lesion. We report the case of a female patient presenting with headache and facial deformity and later diagnosed with polyostotic fibrous dysplasia (PFD). A 29-year-old woman visited Mealhada Primary Health Care Unit complaining of headache, nasal congestion, and hyposmia for several weeks. She also presented with facial deformity and painful swelling of the upper left orbit. X-ray imaging revealed a suspicious opacity in the left frontal sinus and a right shift of the nasal septum. Computed tomography and bone scintigraphy later confirmed a tumor involving the ethmoid and frontal bone. The patient was referred to the neurosurgery and otorhinolaryngology departments of a central hospital and the suspected diagnosis of PFD was confirmed. A watchful waiting approach with regular imaging screenings was proposed and accepted by the patient, who is now free of symptoms and more acceptant of the benign condition of her tumor. With this case, we aim to make family physicians more aware of this rare but relevant condition that can be difficult to diagnose. FD is a rare but benign tumor that occurs mainly in adolescents and young adults. Symptoms depend on the location and type of the tumor and include facial deformity, vision changes, nasal congestion, and headache. No clear guidelines exist for its treatment, and options include monitoring the progression of the tumor, in addition to medical or surgical approaches.
Adolescent ; Adult ; Bone Neoplasms ; Congenital Abnormalities ; Diagnosis ; Estrogens, Conjugated (USP) ; Female ; Fibrous Dysplasia of Bone ; Fibrous Dysplasia, Polyostotic* ; Frontal Bone ; Frontal Sinus ; Headache ; Humans ; Mass Screening ; Nasal Septum ; Neurosurgery ; Orbit ; Otolaryngology ; Physicians, Family ; Primary Health Care* ; Radionuclide Imaging ; Watchful Waiting ; Young Adult

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 purpose of this study was to investigate the correlations between tumor-to-background ratio (TBR) obtained from breast-specific gamma imaging (BSGI) and the prognostic factors of breast cancer. Sixty-seven patients with invasive ductal carcinoma who underwent preoperative BSGI were enrolled. The BSGI images were visually scored from 1 to 5 according to a breast imaging reporting and data system (BIRADS). The TBR results obtained from positive BSGI images were compared according to the following prognostic factors: tumor size; axillary lymph node metastasis; nuclear grade (NG); histologic grade (HG); subtype; Ki-67; and the expression profile of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Among 67 images, 60 were classified as a positive finding (sensitivity 89.6%). A higher TBR value was significantly correlated with tumor size ≥ 2 cm (P = 0.001), axillary lymph node metastasis (P = 0.007), high HG (P = 0.029), negative PR status (P = 0.036), and Ki-67 ≥ 14% (P = 0.007). The TBR showed a significant difference between the luminal A and non-luminal A subtypes (P = 0.007). On multivariate analysis, TBR had a high correlation with tumor size ≥ 2 cm, axillary lymph node metastasis, and negative PR status (P = 0.003, 0.048, and 0.030, respectively). A high TBR on BSGI was significantly correlated with poor prognostic factors of breast cancer. Luminal A subtype, a breast cancer subtype with more favorable prognosis, was associated with a low TBR on BSGI.
Breast Neoplasms* ; Breast* ; Carcinoma, Ductal ; Estrogens ; Humans ; Information Systems ; Lymph Nodes ; Multivariate Analysis ; Neoplasm Metastasis ; Phenobarbital ; Prognosis ; Radionuclide Imaging ; Receptor, Epidermal Growth Factor ; Receptors, Progesterone

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

The first step to nuclear medicine in Korea started with introduction of the gamma camera in 1969. Although planar images with the gamma camera give important functional information, they have the limitations that result from 2-dimensional images. Single-photon emission computed tomography (SPECT) due to its 3-dimensional image acquisition is superior to earlier planar gamma imaging in image resolution and diagnostic accuracy. As demand for a hybrid functional and anatomical imaging device has increased, integrated SPECT/CT systems have been used. In Korea, SPECT/CT was for the first time installed in 2003. SPECT/CT can eliminate many possible pitfalls on SPECT-alone images, making better attenuation correction and thereby improving image quality. Therefore, SPECT/CT is clinically preferred in many hospitals in various aspects.More recently, additional SPECT/CT images taken from the region with equivocal uptake on planar images have been helpful in making precise interpretation as part of their clinical workup in postoperative thyroid cancer patients. SPECT and SPECT/CT have various advantages, but its clinical application has gradually decreased in recent few years. While some researchers investigated the myocardial blood flow with cardiac PET using F-18 FDG or N-13 ammonia, myocardial perfusion SPECT is, at present, the radionuclide imaging study of choice for the risk stratification and guiding therapy in the coronary artery disease patients in Korea. New diagnostic radiopharmaceuticals for AD have received increasing attention; nevertheless, brain SPECT will remain the most reliable modality evaluating cerebral perfusion.
Ammonia ; Brain ; Coronary Artery Disease ; Gamma Cameras ; Humans ; Korea ; Nuclear Medicine ; Perfusion ; Radionuclide Imaging ; Radiopharmaceuticals ; Thyroid Neoplasms ; Tomography, Emission-Computed ; Tomography, Emission-Computed, Single-Photon

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

INTRODUCTIONA paradigm shift appears to have occurred worldwide in surgery for primary hyperparathyroidism with the advent of sensitive preoperative imaging techniques. Preoperative imaging for parathyroid adenoma localisation was not found to be useful in a study conducted in Singapore in the 1990s. This study aimed to explore what the change has been in preoperative localisation tools compared to the previous study and if the ability of these tools to correctly localise pathologic parathyroid glands has improved.

MATERIALS AND METHODSA retrospective review of patients who had surgery for primary hyperparathyroidism at our institution during the period 2005 to 2014 was carried out. Individuals with positive, as opposed to those with negative preoperative imaging, were compared with regard to whether they underwent limited focal or bilateral neck exploration. Length of hospital stay (LOHS) was also compared between patients who underwent limited versus bilateral exploration.

RESULTSFifty-eight patients who had preoperative imaging and surgery were evaluated. True positive rates of sestamibi, ultrasound and 4-dimensional (4D) computed tomography (CT) scans were 63.8%, 72.4% and 90%, respectively. Eighty percent of patients who had positive localisation had limited exploration. LOHS was 2.8 days (1.6, 4.8) and 4.3 days (2.1, 9.0) for limited and bilateral exploration respectively, P = 0.011.

CONCLUSIONOur study highlights the marked change in the surgical landscape for primary hyperparathyroidism in the last 2 decades in Singapore. Improved preoperative localisation has resulted in a swing from predominantly bilateral, to limited exploration in almost all cases of primary hyperparathyroidism due to solitary adenoma. LOHS was significantly shorter in patients who had limited as compared to those who had bilateral exploration.

Adenoma ; diagnostic imaging ; surgery ; Four-Dimensional Computed Tomography ; Humans ; Hyperparathyroidism, Primary ; diagnostic imaging ; surgery ; Length of Stay ; Parathyroid Neoplasms ; diagnostic imaging ; surgery ; Parathyroidectomy ; Practice Patterns, Physicians' ; Radionuclide Imaging ; Radiopharmaceuticals ; Retrospective Studies ; Sensitivity and Specificity ; Singapore ; Technetium Tc 99m Sestamibi ; Ultrasonography

OBJECTIVE: We investigated the prognostic value of intratumoral [18F]fluorodeoxyglucose (FDG) uptake heterogeneity (IFH) derived from positron emission tomography/computed tomography (PET/CT) in patients with cervical cancer. METHODS: Patients with uterine cervical cancer of the International Federation of Obstetrics and Gynecology (FIGO) stage IB to IIA were imaged with [18F]FDG PET/CT before radical surgery. PET/CT parameters such as maximum and average standardized uptake values (SUV(max) and SUV(avg)), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and IFH were assessed. Regression analyses were used to identify clinicopathological and imaging variables associated with progression-free survival (PFS). RESULTS: We retrospectively reviewed clinical data of 85 eligible patients. Median PFS was 32 months (range, 6 to 83 months), with recurrence observed in 14 patients (16.5%). IFH at an SUV of 2.0 was correlated with primary tumor size (p<0.001), SUV(tumor) (p<0.001), MTV(tumor) (p<0.001), TLG(tumor) (p<0.001), depth of cervical invasion (p<0.001), and negatively correlated with age (p=0.036). Tumor recurrence was significantly associated with TLG(tumor) (p<0.001), MTV(tumor) (p=0.001), SUV(LN) (p=0.004), IFH (p=0.005), SUV(tumor) (p=0.015), and FIGO stage (p=0.015). Multivariate analysis identified that IFH (p=0.028; hazard ratio, 756.997; 95% CI, 2.047 to 279,923.191) was the only independent risk factor for recurrence. The Kaplan-Meier survival graphs showed that PFS significantly differed in groups categorized based on IFH (p=0.013, log-rank test). CONCLUSION: Preoperative IFH was significantly associated with cervical cancer recurrence. [18F]FDG based heterogeneity may be a useful and potential predicator of patient recurrence before treatment.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Squamous Cell/metabolism/*radionuclide imaging/secondary ; Disease-Free Survival ; Female ; Fluorodeoxyglucose F18/*pharmacokinetics ; Glycolysis ; Humans ; Middle Aged ; Multimodal Imaging ; Neoplasm Invasiveness ; Neoplasm Recurrence, Local/metabolism/radionuclide imaging ; Neoplasm Staging ; *Positron-Emission Tomography ; Predictive Value of Tests ; Radiopharmaceuticals/*pharmacokinetics ; Retrospective Studies ; Tomography, X-Ray Computed ; Tumor Burden ; Uterine Cervical Neoplasms/metabolism/pathology/*radionuclide imaging