99mTc-MIBI Scintigraphy Research Articles

A case of intrathyroid parathyroid tumor that was difficult to diagnose by ultrasonography

BackgroundWith advances in diagnostic imaging such as ultrasonography (US), computed tomography (CT), and 99mTc-MIBI-sestamibi (MIBI) scintigraphy, localized diagnosis of hyperparathyroidism (pHPT) has become possible with considerable accuracy. However, even with the use of these imaging techniques, since intrathyroid parathyroid tumors exist as a mass within the thyroid, it is often difficult to distinguish from thyroid masses. Although there have been various reports on US images of intraparathyroid tumors, we experienced a case with US images that were distinct from previous reports. Herein we present a case of an intrathyroid parathyroid adenoma (IPA) that was difficult to diagnose, with a main focus on US images.Case presentationA 53-year-old man with a diagnosis of hyperparathyroidism was referred to our department in December 2018. Ultrasonography revealed a tumor that was located in the inferior pole of the right lobe of the thyroid gland and no parathyroid mass was observed. The tumor had an irregular round shape and showed heterogeneous hyperechogenicity with a defined margin, but within it, there were a few irregular and hypoechogenic area with unclear margins, while the tumor had a mosaic appearance at first glance. Although 99mTc-MIBI scintigraphy showed accumulation at the same location in delayed phase, it was difficult to determine the presence of a parathyroid tumor on the image. The patient underwent an operation on April 2019 and the tumor could not be identified on both naked eye and palpation. We used US intraoperatively to define the location and resected the tumor. A parathyroid adenoma was diagnosed by frozen section and the final diagnosis was an intrathyroid parathyroid adenoma.ConclusionWe experienced an IPA presenting an US image that was atypical and has previously not been reported. IPA has no established US image to confirm the diagnosis and even with the use of other imaging techniques, a definitive diagnosis often cannot be established. Thus, our recommendation based on the current situation is that operation with intraoperative diagnosis using frozen section should be conducted if hypercalcemia and high I-PTH are observed and when localization sites in MIBI and US coincide.

High capacity of ultrasound for locating parathyroid adenomas in endocrinology (the ETIEN 4 study)

ObjectiveTo assess the diagnostic performance of neck ultrasound examination performed by endocrinologists to locate parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). MethodologyA retrospective observational study in 135 patients (mean age, 60.0±12.3 years; 74.8% females) seen at endocrinology for PHPT (mean calcium level, 11.3±1.2mg/dl and mean PTH level, 240.4±346.8pg/ml) who underwent neck ultrasound examinations at the endocrinology department. 99mTc-MIBI parathyroid scintigraphy was performed before surgery in all patients. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated in surgical patients. ResultsNinety-eight patients underwent surgery for PHPT and 97.8% were cured at 6 months. Parathyroid ultrasound had a sensitivity of 85% (95% CI: 75.7%–91.2%) and a positive predictive value (PPV) of 95.2% (95% CI: 87.5%–98.4%) to locate parathyroid adenomas 1.7±0.9cm in maximum diameter (69.4% in smaller glands), showing a high correlation (r=0.661 and r=0.716) with maximum diameter and volume of the excised adenoma. Sixty percent of patients had nodular thyroid disease (64.2% bilateral nodules with mean maximum diameter of 1.5±0.9cm), and thyroidectomy was performed in 31.6%. The highest diagnostic performance was seen with a combination of neck ultrasound and 99mTc-MIBI scintigraphy (sensitivity: 96.8% and PPV: 95.8%). ConclusionIn our area, parathyroid adenoma localization with ultrasound performed by endocrinologists has a high diagnostic yield and allows for detecting nodular thyroid disease in 60% of patients.

Factors Influencing the Sensitivity of Ultrasound and Gamma Location of the Parathyroid Adenoma

IntroductionThe treatment of choice for primary hyperparathyroidism (PHPT) when there is proper preoperative localization of the adenoma is minimally invasive parathyroidectomy. However, imaging techniques are not always able to provide the exact location. The objective is to identify potential factors that might influence the sensitivity and concordance of ultrasound (US) and 99mTc-methoxy-isonitrile parathyroid scintigraphy (MIBI-PS) and the actual location of the adenoma. MethodsWe reviewed the data of patients who underwent parathyroidectomies for PHPT. All patients had undergone ultrasound and 99mTc-MIBI scintigraphy as a preoperative location study. Multiple endocrine neoplasms, other hyperplasias and non-cervical ectopic adenomas were excluded. The sensitivity, PPV and concordance have been estimated for the location of the gland in both tests compared with the intraoperative location, using a multivariable analysis of the factors that might influence their localization capacity. Results139 patients (82% women) have been analysed. The US sensitivity was 56.7%, concordance (Kappa index) 0.387 and PPV 96.3%. The MIBI-PS sensitivity was 81.6%, the concordance (Kappa index) 0.669 and the PPV 97.4%. The factor that improved localization of the glands by US in the multivariable analysis was the absence of a concomitant thyroid pathology. The factor that improved the MIBI-PS results was a gland weight greater than 600 mg. ConclusionsUS sensitivity improves when there is no concomitant thyroid pathology. MIBI-PS sensitivity improves when the gland weight is greater than 600 mg.

Lower limb perfusion scintigraphy with 99mTc-MIBI scintigraphy and determination of endothelin in diabetic and nondiabetic patients

Background/Aim. Peripheral artery disease (PAD) is a common macrovascular complication in patients with diabetes mellitus (DM) as a result of impairment of homeostatic mechanisms of the endothelium, thus initiating the process of atherosclerosis. The imbalance between endothelium- derived vasodilators and vasoconstrictors plays an important role in the pathogenesis of diabetic microangiopathy, as well as in other vascular complications in diabetes. Perfusion scintigraphy using technetium-99m-methoxyisobutyl isonitrile (99mTc-MIBI) can be very useful method for evaluation of the lower limbs muscle perfusion. The aim of this study was: to compare the results of dynamic and static studies of lower limbs tissue muscle perfusion scintigraphy with 99mTc-MIBI (one-day rest-stress protocol) in patients with and without DM and to determine the perfusion reserve for diagnostic evaluation of PAD in patients with DM type 2, as well as to assess the endothelin-1 (ET-1) levels as a vasoconstrictor agent in patients with and without diabetes. Methods. Prospective study was performed in 90 patients, divided into two groups according to the presence of DM ? patients with DM type 2 (DP), 60/90 (67%), and patients without DM (NDP), 30/90 (33%). Lower limbs tissue muscle perfusion scintigraphy was done with 99mTc-MIBI including two studies (?rest? and ?stress?). Results. In the DP group significantly lower pick of radioactivity was detected in comparison with the NDP group, in both phases (rest and stress), for both calves. Lower counts from the static phase were registered in the region of both calves. Lower inter-extremity indexes as well as perfusion reserve were found in the DP group. There was a significant difference in concentrations of ET-1 between groups (higher concentrations were found in tzhe DP group). Conclusion. This one-day protocol (rest-stress with 99mTc-MIBI) of perfusion scintigraphy of lower limbs is considered a useful procedure in PAD assessment in patients with DM type 2, especially the asymptomatic form.

MODERN DIAGNOSTIC AND MINIMALLY INVASIVE TECHNOLOGY IN THYROID SURGERY

Purpose of the study: to evaluate the role of the main instrumental methods of diagnostics and to determine the criteria for selecting patients with surgical diseases of the thyroid gland (TG) for the reasonable implementation of optimal minimally invasive surgical interventions. Materials and methods: the results of the examination and treatment of 340 patients with surgical diseases of the TG, who underwent variety of minimally invasive techniques were analyzed. Results: we compared the sensitivity, specificity, accuracy, positive and negative predictive values of the multiparametric neck ultrasonography, 99mTc-MIBI scintigraphy TG and fine-needle cytology. Minimally invasive video-assisted procedure was performed in 29,4% patients, nonendoscopic - in 38,2%, endoscopic - in 32,4%. Postoperative specific complications were revealed in 4,4% who underwent surgery: transitory recurrent laryngeal nerve palsy - in 1,5%, transient hypoparathyroidism - in 1,6%, hematoma - in 0,8%. It was stated that the main criteria that determine the rationale for minimally invasive interventions on the TG are: the nodule size and the TG volume; hyperfunctioning thyroid and clinical thyroiditis; substernal extension; extrathyroid extension and the necessity of implementation of central neck dissection due to central and laterocervical lymph node metastases. Conclusion: the application of the determined criteria based on the integrated use of modern diagnostic techniques for patients with surgical diseases of the TG can justify the selection of optimal minimally invasive surgical interventions, avoid unreasonable operations, to avoid increasing of the frequency of specific complications, reduces surgical trauma and duration of stay in hospital, improves cosmetic outcome and enhances the quality of life of the patients.

Factores que condicionan la sensibilidad de la ecografía y la gammagrafía en la localización del adenoma paratiroideo

IntroductionThe treatment of choice for primary hyperparathyroidism (PHPT) when there is proper preoperative localization of the adenoma is minimally invasive parathyroidectomy. However, imaging techniques are not always able to provide the exact location. The objective is to identify potential factors that might influence the sensitivity and concordance of ultrasound (US) and 99mTc-methoxy-isonitrile parathyroid scintigraphy (MIBI-PS) and the actual location of the adenoma. MethodsWe reviewed the data of patients who underwent parathyroidectomies for PHPT. All patients had undergone ultrasound and 99mTc-MIBI scintigraphy as a preoperative location study. Multiple endocrine neoplasms, other hyperplasias and non-cervical ectopic adenomas were excluded. The sensitivity, PPV and concordance have been estimated for the location of the gland in both tests compared with the intraoperative location, using a multivariable analysis of the factors that might influence their localization capacity. Results139 patients (82% women) have been analysed. The US sensitivity was 56.7%, concordance (Kappa index) 0.387 and PPV 96.3%. The MIBI-PS sensitivity was 81.6%, the concordance (Kappa index) 0.669 and the PPV 97.4%. The factor that improved localization of the glands by US in the multivariable analysis was the absence of a concomitant thyroid pathology. The factor that improved the MIBI-PS results was a gland weight greater than 600mg. ConclusionsUS sensitivity improves when there is no concomitant thyroid pathology. MIBI-PS sensitivity improves when the gland weight is greater than 600mg.

Hyperparathyroidism in pregnancy and 99mTc-MIBI scintigraphy

IntroductionPrimary hyperparathyroidism (PHPT) during pregnancy can be responsible for serious maternal and foetal complications and should be treated by elective low-risk, minimally invasive surgery. Preoperative assessment of hyperfunctioning parathyroid glands is classically based on high-resolution neck ultrasound (US) and 99mTc-sestamibi/123I scintigraphy. However, administration of any radiopharmaceutical during pregnancy must be limited and justified and US alone may be sufficient to localize an abnormal parathyroid gland. Case reportWe report the case of a 4-month pregnant woman with severe primary hyperparathyroidism, in whom US failed to localize the abnormal parathyroid gland. 99mTc-sestamibi scintigraphy was performed in preference to 18-fluorocholine (FCH)-PET/CT on the basis of a multidisciplinary decision. As 99mTc-MIBI demonstrated an hyperfunctioning right inferior parathyroid, 123I was not administered. A large right paravertebral parathyroid adenoma was successfully removed, as confirmed by decreased postoperative serum parathyroid hormone and calcium levels. The eutrophic newborn infant was delivered at term, with normal serum calcium and TSH levels. DiscussionIn pregnant women with primary hyperparathyroidism, US alone may be sufficient when it localizes the abnormal parathyroid gland, allowing elective low-risk minimally invasive surgery. Otherwise, a multidisciplinary approach is mandatory to select the radiopharmaceutical that can be safely used to identify the hyperfunctioning parathyroid gland with minimal risks for the foetus.

Prediction and evaluation of neoadjuvant chemotherapy using the dual mechanisms of 99mTc-MIBI scintigraphy in patients with osteosarcoma

PurposeTo investigate the feasibility of applying the dual imaging mechanisms of 99mTc-MIBI scintigraphy in predicting and evaluating the response to neoadjuvant chemotherapy in patients with osteosarcoma. Materials and methodsThirty patients with osteosarcoma who underwent both pre-and post-chemotherapy 99mTc-MIBI scintigraphy were enrolled in the study. In each patient, the tumor to background ratio (T/B), tumor washout rate (WR) of MIBI and the alteration rate (AR) of tumor uptake after chemotherapy was calculated, respectively, on MIBI scintigraphy before or after chemotherapy. Based on the tumor necrosis rate histologically confirmed by tumor resection after chemotherapy, the diagnostic performance of MIBI scintigraphy was assessed in predicting tumor response with the WR of pre-chemotherapy imaging, as well as evaluating tumor response with the AR of both pre-and post-chemotherapy imaging. ResultsOn pre-chemotherapy MIBI imaging, no statistical difference was found in T/B values between patients with good response and those with poor response, but the WR in patients with good response was significantly lower. Tumor WR was negatively correlated with the tumor necrosis rate (r = −0.510, P = 0.004). When WR ≤ 25% was taken as the threshold for predicting good response, a sensitivity of 100%, a specificity of 91.7% and an accuracy of 95.8% would be yielded. On post-chemotherapy imaging, T/B values both on early and delayed phases were significantly lower in responders and AR of tumor uptake was significantly higher in these responders. When AR ≥ 38% was used as the threshold for a good response, a sensitivity of 91.7%, a specificity of 94.4% and an accuracy of 93.3% would be yielded. The diagnostic coincidence rate between WR for predicting chemotherapy response and AR for evaluating chemotherapy response was 90.0% (kappa = 0.789, P < 0.001). Conclusion99mTc-MIBI imaging is a useful tool for the evaluation of neoadjuvant chemotherapy in patients with osteosarcoma, and its dual mechanisms could be simultaneously used in predicting and evaluating tumor response to chemotherapy.

Elevada capacidad de localización ecográfica de adenomas paratiroideos en endocrinología (estudio ETIEN 4)

ObjectiveTo assess the diagnostic performance of neck ultrasound examination performed by endocrinologists to locate parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). MethodologyA retrospective observational study in 135 patients (mean age, 60.0±12.3 years; 74.8% females) seen at endocrinology for PHPT (mean calcium level, 11.3±1.2mg/dL mean PTH level, 240.4±346.8pg/mL) who underwent neck ultrasound examinations at the endocrinology department. 99mTc-MIBI parathyroid scintigraphy was performed before surgery in all patients. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated in surgical patients. ResultsNinety-eight patients underwent surgery for PHPT and 97.8% were cured at 6 months. Parathyroid ultrasound had a sensitivity of 85% (95% CI: 75.7%-91.2%) and a positive predictive value (PPV) of 95.2% (95% CI: 87.5%-98.4%) to locate parathyroid adenomas 1.7±0.9cm in maximum diameter (69.4% in smaller glands), showing a high correlation (r=0.661 and r=0.716) with maximum diameter and volume of the excised adenoma. Sixty percent of patients had nodular thyroid disease (64.2% bilateral nodules with mean maximum diameter of 1.5±0.9cm), and thyroidectomy was performed in 31.6%. The highest diagnostic performance was seen with a combination of neck ultrasound and 99mTc-MIBI scintigraphy (sensitivity: 96.8% and PPV: 95.8%). ConclusionIn our area, parathyroid adenoma localization with ultrasound performed by endocrinologists has a high diagnostic yield and allows for detecting nodular thyroid disease in 60% of patients.

Efficacy of Scintigraphy, Ultrasound and Both Scintigraphy and Ultrasonography in Preoperative Detection and Localization of Primary Hyperparathyroidism.

Objective: The aim of our study was to evaluate the efficacy of preoperative dual-phase 99mTc-methoxyisobutylnitrile (MIBI) parathyroid scintigraphy (PS), and ultrasound (US) in primary hyperparathyroidism (pHPT) diagnosis and compare the results with the surgical findings.Methods: Forty-five patients were enrolled in this study. Preoperative serum parathyroid hormone (PTH) levels, calcium (Ca), phosphate (P), and alkaline phosphatase (AP) levels were measured. All parathyroid patients were evaluated by ultrasonography, dual phase 99mTc-MIBI. Surgical findings were used as a reference standard.Results: Of the 45 patients included in this study, 30 were females (66.7%) with an age range between 30 years and 70 years (mean age 41± 13). The sensitivity and specificity of 99mTc-MIBI scintigraphy was 97.4% and 71.4%, respectively, while the sensitivity of ultrasound was 94.4% and specificity 44.4%. The sensitivity, specificity, and accuracy of combined scintigraphy and ultrasound was higher-97.4%, 83.3%, and 95.6%, respectively.Conclusions: The combination of MIBI and US appears promising for localizing parathyroid pathology in patients with primary hyperparathyroidism. The concordance rate is high together with a lower chance of missing concomitant thyroid pathology, which might alter the surgical approach.

99mTc-MIBI SPECT/CT imaging contribution in the diagnosis of patients with hyperparathyroidism

Introduction: Hyperparathyroidism is presented with increased parathyroid hormone (PTH) secretion due to hyperfunctioning of one or more of the four parathyroid glands. Primary hyperparathyroidism (p-HPT) can be due to parathyroid adenoma, hyperplasia or carcinoma of the parathyroid gland. Secondary hyperparathyroidism (s-HPT) is usually a response to hypocalcaemia and consecutive hyperplasia of the glands. Our aim was to compare the efficacy of 99mTcmethoxyisobutylisonitrile (MIBI) SPECT/CT in identification of the location of the lesion(s) in cases of HPT by comparing these results with the findings of ultrasound (US) and planar scintigraphy. Methods: Forty one consecutive patients (54±17 age, 12 males and 29 females) with primary or secondary hyperparathyroidism were included. All patients were examined by US and afterwards patients underwent conventional double-phase 99mTc-MIBI scintigraphy combined with neck SPECT/CT procedure. Planar images (early and delayed), US and SPECT/CT image sets were evaluated for adenoma localization at the neck and thorax. Regions of interest (ROIs), equal sized, were selected and compared, over the hyperfunctioning parathyroid tissue (accumulated impulses-counts value) and over the contralateral lobe of the thyroid gland (control counts value). Results: The ultrasonography detected 24 positive findings. The late phase of planar scan detected 26 positive findings. SPECT/CT presented with bigger detection rate than late planar phase or US (75.6%, 63.4%, 61.5%) and with higher sensitivity (100%, 83.8%, 77.4%), respectively. Conclusion: The SPECT/CT study seems reliable, sensitive and with added value in diagnosing hyperparathyroidism as a complementary method to planar scintigraphy. US as compatible method, should be performed prior the scintigraphy protocols.

Diagnostic Value of Ultrasound and Tc-99m MIBI scintigraphy and SPECT/CT for Pre-operative Localization of Parathyroid Adenoma in Patients with Primary Hyperparathyroidism: A Single-Center Comparative Study

Diagnostic Value of Ultrasound and Tc-99m MIBI scintigraphy and SPECT/CT for Pre-operative Localization of Parathyroid Adenoma in Patients with Primary Hyperparathyroidism: A Single-Center Comparative Study

Relationship between parathyroid gland scintigraphy and its histopathology, oxyphil cell content and volume: a retrospective study.

Mechanisms that are responsible for positive 99mTc-MIBI uptake in parathyroid glands are not clearly understood, some authors suggest there is a correlation between 99mTc MIBI accumulation and oxyphil cell content or parathyroid gland volume. The aim of our work was to assess the relationship between the pathological structure of parathyroids, their volume, oxyphil cell content and parathyroid 99mTc-MIBI retention. A total of 62 hyperfunctioning parathyroid glands in 46 patients were retrospectively analyzed. Preoperative 99mTc-MIBI scintigraphy was performed according to the double-phase and subtraction protocol. After surgery all glands were evaluated histologically, oxyphil cell content was assessed and volume of each excised gland was calculated. Scintigraphy was positive in 41 of 62 parathyroid glands (66%). The median volume of positive glands was larger than that of negative glands (1.33 ml vs 0.7 ml, p = 0.015). Of the parathyroid lesions, there were 14 (22.6%) cases of nodular hyperplasia, 23 (37.1%) cases of diffuse hyperplasia, and 25 (40.3%) cases of adenomas. A high (≥ 25%) oxyphil cell content was found in 16 glands (25.8%) and a low ( < 25%) oxyphil cell content in 46 (74.2%) glands. Histopathology of parathyroid glands was related to the scintigraphy result (p = 0.002), but not to the 99mTc-MIBI uptake pattern (p = 0.868). The overall result of scintigraphy was not related to the oxyphil cell content (p = 0.797). 99mTc-MIBI uptake pattern wasn't related to the oxyphil cell content (p = 0.833). In general, parathyroid lesions with low oxyphil cell content were larger than parathyroid glands with high oxyphil cell content (1.33 ml vs 0.5 ml, respectively; p = 0.01). The median volume of parathyroids containing a high number of oxyphil cells and having a prolonged 99mTc-MIBI retention was larger than those without prolonged 99mTc-MIBI retention (1.62 ml vs 0.3 ml, respectively; p = 0.008). The median volume of parathyroids with low oxyphil cells content and showing prolonged 99mTc-MIBI retention was larger than those without prolonged 99mTc-MIBI retention (1.95 ml vs 1.07 ml, respectively; p = 0.014). Our findings suggest that a positive scintigraphy result depends on parathyroid histopathology and gland volume and does not depend on the presence of oxyphil cells. Prolonged 99mTc-retention is not related to the parathyroid gland histopathology and the presence of oxyphil cells but to the gland volume.

The Effectiveness of Preoperative Ultrasonography and Scintigraphy in the Pathological Gland Localization in Primary Hyperparathyroidism Patients.

Objectives:Primary hyperparathyroidism (pHPT) is a common disease, and its curative treatment is surgical. Nowadays, preoperative localization studies have become standard before surgical treatment, and the first stage imaging methods are ultrasonography and/or scintigraphy. With the contribution of these studies to the localization of the pathological gland, focused surgery has become the first standard of choice. In this study, we aimed to evaluate the efficacy of ultrasonography and scintigraphy in the preoperative localization of the pathologic gland or glands in patients who underwent surgical treatment and cure for pHPT.Methods:In this study; the data of the biochemically diagnosed pHPT patients, who had Tc 99m-MIBI scintigraphy and/or ultrasonography for localisation preoperatively, were evaluated retrospectively. The lesion, which was positive in USG or scintigraphy for localization, was evaluated according to the neck side or neck quadrant, and the results were compared with intraoperative localization findings. The effectiveness of both methods and combinations was evaluated with the localization rates, sensitivity and positive predictive values (PPV). The three methods were compared with the Youden index (J).Results:The mean age of 380 patients included in this study was 54.8±12.8 years (20-83). Three hundred eight of them were female, and 72 were male. Scintigraphy was performed in 339 patients, USG was performed in 344 patients, and both USG and scintigraphy were performed in 306 patients. One hundred twenty patients (32%) underwent bilateral neck exploration (BNE), and 260 patients (68.4%) underwent minimally invasive parathyroidectomy (MIP) (unilateral exploration or focused surgery). Single adenoma was detected in 358 (94%), double adenoma in 10 (3%) and hyperplasia in 12 (3%) patients.Localization rates of USG, scintigraphy, USG and scintigraphy combinations were 53%, 74%, 75%; their sensitivity was 56%, 85%, 89%; PPDs were 90%, 86%, 83%. The efficiency of scintigraphy is higher than USG (J: 0.743 vs 0.527). The contribution of scintigraphy to USG in combination with USG was limited (J: 0.743 vs 0.754).The localization rates of USG, scintigraphy, USG and scintigraphy combinations were 46%, 64%, 66%; their sensitivity was 51%, 83%, 88%; PPDs were 79%, 74%, 73%. The efficiency of scintigraphy is higher than that of USG (J: 0.64 vs 0.427). The contribution of scintigraphy to USG in combination with USG was limited (J: 0.64 vs 0.66).Conclusion:In patients with pHPT, scintigraphy is a more effective method for USG as the first step preoperative imaging and should be preferred as the first method if there is no contraindication. A combination of scintigraphy with USG may contribute minimally to the efficacy of scintigraphy. It may be advantageous for early detection of the pathologic gland in patients with incompatible two imaging and initiating surgery on the positive side of the first scintigraphy. Scintigraphy and USG methods may allow successful MRP surgery in the majority of patients with pHPT.

Minimally invasive parathyroidectomy in a community based teaching hospital: The role of dual-phase parathyroid scintigraphy and surgeon experience

Aim: In a community based teaching hospital setting, to explore role of dual-phase parathyroid scintigraphy and surgeon experience in minimally invasive parathyroidectomy.Material and Methods: During 4-year period, from January 2013 to December 2016, 136 of 170 patients those were diagnosed with primary hyperparathyroidism were selected for this retrospective study. For detection of hyper-functioning parathyroid tissue, routine neck ultrasound and 99mTc-MIBI dual phase parathyroid scintigraphy were performed. All scintigraphy scans were evaluated by nuclear medicine physicians and surgeons together. Patients with suspected multiglandular diseases and familial cases were excluded. Enlarged glands were identified by surgeons intraoperatively. Specimens were sent for frozen section analysis.Results: Without using intraoperative parathormone monitoring or gamma probe, combination of neck ultrasound, surgeon-nuclear physician evaluated parathyroid scintigraphy scan and resection of surgeon-identified diseased gland resulted in 100% cure rate for this group of patients. Conclusion: Operative experience of surgeon and review of preoperative parathyroid scintigraphy scan had remarkable impact on outcomes. Minimally invasive parathyroidectomy can be held successfully at community-based hospitals under specific conditions without using intraoperative parathormone or gamma probe.

99mTc-MIBI SPECT/CT imaging had high sensitivity in accurate localization of parathyroids before parathyroidectomy for patients with secondary hyperparathyroidism

Purpose: Accurate preoperative parathyroid localization is important for successful parathyroidectomy (PTX). The aim of our study was to investigate whether SPECT/CT has enhanced effect in preoperative localization of parathyroids.Methods: In our retrospective cohort study, we evaluated the effects of technetium-99m methoxyisobutylisonitrile-single-photon emission computed tomography/computed tomography (99mTc-MIBI SPECT/CT) on preoperative parathyroid localization for 645 secondary hyperparathyroidism (SHPT) patients. Among them, 569 successful PTX patients were divided into group A (received 99mTc-MIBI scintigraphy, n = 175) and group B (received 99mTc-MIBI scintigraphy and SPECT/CT imaging, n = 394). Sensitivity, specificity, and consistency of two imaging methods in preoperative localization of parathyroids were compared.Results: Overall sensitivity and consistency were higher in group B, while there was no difference in specificity between the two groups. In group A, the sensitivity of 99mTc-MIBI was 50.00%, 77.11%, 61.76%, and 76.54% in the right upper gland (RU), right lower gland (RL), left upper gland (LU), and left lower gland (LL) subgroups, while the consistency was 52.00%, 76.57%, 61.71%, and 75.43%, respectively. In group B, the sensitivity of 99mTc-MIBI with SPECT/CT was 69.39%, 90.03%, 78.07%, and 84.27%, and the consistency was 69.54%, 88.32%, 78.43%, and 84.26%, respectively. The sensitivity and consistency in lower glands were higher than in upper glands in both groups. Sensitivity for eutopic parathyroid was higher in group B, while there was no difference for ectopic parathyroid.Conclusions: 99mTc-MIBI SPECT/CT can increase the sensitivity and consistency of preoperative localization of eutopic parathyroid glands, and it can accurately locate ectopic parathyroid without sensitivity improvement.

Досвід застосування сцинтиґрафії з 99mTc-MIBI для передопераційної візуалізації прищитоподібних залоз у пацієнтів з гіперпаратиреозами

Досвід застосування сцинтиґрафії з 99mTc-MIBI для передопераційної візуалізації прищитоподібних залоз у пацієнтів з гіперпаратиреозами

99mTcO4-/99mTc-MIBI dual-tracer scintigraphy for preoperative localization of parathyroid adenomas.

ObjectiveTo investigate the accuracy of dual-tracer scintigraphy for locating parathyroid adenomas in patients with primary hyperparathyroidism (PHPT).MethodsWe reviewed 268 patients with PHPT. All patients underwent technetium-99m pertechnetate (99mTcO4-) scintigraphy and technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) dual-tracer scintigraphy of the thyroid and parathyroid glands, respectively. 99mTcO4- planar scintigraphy was carried out initially followed by dual-phase 99mTc-MIBI single-photon emission computed tomography (SPECT)/CT the next day. The findings were combined and interpreted. Individual 99mTc-MIBI and dual-tracer scintigraphy were both analyzed. The sensitivity, specificity, and accuracy were determined in relation to surgical findings. The average interval between scan and surgery was 13 days.ResultsThe positive and negative predictive values of 99mTc-MIBI SPECT/CT were 92.0% and 71.3%, respectively, and the sensitivity, specificity, and accuracy were 88.3%, 79.2%, and 85.8%, respectively. The positive and negative predictive values of dual-tracer scintigraphy were 96.3% and 82.3%, respectively, and the sensitivity, specificity, and accuracy were 92.9%, 90.3%, and 92.2%, respectively. Youden’s index for dual-tracer scintigraphy and 99mTc-MIBI SPECT/CT were 0.83 and 0.63, respectively.ConclusionsThese finding suggest that 99mTcO4- and 99mTc-MIBI dual-tracer scintigraphy is more accurate than other scintigraphy methods for detecting parathyroid adenoma, and may thus be the most suitable imaging technique in patients with PHPT.

OA222] Analysis of radiation protection of breastfed babies when mother is undergoing diagnostic nuclear medicine examination (F18-FDG PET, TC-99M MIBI)

Purpose The aim of the study is to evaluate whether national radiation protection procedures of breast feeding patient undergoing diagnostic nuclear medicine procedures including F-18 FDG PET and Tc99m – MIBI scintigraphy are in line with the international radiation protection standards and policy in this area. Methods National legislation has been checked and compared with international recommendation. Radioactivity of mother milk after undergoing diagnostic nuclear medicine procedures has been estimated, based on the fraction of administrated activity present in mother’s milk. Effective dose to child has been calculated using factors given in national standard procedures which are as follow: for F-18 FDG PET examination 0,095 mSv/MBq, while for Tc99m MIBI scintigraphy 0,053 mSv/MBq. Conservative approach has been applied means that for the calculation purposes the radioactive dacy has been neglected, also the fraction of activity excreted in urine before F-18 FDG PET examination, time of the procedure was not taken into account and direct amount of administrated activity was used for evaluation of dose to child. Results Limits for effective dose for breastfed child is 1 mSv. International recommendation for given nuclear procedures stated that there’s no need for suspending breastfeeding. National legislation state that there is no need for suspending breast feeding but it is mandatory to no to give the baby first part of milk just after above mentioned the NM procedures. For TC-99m MIBI examination and administrated activity 150 MBq effective dose is 0,008 μSv, 400 MBq–0,021 μSv, 700 MBq–0,037 μSv. For F-18 FDG PET for administrated activity 200 MBq–0,19 μSv, 350 MBq–0,33 μSv, 700 MBq–0,67 μSv and this is around 1500 (one and half thousand) times less than a set limit 1 mSv. Conclusions Discrepancy between the recommendations, particularly to waste first part of the food after NM procedure, statement in national recommendation, seems to have no scientific basis and do not contribute to better radiation protection of breastfed children. In the other hand this too conservative approach might contribute to unnecessary fear of the radiation among public and give wrong impression about potential risk of diagnostic NM procedures, like F-18 FDG PET or TC-99m MIBI scintigraphy.

Complementary role of parathormone washout test to 99mTc-MIBI parathyroid scintigraphy and histopathologic analysis of cell types in parathyroid adenomas.

Parathyroid scintigraphy (PS) can be negative or equivocal (N/E) in a considerable number of cases with highly suspicious clinical findings and biochemical results for parathyroid adenoma (PA). The aims of this study were to investigate the complementary role of parathormone washout test (PWT) to PS in patients with primary hyperparathyroidism (PHPT) and evaluate histopathologic aspects of PAs in comparison with PS results. Thirty-eight patients with PHPT referred for PS were included in the study. Seventeen patients had both scintigraphic and ultrasonographic findings concordant with PA (Group A). Twenty-one patients having N/E PS, but suspected lesions for PA on ultrasonography (US) formed Group B. PWT was performed for all patients and they underwent the surgical intervention. An adenoma was removed in all patients and the histopathologic cell characteristics were established. The tumor size on US was larger in those patients whose adenomas were seen on the PS (P<.001). The percentages of chief (or principal), oxyphilic and clear cells in PAs were not statistically different between the groups. Serum parathormone level and PWT were not statistically significant between Group A and Group B (P=.095 and P=.04, respectively). Although there is not a definitive threshold value, the sensitivity of PS increases with lesion size. While chief cell and oxyphilic cell content of PAs tend to deplete in N/E PS, clear cell rate increases substantially. Combining PS with both US and PWT increases the sensitivity of detection and localization of PAs.