Anatomic imaging with contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) has long been the mainstay of renal mass characterization. However, those modalities are often unable to adequately characterize indeterminate, solid, enhancing renal masses - with some exceptions, such as the development of the clear-cell likelihood score on multi-parametric MRI. As such, molecular imaging approaches have gained traction as an alternative to anatomic imaging. Mitochondrial imaging with 99mTc-sestamibi single-photon emission computed tomography/CT is a cost-effective means of non-invasively identifying oncocytomas and other indolent renal masses. On the other end of the spectrum, carbonic anhydrase IX agents, most notably the monoclonal antibody girentuximab - which can be labeled with positron emission tomography radionuclides such as zirconium-89 - are effective at identifying renal masses that are likely to be aggressive clear cell renal cell carcinomas. Renal mass biopsy, which has a relatively high non-diagnostic rate and does not definitively characterize many oncocytic neoplasms, nonetheless may play an important role in any algorithm targeted to renal mass risk stratification. The combination of molecular imaging and biopsy in selected patients with other advanced imaging methods, such as artificial intelligence/machine learning and the abstraction of radiomics features, offers the optimal way forward for maximization of the information to be gained from risk stratification of indeterminate renal masses. With the proper application of those methods, inappropriately aggressive therapy for benign and indolent renal masses may be curtailed.

Technetium-99m sestamibi single-photon emission computed tomography/computed tomography (99mTc-sestamibi SPECT/CT) is a mainstay of the pre-operative localization of parathyroid lesions. We report here the case of a 30 year-old woman with a fortuitously discovered 2 cm cervical mass for which a parathyroid origin was originally suspected due to its retro-thyroidal localization and a personal history of nephrolithiasis. Normal serum calcium and parathyroid hormone (PTH) levels excluded primary hyperparathyroidism, raising suspicion of a non-functional parathyroid adenoma, and SPECT/CT imaging showed that the mass was 99mTc-sestamibi-avid. Fine-needle aspiration (FNA) was performed; cytology was non-diagnostic but the needle washout was negative for thyroglobulin, calcitonin and PTH, arguing against a thyroidal or parathyroidal origin of the mass. Core needle biopsy revealed a schwannoma, ostensibly originating from the recurrent laryngeal nerve; upon surgical resection, it was finally found to arise from the esophageal submucosa. This case illustrates the fact that endocrinologists, radiologists, nuclear medicine, head and neck, and other specialists investigating patients with cervical masses should be aware that schwannomas need to be considered in the differential diagnosis of focal 99mTc-sestamibi uptake in the neck region.

OBJECTIVE: We conducted a cost-effectiveness analysis in which we compared a preoperative [18F]Fluorocholine PET/CT-based one-stop-shop imaging strategy with current best practice in which [18F]Fluorocholine PET/CT is only recommended after negative or inconclusive [99mTc]Tc-methoxy isobutyl isonitrile SPECT/CT for patients suffering from primary hyperparathyroidism. We investigated whether the one-stop-shop strategy performs as well as current best practice but at lower costs.
METHODS: We developed a cohort-level state transition model to evaluate both imaging strategies respecting an intraoperative parathyroid hormone monitored treatment setting as well as a traditional treatment setting. The model reflects patients\' hospital journeys after biochemically diagnosed primary hyperparathyroidism. A cycle length of twelve months and a lifetime horizon were used. We conducted probabilistic analyses simulating 50,000 cohorts to assess joint parameter uncertainty. The incremental net monetary benefit and cost for each quality-adjusted life year were estimated. Furthermore, threshold analyses regarding the tariff of [18F]Fluorocholine PET/CT and the sensitivity of [99mTc]Tc-methoxy isobutyl isonitrile SPECT/CT were performed.
RESULTS: The simulated long-term health effects and costs were similar for both imaging strategies. Accordingly, there was no incremental net monetary benefit and the one-stop-shop strategy did not result in lower costs. These results applied to both treatment settings. The threshold analysis indicated that a tariff of €885 for [18F]Fluorocholine PET/CT was required to be cost-effective compared to current best practice.
CONCLUSIONS: Both preoperative imaging strategies can be used interchangeably. Daily clinical practice grounds such as available local resources and patient preferences should inform policy-making on whether a hospital should implement the one-stop-shop imaging strategy.

Diaphragmatic eventration is the elevation of hemi-diaphragm without any disruption to diaphragmatic continuity which can be congenital or acquired. The most common acquired cause is phrenic nerve paralysis due to traumatic causes and is usually incidentally diagnosed on chest radiograph or computed tomography. We hereby report a case of a patient who had road traffic accident with fracture of the left proximal femur. Stress Myocardial Perfusion Imaging (MPI) done for pre-operative clearance showed an incidental tracer avidity adjoining to left myocardium in the thorax. It was confirmed on anatomical imaging to be gastric cavity uptake due to diaphragm eventration.

Parathyroid adenoma (PA) and parathyroid hyperplasia (PH) are common causes of primary hyperparathyroidism (PHPT), for which the only definitive treatment is surgery. Abnormalities in the parathyroid glands can be identified with various imaging modalities including ultrasound (US), sestamibi scan (MIBI), 4-dimensional computed tomography (4D-CT), and positron emission tomography/computed tomography (PET/CT). While it is not uncommon for parathyroid pathology to be undetected on imaging, this is more typical of low-volume hyperplasia and smaller-sized adenomas. We present the case of a 65-year-old man with PHPT who initially had a solitary parathyroid mass detected by US, but who was ultimately discovered to have massive PH with hyperplastic glands not visualized on US or MIBI. This atypical presentation may help guide providers in decisions on ordering and interpreting various imaging modalities for patients with PHPT. In this case, 4D-CT was the only modality in which large hyperplastic glands were identified, suggesting superior sensitivity. This case also highlights the importance of intraoperative parathyroid hormone testing to aid in diagnostic prediction.

Ultrasonography neck and dual-phase 99m Tc-sestamibi (MIBI) scan are standard imaging techniques for the detection of parathyroid adenomas in primary hyperparathyroidism. However, in presence of coexistent thyroid disease or small size of adenomas, the accuracy of these imaging modalities is low and leads to delayed diagnosis. We here present a report of two patients with primary hyperparathyroidism and with a nondiagnostic MIBI scan, who subsequently underwent successful surgery after positive localization of adenomas on 18 F-fluorocholine positron emission tomography-computed tomography.

The diagnostic accuracy of current imaging techniques in differentiating benign from malignant neoplasms in the case of indeterminate renal masses is still suboptimal.
To evaluate the diagnostic accuracy of 99mTc-sestamibi (SestaMIBI) single-photon emission tomography computed tomography (SPECT)/CT in characterizing indeterminate renal masses by differentiating renal oncocytoma and hybrid oncocytic/chromophobe tumor (HOCT) from (1) all other renal lesions and (2) all malignant renal lesions. Secondary outcomes were: (1) benign versus malignant; (2) renal oncocytoma and HOCT versus clear cell (ccRCC) and papillary (pRCC) renal cell carcinoma; and (3) renal oncocytoma and HOCT versus chromophobe renal cell carcinoma (chRCC).
A literature search was conducted up to November 2022 using the PubMed/MEDLINE, Embase, and Web of Science databases. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to identify eligible studies. Studies included were prospective and retrospective cross-sectional studies in which SestaMIBI SPECT/CT findings were compared to histology after renal mass biopsy or surgery.
Overall, eight studies involving 489 patients with 501 renal masses met our inclusion criteria. The sensitivity and specificity of SestaMIBI SPECT/CT for renal oncocytoma and HOCT versus all other renal lesions were 89% (95% confidence interval [CI] 70-97%) and 89% (95% CI 86-92%), respectively. Notably, for renal oncocytoma and HOCT versus ccRCC and pRCC, SestaMIBI SPECT/CT showed specificity of 98% (95% CI 91-100%) and similar sensitivity. Owing to the relatively high risk of bias and the presence of heterogeneity among the studies included, the level of evidence is still low.
SestaMIBI SPECT/CT has good sensitivity and specificity in differentiating renal oncocytoma and HOCT from all other renal lesions, and in particular from those with more aggressive oncological behavior. Although these results are promising, further studies are needed to support the use of SestaMIBI SPECT/CT outside research trials.
A scan method called SestaMIBI SPECT/CT has promise for diagnosing whether kidney tumors are malignant or not. However, it should still be limited to research trials because the level of evidence from our review is low.

99mTc-sestamibi scintigraphy localizes parathyroid adenoma as a persistent focus of uptake on delayed images, whereas thyroid glands in normal or ectopic locations are seen on only early images and wash out on delayed images. We report a case of absence of eutopic neck thyroid activity and synchronous ectopic lingual thyroid and mediastinal parathyroid adenoma on scintigraphy confirmed with CT.

UNASSIGNED: To investigate the value of presurgical 18F-FCH PET/CT in detecting additional hyperfunctioning parathyroids despite a positive 99mTc-sestamibi parathyroid scintigraphy in patients with primary hyperparathyroidism (pHPT).
UNASSIGNED: This is a retrospective study involving patients with pHPT, positive parathyroid scintigraphy performed before 18F-FCH PET/CT, and parathyroid surgery achieved after PET/CT. Imaging procedures were performed according to the EANM practice guidelines. Images were qualitatively interpreted as positive or negative. The number of pathological findings, their topography, and ectopic location were recorded. Histopathology, Miami criterion, and biological follow-up were considered to ensure effective parathyroidectomy confirming the complete excision of all hyperfunctioning glands. The impact of 18F-FCH PET/CT on therapeutic strategy was recorded.
UNASSIGNED: 64/632 scanned pHPT patients (10%) were included in the analysis. According to a per lesion-based analysis, sensitivity, specificity, positive predictive value, and negative predictive value of 99mTc-sestamibi scintigraphy were 82, 95, 87, and 93%, respectively. The same values for 18F-FCH PET/CT were 93, 99, 99, and 97%, respectively. 18F-FCH PET/CT showed a significantly higher global accuracy than 99mTc-sestamibi scintigraphy: 98% (CI: 95-99) vs. 91% (CI: 87-94%). Youden Index was 0.79 and 0.92 for 99mTc-sestamibi scintigraphy and 18F-FCH PET/CT, respectively. Scintigraphy and PET/CT were discordant in 13/64 (20%) patients (49 glands). 18F-FCH PET/CT identified nine pathologic parathyroids not detected by 99mTc-sestamibi scintigraphy in 8 patients (12.5%). Moreover, 18F-FCH PET/CT allowed the reconsideration of false-positive scintigraphic diagnosis (scinti+/PET-) for 8 parathyroids in 7 patients (11%). The 18F-FCH PET/CT influenced the surgical strategy in 7 cases (11% of the study population).
UNASSIGNED: In a preoperative setting, 18F-FCH PET/CT seems more accurate and useful than 99mTc-sestamibi scan in pHPT patients with positive scintigraphic results. Positive parathyroid scintigraphy could be not satisfactory before neck surgery particularly in patients with multiglandular disease, suggesting a need to evolve the practice and define new preoperative imaging algorithms including 18F-FCH PET/CT at the fore-front in pHPT patients.

OBJECTIVE: We aimed to evaluate the effectiveness of high-dose and low-dose use of radioactive material in intraoperative gamma probe application methods in patients diagnosed with primary hyperparathyroidism and planned for surgery.
METHODS: 47 patients with primary hyperparathyroidism underwent minimally-invasive parathyroid surgery (MIS) after preoperative imaging studies consisting of ultrasonography (USG) and sestamibi parathyroid scintigraphy (SPS) showed a possible primary parathyroid lesion (PPL). All patients received Tc-99 sestamibi on day-of-surgery imaging (DOSI) to help with the localization of a primary parathyroid lesion (PPL) via both DOSI and intraoperative gamma probe (IGP). Patients in Group I were administered 20-25 mCi Tc-99m sestamibi (methoxy isobutyl isonitrile) and images were obtained at the 20th and 120th minutes. Patients in Group II were administered 8-10 mCi doses and images were obtained at the 20th and 40th minutes. Two nuclear medicine specialists independently evaluated the images. Lesions in the localizations determined by DOSI and IGP were compared with the histopathological results of these lesions.
RESULTS: 47 patients, 35 females, and 12 males were included in the study. The mean age of 28 patients in the first group given the high dose was 54 (41-60), and the mean age was 48 (42-57) in the second group given the low dose (p=0.011). In the group given low-dose radioactive material during intraoperative gamma probe application, the observer\'s sensitivity, specificity, positive, and negative predictive values for finding pathology were 61.1, 100, 100, and 12.5, respectively. In the group given high-dose radioactive material, the same values were 90.9, 33.3, 50, and 83.3, respectively. While the success of MIS increases with the use of DOSI and IGP in large lesions, the success decreases with the prolongation of the accumulation time of the given dose.
CONCLUSIONS: In the intraoperative gamma probe technique used in primary hyperparathyroidism patients, the method used with low-dose radioactive material has lower sensitivity but higher specificity in estimating the post-operative pathology compared to the high-dose technique.