Utility of 99mTc-Sestamibi Single-Photon Emission Computed Tomography (SPECT)/CT Single Imaging Strategy in the Preoperative Localization of Parathyroid Adenoma.

Background Primary hyperparathyroidism is an endocrinopathy associated with dysregulated calcium homeostasis. The most common etiology is a parathyroid adenoma most definitely managed via a parathyroidectomy. The two main surgical approaches include a minimally invasive parathyroidectomy (MIP) and open four-gland exploration (4-GE). MIP is the preferred operative strategy since it is associated with less postoperative complications. Accurate preoperative imaging is essential in informing the optimal approach to surgery. MIP is only considered if adenoma is able to be localized precisely. The most commonly used imaging modality includes ultrasound and sestamibi single-photon emission computed tomography (SPECT)/CT, either as a single or combination strategy. Other options include MRI, PET, and 4D CT. There is no universally accepted preoperative imaging strategy. The literature is discordant and recommendations proposed by existing guidelines are incongruous. Objectives This study aimed to evaluate currently utilized preoperative parathyroid imaging modalities at our institution and correlate them with surgical and histological findings to determine the most efficient imaging strategy to detect adenomas for our patient cohort. This will ultimately guide the best surgical approach for patients receiving parathyroidectomies. Methods This is a retrospective observational study of all patients undergoing first-time surgery for biochemically proven primary hyperparathyroidism at our institution over the past five years. Multiple data points were collected including modality of preoperative disease localization, operation type, final histopathology, biochemical investigations, and cure rate. Patients were categorized into one of three groups based on the method of disease localization. Results A total of 244 patients had parathyroidectomies performed at our institution in the past five years from January 2018 to December 2022. Ninety-six percent (n=235) of all patients received dual imaging preoperatively with SPECT/CT and ultrasound performed on the same day and therefore included in this study. A total of 64.3% (n=151) underwent MIP. Eighty percent (n=188) of all histopathology revealed adenomas and 26.8% (n=63) of patients had adenoma localized on SPECT/CT only (sensitivity: 58.1%, specificity: 71%, and positive predictive value {PPV}: 85.7%). A total of 9.8% (n=23) had adenoma localized on ultrasound only (sensitivity: 15.6%, specificity: 73.3%, and PPV: 65.2%). A total of 45.1% (n=106) were dual localized on both SPECT/CT and ultrasound (sensitivity: 75.6%, specificity: 46.6%, and PPV: 84.9%). The cure rate was 91.5% in the dual-localized group, 86% in the dual-unlocalized group, and 96.5% when localized with SPECT/CT alone. Conclusion A dual-imaging modality with SPECT/CT and ultrasound should remain the first-line imaging strategy. This approach has higher sensitivity rates and poses no inherent patient or surgical-related risks. Patients with disease unlocalized on SPECT/CT alone had a positive predictive value, specificity, and likelihood ratio for adenoma detection comparable to dual-localized patients. Therefore, SPECT/CT alone is sufficient for directing MIP in the presence of a negative ultrasound.

Are 99mTC-Sestamibi Single Photon Emission Computed Tomography Scan Results Associated to the Parathyroid Cell Type in Primary Hyperparathyroidism?

INTRODUCTION: 99mTC-sestamibi scintigraphy (SPECT-CT) is a common imaging modality for parathyroid localization in primary hyperparathyroidism (PHPT). Prior studies have suggested that the cellular composition of parathyroid adenomas influences SPECT-CT imaging results. Other biochemical and anatomical factors may also play a role in false negative results. Therefore, after controlling for confounding variables, we sought to determine whether the histologic composition of parathyroid adenomas is associated to SPECT-CT results in patients with single gland disease causing PHPT. METHODS: A retrospective review of patients with PHPT due to confirmed single gland disease was performed over a 2-y period. A 1:1 propensity score matching was done between patients with positive and negative SPECT-CT results with regard to demographical, biochemical, and anatomical characteristics followed by blinded pathologic examination of cell composition in the matched pairs. RESULTS: Five hundred forty two patients underwent routine four gland exploration and 287 (53%) patients were found to have a single adenoma. Of those, 26% had a negative SPECT-CT result. There were significant differences between groups with regards to biochemical profile, gland location, and gland size. All of which became nonsignificant after propensity score matching. Adenomas were primarily composed of chief cells, with no difference between groups (95% versus 97%, P = 0.30). In the positive SPECT-CT group, chief cells were the dominant cell type in 68% of the cases, followed by mixed type (13%), oxyphil cells (12%), and clear cells (7%). This was similar to the negative SPECT-CT group (P = 0.22). CONCLUSIONS: While certain patient's clinical characteristics are associated with SPECT-CT imaging results, histologic cell type is not significantly associated.

Role of 18Fluorocholine Positron Emission Tomography/Computed Tomography in the Localization of Culprit Lesions in Patients of Persistent/Recurrent Primary Hyperparathyroidism: A Prospective Study in COVID Times.

Introduction: Recurrent/persistent primary hyperparathyroidism in patients who have undergone previous parathyroidectomy is a challenging condition. Imaging is important for localizing the parathyroid adenoma for re-exploration and 18F-Fluorocholine (18F-FCH) positron emission tomography/computed tomography (PET/CT) seems ideal for this purpose. Aim: This prospective study attempted to ascertain the utility of 18F-FCH PET/CT as an investigation in preoperative localization of abnormal parathyroid tissue in recurrent/persistent primary hyperparathyroidism while comparing it with 99mTc-Sestamibi dual-phase scintigraphy with early single-photon emission CT (SPECT)/CT and neck ultrasonography (USG). Methods: Twenty patients with biochemical features of recurrent/persistent primary hyperparathyroidism were enrolled into this study. They underwent neck USG, 99mTc-Sestamibi dual-phase scintigraphy with early SPECT/CT and 18F-FCH PET/CT for localization of parathyroid lesions. Six patients underwent surgical resection of the detected lesions, 3 were awaiting surgery, and 11 were managed conservatively. One patient died due to COVID. Results: The calculated positive predictive values on a per-lesion basis of neck USG, 99mTc-sestamibi scintigraphy and early SPECT/CT and 18F-FCH PET/CT in the cohort of the 5 operated patients were 75% (3/4), 71.4% (5/7), and 71.4% (5/7), respectively. On a per-patient basis, the lesion detection rate was 100% for 99mTc-sestamibi scan and FCH PET (5/5) and 80% on neck USG (4/5). Conclusion: 18F-FCH PET/CT is a highly accurate imaging modality for the detection of parathyroid lesions in patients with recurrent/persistent primary hyperparathyroidism.

Machine Learning Integrating 99mTc Sestamibi SPECT/CT and Radiomics Data Achieves Optimal Characterization of Renal Oncocytic Tumors.

The increasing evidence of oncocytic renal tumors positive in 99mTc Sestamibi Single Photon Emission Tomography/Computed Tomography (SPECT/CT) examination calls for the development of diagnostic tools to differentiate these tumors from more aggressive forms. This study combined radiomics analysis with the uptake of 99mTc Sestamibi on SPECT/CT to differentiate benign renal oncocytic neoplasms from renal cell carcinoma. A total of 57 renal tumors were prospectively collected. Histopathological analysis and radiomics data extraction were performed. XGBoost classifiers were trained using the radiomics features alone and combined with the results from the visual evaluation of 99mTc Sestamibi SPECT/CT examination. The combined SPECT/radiomics model achieved higher accuracy (95%) with an area under the curve (AUC) of 98.3% (95% CI 93.7-100%) than the radiomics-only model (71.67%) with an AUC of 75% (95% CI 49.7-100%) and visual evaluation of 99mTc Sestamibi SPECT/CT alone (90.8%) with an AUC of 90.8% (95%CI 82.5-99.1%). The positive predictive values of SPECT/radiomics, radiomics-only, and 99mTc Sestamibi SPECT/CT-only models were 100%, 85.71%, and 85%, respectively, whereas the negative predictive values were 85.71%, 55.56%, and 94.6%, respectively. Feature importance analysis revealed that 99mTc Sestamibi uptake was the most influential attribute in the combined model. This study highlights the potential of combining radiomics analysis with 99mTc Sestamibi SPECT/CT to improve the preoperative characterization of benign renal oncocytic neoplasms. The proposed SPECT/radiomics classifier outperformed the visual evaluation of 99mTc Sestamibii SPECT/CT and the radiomics-only model, demonstrating that the integration of 99mTc Sestamibi SPECT/CT and radiomics data provides improved diagnostic performance, with minimal false positive and false negative results.

The Role of [99mTc]Tc-Sestamibi in Functional Imaging of the Iodine-Loaded Thyroid Gland.

Due to high iodine loading from iodinated contrast media, the thyroid uptake of common radiopharmaceuticals ([99mTc]NaTcO4 and [123I]NaI) can be influenced up to 2 mo after administration. In such cases, and generally when differential diagnosis between productive and destructive thyrotoxicosis is necessary, [99mTc]Tc-sestamibi scintigraphy could be an option. This case highlights the role of [99mTc]Tc-sestamibi in the evaluation of thyrotoxicosis in a patient with a blocked thyroid gland as a result of stable iodine saturation.

SPECT myocardial blood flow quantitation for the detection of angiographic stenoses with cardiac-dedicated CZT SPECT.

PURPOSE: CZT SPECT with the enhanced imaging characteristic facilitates SPECT myocardial blood flow (MBF) quantitation moving toward a clinical utility to uncover myocardial ischemia. The purpose of this study was to investigate the diagnostic performance of stress MBF, myocardial flow reserve (MFR) and myocardial flow capacity (MFC) derived from CZT SPECT in the detection of coronary artery disease (CAD). METHODS: One-hundred and eighty patients underwent two-day rest/adenosine-stress scans for SPECT MBF quantitation. All dynamic SPECT images were reconstructed and corrected with necessary corrections. The one-tissue two-compartment kinetic model was utilized to fit kinetic parameters (K1, k2 and FBV) by numeric optimization and converted to MBF from K1. Rest MBF, stress MBF and MFR in left ventricle and coronary territories were calculated from flow polar maps. MFC was assessed by extents of moderately and severely abnormal flow statuses using an integrated flow diagram. Per-patient and per-vessel analyses were performed to determine cutoff values for the detection of angiographically obstructive and flow-limited CAD. RESULTS: Using the threshold of ≥ 50% stenosis, 149 patients (82.78%) were classified to have obstructive lesions in 355 vessels (65.74%). Using the threshold of ≥ 70% stenosis, 113 patients (62.78%) were classified to have flow-limited lesions in 282 vessels (52.22%). On per-patient analysis, the optimal cutoff values of stress MBF and MFR to detect ≥ 50% stenosis were (1.44 ml/min/g, 1.96) and (1.34 ml/min/g and 1.75) to detect ≥ 70% stenosis. The optimal cutoff values for severely and combined moderately severely abnormal MFC extents were (2.3-2.5%, 23.1%) and (7.5%, 29.4%), respectively. The overall sensitivity of MFC (0.84-0.86, 0.86-0.90) to detect ≥ 50% and ≥ 70% lesions surpassed those of stress MBF (0.78. 0.78) and MFR (0.80, 0.75) (all p < 0.05) with similar specificity (MFC = 0.84-0.90, 0.87-0.91; stress MBF = 0.87, 0.91; MFR = 0.84, 0.89) (all p≥ 0.05). CONCLUSION: The non-invasive SPECT MBF quantitation using CZT SPECT is a reliable method to detect angiographically obstructive and flow-limited CAD. Myocardial flow capacity can outperform with higher diagnostic sensitivity than stress MBF or MFR alone.

Widespread presentation of brown tumors mimicking multiple myeloma.

Brown tumors or osteitis fibrosa cystica has become a rare presentation of primary hyperparathyroidism in up-to-date clinical practice. Here, we describe a case of longstanding untreated hyperparathyroidism presenting itself with brown tumors in a 65-year-old patient. During the diagnostic work-up of this patient, bone SPECT/CT and 18F-FDG-PET/CT revealed multiple widespread osteolytic lesions. Differentiating from other bone tumors such as multiple myeloma is challenging. In this case, the final diagnosis was made by integrating the medical history, biochemical diagnosis of primary hyperparathyroidism, pathological findings and medical imaging.

Molecular Imaging Diagnosis of Renal Cancer Using 99mTc-Sestamibi SPECT/CT and Girentuximab PET-CT-Current Evidence and Future Development of Novel Techniques.

Novel molecular imaging opportunities to preoperatively diagnose renal cell carcinoma is under development and will add more value in limiting the postoperative renal function loss and morbidity. We aimed to comprehensively review the research on single photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography computed tomography (PET-CT) molecular imaging and to enhance the urologists' and radiologists' knowledge of the current research pattern. We identified an increase in prospective and also retrospective studies that researched to distinguish between benign and malignant lesions and between different clear cell renal cell carcinoma subtypes, with small numbers of patients studied, nonetheless with excellent results on specificity, sensitivity and accuracy, especially for 99mTc-sestamibi SPECT/CT that delivers quick results compared to a long acquisition time for girentuximab PET-CT, which instead gives better image quality. Nuclear medicine has helped clinicians in evaluating primary and secondary lesions, and has lately returned with new and exciting insights with novel radiotracers to reinforce its diagnostic potential in renal carcinoma. To further limit the renal function loss and post-surgery morbidity, future research is mandatory to validate the results and to clinically implement the diagnostic techniques in the context of precision medicine.

Diagnostic Accuracy of 99mTc-Sestamibi SPECT/CT for Characterization of Solid Renal Masses.

Our objective was to assess the diagnostic accuracy of 99mTc-sestamibi SPECT/CT for characterizing solid renal masses. Methods: Imaging and clinical records of patients who underwent 99mTc-sestamibi SPECT/CT for clinical work-up of their solid renal masses from September 2018 to October 2021 were retrospectively reviewed. Histopathology formed the reference standard, and the diagnoses were categorized as malignant/concerning (renal cell carcinomas [RCCs] other than chromophobe histology) and benign/nonconcerning (oncocytic tumors including chromophobe RCC, other benign diagnoses) to calculate the sensitivity and specificity of 99mTc-sestamibi SPECT/CT and contrast-enhanced CT (ceCT). The clinical reads of the SPECT/CT images were used for visual classification of the lesions. Additionally, the SPECT images were manually segmented to obtain the maximum and mean counts of the lesion and adjacent renal cortex and maximum and mean lesion Hounsfield units. Results: 99mTc-sestamibi SPECT/CT was performed on 42 patients with 62 renal masses. A histopathologic diagnosis was available for 27 patients (18 male, 9 female) with 36 solid renal masses. ceCT findings were available for 20 of these patients. The most commonly identified single histologic type was clear cell RCC (13/36; 36.1%). Oncocytic tumors were the most common group of nonconcerning lesions (15/36), with oncocytoma as the predominant histologic type (n = 6). The sensitivity and specificity of SPECT/CT for diagnosing a nonconcerning lesion were 66.7% and 89.5%, respectively, compared with 10% and 75%, respectively, for ceCT. The lesion-to-kidney ratios for maximum and mean counts and maximum lesion Hounsfield units showed significant differences between the 2 groups (P < 0.05). The lesion-to-kidney mean count ratio at a cutoff of 0.46 showed a sensitivity and specificity of 87.5% and 86.67%, respectively, for detecting nonconcerning lesions, which was significantly higher than that of ceCT. Conclusion: The current literature on the utility of 99mTc-sestamibi SPECT/CT for characterization of solid renal masses is limited. We offer additional evidence of the incremental value of 99mTc-sestamibi SPECT/CT over ceCT for differentiating malignant or aggressive renal tumors from benign or indolent ones, thereby potentially avoiding overtreatment and its associated complications. Quantitative assessment can further increase the diagnostic accuracy of SPECT/CT and may be used in conjunction with visual interpretation.

An Incidentally Detected Case of Atypical Bronchial Carcinoid on Stress Myocardial Perfusion SPECT/CT.

Myocardial perfusion imaging is primarily done to look for stress-induced perfusion defects in patients suspected of having coronary artery disease. However, the rotating raw images can provide significant information on the surrounding structures. The lungs lie near the heart, and any abnormality showing increased uptake can be seen on myocardial perfusion imaging. We report the case of a 52-y-old man with a history of diabetes for the previous 5 y, who presented to the cardiology outpatient department because of occasional chest pain and dyspnea. Electrocardiography and echocardiography showed no significant abnormality. The patient was referred to the nuclear medicine department for stress-induced myocardial perfusion scintigraphy. The raw 99mTc-sestamibi images showed abnormal uptake in the hilar region of the right lung, which, on subsequent investigations, was diagnosed as atypical bronchial carcinoid tumor.

Molecular Breast Imaging in the Screening Setting.

Early detection of breast cancer through screening mammography saves lives. However, the sensitivity of mammography for breast cancer detection is reduced in women with dense breast tissue. Imaging modalities for supplemental breast cancer screening include MRI, whole breast US, contrast-enhanced mammography, and molecular breast imaging (MBI). Molecular breast imaging with 99mTc-sestamibi is a functional imaging test to identify metabolically active areas in the breast with positioning analogous to mammography. Since 2011, there have been six large, published studies of screening MBI as a supplement to mammography involving over 6000 women from four different institutions. A multicenter, prospective clinical trial of 3000 women comparing breast cancer detection using screening digital breast tomosynthesis alone or in combination with MBI recently completed enrollment. This review focuses on the current evidence of MBI use for supplemental breast cancer screening, the strengths and limitations of MBI, and recent technological advances.

Comparison of [18F]fluorocholine PET/CT with [99mTc]sestamibi and ultrasonography to detect parathyroid lesions in primary hyperparathyroidism: a prospective study.

Background: Primary hyperparathyroidism is a common endocrine disorder produced by the increase of parathyroid hormone (PTH) due to a benign adenoma of a single parathyroid gland, or as multiple gland hyperplasia, or as a rare malignant tumor. Preoperative imaging scans are frequently necessary for the minimally invasive parathyroidectomies to identify the location of enlarged parathyroid glands and to design the procedure. Methods: The diagnostic reliability of [18F]fluorocholine positron emission tomography/computed tomography (FCH PET/CT), [99mTc]sestamibi [multiplexed ion beam imaging (MIBI)] and cervical ultrasonography was analyzed in 37 patients diagnosed with primary hyperparathyroidism undergoing minimally invasive parathyroidectomy. The three preoperative imaging techniques were correlated with intraoperative and histopathological findings as well as changes in biochemical parameters (serum PTH and calcium levels). Statistical analysis was carried out with SPSS version 24.0. Results: In 30 of 37 patients (81.1%), FCH PET/CT correctly localized the pathological gland. In 3 cases of ectopic adenomas, the accuracy of the techniques was 100% (3/3) for FCH PET/CT, 66.7% (2/3) for MIBI, and 33.3% (1/3) for neck ultrasonography. Neither neck ultrasonography nor MIBI were able to locate pathological parathyroid glands in those patients with multiglandular disease, while FCH PET/CT correctly located one patient (1/3, 33.3%) with two adenomas and 3 patients (3/6, 50.0%) with hyperplasia. The three imaging techniques, FCH PET/CT, MIBI and neck ultrasound yielded a sensitivity of 92.1%, 57.9% and 32.4%, a positive predictive value of 94.6%, 84.6% and 78.6%, and a diagnostic accuracy of 96.4%, 85.7% and 79.0%, respectively. Conclusions: In this group of patients diagnosed with primary hyperparathyroidism, FCH PET/CT was superior to MIBI and neck ultrasound in detecting adenomas, particularly in the presence of ectopic glands or multiglandular disease.

Normal and Range Value Evaluations Using Heart Risk View-Function Based on the Japanese Societyof Nuclear Medicine Working Group Database.

Background: Gated myocardial perfusion single-photon emission computed tomography (SPECT) has been used to non-invasively evaluate the left ventricular (LV) volume and function. This study aimed to measure the normal and range values for heart risk view-function (HRV-F) software using the Japanese Society of Nuclear Medicine Working Group (JSNM-WG) normal database and clarify the characteristics of the normal database. Methods:We used 206 myocardial perfusion short-axis images from the normal database. Ejection fraction (EF), end-systolic volume (ESV), end-diastolic volume (EDV), peak filling rate (PFR), 1/3 mean filling rate (MFR), time to PFR (TTPF), and TTPF divided by RR interval (TPFR/RR) were calculated. Phase parameters of 95% histogram bandwidth and standard deviation were also computed using the phase analysis. The relationships among phase parameters, LV volumes, and body surface area (BSA) were evaluated in the age group of ≤65 years. Results: Higher EF was observed in females than in males (p<0.0001). EDV and ESV were significantly higher in males than in females (p<0.0001). Additionally, PFR and 1/3 MFR significantly differed between sexes (p≤0.075). Phase parameters were higher in males than in females, and higher at stress than at rest. All diastolic parameters showed no significant differences between sexes in any age group, whereas differences have remained in phase values. Phase parameters were weakly correlated with EDV (r=0.31), ESV (r=0.43), and BSA (r=0.27), respectively. Conclusions: Mean normal and range values of the normal database were determined using the HRV-F software. The normal and range values can help diagnose gated SPECT data in patients with cardiac diseases.

99mTc-Sestamibi SPECT/CT and histopathological features of oncocytic renal neoplasia.

BACKGROUND: 99mTc-Sestamibi Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) contributes to the non-invasive differentiation of renal oncocytoma (RO) from renal cell carcinoma (RCC) by characterising renal tumours as Sestamibi positive or Sestamibi negative regarding their 99mTc-Sestamibi uptake compared to the non-tumoral renal parenchyma. PURPOSE: To determine whether 99mTc- Sestamibi uptake in renal tumour and the non-tumoral renal parenchyma measured using Standard Uptake Value (SUV) SPECT, has a beneficial role in differentiating RO from RCC. MATERIAL AND METHODS: Fifty-seven renal tumours from 52 patients were evaluated. In addition to visual evaluation of 99mTc-Sestamibi uptake, SUVmax measurements were performed in the renal tumour and the ipsilateral non-tumoral renal parenchyma. Analysis of the area under the receiver operating characteristic curve identified an optimal cut-off value for detecting RO, based on the relative ratio of 99mTc- Sestamibi uptake. RESULTS: Semiquantitative evaluation of 99mTc-Sestamibi uptake did not improve the performance of 99mTc- Sestamibi SPECT/CT in detecting RO. 99mTc- Sestamibi SPECT/CT identifies a group of mostly indolent Sestamibi-positive tumours with low malignant potential containing RO, Low-Grade Oncocytic Tumours, Hybrid Oncocytic Tumours, and a subset of chromophobe RCCs. CONCLUSION: The imaging limitations for accurate differentiation of Sestamibi-positive renal tumours mirror the recognised diagnostic complexities of the histopathologic evaluation of oncocytic neoplasia. Patients with Sestamibi-positive renal tumours could be better suited for biopsy and follow-up, according to the current active surveillance protocols.

Questionable value of [99mTc]-sestamibi scintigraphy in patients with pHPT and negative ultrasound.

PURPOSE: A successful focused surgical approach in primary hyperparathyroidism (pHPT) relies on accurate preoperative localization of the parathyroid adenoma (PA). Most often, ultrasound is followed by [99mTc]-sestamibi scintigraphy, but the value of this approach is disputed. Here, we evaluated the diagnostic approach in patients with surgically treated pHPT in our center with the aim to further refine preoperative diagnostic procedures. METHODS: A single-center retrospective analysis of patients with pHPT from 01/2005 to 08/2021 was carried out followed by evaluation of the preoperative imaging modalities to localize PA. The localization of the PA had to be confirmed intraoperatively by the fresh frozen section and significant dropping of the intraoperative parathyroid hormone (PTH) levels. RESULTS: From 658 patients diagnosed with pHPT, 30 patients were excluded from the analysis because of surgery for recurrent or persistent disease. Median age of patients was 58.0 (13-93) years and 71% were female. Neck ultrasound was carried out in 91.7% and localized a PA in 76.6%. In 23.4% (135/576) of the patients, preoperative neck ultrasound did not detect a PA. In this group, [99mTc]-sestamibi correctly identified PA in only 25.4% of patients. In contrast, in the same cohort, the use of [11C]-methionine or [11C]-choline PET resulted in the correct identification of PA in 79.4% of patients (OR 13.23; 95% CI 5.24-33.56). CONCLUSION: [11C]-Methionine or [11C]-choline PET/CT are superior second-line imaging methods to select patients for a focused surgical approach when previous ultrasound failed to identify PA.

The value of sestamibi single-photon emission computed tomography/computed tomography in differentiating and staging renal cell carcinomas: A systematic review.

Misdiagnosis of benign renal neoplasms can lead to unnecessary surgical resections, which increases the risk of other morbidities and mortality. Therefore, it is crucial to find a diagnostic modality for differentiation between benign and malignant renal masses. In the current study, we summarized published pieces of evidence concerning the use of technetium-99m (99mTc)-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) as a promising diagnostic nuclear imaging modality for the differentiation of renal neoplasms. The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement for Systematic Reviews and Meta-Analyses. We conducted a systematic electronic database search for suitable studies from inception till February 20, 2020 in 9 databases. The risk of bias was assessed for the included studies using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We identified 9373 records after exclusion of 8978 duplicates using EndNote software. Title and abstract screening resulted in 761 records for further full-text screening. Finally, four studies were included with total sample size of 80 patients. The overall risk of bias was low to moderate. The results of all the included studies supported using 99mTc-sestamibi SPECT/CT for the differentiation between benign and malignant renal neoplasms. The use of 99mTc-sestamibi SPECT/CT could be a rapid, less invasive, promising diagnostic modality for histological diagnosis and staging of renal neoplasm, as well as monitoring post-therapy tumor's response. However, more studies with large sample sizes are essential to confirm the reliability and accuracy of this modality for usage.

Technetium-99 m-sestamibi single-photon emission computerised tomography (CT)/CT in the prediction of malignant versus benign small renal masses.

OBJECTIVES: To determine the effectiveness of technetium-99m (99m Tc)-sestamibi single-photon emission computerised tomography/computerised tomography (SPECT/CT) in distinguishing between malignant and benign renal lesions. PATIENTS AND METHODS: Between June 2018 and October 2020 all patients with new indeterminate small renal masses (SRMs) underwent 99m Tc-sestamibi renal SPECT/CT before biopsy or surgery. The accuracy of 99m Tc-sestamibi imaging diagnoses was assessed against histopathology. Receiver operating characteristic (ROC) analysis was used to determine the optimum cut-off for the tumour:normal uptake ratio. Logistic regression was used to determine if quantitative analysis significantly added to visual interpretation alone. RESULTS: A total of 74 patients with SRMs were investigated with 99m Tc-sestamibi SPECT/CT. The SPECT/CT correctly identified 49 malignant tumours and 11 benign tumours, resulting in a sensitivity of 0.89 (95% confidence interval [CI] 0.77-0.95) and a specificity of 0.73 (95% CI 0.45-0.91). The ROC analysis of uptake ratios demonstrated that a tumour:normal uptake ratio of 0.41 provided optimal diagnostic accuracy (sensitivity 0.81, specificity 0.88, area under the curve 0.883 [95% CI 0.794-0.971]). The uptake ratio was also highly significant in excluding malignancy on univariate logistic regression analysis whereby the higher the uptake ratio, the lower the chances were for malignancy (odds ratio 0.009, 95% CI 0.001-0.118, P < 0.001). However, this did not improve diagnostic accuracy when compared to visual interpretation alone. CONCLUSION: 99m Tc-sestamibi SPECT/CT is a non-invasive technique with good accuracy in determining if a SRM is benign or malignant.

Deep learning-based detection of parathyroid adenoma by 99mTc-MIBI scintigraphy in patients with primary hyperparathyroidism.

OBJECTIVE: It is important to detect parathyroid adenomas by parathyroid scintigraphy with 99m-technetium sestamibi (99mTc-MIBI) before surgery. This study aimed to develop and validate deep learning (DL)-based models to detect parathyroid adenoma in patients with primary hyperparathyroidism, from parathyroid scintigrams with 99mTc-MIBI. METHODS: DL-based models for detecting parathyroid adenoma in early- and late-phase parathyroid scintigrams were, respectively, developed and evaluated. The training dataset used to train the models was collected from 192 patients (165 adenoma cases, mean age: 64 years ± 13, 145 women) and the validation dataset used to tune the models was collected from 45 patients (30 adenoma cases, mean age: 67 years ± 12, 37 women). The images were collected from patients who were pathologically diagnosed with parathyroid adenomas or in whom no lesions could be detected by either parathyroid scintigraphy or ultrasonography at our institution from June 2010 to March 2019. The models were tested on a dataset collected from 44 patients (30 adenoma cases, mean age: 67 years ± 12, 38 women) who took scintigraphy from April 2019 to March 2020. The models' lesion-based sensitivity and mean false positive indications per image (mFPI) were assessed with the test dataset. RESULTS: The sensitivity was 82% [95% confidence interval 72-92%] with mFPI of 0.44 for the scintigrams of the early-phase model and 83% [73-92%] with mFPI of 0.31 for the scintigrams of the delayed-phase model in the test dataset, respectively. CONCLUSIONS: The DL-based models were able to detect parathyroid adenomas with a high sensitivity using parathyroid scintigraphy with 99m-technetium sestamibi.

"Ebstein's Anomaly" a Potential Cause of Misinterpretation on Myocardial Perfusion Imaging.

Ebstein's anomaly is a rare congenital heart disease. We present the case of a 47-year-old woman with history of Ebstein's anomaly who was referred to nuclear medicine department for a myocardial perfusion single-photon emission computed tomography (SPECT) imaging during pre-anesthetic check-up. Myocardial SPECT perfusion images with (99mTc)-Sestamibi demonstrated medium sizes fixed perfusion defect in the mid and proximal infero-septal wall adjacent inferior wall. This is a cause of potential misinterpretation on myocardial SPECT perfusion imaging as this perfusion defect was due to fibrosis rather than scarred myocardium.

Multimodality Molecular Imaging in Arthropathy Associated with Multiple Myeloma.

We report a patient with multiple myeloma (MM) and polyarthritis of large joints. During the staging of the disease, bone marrow diffusely involved by MM was clearly demonstrated by 99mTc-2-methoxy-isobutyl-isonitrile (MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) but not by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/CT images. On the other hand, a very intense uptake of 18F-FDG was detected in periarticular tissues of multiple joints, with nonabnormal 99mTc-MIBI accumulation. Rheumatology tests were negative. A subsequent bone scintigraphy demonstrated radiolabeled bisphosphonate accumulation in periarticular tissues, suggesting amyloid arthropathy.