Tc-sestamibi Scan Research Articles

PD15-01 EVALUATING 99M TC-SESTAMIBI SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY/COMPUTED TOMOGRAPHY CONCORDANCE WITH SURGICAL PATHOLOGY FOR RENAL MASSES

You have accessJournal of UrologyCME1 May 2022PD15-01 EVALUATING 99M TC-SESTAMIBI SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY/COMPUTED TOMOGRAPHY CONCORDANCE WITH SURGICAL PATHOLOGY FOR RENAL MASSES Shilpa Argade, Carrie Ronstrom, Joel Vetter, Brijesh Patel, Mark Biebel, Joyce Mhlanga, and Robert Figenshau Shilpa ArgadeShilpa Argade More articles by this author , Carrie RonstromCarrie Ronstrom More articles by this author , Joel VetterJoel Vetter More articles by this author , Brijesh PatelBrijesh Patel More articles by this author , Mark BiebelMark Biebel More articles by this author , Joyce MhlangaJoyce Mhlanga More articles by this author , and Robert FigenshauRobert Figenshau More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002547.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Benign renal masses are challenging to differentiate from malignant renal masses using noninvasive techniques. 99m Tc-sestamibi scan single photon emission computed tomography/computed tomography (sestamibi scan) has emerged as a potential diagnostic tool. Already widely utilized in the diagnosis of hyperparathyroidism, sestamibi scans differentiate renal masses on the basis of differences in mitochondrial content between malignant renal masses and oncocytomas. This study sets out to evaluate the concordance between renal mass sestamibi scan interpretation and surgical pathology. METHODS: We retrospectively identified patients undergoing sestamibi scan and renal mass biopsy or excision between September 2016 and May 2021 at our institution. The sestamibi scan final diagnostic report and surgical pathology results were compared. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS: We identified 26 patients with 31 tumors. The average age of patients was 65.7 years. Sestamibi scan identified 7 oncocytomas, 20 renal cell carcinomas, and 4 mixed tumors with average size 4.8 cm, 3.2 cm, and 4.9 cm, respectively. Surgical pathology from 12 renal mass biopsies and 19 renal mass excisions showed 8 oncocytomas, 22 renal cell carcinomas, and 1 angiomyolipoma. Sestamibi scan overall accuracy was 61.3% with sensitivity 70.8%, specificity 28.6%, positive predictive value 77.3%, and negative predictive value 22.2% (Table 1). CONCLUSIONS: Previous studies have shown that as many as 20-30% of excised renal masses are benign, calling attention to the need for improved diagnostic techniques. While the overall accuracy of sestamibi scans was moderate, positive predictive value was the highest at 77.3%. This study demonstrates that sestamibi scans can be a useful noninvasive adjunct to differentiate between benign and malignant renal masses. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e262 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Shilpa Argade More articles by this author Carrie Ronstrom More articles by this author Joel Vetter More articles by this author Brijesh Patel More articles by this author Mark Biebel More articles by this author Joyce Mhlanga More articles by this author Robert Figenshau More articles by this author Expand All Advertisement PDF DownloadLoading ...

A Challenging Diagnosis of Primary Hyperparathyroidism in an Adolescent Female

Background: Hypercalcemia secondary to primary hyperparathyroidism (PHPT) is less common in children than adults. Single parathyroid adenoma is commonly the cause of primary hyperparathyroidism in children. Clinical Case: We present a 15-year-old female with one-week history of abdominal pain despite taking over the counter antacids. Her initial work up by her primary care provider revealed serum calcium of 11.8 mg/dL (9.0–11.5) and creatinine of 0.8 mg/dL (0.4–1.2). A week later, she presented to the emergency department with same complaint. In ED, she was found to have hypercalcemia (12.8 mg/dl) with elevated parathyroid hormone (PTH) at 78.5 pg/mL (15–65). Her random urine calcium creatinine ratio was high at 2.1. Her 25OHD was 25 ng/mL (30–100). She had negative urine pregnancy test but had trace ketones, leukocyte esterase, blood and bacteria. CBC and CMP were otherwise unremarkable. She continued to complain abdominal pain with nausea, decrease appetite, fatigue, and general muscle weakness. There was no known family history of calcium or metabolic bone disorders. Her vital signs and physical exam were normal. Subsequent labs showed mild improvement of calcium between (11–12.3 mg/dL), PTH between 54.5 and 77 pg/mL, normal thyroid function. Ionized calcium was mildly elevated 6.0 mg/dL (4.5–5.3) but her repeat 25OHD was low at18 ng/mL. Serum phosphorus levels were relatively normal with lowest level of 2.5 mg/dL (2.7–4.5). Gliadin Deamidated IgA was detectable 15 U/mL (< 15.0 U/). Ultrasound of abdomen was significant for nonspecific mild hepatomegaly; kidneys were normal in size and appearance. Ultrasound of thyroid was significant for probably intrathyroid parathyroid, measuring 6 x 8 x 8 mm. Tc-Sestamibi scan did not confirm a parathyroid adenoma. Genetic testing for MEN-1 was negative. FHH- related genes (i.e. CASR) was positive for p.R990G variant resulting in a mild gain of function of the calcium-sensing receptor. Although previous Tc-Sestamibi scan was unremarkable, an over read of it raised a concern for questionable uptake in the left superior lobe. SPEC-CT demonstrated possible abnormal parathyroid tissue in the upper pole of the left thyroid. FNA of the left thyroid nodule confirmed likely intrathyroidal parathyroid adenoma. Subsequent follow up and treatment, including parathyroidectomy, was done by another institution. She underwent a left parathyroidectomy with normalization of serum calcium and PTH levels post operatively (10.1 mg/dl and 8 pg/mL, respectively) and has complete resolution of her previous abdominal and gastrointestinal symptoms. Conclusion: PHPT is uncommon in children and adolescents and is typically associated with a single parathyroid adenoma. High index of suspicion is key for early diagnosis of PHPT despite a negative Tc-Sestamibi initially.

Osteoblasts to the Rescue – A Rare Case of Secondary Myelofibrosis

A 36-year-old female patient presented with joint pain, generalized weakness, and bleeding gums. There was no significant history of other illnesses or intake of drugs. Examination revealed pallor and splenomegaly. Peripheral smear examination showed pancytopenia. A large number of osteoblasts and a few scattered osteoclasts were seen in the bone marrow aspirate. The trephine biopsy revealed marrow fibrosis. A suggestion to investigate for hyperparathyroidism was made. Serum calcium, ionized calcium, and PTH were increased. 99m Tc-Sestamibi scan was done and adenoma was detected in the right inferior parathyroid and subsequently excised. Postsurgery, hematological parameters and bone markers improved. Follow-up bone marrow biopsy revealed hypercellular marrow with marked regression of fibrosis. Splenomegaly was reversed. We concluded that pancytopenia was due to bone marrow fibrosis, resulting from primary hyperparathyroidism. It is important to consider secondary causes of myelofibrosis in the appropriate clinical setting.

Factors related to a non-localising technetium 99m sestamibi scan result during parathyroid adenoma imaging in primary hyperparathyroidism.

The aim of this study is to investigate factors that are associated with having a non-localising 99m Tc-sestamibi scan. A retrospective study was performed on patients that underwent parathyroid surgery performed within a single institution between 2001 and 2018. Single tertiary centre for parathyroid surgery. 230 patients underwent surgery for primary hyperparathyroidism due to a solitary parathyroid adenoma and had preoperative 99m Tc-sestamibi imaging. Variables including age, gender, intra-operative location of parathyroid adenoma, adenoma weight and pre- and postoperative calcium and parathyroid hormone levels were investigated through univariate and multivariate analysis to identify any association with having a non-localising (negative) 99m Tc-sestamibi scan result. Multivariate analysis identified that right-sided adenomas (P=.038), superior adenomas (P=.042) and a lower preoperative PTH level (P=.034) were all individual factors associated with having a negative 99m Tc-sestamibi scan result. Although the weight of the adenoma was significant on univariate analysis (P=.029), this was not demonstrated on multivariate analysis (P=.422). Factors that were associated with having non-localising 99m Tc-sestamibi scan were right-sided adenomas, superior adenomas and lower preoperative PTH level. Further large prospective multicentre studies are needed to further evaluate these initial findings.

Dual-tracer radionuclide imaging in hyperparathyroidism: thallium-201 parathyroid scintigraphy revisited.

Tc-sestamibi is the current radiopharmaceutical of choice for the localization of hyperactive lesions of the parathyroid glands in patients with hyperparathyroidism. However, there are multiple factors that adversely affect the accumulation and retention Tc-sestamibi in the hyperfunctioning parathyroid tissue, resulting in a false-negative scan. The objective of this study was to investigate the possibility of an incremental diagnostic role of thallium-201 parathyroid scintigraphy in patients with presumably false-negative Tc-sestamibi scan results. The study comprised of 22 patients including 16 with primary hyperparathyroidism (PHPT) and 6 with secondary hyperparathyroidism where Tc-sestambi scan was initially negative, inconclusive or where additional lesions were suspected on the single-photon computed tomography/computed tomography (SPECT/CT) scan with the CT component identifying lesion(s) without significant Tc-sestamibi uptake. The results of our study show that in 22 patients (5 male, 17 female; age range 26-81; median age 53.4) further imaging with thallium-201 SPECT/CT scan showed 46.5% additional lesions in patients with hyperparathyroidism caused by an adenomatous or hyperplastic parathyroid lesion. In patients with PHPT caused by an adenomatous or hyperplastic parathyroid lesion, further imaging with thallium-201 showed 59% additional hyperactive parathyroid lesions. In patients with secondary hyperparathyroidism, further imaging with thallium-201 SPECT/CT showed additional 33.3% hyperplastic parathyroid lesions. The results of this pilot study strongly advocate a role for thallium parathyroid SPECT/CT imaging in patients with primary and secondary hyperparathyroidism where the initial Tc-sestamibi scan is deemed to be false-negative in the presence of biochemical hyperparathyroidism.

Quantitatively accurate activity measurements with a dedicated cardiac SPECT camera: Physical phantom experiments.

Recently, there has been increased interest in dedicated cardiac single photon emission computed tomography (SPECT) scanners with pinhole collimation and improved detector technology due to their improved count sensitivity and resolution over traditional parallel-hole cameras. With traditional cameras, energy-based approaches are often used in the clinic for scatter compensation because they are fast and easily implemented. Some of the cardiac cameras use cadmium-zinc-telluride (CZT) detectors which can complicate the use of energy-based scatter correction (SC) due to the low-energy tail-an increased number of unscattered photons detected with reduced energy. Modified energy-based scatter correction methods can be implemented, but their level of accuracy is unclear. In this study, the authors validated by physical phantom experiments the quantitative accuracy and reproducibility of easily implemented correction techniques applied to (99m)Tc myocardial imaging with a CZT-detector-based gamma camera with multiple heads, each with a single-pinhole collimator. Activity in the cardiac compartment of an Anthropomorphic Torso phantom (Data Spectrum Corporation) was measured through 15 (99m)Tc-SPECT acquisitions. The ratio of activity concentrations in organ compartments resembled a clinical (99m)Tc-sestamibi scan and was kept consistent across all experiments (1.2:1 heart to liver and 1.5:1 heart to lung). Two background activity levels were considered: no activity (cold) and an activity concentration 1/10th of the heart (hot). A plastic "lesion" was placed inside of the septal wall of the myocardial insert to simulate the presence of a region without tracer uptake and contrast in this lesion was calculated for all images. The true net activity in each compartment was measured with a dose calibrator (CRC-25R, Capintec, Inc.). A 10 min SPECT image was acquired using a dedicated cardiac camera with CZT detectors (Discovery NM530c, GE Healthcare), followed by a CT scan for attenuation correction (AC). For each experiment, separate images were created including reconstruction with no corrections (NC), with AC, with attenuation and dual-energy window (DEW) scatter correction (ACSC), with attenuation and partial volume correction (PVC) applied (ACPVC), and with attenuation, scatter, and PVC applied (ACSCPVC). The DEW SC method used was modified to account for the presence of the low-energy tail. T-tests showed that the mean error in absolute activity measurement was reduced significantly for AC and ACSC compared to NC for both (hot and cold) datasets (p < 0.001) and that ACSC, ACPVC, and ACSCPVC show significant reductions in mean differences compared to AC (p ≤ 0.001) without increasing the uncertainty (p > 0.4). The effect of SC and PVC was significant in reducing errors over AC in both datasets (p < 0.001 and p < 0.01, respectively), resulting in a mean error of 5% ± 4%. Quantitative measurements of cardiac (99m)Tc activity are achievable using attenuation and scatter corrections, with the authors' dedicated cardiac SPECT camera. Partial volume corrections offer improvements in measurement accuracy in AC images and ACSC images with elevated background activity; however, these improvements are not significant in ACSC images with low background activity.

Eleven-Year Prognostic Value of Dobutamine Stress 99mTc-Sestamibi Myocardial Perfusion Imaging in Patients With Limited Exercise Capacity

Myocardial perfusion single-photon emission computed tomography is a routine technique for the evaluation of coronary artery disease. However, information on the very long term prognostic value of dobutamine stress single-photon emission computed tomographic myocardial perfusion imaging (MPI) in patients with limited exercise capacity is scarce. The aim of this study was to assess the long-term prognostic value of dobutamine stress technetium-99m ((99m)Tc)-sestamibi MPI in these patients. The study population consisted of a high-risk cohort of 531 consecutive patients with limited exercise capacity who underwent dobutamine stress (99m)Tc-sestamibi MPI for the assessment of known or suspected coronary artery disease. Follow-up was successful in 528 patients. Because of early revascularization, 55 patients were excluded. The present data are based on 473 patients. The end points were all-cause mortality, cardiac death, nonfatal myocardial infarction, and late (>60 days) coronary revascularization. Kaplan-Meier survival curves were performed and univariate and multivariate analyses were performed to identify predictors of very long term outcome. The mean age of the patients was 61 ± 12 years, and 58% were men. Abnormal results (defined as the presence of reversible or fixed defects) were observed in 312 patients (66%). During a mean follow-up period of 11.3 ± 6.7 years, 287 patients (61%) died (all-cause mortality), of whom 125 (26%) died due to cardiac causes. Nonfatal myocardial infarction occurred in 59 patients (12%). Late coronary revascularization was performed in 61 patients (13%). Univariate predictors of major cardiac events included age, male gender, previous infarction, diabetes mellitus, history of angina, heart failure, ST-segment changes, abnormal results on (99m)Tc-sestamibi scan, reversible defect, fixed defect, summed rest score, and summed stress score. Multivariate analysis identified abnormal results on MPI as a strong independent predictor of major adverse cardiac events. In conclusion, in patients with limited exercise capacity, dobutamine stress (99m)Tc-sestamibi single-photon emission computed tomography provides incremental prognostic information in addition to clinical and stress test parameters for the prediction of very long term outcomes.

Comparison of Ultrasonography and99mTc-sestamibi Scan for Preoperative Localization of Parathyroid Adenoma

목적: 부갑상선선종의 수술 전 국소화에 있어 경부 초음파 검사와 MIBI 스캔의 역할을 비교하고자 하였다. 방법: 2004년 4월부터 2013년 5월까지 화순전남대학교 병원에서 수술 후 병리 조직검사상 단일 부갑상선선종으로 진단된 40예 환자들의 초음파, MIBI 스캔상의 위치와 수술 시의 위치를 비교한 후향적 연구이다. 결과: 초음파의 민감도는 95%, MIBI 스캔의 민감도는 92.5% 였으며, 29예(76.3%)의 환자에서 전형적인 초음파 소견을 보였다. 비전형적 초음파 소견을 보인 경우 8예와 초음파상 확인되지 않은 2예가 있어 MIBI 스캔이나 CT로 병변을 확인한 후 수술하였다. 스캔상 확인되지 않았던 한 예에서 세침흡인 검사를 통한 낭액의 iPTH를 확인 후 수술하였다. 초음파상 확인되지 않았던 2예는 모두 상부의 선종이었다. 결론: 경부 초음파 검사는 초음파상 전형적이거나 하부에 위치한 선종의 경우 특히 수술 전 국소화에 민감도와 정확도가 높은 검사이다. 이에 저자는 경부 초음파 검사를 수술 전 국소화에 우선적으로 추천하며, 초음파상 확인되지 않는 경우 추가적인 MIBI 스캔이나 CT 등의 검사가 필요하겠다.

Effects of Tirofiban Maintenance Duration on Myocardial Perfusion Defect Severity in Anterior Myocardial Infarction

Percutaneous coronary intervention (PCI) does not often produce optimal results, despite restoration of coronary blood flow at myocardial recovery, because of impaired microvascular perfusion. This study aimed to investigate and evaluate with (99m)Tc-sestamibi scan whether the results of PCI can be changed by maintenance infusion of tirofiban for 24 or 48 h in patients presenting with anterior ST-elevation myocardial infarction (STEMI). The study included 84 patients with anterior STEMI who were candidates for primary PCI and whose occlusion was in the proximal or mid-left anterior descending artery. Patients were given 25 μg/kg/3 min tirofiban and randomized to receive maintenance infusion at 0.15 μg/kg/min for 24 or 48 h. A resting (99m)Tc sestamibi scan was performed on the 5th day post-procedure before discharge. The primary efficacy endpoint was a patient's score on a 5-point scoring system for perfusion defect severity. Major adverse cardiac events (MACE) were defined as death from any cause, re-infarction, and clinically driven target-vessel revascularization within the first 6 months. Baseline characteristics of the patients were similar in the two infusion groups (n = 42 per group). There was no significant difference in the symptom onset-to-presentation time or door-to-balloon time between the two groups. With the exception of basal anteroseptal and basal anterior segments, significant reductions were obtained on the 5-point scoring system for perfusion defect severity in segments and in the summed rest scores. No significant differences were observed between the two groups in the incidence of MACE at 6 months. The safety profile did not differ between 24 and 48 h infusions of tirofiban. The use of tirofiban, when administered at a high bolus dose and maintained for 48 h, was safe and significantly reduced perfusion defect severity in patients with anterior STEMI presenting early after symptom onset and undergoing primary PCI.

99mTc-Sestamibi Scintigraphy to Monitor the Long-Term Efficacy of Enzyme Replacement Therapy on Bone Marrow Infiltration in Patients with Gaucher Disease

Assessing the skeletal response to enzyme replacement therapy (ERT) in Gaucher disease (GD) is problematic. We investigated the reliability of (99m)Tc-sestamibi scintigraphy in monitoring changes in bone marrow involvement induced by ERT. In 52 GD patients, the efficacy of ERT on bone marrow disease was monitored using at least 2 sequential (99m)Tc-sestamibi scans; 17 patients were receiving ERT at enrollment, and 35 were ERT-naïve. We elaborated a dose-response model by statistical analysis based on linear mixed models. Patients whose marrow disease improved had received a significantly higher ERT dose per month than patients who did not improve. Significantly more patients reached near-disappearance of marrow disease if their disease burden at enrollment had been lower and the duration of clinical signs shorter. The response of the marrow scintigraphic score was more pronounced in ERT-naïve patients. No relevant effect of ERT on marrow disease was observed until platelet count and splenomegaly had improved. Although based on localized evaluation, changes in the (99m)Tc-sestamibi score closely correlated with the main determinants of ERT, with a definite dose-response relationship. The threshold at which ERT induced any improvement in bone marrow disease was 35-36 U/kg/mo; in ERT-naïve patients, the scintigraphic score declined by 1 unit after ERT at 28 U/kg/mo.

Radionuclide parathyroid imaging: a concise, updated review.

The hypercalcemia of hyperparathyroidism (HPT) can cause devastating effects to the patient and only surgical removal of the hyperfunctioning parathyroid tissue can definitely cure the disease. Radionuclide parathyroid imaging has no role in the diagnosis of hyperparathyroidism or in the selection of the type of treatment. However, once surgery is decided (99m)Tc-sestamibi scanning can localize abnormal parathyroid glands preoperatively. In primary HPT radionuclide assessment may occasionally be helpful before bilateral neck exploration, it can identify patients suitable for focused surgery and is a prerequisite of the minimally invasive radioguided parathyroidectomy. In secondary and tertiary HPT the clinical value of parathyroid scintigraphy remains debatable, but in persistent or recurrent disease this modality is a first line examination before reoperation. In conclusion, (99m)Tc-sestamibi assessment has a well defined clinical role in the surgical management of patients with primary hyperparathyroidism and in recurrent disease, but its usefulness in cases of secondary hyperparathyroidism is not clearly established.

Three‐Dimensional Metabolic and Radiologic Gathered Evaluation Using VR‐RENDER Fusion: A Novel Tool to Enhance Accuracy in the Localization of Parathyroid Adenomas

The aim of this study was to assess the accuracy of a novel imaging modality, three-dimensional (3D) metabolic and radiologic gathered evaluation (MeRGE), for localizing parathyroid adenomas (PAs). Consecutive patients presenting with primary hyperparathyroidism who underwent both thin-slice cervical computed tomography (CT) and (99m)Tc-sestamibi (MIBI) scanning were included. 3D-CT reconstruction was obtained using VR-RENDER, which was used to perform 3D virtual neck exploration (3D-VNE). The MIBI scan was then fused with the 3D reconstruction to obtain 3D-MeRGE. Sensitivity, specificity, and accuracy were assessed. Parathyroid gland volume and preoperative parathormone (PTH) levels were analyzed as predictive factors of correct localization (i.e., correct quadrant). A total of 108 cervical quadrants (27 patients) were analyzed. Sensitivities were 79.31, 75.86, 65.51, and 58.61 % with 3D-MeRGE, 3D-VNE, MIBI, and CT, respectively. Specificity was highest with CT (94.93 %) followed by 3D-VNE (92.4 %). MIBI and 3D-MeRGE had the same specificity (88.6 %). 3D-MeRGE and 3D-VNE achieved higher accuracy than MIBI or CT alone. Mean PTH values were significantly higher in patients with lesions that were correctly identified (true positive, TP) than in those whose lesions were missed (false negative, FN) with 3D-VNE (219.60 ± 212.77 vs. 98.75 ± 12.76 pg/ml; p = 0.01) and 3D-MeRGE (217.69 ± 213.76 vs. 09.75 ± 20.48 pg/ml; p = 0.02). The mean parathyroid gland volume difference between TP and FN was statistically significant with all modalities except CT. 3D-MeRGE and 3D-VNE showed high accuracy for localization of PAs. 3D-MeRGE performed better than MIBI or CT alone for detecting small adenomas and those with a low PTH level.

Planar Scintigraphy with 123I/99mTc-Sestamibi, 99mTc-Sestamibi SPECT/CT, 11C-Methionine PET/CT, or Selective Venous Sampling Before Reoperation of Primary Hyperparathyroidism?

All patients with primary hyperparathyroidism should undergo localization studies before reoperation, but it is not known which method is most accurate. The purpose of this prospective study was to compare the performance of planar scintigraphy with (123)I/(99m)Tc-sestamibi, (99m)Tc-sestamibi SPECT (SPECT/CT), (11)C-methionine PET/CT, and selective venous sampling (SVS) in persistent primary hyperparathyroidism. Twenty-one patients referred for reoperation of persistent hyperparathyroidism were included and investigated with (123)I/(99m)Tc-sestamibi, SPECT/CT (n = 19), (11)C-methionine PET/CT, and SVS (n = 18) before reoperation. All patients had been operated on 1-2 times previously because of hyperparathyroidism. The results of the localization studies were compared with operative findings, histology, and biochemical cure. Eighteen (86%) of 21 patients were biochemically cured. Nineteen parathyroid glands (9 adenomas, 1 atypical adenoma, and 9 hyperplastic glands) were removed from 17 patients, and 1 patient who was biochemically cured had an unclear histology result. The accuracy for localizing a pathologic parathyroid gland to the correct side of the neck was 59% (95% confidence interval [CI], 36%-79%) for (123)I/(99m)Tc-sestamibi, 19% (95% CI, 5%-42%) for SPECT/CT, 65% (95% CI, 43%-84%) for (11)C-methionine PET/CT, and 40% (95% CI, 19%-65%) for SVS (P < 0.01 for (123)I/(99m)Tc-sestamibi vs. SPECT/CT). The corresponding accuracy for the correct quadrant or more specific site was 48% (95% CI, 27%-69%) for (123)I/(99m)Tc-sestamibi, 14% (95% CI, 3%-36%) for SPECT/CT, 61% (95% CI, 39%-80%) for (11)C-methionine PET/CT, and 25% (95% CI, 9%-49%) for SVS (P < 0.02 for (123)I/(99m)Tc-sestamibi vs. SPECT/CT). In the 3 patients not cured, preoperative (123)I/(99m)Tc-sestamibi and SPECT/CT remained negative, SVS was false predictive in all, and (11)C-methionine PET/CT in 1. (11)C-methionine PET/CT accurately revealed the pathologic gland in 4 of 8 (50%) patients with a negative (123)I/(99m)Tc-sestamibi scan result, all of whom were biochemically cured after reoperation. Planar scintigraphy with (123)I/(99m)Tc-sestamibi performs well in complicated primary hyperparathyroidism and is recommended as first-line imaging before reoperation. (11)C-methionine PET/CT provides valuable additional information if (123)I/(99m)Tc-sestamibi scan results remain negative. (99m)Tc-sestamibi SPECT/CT and SVS provide no additional information, compared with the combined results of (123)I/(99m)Tc-sestamibi and (11)C-methionine PET/CT imaging.

The use of positron emission tomography with 11C-methionine in patients with primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a common endocrine disorder, which is nowadays often discovered incidentally by the finding of increased serum calcium and PTH in routine blood tests [1]. PHPT is due to a single adenoma in the majority of cases (85–90 %), whereas hyperplasia of all parathyroid glands occurs in 10–15 % and carcinoma is found in less than 1 %. PHPT may occur sporadically or as a part of hereditary forms [2]. Pathological parathyroid glands are mainly located close to the thyroid gland, but ectopic localization in the mediastinum, or lateral to the carotid sheath, in the carotid bifurcation and very rarely within the thyroid or the thymus may occur in up to 20 % of cases [3]. Parathyroidectomy (PTx) is the only definitive cure of PHPT and, if performed by an experienced endocrine surgeon, is successful in up to 95 % of cases. In recent years, the minimally invasive PTx (MIP) has almost replaced the traditional full neck exploration [4]. A preoperative identification of the enlarged parathyroid lesion(s) is required to perform MIP [5]. Many imaging techniques are available for locating enlarged parathyroid glands, but Tc sestamibi scan and cervical ultrasound are the most commonly used [5]. Sestamibi is taken up both by thyroid and parathyroid tissues, but it persists longer in the latter; thus a late scan can show an uptake which is rather specific for the parathyroid gland. Planar parathyroid scintigraphy may miss small or ectopic lesions. The single photon emission computed tomography (SPECT) may be helpful for giving a more precise localization of enlarged parathyroid gland(s). The sensitivity varies in different series and may reach 90–95 % using SPECT, but may be lower using planar scintigraphy [6]. The sensitivity for small adenomas, double adenomas or hyperplasia is much lower, and in the latter case computed tomography (CT)-sestamibi SPECT image fusion is superior to CT or sestamibi SPECT alone [7]. Neck ultrasound is a widely available, safe and low-cost technique and may identify a coexisting thyroid disease. The accuracy of neck ultrasound is operator-dependent. Its sensitivity can range from 42 to 82 % with a specificity of approximately 90 % [8]. CT of the neck and mediastinum and magnetic resonance imaging (MRI) are generally used in patients with persistent or recurrent PHPT, or when ultrasound and sestamibi imaging studies are negative or contradictory [5]. The TC sensitivity ranges from 50 to 88 % [5]. MRI is time-consuming and less sensitive than TC. Invasive localization techniques such as arteriography and selective venous sampling for PTH assay in the draining thyroid veins are nowadays rarely used and could be reserved to patients with prior PTx and negative imaging studies [5]. Positron emission tomography (PET) has a spatial resolution higher than that of sestamibi scintigraphy and, alone or with simultaneous CT scan (PET/CT), could be an useful tool for the identification of enlarged parathyroid glands in patient with persistent or recurrent PHPT when the results of other imaging techniques are negative or conflicting. In patients with PHPT, the PET with F-fluorodeoxyglucose (FDG-PET) showed a diagnostic accuracy lower than that of sestamibi SPECT. On the other hand, PET with C-methionine (C-Met-PET) has a sensitivity higher than that of FDG-PET [9]. C-methionine is considered to be more specific, since C-methionine seems to concentrate specifically in the enlarged parathyroid F. Cetani (&) C. Marcocci Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy e-mail: cetani@endoc.med.unipi.it

Delayed Surgery for Parathyroid Adenoma Misdiagnosed as a Thyroid Nodule and Treated with Radiofrequency Ablation

Primary hyperparathyroidism occurs as a result of isolated parathyroid adenoma in 80% to 85% of all cases. A 99mtechnetium (99mTc) sestamibi scan or neck ultrasonography is used to localize the neoplasm prior to surgical intervention. A 53-year-old female was referred for the exclusion of metabolic bone disease. She presented with low back pain that had persisted for the past 6 months and elevated serum alkaline phosphatase (1,253 IU/L). Four years previously, she had been diagnosed at a local hospital with a 2.3-cm thyroid nodule, which was determined to be pathologically benign. Radiofrequency ablation was performed at the same hospital because the nodule was still growing during the follow-up period 2 years before the visit to our hospital, and the procedure was unsuccessful in reducing the size of the nodule. The results of the laboratory tests in our hospital were as follows: serum calcium, 14.6 mg/dL; phosphorus, 3.5 mg/dL; and intact parathyroid hormone (iPTH), 1,911 pg/mL. Neck ultrasonography and 99mTc sestamibi scan detected a 5-cm parathyroid neoplasm in the left lower lobe of the patient's thyroid; left parathyroidectomy was performed. This case indicated that thyroid ultrasonographers and pathologists need to be experienced enough to differentiate a parathyroid neoplasm from a thyroid nodule; 99mTc sestamibi scan, serum calcium, and iPTH levels can help to establish the diagnosis of parathyroid neoplasm.

Acute pancreatitis caused by an ectopic mediastinal parathyroid adenoma.

A 22-year-old man was admitted to our hospital because of epigastric pain. Blood tests showed leukocytosis (8940cells/mm(3)) and increased serum amylase levels (787IU/L); an abdominal computed tomography (CT) scan revealed an enlarged pancreas and peripancreatic fluid collection. On the basis of these findings, he was diagnosed with acute pancreatitis. Hypercalcemia (13.5mg/dL) and increased levels of parathormone (>3200pg/dL) were also detected using a high-sensitivity assay; we therefore considered hypercalcemia and primary hyperparathyroidism to be the possible causes of the acute pancreatitis. A (99m)Tc-sestamibi scan showed accumulation of parathyroid tissue in the left mediastinum, and a tumor was noted on the left side of the aortic arch on a thoracic CT scan. Our final diagnosis was acute pancreatitis due to hypercalcemia induced by an ectopic mediastinal parathyroid adenoma. Ectopic parathyroid tumors can thus cause acute pancreatitis, and (99m)Tc-sestamibi and CT scans are useful for their diagnosis and localization.

Study of radioactivities in parathyroid and near tissues during radioguided parathyroidectomy

To determine the radioactivities in parathyroid and near tissues during radioguided parathyroidectomy in patients with hyperparathyroidism and the utility of parathyroidectomy in patients with negative (99m)Tc-sestamibi scans. Between August 2010 and August 2011, 21 patients underwent radioguided parathyroidectomy for hyperthyroidism. The levels of parathyroid hormone (PTH) and serum calcium before and after surgery were detected respectively. In vivo and ex vivo radioactivities in parathyroid and near tissues were examined. According to the radioactivity in parathyroid, the patients were divided into two groups, positive group and negative group. All data was descriptively analyzed and underwent a t test and an analysis of variance. In all patients both PTH and calcium levels decreased significantly after parathyroidectomy when compared to those before surgery (t' = 17.71 and t = 10.00, respectively, P < 0.001). In vivo and ex vivo radioactivities in enlarged parathyroid glands were higher than those in thyroid and fat tissue (F = 75.25 and 37.81, respectively, P < 0.001). In vivo and ex vivo radioactivities of the enlarged parathyroid with negative sestamibi scans were significantly greater than background radioactivity. There are significant differences in (99m)Tc-sestamibi radioactivities among enlarged parathyroid glands, thyroid glands and fat tissues. This radioguided technique is helpful to identify abnormal parathyroid gland in patients with hyperparathyroidism during parathyroidectomy.

Comparative Study of Preoperative Imaging Detection and Localization Test for Hyperparathyroidism

Received April 12, 2012 Revised June 15, 2012 Accepted June 18, 2012 Address for correspondence Kyung Tae, MD Department of OtolaryngologyHead and Neck Surgery, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-792, Korea Tel +82-2-2290-8585 Fax +82-2-2293-3335 E-mail kytae@hanyang.ac.kr Background and ObjectivesZZAccurate preoperative localization of abnormal parathyroid gland is essential for successful parathyroidectomy. The aim of this study was to evaluate the accuracy of a localization test for hyperparathyroidism including ultrasonography (US), computed tomography (CT) and Tc-sestamibi scan. Subjects and MethodZZWe studied 47 patients with hyperparathyroidism who underwent parathyroidectomy from January 2003 through December 2010, retrospectively. Tc-sestamibi scan, US and CT were carried out as a preoperative localization test and their accuracy were analyzed according to the size, location and pathology of parathyroid lesions. ResultsZZThe accuracy of Tc-sestamibi scan, US and CT were 93%, 77% and 65%, respectively. The accuracy of Tc-sestamibi scan and CT combined was 94% and US and CT 73%. The accuracy of combination of US and Tc-sestamibi scan was 96%, which was not different depending on size, location and pathology of parathyroid lesions. ConclusionZZThe combination of Tc-sestamibi scan and US is the most effective method for preoperative detection and the localization of hyperparathyroidism. Korean J Otorhinolaryngol-Head Neck Surg 2012;55:565-70

A Comparison of Outcomes for Younger and Older Adult Patients Undergoing Surgery for Primary Hyperparathyroidism

In adolescents and young adults, primary hyperparathyroidism (PHPT) is an uncommon diagnosis. We compared the clinical characteristics of these patients to those of older adult patients with PHPT. We hypothesized that PHPT in adolescents and young adults is more often caused by single-gland disease and is amenable to minimally invasive parathyroidectomy (MIP). We retrospectively reviewed the medical records of 452 consecutive patients who had surgery for PHPT. Patients ranged in age from 13 to 94 years and were dichotomized into younger (age <30 years, n = 17, 3.8%) and older (age ≥ 30 years, n = 435, 96.2%) patients. Continuous baseline and intraoperative and postoperative measures were not normally distributed and were summarized with medians and interquartile ranges (IQRs). Groups were compared using Wilcoxon rank sum test or Fisher exact test, and significance was set at P < .05. Median [IQR] age was 24 [23-27] years for the younger group and 58 [51-66] years for the older group. Though not statistically significant, a smaller proportion of the younger patients compared with the older patients had a positive (99m)Tc-sestamibi scan (71%; 95% confidence interval [95% CI] = 44-90% vs. 83%; 95% CI = 79-86%) and showed a suspected parathyroid adenoma on ultrasound (65%; 95% CI = 38-86% vs. 80%; 95% CI = 76-83%). The younger and older age groups did not significantly differ on preoperative serum PTH levels (median [IQR]: 111 [76-145] pg/ml vs 110 [84-152] pg/ml; P = .73 respectively). The younger group had higher serum calcium levels (11.6 [11.1-12.2] mg/dl) compared with the older group (11.1 [10.7-11.5] mg/dl; P = .01). MIP was performed less frequently on the younger patients (70.6%) compared with older patients (88.7%; P = 0.04). Though the incidence of a single adenoma was somewhat more frequent in older patients (90%; 95% CI = 87-93%) than in younger patients (82%; 95% CI = 57-96%) it was the most frequent cause of PHPT in the younger patients. The younger and older groups did not significantly differ on percent drop from baseline for intraoperative PTH monitoring (81.7 vs 79.3%; P = .46), respectively. Younger patients with PHPT present with significantly higher serum calcium levels than older patients. However, younger patients are less likely to localize abnormal parathyroid glands on sestamibi or ultrasound. Though younger patients appear to have a higher incidence of hyperplasia compared with older patients, single gland disease is still the overall most frequent cause. Our data suggest that MIP should be more frequently considered in younger patients because of the high incidence of single gland disease.

An unusual association of neuroendocrine tumors in MEN 1A

Multiple Endocrine Neoplasia type 1 is an autonomic dominant disease with a high degree of penetrance. It is characterized by combinations of over 20 different endocrine and nonendocrine tumors. A 25-year-old woman was referred for 1 year-evolution amenorrhea and bilateral galactorrhea. She also had fasting hypoglycaemia and hypercalcemia, and she was diagnosed of Multiple Endocrine Neoplasia type 1A. Resection of three parathyroid glands was performed showing hyperplasia of principal cells. Post-parathyroidectomy serum levels of calcium and intact PTH were normal but 3 years later serum calcium levels rose again. A 99mTc-sestamibi scan showed increased uptake in the low right area compatible with adenoma. After biochemical test showing probable insulinoma, somatostatin receptor scintigraphy showed a focal captation in head and body of pancreas. MRI found two nodules in the same localization. An antral gastrectomy, total pancreatoduodenectomy, colecistectomy and truncal vagotomy was performed and histopathologic examination revealed a combination of neuroendocrine tumors: gastrinomas, somastotinomas, glucagonomas and insulinomas. After surgery she started with tingling in fingers, toes and lips, and calcium levels was 5.9 mg/dl and PTH intact 3 pg/ml. A new 99m Tc-sestamibi scan showed no captation and cervical ultrasonography was normal. Now, 2 years later, she continues with normal calcium and i-PTH levels. This report represents an unusual case of MEN 1A with association of insulinomas, gastrinomas glucagonomas and somatostatinomas in the same patient.