MIBI Scintigraphy Research Articles

O-05 A novel mutation of MEN1 gene in familial Multiple Endocrine Neoplasia Type 1 (MEN1): A report of two cases

Abstract Introduction Multiple Endocrine Neoplasia Type 1 (MEN1) is a rare (1-9/100000) autosomal dominant disease. It is characterized by primary hyperparathyroidism (90%), enteropancreatic tumor (60-70%), non-functional adrenal adenomas (30%) and pituitary tumors (10-20%). Herein, we present two cases in the same family with MEN1 syndrome caused by a novel mutation. Clinical Case 1: 49-year-old male presented to our clinic with fasting hypoglycemia. Fasting serum glucose (FSG) was 51 mg/dl and serum cortisol was 18 ug/dl. During the hypoglycemia in prolonged fasting test, the serum levels of glucose, insulin and C-peptide were 37 mg/dl, 17.3 mu/l, 7.75 ng/ml respectively (Table 1). Abdominal MRI revealed mass lesions in the pancreas (Figure 1). Ultrasonography of the neck and MIBI scintigraphy performed because of the high levels of calcium and parathyroid hormone (PTH), were consistent with parathyroid adenoma (Table 2). Pituitary MRI showed a 12 mm macroadenoma. He underwent parathyroidectomy and distal pancreatectomy simultaneously. The resected specimens revealed a well-differentiated neuroendocrine tumor (NET) of the pancreas and parathyroid adenoma. The patient had no new hypoglycemic episodes after surgery and serum calcium remained within the normal range (Table 2). Central hypothyroidism and hypogonadotropic hypogonadism which was resulted from the pressure of the adenoma was managed medically. Genetic testing revealed a heterozygous mutation in NM_001370251.1:c.949del(HET). First degree relatives of the patient were screened for MEN. Clinical Case 2: The son of case 1, an 18-year-old male, presented with fasting hypoglycemia. He had a BMI of 37 kg/m2 and underwent gastric botox 3 months prior to his presentation. FPG was 52 mg/dl and serum cortisol was 20 ug/dl. Prolonged fasting test confirmed the diagnosis of insulinoma (Table 1). Abdominal MRI showed a pancreatic tail mass 37×22 mm in size. Gallium 68 PET/CT DOTATATE revealed increased uptake in multiple lesions in the pancreas. Ultrasonography and MIBI scintigraphy showed a parathyroid adenoma. A nonfunctional microadenoma was detected in pituitary MRI. The patient underwent distal pancreatectomy. Following pancreatectomy, right superior and left inferior parathyroidectomies were performed. Since his serum calcium levels started to increase in 48 hours after the operation, the patient has had second operation for left superior parathyroidectomy. After the operation, the serum calcium and parathyroid hormone levels were 9.2 mg/dl, 58 pg/ml respectively. Specimens revealed well-differentiated NET and atypical parathyroid adenoma. The patient was found to have the same genetic mutation with his father and during the follow up the serum glucose and calcium levels remained within the normal range (Table 2). Conclusion In the genetic examination the heterozygous mutation NM_001370251.1:c.949del(HET) in exon 7/11 of the MEN1 gene found in our patients represents a novel mutation.Figure 1.MRI showing pancreatic masses Table 1.Laboratory findings Table 2.Prolonged fasting test

KÜÇÜK HÜCRELİ DIŞI AKCİĞER TÜMÖRLERİNİN DEĞERLENDİRİLMESİNDE Tc-99m MIBI SPECT’İN YERİ

Objective: In this study, it was aimed to investigate the role of Tc-99m MIBI scintigraphy in the diagnosis and evaluation of non-small cell lung cancers and also to evaluate the use of MIBI scintigraphy and MDP bone scintigraphy together in the detection of metastases. Methods: For this purpose, 30 patients with non-small cell lung cancer and 15 patients with benign lesions other than lung cancer (as a control group) were included in the study. By applying Tc-99m MIBI and Tc99m MDP scintigraphy to whole patients with benign and malign lung lesions, anterior-posterior planar and SPECT MIBI images were obtained. Bone scintigraphy was performed as whole-body images. Scintigraphic findings were compared with the histopathological diagnosis of patients. Data were analyzed statistically. Results: According to the result of the findings, the sensitivity, specificity, positive, predictive value, negative predictive value, and accuracy rate of Tc-99m MIBI scintigraphy in the detection of non-small cell lung tumors were determined as 87%, 93.5%, 96%, 77.7%, and 88.8%, respectively. Scintigraphic findings were evaluated quantitatively and visually. While there was no statistically significant difference between the early uptake rates of non-small cell lung tumors and benign lesions in the quantitative evaluation using planar MIBI images, late Tc-99m MIBI uptake rates were significantly higher in lesions with non-small cell lung tumors than that of benign lesions. However, it was detected that both the early and late uptake ratios were significantly higher in malign lesions than in benign lesions in the quantitative evaluation of SPECT images. It was observed that MIBI washout in benign lesions was higher than in malignant lesions in visual washout analysis. Additionally, multiple bone metastases were observed in 14 patients on the visual evaluation of bone scan of the patients with non-small cell lung cancer. Tc-99m MDP uptake was not observed in the malignant lung lesion region or in the soft tissue except the lesion. Conclusion: In light of the findings, it was concluded that Tc-99m MIBI scintigraphy is a noninvasive method with high sensitivity and specificity that can be used to differentiate non-small cell lung tumors from benign lesions.

Visualizing hyperparathyroidism: A pictorial essay of Tc-99m MIBI parathyroid imaging across different etiologies

AbstractParathyroid scintigraphy is an imaging technique that uses gamma-emitting radionuclide to locate hyperfunctioning parathyroid glands in patients with hyperparathyroidism. It is valuable for preoperative assessment before parathyroidectomy, which is a curative surgery in most cases of primary hyperparathyroidism and some cases of secondary hyperparathyroidism. There are several different techniques for parathyroid scintigraphy. In general, the scintigraphy is performed with Tc-99m MIBI, a mitochondria-targeting radiotracer. Some techniques also supply the Tc-99m MIBI scintigraphy with thyroid scintigraphy to differentiate between thyroid and parathyroid tissue. Parathyroid scintigraphy can detect primary hyperparathyroidism with a sensitivity of 80% and a specificity of 84%. It can also detect secondary hyperparathyroidism with a sensitivity of 58% and a specificity of 93%. The unique advantage of parathyroid scintigraphy is the ability to identify supernumerary and ectopic parathyroid abnormalities, which can significantly affect surgical planning and outcomes.

The usefulness of [99mTc]MIBI scintigraphy in the diagnostic algorithm of ultrasonographical suspected thyroid nodules by using EU-TIRADS criteria.

Although not yet involved in the algorithm of thyroid nodules, 99mTc-methoxy-isobutyl-isonitrile ([99mTc]MIBI) scintigraphy may help in the individual diagnostic workup of a thyroid patient, especially where indeterminate fine needle aspiration biopsy (FNAB) is present. The aim of this study was to evaluate the usefulness of [99mTc]MIBI thyroid scintigraphy in the diagnostic algorithm of thyroid nodules, particularly in ultrasound EU-TIRADS 4 or 5 lesions, that cytologically were either indeterminate or benign. ETHODS: A retrospective randomized study, including 42 thyroid patients, with mean age 47 ± 17 years, was conducted. [99mTc]MIBI scan was compared with ultrasound (US) EU-TIRADS criteria, pertechnetate scan, FNAB and histopathological findings for the differentiation of malignant thyroid nodules from benign lesions. The US mainly detected hypoechoic inhomogeneous presentation of the thyroid nodules (35/42, 83.33%), 4 cases with isoechoic nodules and 2 cases presented with hyperechoic thyroid nodules. Histopathology revealed malignancy in 15/42 (35.71%), while all other patients 27/42 (64.29%) were benign. Visual analysis score showed that patients scored with 1+ and 2+ were statistically significant to be benign, while 13 vs. 10 pts that were visual score 3+ were malignant vs. benign (p > 0.05). Sensitivity was 100%, while specificity was very low 22.22%, PPV was 41.67%. Even [99mTc]MIBI scan is not routinely used as a daily practice diagnostic tool of thyroid nodules, we will further apply it on a larger group of patients and try to quantify the uptake of the radiotracer to see whether it will help in the diagnostic algorithm of thyroid nodules.

FCH-PET/CT in Primary Hyperparathyroidism With Discordant/Negative MIBI Scintigraphy and Ultrasonography.

The contribution of [18F]F-fluorocholine (FCH)-positron emission tomography (PET)/computed tomography (CT) in normocalcemic primary hyperparathyroidism (nPHPT) remains unknown. To evaluate the sensitivity and specificity of FCH-PET/CT in a cohort of osteoporotic patients with nPHPT and discordant or negative [99mTc]Tc-sestamibi scintigraphy and ultrasonography who all underwent parathyroidectomy (PTX). Longitudinal retrospective cohort study in patients referred for osteoporosis with mild biological primary hyperparathyroidism. Tertiary referral center with expertise in bone metabolism and surgical management of hyperparathyroidism. Among 109 patients with PHPT analyzed, 3 groups were individualized according to total serum calcium (tCa) and ionized calcium (iCa): 32 patients with hypercalcemia (HtCa group), 39 patients with normal tCa and elevated iCa (NtCa group), and 38 patients with both normal tCa and iCa (NiCa). All patients had biochemical follow-up confirming or not the success of PTX. To evaluate the performance of FCH-PET/CT in terms of sensitivity and specificity, and to compare with first-line imaging procedures in the setting of nPHPT. The sensitivity of FCH-PET/CT was 67% in the hypercalcemic group, 48% in the NtCa group (P = .05 vs HtCa), and 33% in the NiCa group (P = .004 vs HtCa). Specificity ranged from 97% to 99%. FCH-PET/CT was positive in 64.3% of patients with negative conventional imaging, with biochemical resolution after PTX in 77.8% of patients. Triple negative imaging was observed in 20 patients, with PHPT resolution in 85% of these patients. This study highlights the contribution of FCH-PET/CT in a well-phenotyped cohort of normocalcemic patients with discordant or negative findings in [99mTc]Tc-sestamibi scintigraphy and ultrasonography. However, negative imaging in nPHPT does not rule out the possibility of surgical cure by an experienced surgeon.

Does the sonography-scintigraphy correlation affect the success of minimally invasive parathyroid Surgery? Results from a single center

In patients with primary hyperparathyroidism, complete surgical resection of all hyperfunctioning parathyroid tissue is essential. The aim of this study was to evaluate the success rates of minimally invasive parathyroidectomies for primary hyperparathyroidism performed after localization studies with 99mTc-sestamibi (MIBI) scintigraphy and neck ultrasonography (USG). And also, we aimed to determine the factors affecting the success rate in surgery. Retrospective analysis of 58 consecutive patients with a diagnosis of primary hyperparathyroidism who underwent parathyroidectomy between January 2018 and December 2021 in our institution. The patients were evaluated according to Miami criteria and divided into two groups as successful or unsuccessful surgery. Demographic and clinical characteristics of the patients were obtained from hospital records. Surgical success was achieved in 50 (86.2%) of the 58 patients included in the study. In both groups, neck USG and MIBI scintigraphy showed the same localization for the lesion in a correlated manner. The clinical complaints of the patients, preoperative PTH, Ca and 24-hour urinary Ca levels were similar in both groups. In 10 (17.2%) patients, inconsistency in localization was found between USG and MIBI scintigraphy, and surgical failure was found in 4 (40%) of these patients. Surgical failure was statistically significant in patients with inconsistency in localization between USG and MIBI scintigraphy. The sono-scintigraphic scan concordance increases surgical success rates in cases where minimally invasive parathyroid surgery is planned. If there is an inconsistency between USG and MIBI, preoperative four dimentional computed tomography, intraoperative rapid PTH, gamma probe or frozen method can be used. It should be kept in mind that multiple gland pathologies may be more common in addition to solitary adenoma in lesions smaller than 1 cm in USG. In addition, in these cases, as the diagnostic value of scintigraphy is low, surgical success will also decrease.

Innovative Approach of Endosonographic Radioactive Labeling of an Ectopic Parathyroid Adenoma by Technetium-99m Human Serum Albumin: A Case Report

Primary hyperparathyroidism caused by parathyroid adenoma requires surgical resection. To confine the extent of surgery to the very minimum and to exclude an atypical adenoma location, preoperative imaging aims at identifying the suspicious gland. For this purpose, Technetium-99m (99mTc)-sestamibi scintigraphy and SPECT have become the international imaging standard, in inconclusive cases also with C-11 methionine and F-18 choline PET/CT. We present a case of surgery for an ectopic retroesophageal adenoma resected under gamma probe guidance after preoperative radioactive targeting. A 73-year-old patient, who was diagnosed with primary hyperparathyroidism, presented to our outpatient clinic. The patient was symptom-free, but during a routine check-up, parathormone levels of 127 pg/ml (normal range 15-65) were detected. Parathyroid MIBI scintigraphy, including SPECT/CT, failed to locate an adenoma. Therefore, a PET/MRI scan with 164 MBq F-18 choline was applied and a single parathyroid adenoma was detected in a very untypical retroesophageal and prevertebral position, respectively. Due to its esophageal proximity and to enable a very confined surgery, endosonography was performed and the adenoma was transesophageally injected with 75 MBq 99mTc-human serum albumin (HSA). The next day gamma probe-guided minimally invasive resection was performed without any intra- or postoperative complications. Minimally invasive resection of parathyroid adenomas should be the standard but may be difficult in deep collar and atypical locations. Marking the adenoma with a radioactive nanocolloid tracer for gamma probe-guided surgery can be considered an innovative approach to maintain minimal invasive therapy for ectopic adenomas.

Multiglandular Parathyroid Disease in Primary Hyperparathyroidism With Inconclusive Conventional Imaging.

Inconclusive preoperative imaging is a strong predictor of multiglandular parathyroid disease (MGD) in patients with primary hyperparathyroidism (PHPT). MGD was investigated in a cohort of 17 patients with PHPT (mean age 64.9 years, total calcium 2.75 mmol/l and parathyroid hormone (PTH) 113.3 ng/l) who underwent 18F-fluorocholine PET/CT (FCH) imaging before surgery. The initial MIBI SPECT scintigraphy (MIBI) and/or neck ultrasound were not conclusive or did not localize all pathological parathyroid glands, and PHPT persisted after surgery. Sporadic MGD was present in 4 of 17 patients with PHPT (24 %). In 3 of 4 patients with MGD, FCH correctly localized 6 pathological parathyroid glands and surgery was successful. Excised parathyroid glands were smaller (p <0.02) and often hyperplastic in MGD than in single gland disease. In two individuals with MGD, excision of a hyperplastic parathyroid gland led to a false positive decline in intraoperative PTH and/or postoperative serum calcium. Although in one patient it was associated with partial false negativity, parathyroid imaging with FCH seemed to be superior to neck ultrasound and/or MIBI scintigraphy in MGD.

Primary hyperparathyreoidism - diagnostic procedures and management

Hypercalcemia as a laboratory result is often diagnosed during evaluation for osteoporosis. Any form of hypercalcemia should be evaluated further. Owing to fluctuating calcium levels, the measurement should be repeated and corrected for elevated albumin levels by calculation or by measuring ionized calcium. In the diagnosis of primary hyperparathyroidism, measurement of parathyroid hormone, creatinine/glomerular filtration rate, phosphate, 25-OH vitamin D3 and 24-hour urine values are essential for differential diagnosis. Kidney ultrasound is used to detect nephrocalcinosis or kidney stones, and dual-energy X-ray absorptiometry (DXA) to determine bone mineral density (BMD) at the lumbar spine, femoral neck, total femur, and distal forearm. Complete cure is only possible through surgical resection of the adenoma(s). The indication for surgery is dependent on the age of the patient, existing complications, and the patient's preference. Diagnostic imaging should only be performed if surgery is planned. Typically, neck ultrasound and 99mTc MIBI scintigraphy are sufficient to localize the parathyroid adenoma. Presurgical diagnostic evaluation of the thyroid is reasonable for surgical planning. Vitamin-D deficiency should be normalized before surgery. Postsurgical calcium and vitamin-D administration will prevent postsurgical hypocalcemia and hungry-bone disease, and may optimize the outcome of BMD. Treatment of osteoporosis without fractures might not be necessary, owing to normalization of BMD several years after parathyroid surgery. The continuation of specific anti-osteoporotic treatment with bisphosphonates post-surgery did not have any advantage and hence cannot be recommended.

Diagnostic Performance of Cervical Ultrasound, 99mTc-Sestamibi Scintigraphy, and Contrast-Enhanced 18F-Fluorocholine PET in Primary Hyperparathyroidism.

Preoperative localization of pathologic parathyroids is crucial for minimally invasive treatment of primary hyperparathyroidism (PHPT). This study compared contrast-enhanced 18F-fluorocholine PET/CT, cervical ultrasonography (CU), and conventional scintigraphic imaging modalities (MIBI scintigraphy, consisting of 99mTc-sestamibi/123I-sodium iodide SPECT/CT, 99mTc-sestamibi/123I-sodium iodide planar subtraction imaging, and 99mTc-sestamibi planar dual-phase imaging), combined and individually, for preoperative localization of hyperfunctional parathyroids in PHPT. The gold standard was histologic examination. Methods: Data from consecutive patients with clinically suspected PHPT were retrospectively collected. All 3 imaging modalities were systematically performed. The ability of 18F-fluorocholine PET/CT, CU, and MIBI scintigraphy to identify a hyperfunctional parathyroid and specify the side or identify an ectopic location was noted. Patients underwent surgical exploration if at least 1 examination was positive. The findings of CU + MIBI scintigraphy combined were considered positive if CU and MIBI scintigraphy separately showed a hyperfunctional parathyroid gland on the same side or in the same ectopic location; any findings other than these were considered negative. The composite judgment criterion for pathologic parathyroid was a combination of histologic analysis and normalization of parathyroid hormone and calcium levels. Results: In total, 149 pathologic parathyroids were found in 143 of the 144 included patients. 18F-fluorocholine PET/CT diagnosed 148 of 149 pathologic parathyroids. Only 4 false-positives and 1 false-negative were found. The 18F-fluorocholine PET/CT sensitivity of 99.3% was superior to that of CU, at 75.2% (P < 0.0001); MIBI scintigraphy, at 65.1% (P < 0.0001); and CU + MIBI scintigraphy, at 89.9%, (P = 0.0009). Five of the 5 ectopic locations were diagnosed by 18F-fluorocholine PET/CT, 2 of the 5 by MIBI scintigraphy, and none by CU. Accuracy was better for 18F-fluorocholine PET/CT, at 98%, than for CU, at 84% (P < 0.0001); MIBI scintigraphy, at 81% (P < 0.0001); or CU + MIBI scintigraphy, at 91% (P < 0.0001). Among the 72 (50%) patients who had a negative CU + MIBI scintigraphy result, 18F-fluorocholine PET/CT correctly identified hyperfunctional thyroids in 70 (97.2%). Average uptake in the 18F-fluorocholine PET/CT hyperfunctional parathyroid was higher than that in the adjacent thyroid (SUVmax adjusted for lean body mass, 6.45 vs. 2.15) (P < 0.0001). Conclusion: The accuracy of 18F-fluorocholine PET/CT is higher than that of CU and MIBI scintigraphy for localization of hyperfunctional parathyroids, justifying the systematic use of 18F-fluorocholine PET/CT as the first-line method for PHPT diagnosis.

Cushing’s Disease (CD) Due to ACTH-Secreting Pituitary Microadenoma Incidentally Discovered on a Sestamibi Scan for Primary Hyperparathyroidism

Introduction: MIBI scintigraphy is commonly being used for the preoperative localization of parathyroid adenomas. Multiple studies showed MIBI uptake in pituitary adenomas are likely due to higher metabolic activity. When hyperfunctioning pituitary adenomas were reported, both had CD [1,2]. We present the third case of increased pituitary uptake on a MIBI scan later confirmed as CD. CaseA 64-year-old Caucasian female s/p renal transplantation for RPGN who presented for evaluation of hypercalcemia. Evaluation confirmed primary hyperparathyroidism with persistently elevated PTH levels 74-108 pg/ml (11-68), serum calcium levels 10.0-10.4 mg/dl (8.4-10.3), albumin 4.1-4.3 g/dl (3.6-5.1), phosphorus 3.0-3.2 mg/dl (2.5-4.5), creatinine 0.94-1.07 mg/dl. 24-hour urine calcium 60 mg/day (35-250). Vitamin D-25 OH level was 37 ng/dL (30-100). A sestamibi scan showed uptake in the right lower parathyroid, the midsternal chest region and the pituitary gland. MRI of the pituitary revealed a 7mm cystic pituitary microadenoma in the right posterior pituitary. CD was confirmed by the findings of persistently elevated 8 AM serum cortisol levels of 28.4 and 24.2 mcg/dl (4-22), ACTH levels of 59 and 39 pg/ml (10-48), and an elevated plasma free cortisol of 1.43 mcg/dl (0.07-0.93). CT of the abdomen showed L adrenal thickening suggesting adrenal hyperplasia from CD. Plasma cortisol suppressed to 1.2 mg/dl following 1 mg of dexamethasone. 24 urine for free cortisol 26.7 mcg/day (4-50). The patient had no proximal muscle weakness, striae or Cushingoid facial features. She had no hyperglycemia or hypertension. Patient was diagnosed with an ACTH secreting pituitary microadenoma with mild CD and adrenal hyperplasia. Her DXA scan showed osteoporosis. Genetic testing for MEN1 mutation was negative. Patient did not wish surgery for either her hyperparathyroidism or her CD and is being evaluated for medical treatment of hypercortisolism. Conclusion: There are two prior case reports of an incidentally discovered pituitary adenoma on sestamibi scan later diagnosed as CD [1,2]. Corticotrophs may have a strong affinity for sestamibi. Our case is the first, to our knowledge, of pituitary MRI confirmation of the ACTH secreting pituitary incidentaloma initially suspected by pituitary uptake on a sestamibi scan in a patient with hyperparathyroidism. Reference1. Kuhadiya ND et al. Incidentally Discovered ACTH-Secreting Pituitary Adenoma on a Sestamibi Scan in a Patient With Hyperparathyroidism. AACE Clinical Case Reports. 2015;1(3):e152-5. 2. Gierach M et al. The case of Cushing’s disease imaging by SPECT examination without manifestation of pituitary adenoma in MRI examination. Nuclear Medicine Review. 2005;8(2):137-9.

A Case Report on Parathyroid Carcinoma - an Extremely Rare Endocrine Malignancy

Abstract Background: Parathyroid carcinoma is an extremely rare endocrine malignancy with a prevalence of &amp;It 1%. It is associated with hyperparathyroidism-jaw tumor syndrome (HJTS), multiple endocrine neoplasia (MEN) type 1 or 2A syndromes, secondary hyperparathyroidism, and chronic kidney disease. Incidence is equal in both men and women. Patients may present with symptoms of hypercalcemia, and should be further worked up with neck ultrasound, Tc-99m sestamibi imaging, single-photon emission computed tomography, magnetic resonance imaging, positron emission tomography combined with CT scan, and biopsy of the parathyroid mass. Parathyroid carcinoma can be treated surgically with complete resection. Patients treated with En-bloc resection with microscopically negative margins remain cancer-free for at least three years to a maximum of twenty years. Case Report: A 50-year-old female treated with laparoscopic sleeve gastrectomy for morbid obesity, came for the follow-up visit. She denied any active complaint. Routine Lab work showed mild hypercalcemia, hypophosphatemia, elevated PTH, and alkaline phosphatase. Neck ultrasound showed a cystic lesion adjacent to the right thyroid lobe. Sestamibi (MIBI) parathyroid scintigraphy showed increased radiopharmaceutical uptake by the right superior parathyroid gland without any enlarged or suspicious lymph nodes. Dexa scan was positive for osteopenia. The patient underwent right superior parathyroidectomy along with en-bloc right thyroid lobectomy. Histological examination revealed anaplastic regions, giant cells with abundant cytoplasm, and polymorphous nuclei with a Ki-67 labeling index of 10% consistent with parathyroid carcinoma. Post-surgery imaging with ultrasound and magnetic resonance imaging of the neck computed tomography of the chest, and abdomen, whole-body MIBI scintigraphy was negative for residuals or metastatic disease. She was started on oral calcium carbonate and was monitored regularly with routine lab work. The most recent lab work was within normal limits. Conclusion: Most of the patients with parathyroid carcinoma present in the early stage with the symptoms of hypercalcemia. Many of them do not have symptoms of mass or tumor effects. Parathyroid cancer is a rare malignancy and can be missed, therefore all patients with hypercalcemia should be further evaluated with lab work, imaging, and biopsy to rule out parathyroid carcinoma. Early diagnosis and treatment have a better outcome.

Mediastinal ectopic parathyroid adenomas: diagnostic and therapeutic challenge.

IntroductionMediastinal parathyroid adenomas are a rare condition.AimAnalysis of epidemiological data, clinical manifestation of mediastinal parathyroid adenoma (MPA), including imaging modalities, and therapeutic approach to this condition.Material and methodsA retrospective study of documented cases of mediastinal parathyroid adenoma that were managed at our Department of Thoracic Surgery of the Military Teaching Hospital Mohammed V, between January 2010 and December 2019.ResultsDuring a 9-year period in our department, 21 documented cases of MPA were treated surgically. Patients ranged in age from 20 to 69 years, with a mean age of 45 years, and there was no gender predominance. The most frequently reported manifestations were osteoarticular, with bone pain in 66.6% (14/21), pathological fractures in 28.5% (6/21), and osteoporosis in 23.8% (5/21). Cervical ultrasound, MIBI scintigraphy and cervico-thoracic computed tomography scan were performed respectively in 28.5% (n = 06/21), in 47.6% (n = 10/21) and 100% (n = 21), and allowed positive diagnosis of MPA. All patients benefited from resection surgery, through a classical transverse cervicotomy which was extended in some cases to the manubrium, and in only one case treated with thoracotomy.ConclusionsManagement of mediastinal parathyroid adenoma is based on the diagnosis imaging assessment step, usually by MIBI scintigraphy. Surgical ablation is a radical treatment. Peroperative hormonal evaluation is mainly recommended.

Is the result of breast Tc-99m mibi scintigraphy a prognostic factor for survival in invasive breast cancer?

BackgroundBreast scintigraphy with Tc-99m MIBI showed utility in diagnosing and monitoring response to neoadjuvant treatment. This work studies if there are differences in long-term survival in breast carcinomas depending on the result of Tc-99 MIBI scintigraphy and to analyze their relationship with other variables of prognostic value. Material and methodsA prospective observational study on a series of cases of breast cancer in which scintigraphy with Tc-99m MIBI was carried out prior to its treatment, and which had a minimum follow-up of ten years. Clinical–epidemiological, histopathological and immunohistochemical variables were recorded. Bivariate and multivariate analysis were performed studying the result of Tc99m-MIBI scintigraphy. Differences in OS and DFS were studied using Kaplan Meier curves with the log-rank test between factors. ResultsThe significant relationship was found between Tc-99m-MIBI positive result and palpable tumors (p=0.0001), poorly differentiated (p=0.003), with lymph node involvement (p=0.038) and high cell proliferation (p=0.007), although only the palpability and tumor size are related after multivariate analysis.Patients with Tc-99m MIBI positive tumors showed a worse OS (p=0.043) and DFS (p=0.026), independently of size and palpability of the lesión. ConclusionTc-99m MIBI scintigraphy showed prognostic importance in invasive breast cancer, relating its positivity to reduced long-term survival.

Will 18F-fluorocholine PET/CT replace other methods of preoperative parathyroid imaging?

Primary hyperparathyroidism (PHPT) is a common endocrine disorder usually due to hyperfunctioning parathyroid glands (HPs). Surgical removal of the HPs is the main treatment for PHPT, making the correct detection and localization of HPs crucial to guiding targeted and minimally invasive surgical treatment in patients with PHPT. To date, different imaging methods have been used to detect and localize HPs, including radiology, nuclear medicine, and hybrid techniques. The present work discusses the role and value of different imaging methods in PHPT and, particularly, evaluates the potential role of 18F-fluorcholine PET/CT as a "one-stop-shop" method for preoperative parathyroid localization in patients with PHPT. Cervical ultrasound (US) and parathyroid scintigraphy using 99mTc-MIBI are the most commonly employed methods in clinical practice. More recently, four-dimensional computed tomography (4D CT) and positron emission tomography (PET) with radiolabeled choline have emerged as useful alternatives in cases of negative or discordant findings from first-line imaging methods. Due to the excellent diagnostic performance of radiolabeled choline PET/CT and the low radiation burden, this technique seems to be an ideal candidate to substitute current imaging procedures including US, MIBI scintigraphy, 4D CT and MRI and perform a fast and reliable "one-stop-shop" preoperative localization of HP in patients with PHPT, including challenging cases of postoperative persistent/recurrent disease.

The role of Tc-99m MIBI scintigraphy in clinical T1 renal mass assessment: Does it have a real benefit?

IntroductionDespite the increasing accuracy of imaging modalities, the rate of benign renal tumors misclassified as malignant before surgery still non-negligible. Tc-99m sestamibi was demonstrated to be a possible reliable agent in discriminating oncocytoma from renal cell carcinoma (RCC). We aimed to study the efficacy of Tc-99m MIBI tumor scintigraphy in evaluating clinical T1 renal masses. Methods and MaterialsBetween July 2017 and March 2019, patients with clinical T1 renal mass underwent preoperative Tc-99m sestamibi tumor scintigraphy. Tc-99m sestamibi tumor scintigraphy findings were correlated with the postoperative pathology results. ResultsA total of 90 renal masses were included in the study. Male to female ratio was 67/23. The mean age and tumor size were 55.5 ± 11.4 years and 4 ± 1.4 cm, respectively. In pathological evaluation, 20% (18/90) of masses were reported as benign (10 oncocytomas, 4 angiomyolipomas (AML), 2 chronic sclerosis, 1 fibroma and 1 hydatid cyst).While Tc-99m sestamibi uptake was positive in all oncocytomas; 6 patients with chronic sclerosis, fibroma, hydatid cyst and angiomyolipoma pathologies had no uptake. Except for 5 chromophobe cell RCC and 3 oncocytic papillary RCC masses, malignant lesions had no uptake.In predicting benign pathology, Tc-99m sestamibi tumor scintigraphy had positive and negative predictive value of 60% and 91.3%, respectively. The mean Tc-99m 2-methoxy isobutyl isonitrile lesion/normal renal parenchyma ratio of benign and malignant lesions was 0.6 and 0.37, respectively. A relative uptake of 0.49 was an acceptable cutoff point to discriminate oncocytomas from all other pathologies. ConclusionTc-99m sestamibi tumor scintigraphy has a beneficial role in the assessment of clinical T1 renal mass. Masses with negative uptake harbor high probability of being malignant. While evaluating masses with positive uptake, it should be kept in mind that some malignant pathologies may demonstrate similar results.

MIBI Scintigraphy in a patient with hyalinizing trabecular tumor of the thyroid

MIBI Scintigraphy in a patient with hyalinizing trabecular tumor of the thyroid

Performance of F-18 Fluorocholine PET/CT for Detection of Hyperfunctioning Parathyroid Tissue in Patients with Elevated Parathyroid Hormone Levels and Negative or Discrepant Results in conventional Imaging.

ObjectiveOur aim was to assess the diagnostic performance of F-18 fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) in detecting hyperfunctioning parathyroid tissue (HPT) in patients with elevated parathyroid hormone levels with negative or inconclusive conventional imaging results and to compare the findings with those obtained using technetium-99m sestamibi (MIBI) scintigraphy and neck ultrasonography (US).Materials and MethodsImages of 105 patients with hyperparathyroidism who underwent FCH PET/CT, dual-phase MIBI parathyroid scintigraphy (median interval: 42 days), and neck US were retrospectively analyzed. The gold standard was histopathological findings for 81 patients who underwent parathyroidectomy and clinical follow-up findings in the remaining 24 patients. Sensitivities, positive predictive values (PPVs), and accuracies were calculated for all imaging modalities.ResultsAmong the 81 patients who underwent parathyroidectomy, either parathyroid adenoma (n = 64), hyperplasia (n = 9), neoplasia (n = 4), or both parathyroid adenoma and hyperplasia (n = 1) were detected, except 3 patients who did not show HPT. Of the 24 (23%) patients who were followed-up without operation, 22 (92%) showed persistent hyperparathyroidism. FCH PET/CT showed significantly higher sensitivity than MIBI scintigraphy and US in detection of HPT (p < 0.01). Sensitivity, PPV, and accuracy of FCH PET/CT were 94.1% (95/101), 97.9% (95/97), and 92.4% (97/105), respectively. The corresponding values for MIBI scintigraphy and US were 45.1% (46/102), 97.9% (46/47), and 45.7% (48/105) and 44.1% (45/102), 93.8% (45/48), and 42.9% (45/105), respectively. Among the 35 patients showing negative MIBI scintigraphy and neck US findings, 30 (86%) showed positive results on FCH PET/CT. FCH PET/CT could demonstrate ectopic locations of HPT in 11 patients whereas MIBI and US showed positive findings in only 6 and 3 patients, respectively.ConclusionFCH PET/CT is an effective imaging modality for detection of HPT with the highest sensitivity among the available imaging techniques. Therefore, FCH PET/CT can be recommended especially for patients who show negative or inconclusive results on conventional imaging.

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.

Interobserver Agreement of Planar and SPECT Tc99m-MIBI Scintigraphy for the Assessment of Hypofunctioning Thyroid Nodules.

Thyroid scintigraphy with 99mTc-methoxyisobutylisonitrile (MIBI) is a helpful tool for the risk stratification of thyroid nodules (TN). Whereas a nodule with low or hypointense MIBI uptake has a low risk for malignancy, a hyperintense uptake may indicate a malignant nodule, which requires surgical resection. The appropriate diagnostic or therapeutic regimen of an isointense nodule with an uptake similar to the paranodular tissue is discussed controversially. Aim of this study was to assess the interobserver agreement (IA) for the assignment of TN to the three categories: hypo-, iso-or hyperintense. Retrospective analysis of planar and SPECT images of MIBI scintigraphy was performed in 36 randomly selected patients with hypofunctioning TN and histological diagnosis. Four observers with different levels of experience in MIBI-scintigraphy analyzed MIBI uptake and assigned the nodules to the appropriate category. To assess the IA, Fleiss' Kappa was calculated. The study cohort included 11 patients with papillary thyroid carcinoma (diameter 20.3 mm) and 25 patients with benign nodules (diameter 24.8 mm). The IA for all nodules using planar images was 0.76 compared to 0.80 for SPECT images. The IA was better in the subgroup of malignant nodules for planar images as well as SPECT images (Kappa 0.91 and 0.90, respectively) compared to benign nodules (0.65 and 0.76, respectively). Using SPECT images, only one thyroid carcinoma presented with hypointense uptake, the remainder with hyper- or isointense uptake. In contrast, benign nodules were found in all categories. MIBI scintigraphy shows a good IA for the interpretation of thyroid carcinoma. The IA is further improved if MIBI scintigraphy is performed in SPECT technique.