Sestamibi Research Articles

In Vivo Detection of Multidrug-Resistance Related Proteins in Locally Advanced Breast Cancer Using 99mTc-MIBI SPECT/CT Imaging: Correlation with Clinical Outcomes.

Neoadjuvant chemotherapy (NACT) is widely used for treating locally advanced Breast cancer (LABC). However, development of multidrug resistance (MDR) is the main underlying factor for chemoresistance. Technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) is a substrate for MDR. This study aimed to analyze the relationship between expression of MDR-related proteins (P-gp and Bcl-2) and 99mTc-MIBI uptake and retention in BC tumor cells, pathologic response to NACT, disease free survival (DFS) and overall survival (OS). prospective analysis recruited 31 patients with LABC who received NACT between January 2019 and March 2020. 99mTc-MIBI planar and SPECT/CT imaging was conducted before and after NACT. Qualitative and quantitative analyses were performed, pre and post-NACT early and delayed lesion to non-lesion (LNL) ratios, and retention index (RI) of 99mTc-MIBI were calculated. Expression of P-gp and Bcl-2 in tumor cells was determined by immunohistochemistry. Quantitively, inter-reader ICC for SPECT/CT based quantification was consistently higher than that of planar images. Post-NACT LNL ratios were significantly higher in patients with pathologic persistent disease (PPD). A change in RI between pre- and post-NACT scans demonstrated a significant association with DFS with a hazard ratio of 0.7 (95%CI: 06-1.0). Qualitatively, SPECT/CT was significantly more accurate compared to planar imaging in identifying residual viable tumor (81% compared to 57%). Her2neu positivity and high post-operative Bcl-2 and P-gp were associated with worse DFS. A significant association was found between increased expression of post-NACT Bcl-2 and PPD, advanced tumor stage and poor OS. 99mTc-MIBI SPECT/CT based qualitative evaluation of BC response to NACT is more accurate than planar imaging. Post-NACT MIBI retention is positively correlated with P-gp and Bcl-2 expression. 99mTc-MIBI SPECT/CT may predict MDR development. High post-NACT Bcl-2 expression is significantly associated with advanced tumor stage and OS. High post-NACT P-gp expression has a worse impact on pathologic response and DFS.

Advances in the application of auxiliary imaging techniques in parathyroid diseases

Hypoparathyroidism is one of the main complications after total thyroidectomy, severely affecting patients’ quality of life. How to effectively protect parathyroid function after surgery and reduce the incidence of hypoparathyroidism has always been a key research area in thyroid surgery. Therefore, precise localization of parathyroid glands during surgery, effective imaging, and accurate surgical resection have become hot topics of concern for thyroid surgeons. In response to this clinical phenomenon, this study compared several different imaging methods for parathyroid surgery, including nanocarbon, indocyanine green, near-infrared imaging techniques, and technetium-99m methoxyisobutylisonitrile combined with gamma probe imaging technology. The advantages and disadvantages of each method were analyzed, providing scientific recommendations for future parathyroid imaging. In recent years, some related basic and clinical research has also been conducted in thyroid surgery. This article reviewed relevant literature and provided an overview of the practical application progress of various imaging techniques in parathyroid surgery.

Four-Dimensional Computed Tomography for Parathyroid Adenoma Localization: A Pre-Operative Imaging Protocol.

Primary hyperparathyroidism (PHPT) affects approximately 0.86% of the population, with surgical resection as the treatment of choice. A 4D computed tomography (CT) is a highly effective tool in localizing parathyroid adenomas; however, there is currently no defined role for 4D CT when stratified against ultrasonography (USG) and nuclear medicine Technetium Sestamibi SPECT/CT (SES) imaging. Retrospective Study. University Hospital. All patients who underwent parathyroidectomy for PHPT between 2014 and 2019 at a single institution were reviewed. Patients who had a 4D CT were included. We compared outcomes of 4D CT as a second line imaging modality to those of USG and SES as first line modalities. An imaging algorithm was proposed based on these findings. There were 84 patients identified who had a 4D CT after unsuccessful first line imaging. A 4D CT localized parathyroid adenoma to the correct quadrant in 64% of cases, and to the correct laterality in 75% of cases. Obese patients had significantly lower rates of adenoma localization with USG (33.4%), compared to non-obese patients (67.5%; P = .006). In determining multigland disease the sensitivity of 4D CT was 86%, while the specificity was 87%. A 4D CT has impressive rates of accurate localization of parathyroid adenomas; however due to the radiation exposure involved, it should remain a second line imaging modality. PHPT patients should first be evaluated with USG, with 4D CT used if this is unsuccessful and patients are greater than 40 years old, have a high BMI, or are having revision surgery.

Technetium-99m Methoxyisobutyl Isonitrile Stress MPI in Suspected Coronary Artery Disease Patients: A Prospective Study to Evaluate Clinical Significance of Adenosine-induced ECG Changes.

The purpose of this study is to evaluate the adenosine pharmacological stress-induced electrocardiogram (ECG) changes and their association with stress-induced ischemic defects on myocardial perfusion scintigraphy (MPS) in the evaluation of coronary artery disease (CAD) and to evaluate event-free survival among patients with positive and negative ECG/MPS image findings. A total of 100 patients were examined using stress MPS from March 2020 to August 2021. Stress-induced ECG changes during adenosine infusion were evaluated. The summed stress score (SSS) was evaluated to identify ischemic defects in myocardium. Association of stress ECG changes and scintigraphic results was evaluated. Out of 100 patients, stress ECG changes during adenosine infusion were seen among 34 patients, whereas 66 patients had normal ECG findings. Positive stress MPS findings with SSS >3 were seen in 22 patients, whereas 78 patients had SSS ≤3. There was no agreement between stress ECG changes and MPS findings with Cohen's kappa coefficient (κ) = -0.023, whereas there was mild agreement between stress ECG changes and SSS >7 with κ = 0.105. Median follow-up of 11 months showed more events among patients with positive ECG changes than negative ECG changes. Adenosine, pharmacological stress is safe to use, but few patients might experience some minor and transient symptoms. Adenosine may induce ECG changes in patients with or without positive MPS findings. Patients with concordant positive findings need aggressive cardiac care, whereas patients with small or no defects on MPS need close monitoring.

SAT573 Incidental Discovery Of CHEK2 Mutation With Papillary Thyroid Cancer

Abstract Disclosure: F.L. Thelmo: None. A. Mehrab: None. S.A. Jabbour: None. A 66-year-old white male had been following steadily with our practice for greater than a decade where we were managing his post-ablative hypothyroidism from toxic multinodular goiter 20 years prior. Many years later, the patient developed hypercalcemia and was found to have asymptomatic primary hyperparathyroidism. He did not meet any indication for parathyroidectomy. In early January 2021, the patient was referred to a clinical geneticist at the behest of his wife as she was concerned that he had a very high rate of cancer in his family. The patient had a total of 11 relatives who either currently had or previously died from a malignancy, of which only one of them was on his maternal side. The patient’s father had a personal history of breast cancer, prostate cancer, and bone cancer at the time he passed away. The patient underwent a full panel of genetic testing and was found to be positive for a CHEK2 (Checkpoint Kinase 2) mutation. Around this time, the patient’s hypercalcemia escalated up to 13mg/dL without evidence of hypoalbuminemia. Decision was made to pursue surgery. In order to localize the parathyroid adenoma, a technetium sestamibi scan and a neck ultrasound were obtained. Sestamibi scan showed increased parathyroid adenomatous activity in the left lower portion of the thyroid bed and ultrasound confirmed the left lower pole parathyroid adenoma with a dominant hypoechoic 2.5cm TI-RADS 5 thyroid nodule which on biopsy was suspicious for papillary thyroid carcinoma. The patient underwent a total thyroidectomy in addition to the parathyroidectomy. Pathological evaluation confirmed a parathyroid adenoma and a classic variant of papillary thyroid carcinoma without angioinvasion and minimal extrathyroidal invasion classified as Stage 1 T2N0M0. The patient did not meet criteria for treatment with radioactive iodine and at the time of this writing is doing well, on levothyroxine with low-normal TSH and undetectable thyroglobulin with normal serum calcium. He has no other signs of malignancy at this time. However, given his CHEK2 mutation, he will require ongoing multi-disciplinary cancer surveillance. We would like to draw attention to this not uncommon oncogenic mutation that due to its incomplete penetrance does not always present such a staggering family history of cancer and thus may go undetected. CHEK2 mutations occur in roughly 1% of all individuals who undergo genetic evaluation for cancer. The mutation moderately increases the patient and their family’s risk for multiple malignancies including: breast, thyroid, prostate, stomach, kidney, and plasma cell malignancies. Individuals with this mutation should be screened thoroughly by a multi-disciplinary team based on the severity of their inherited mutation. These individuals should also receive counseling on family planning if conception is desired. Presentation: Saturday, June 17, 2023

Identification of micro-recurrent lesions using methylene blue for mediastinal ectopic parathyroid adenoma: a case report

BackgroundMediastinal ectopic parathyroid adenomas are rare, and several methods are used to diagnose and localize them preoperatively. Technetium-99m methoxy isobutyl isonitrile scintigraphy has been used to diagnose parathyroid tumors. However, it is difficult to identify tumors buried in adipose tissue during surgery.Case presentationWe report a case in which methylene blue effectively identified small recurrent lesions in a mediastinal ectopic parathyroid adenoma. After intravenous injection of methylene blue prior to surgery, the stained parathyroid adenoma was easily identifiable. Additionally, we identified other small recurrent lesions that could not be confirmed on preoperative imaging using real-time in vivo imaging guidance during surgery. Using this strategy, complete macroscopic resection can be performed during video-assisted thoracic surgery.ConclusionPreoperative intravenous methylene blue injection is useful for identifying small recurrent lesions, even in cases of mediastinal ectopic parathyroid adenoma with suspected recurrence.

The Comparison of Low and High-Dose Scintigraphy Findings in Patients with Primary Parathyroid Lesions in which Intraoperative Gamma-Probe was Applied.

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

Intraoperative Post-parathyroidectomy Correlation of PTH Hormone Values with Preoperative Scintigraphy

Preoperative parathyroid evaluation through nuclear medicine and intraoperative hormone monitoring has significantly increased the success of the surgical intervention. Material and method: Our study is descriptive, the database is retrospective but it is maintained prospectively. The preoperative protocol included single photon emission computed tomography (SPECT) with the use of technetium-99 sestamibi tracer. We preferred this approach as it allowed 3-D localization of the adenomas. PTH values were obtained from blood drawn from the ipsilateral jugular vein at the regular intervals of 5, 10 and 15 minutes post excision. Results: We had 6 cases with false negative which led to the necessary dissection of the contralateral neck. Two had previous surgery and 4 had tumors in other locations which were observed after the surgical intervention through methodical investigations. We encountered 3 patients with false positive results. 2 had intrathyroidal adenomas and 1 was diagnosed with thyroid papillary carcinoma. Causes of a misinterpretation are related to thyroid disease in association with hyperparathyroidism, a history of parathyroid surgery or multiple locations of hyperproductive parathyroid glands.

Giant Parathyroid Adenoma: A case Report.

Giant parathyroid adenoma (GPA) is a large tumor weighing more than 3.5g but can weigh as much as 110g as compared to parathyroid adenomas which usually weigh in the vicinity of 1g and measure around 1-2cm. These mainly present with primary hyperparathyroidism. We describe an interesting case and clinical course of a young woman with giant parathyroid adenoma. A 30-year-old Indian female presented with acute pancreatitis and acute kidney injury and was found to have hypercalcemia and hyperparathyroidism on further evaluation. Her physical examination revealed firm, non-tender, and mobile swelling of size 5 × 2cm on the left side of her neck. USG neck showed a large heterogenous hypoechoic lesion in the left lower pole region of the left thyroid gland measuring 50 × 24 × 29mm with a volume of 18 ccs. A parathyroid scan was performed using 99Tc Sesta MIBI tracer which was suggestive of a large adenoma in relation to the left lobe of the thyroid gland. She underwent minimally invasive parathyroidectomy with excision of left parathyroid adenoma under general anesthesia. Intraoperative frozen section confirmed the specimen to be parathyroid tissue. Her parathyroid hormone (PTH) level decreased from 1900 pg/ml in the pre-operative level to 242 pg/ml in the immediate postoperative period.

A Rare Case of Hyperfunctioning Lipoadenoma Presenting as a Cystic Pararthyroid Lesion.

A 58-year-old woman visited the hospital complaining of fatigue and indigestion lasting for more than 3 months. She had no medical history other than taking a calcium plus vitamin D supplement for osteopenia. The initial blood test showed a high calcium level of 14.0 mg/dL. Additional tests were performed to differentially diagnose hypercalcemia. The blood test results were as follows: serum parathyroid hormone (PTH)=247.0 pg/mL, PTH-related peptide <1.0 pg/mL, phosphorous=2.6 mg/dL, 25-hydroxy-vitamin D=14.5 pg/mL, creatinine=1.09 mg/dL, and 24 hr urine calcium=215 mg/dL. A 4.5 cm sized cystic lesion on the intra-thyroidal space was confirmed on neck sonography and 4-dimensional parathyroid computed tomography, but technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy showed equivocal results. After removal of the cystic lesion, serum calcium and PTH were normalized, and parathyroid lipoadenoma was confirmed in the postoperative pathology. Clinical features of parathyroid lipoadenoma are known to be similar to common parathyroid adenoma, but imaging studies often report negative findings. Therefore, it is necessary to better understand this rare disease for the differential diagnosis. For the final diagnosis and treatment of this disease, parathyroidectomy with intraoperative PTH measurement may be required.

NUCLEAR MEDICINE PROCEDURE VOLUME AND ESTIMATION OF COLLECTIVE EFFECTIVE DOSE IN TAMIL NADU TOWARDS THE ESTABLISHMENT OF DIAGNOSTIC REFERENCE LEVEL.

With an objective to establish adult diagnostic reference levels in the practice of nuclear medicine (NM) in the state of Tamil Nadu (TN), data on the predominant NM procedures carried out in the state are analyzed. In this study, data on total NM diagnostic procedures during the years 2015-19 along with patient-specific diagnostic NM procedure data for the period April-June 2021 from all centers in Tamil Nadu are collected and analyzed using SPSS statistical software. Nine predominant types of NM scans are analyzed. Collective effective dose from NM scans and per capita dose for the TN population are estimated. The 75th percentile of the distribution and average administered activity (AAA) has been derived and local reference levels are reported. Based on the statistical analysis, it is observed that the whole-body positron emission tomography (PET), renal diethylenetriamine pentaacetate (DTPA) scan, bone methylene diphosphonate (MDP) scan, iodine-131 whole body scan, thyroid studies using Technetium per technetate, renal dimercaptosuccinic acid (DMSA), myocardial perfusion methoxyisobutyl isonitrile sestamibi (MIBI), mebrofenin, Galium-68 prostate-specific membrane antigen (PSMA) are the most common procedure covering >90% of the practices carried out. The collective effective dose is 410 man-Sv in the year 2019, leading to a mean effective dose of 0.006mSv per capita of the TN state population. The 75th percentile of the distribution of AA is slightly higher than diagnostic reference level (DRL) as compared with Australian DRL (310MBq). It is also observed that F-18 PET procedures are primarily responsible for most of the collective effective dose, local DRL is 316MBq and it is important to establish national DRLs for NM diagnostic scans to optimize the NM examinations.

Primary hyperparathyroidism presenting as acute hypercalcemic crisis: a case report

BackgroundHyperparathyroid crisis, or “parathyroid storm” is a rare manifestation of primary hyperparathyroidism, characterized by sudden onset of symptomatic, severe hypercalcemia (> 3.5 mmol/L). Hemorrhage into a parathyroid adenoma has rarely been reported as an inciting or associated event. We present a case of hemorrhage into a longstanding adenoma presenting with acute onset of profound hypercalcemia and associated complications.Case presentationA 60-year-old male presented to hospital with sudden onset of confusion, muscle weakness, and ataxia. Initial labs showed serum calcium 4.79 mmol/L, parathyroid hormone 2043 ng/L; creatinine 364 μmol/L. Review of the patient’s medical history indicated a 4-year history of recurrent nephrolithiasis, but no prior documented calcium levels. The hypercalcemia did not respond to 5 days of aggressive medical management with fluid resuscitation, denosumab and calcitonin, and later pamidronate and cinacalcet. He continued to deteriorate, requiring intubation and continuous renal replacement therapy. Imaging demonstrated 4.8 cm cystic right paratracheal mass; Technetium (Tc99m) Sestamibi scintigraphy was non-localizing. Urgent parathyroidectomy was completed, revealing a 5 × 3.3 × 1.8 cm hemorrhagic, atypical hypercellular parathyroid. Unfortunately, the patient died from complications from anticoagulation therapy for treatment of deep vein thrombosis 4 weeks after admission. His renal function had not recovered at the time of his death.ConclusionThis case gives potential insight into the etiology of hyperparathyroid crisis, and the difficulty in achieving control of hypercalcemia with medical means. Surgical intervention is the definitive management in these cases and should be considered urgently.Graphical

Intraoperative intact parathyroid hormone monitoring and frozen section diagnosis are essential for successful parathyroidectomy in secondary hyperparathyroidism.

Total parathyroidectomy (PTx) is often performed to treat secondary hyperparathyroidism (SHPT). Successful PTx is essential to prevent recurrent and persistent SHPT because remnant parathyroid glands (PTGs) in the neck can be stimulated and may secrete excessive parathyroid hormone (PTH) in end-stage renal disease. However, to date, few studies have investigated factors contributing to successful PTx before the completion of surgery. Between August 2010 and February 2020, 344 patients underwent total PTx, transcervical thymectomy, and forearm autograft for SHPT at our institute. Factors contributing to successful PTx before the completion of surgery were investigated. Preoperative imaging diagnoses, including computed tomography, ultrasonography, technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy, intraoperative intact PTH (IOIPTH) monitoring, and frozen section histologic diagnosis, were performed. Successful PTx was defined as intact PTH level < 60 pg/mL on postoperative day 1. A sufficient decrease in IOIPTH level was defined as > 70% decrease in intact PTH levels measured 10 min after total PTx and transcervical thymectomy compared to intact PTH levels measured before skin incision. Logistic regression analysis was conducted to investigate factors contributing to PTx success. Univariate analysis showed that the number of all PTGs identified preoperatively by imaging modalities and the specimens submitted for frozen section diagnosis, which surgeon presumed to be PTGs, were not significant factors contributing to successful PTx. However, multivariate analysis revealed that the number of PTGs identified by frozen section diagnosis (P < 0.001, odds ratio [OR] 4.356, 95% confidence interval [CI] 2.499-7.592) and sufficient decrease in IOIPTH levels (P = 0.001, OR 7.847, 95% CI 2.443-25.204) significantly contributed to successful PTx. Sufficient intact PTH level decrease observed on IOIPTH monitoring and the number of PTGs identified by frozen section diagnosis contributed to successful PTx for SHPT. IOIPTH monitoring and frozen section diagnosis are essential for achieving successful PTx for SHPT.

ODP115 Primary Hyperparathyroidism in Pregnancy

Abstract Introduction Primary hyperparathyroidism (HPT) is characterized by an overproduction of parathyroid hormone (PTH) by a parathyroid adenoma, parathyroid hyperplasia, or parathyroid carcinoma classically causing hypercalcemia. Incidence of this pathology during pregnancy is very low (1%), as the great majority of cases are diagnosed in adults &amp;gt;45 years old. When present,it can be associated with detrimental maternal and fetal outcomes. Complications may include maternal nephrolithiasis, hyperemesis, and pancreatitis, along with miscarriage, fetal demise, low birth weight, neonatal hypocalcemia, and tetany. Considering the incidence of HPT in pregnancy is uncommon, there is limited data regarding diagnostic and treatment options for these patients. Clinical Case This is the case of a 28-year-old pregnant female at 12 weeks gestational age (WGA) who had a history of Type 1 Diabetes Mellitus. She was evaluated regarding metabolic control during pregnancy, however, was incidentally found with hypercalcemia. She denied any history of fractures, abdominal discomfort, bone pains or nephrolithiasis; she also had no pertinent family history associated with hypercalcemia. Laboratories showed a calcium level of 14.9 md/dL (nl, 8.6-10.2) with a phosphorus level of 1.9 mg/dL (nl, 2.5-4.5), which raised the suspicion of HPT. Further workup demonstrated high parathyroid hormone (PTH) 245 pg/mL (nl, 18.4-80.1), vitamin D-25-OH 24.7 ng/mL (nl, 30-100) and 24hr urine calcium collection of 402.5 mg/24hr (nl, 100-300); the latter excluding the possibility of familial hypocalciuric hypercalcemia. Patient was managed conservatively with IV hydration resulting in mild improvement of calcium to 12.4 mg/dL. Thyroid/Neck ultrasound revealed a thyroid gland with normal homogeneous texture and no distinct focal vascularized structure to suggest parathyroid origin. Other diagnostic imaging for localization of parathyroid disease with technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy or single-photon emission Computed Tomography are not recommended in pregnancy due to insufficient safety data and radiation risk. After discussion with a multidisciplinary team including endocrine surgeons, endocrinologists, and obstetricians, an exploratory neck surgery for possible parathyroidectomy was recommended. She underwent surgery at 13 WGA where a left superior adenoma was identified and completely removed without complications. Intraoperative PTH levels revealed a pre-excision PTH of 342 pg/mL (18.4-80.1), post-excision PTH at 5 minutes of 76 pg/mL, and at 10 minutes of 50 ng/mL, suggestive of successful surgical removal. Pathology report was consistent with left superior parathyroid adenoma. Both calcium and phosphorus levels normalized post-surgery [Ca 9.6 mg/dL (nl, 8.6-10.2) and 2.7 mg/dL (2.5-4.5)]. Conclusion This is an unusual case of a patient with asymptomatic severe hypercalcemia associated to HPT diagnosed during pregnancy. In this patient conservative medical treatment proved to be unsuccessful. Parathyroidectomy early on the 2 nd trimester was advantageous to avoid both maternal and fetal complications during pregnancy. Presentation: No date and time listed

The Accuracy of Imaging test (USS and Sesta MiBi scan) for pre-operative localization in a patient with Primary Hyperparathyroidism who underwent parathyroidectomy

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Multiple endocrine neoplasia type 1 or 4: detection of hyperfunctioning parathyroid glands with 18F-fluorocholine PET/CT. Illustrative cases and pitfalls.

18F-fluorocholine (FCH) PET/CT is now well established to detect the hyperfunctioning parathyroid glands (HFPTG) in a case of sporadic primary hyperparathyroidism (pHPT), but only limited evidence is available about the utility of FCH PET/CT to detect the HFPTG in patients with multiple endocrine neoplasia (MEN) type 1 or 4. The pHPT in this context frequently consists in a multiglandular disease with small hyperplastic glands rather than adenomas, which is challenging for imaging modalities. The data of patients with MEN1 or MEN4 after parathyroidectomy referred to FCH PET/CT for presurgical localization of HFPTG were retrospectively reviewed, including follow-up after parathyroidectomy, in search for diagnostic performance and for potential pitfalls. In the present cohort, 16 patients referred to FCH PET/CT as part of their initial pHPT work-up were subsequently operated, 44 abnormal parathyroid glands (PT) were resected, of which 32 (73%) had been detected on FCH PET/CT and 2 considered as equivocal foci. Nine patients referred to FCH PET/CT for recurrent pHPT who were subsequently operated, 14 abnormal PT were resected, all had been detected on FCH PET/CT. FCH PET/CT permitted a unilateral approach for PTx in 4 of them. In one patient with MEN4 and pHPT, the HFPTG could not be visualized on FCH PET/CT but was localized by ultrasonography. Several causes of false positive or false negative results, incidental finding and pitfalls are listed and discussed. FCH PET/CT has a positive benefit/risk ratio in the detection of HFPTG in case of MEN1 (the data in MEN4 being currently very limited) with the most effective detection rate of current imaging modalities for HFPTG, few pitfalls, and an adequate impact on patient management compared to sesta MIBI SPECT and ultrasonography.

SERS Investigations of 2-methoxy-2-methylpropylisonitrile (MIBI) and Its Technetium Complex

"Technetium radiopharmaceuticals remain the most widely available and cost-effective compounds used in nuclear medicine imaging. However, exact information regarding the chemical structure of these compounds is scarce. In this study we present a spectroscopic investigation of Hexakis (2-methoxy-2-methylpropylisonitrile) (MIBI) Technetium (99mTc) (99mTc-sestamibi). Surface Enhanced Raman Scattering spectra of the ligand and the Technetium sestamibi complex were recorded. For the later, the measurements were recorded in solution as administered to patients and at different moments from the time of preparation in order to monitor its stability. The information provided by the vibrational characterization of the MIBI ligand allowed us to understand spectroscopic features pertaining to the SERS spectra of the Technetium complex. Keywords: Technetium; radiopharmaceuticals; SPECT; MIBI; SERS. "

Preoperative diagnostic value of 99mTc- MIBI SPECT/CT imaging combined with semiquantitative analysis in hyperparathyroidism and factors affecting its efficacy

To evaluate the diagnostic efficacy of technetium-99m methoxyisobutylisonitrile single photon emission/ computed tomography (99mTc- MIBI SPECT/CT), 99mTc- MIBI double- phase scintigraphy (DPS) DPS and ultrasound (US) in preoperative localization of hyperparathyroidism (HPT) and explore the factors affecting the diagnostic efficacy of 99mTc-MIBI SPECT/CT. We retrospectively analyzed the data of 104 patients with HPT undergoing surgical resection between January, 2015 and July, 2019. Preoperative 99mTc-MIBI imaging was performed in all the patients, and 82 patients also received US examination preoperatively. Semi-quantitative analysis was used to draw the region of interest and calculate the lesion/ ipsilateral deltoid muscle (T/NT) uptake ratio. The sensitivity and detection performance of 99mTc-MIBI SPECT/CT, DPS and US in the diagnosis of HPT patients were compared, and the correlations of the T/NT ratios of parathyroid adenoma (PA) and parathyroid hyperplasia (PH) with the expression levels of COX-2 and Bcl-2 were analyzed. The diagnostic sensitivity of 99mTc- MIBI SPECT/CT, DPS and US for HPT was 95.19% (99/104), 91.3% (95/104) and 81.71% (67/82), respectively, demonstrating a significantly higher diagnostic sensitivity of 99mTc-MIBI SPECT/CT than US (χ2=9.59, P=0.008). For PH lesions, 99mTc-MIBI SPECT/CT had the highest diagnostic sensitivity, followed by DPS and then by US (P < 0.05), but their sensitivity did not differ significantly for PA (P>0.05). The T/NT ratio in fatty hyperplastic glands was significantly lower than that in fat-free hyperplastic glands (P=0.009). In PA, Bcl-2 expression was significantly lower in false negative lesions than in true positive lesions (P=0.046), but Cox-2 expression did not show such a difference (P>0.05). In PH lesions, the expressions of Bcl-2 and Cox- 2 did not differ significantly between false negative than true positive lesions (P>0.05). 99mTc-MIBI SPECT/CT has a high sensitivity for HPT localization, and the T/NT ratio is positively correlated with the lesion volume. An increased expression of Bcl-2 in PA lesions and a decreased cell fat content in PH lesions can facilitate the detection of HPT glands by 99mTc-MIBI SPECT/CT.

The Detection of Preoperative Parathyroid Lesions: The Success of Ultrasonography, Technetium-99m Methoxyisobutylisonitrile Parathyroid Scintigraphy, and Single-Photon Emission Computed Tomography–Computed Tomography

ObjectiveWe aimed to find and compare the efficacy of ultrasonography (US), technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy (MIBI-S), and single-photon emission computed tomography–computed tomography (SPECT-CT) in detecting the localization of parathyroid adenomas in patients with primary hyperparathyroidism. MethodsIn total, 348 patients were included in this study. Preoperative parathyroid imaging with US, MIBI-S, and SPECT-CT was evaluated and compared with operative findings. The results of the imaging methods were compared with pathology and operation reports. ResultsIn 318 patients (91.3%), one of the imaging methods was able to localize the lesion correctly. US detected the localization of the parathyroid lesions correctly in 268 patients (77%), whereas SPECT-CT and MIBI-S were correct in 254 (73%) and 209 (60%) patients, respectively. There was a statistically significant relationship between the parathyroid hormone (PTH) level and 3 imaging methods’ success rates (P < .05). The PTH cut-off value, which best determined the correct localization, was 152.5 pg/mL for US, 143 pg/mL for MIBI-S, and 143 pg/mL for SPECT-CT. It was observed that the correct localization rate for parathyroid lesions increased with higher PTH levels. ConclusionIn our study population, US was more successful, in most cases, than other imaging methods in localizing parathyroid lesions but SPECT-CT was more accurate in localizing mediastinal lesions. In addition, it was found that preoperative PTH levels affect the accuracy of imaging methods.

Three-dimensional quantitative assessment of myocardial infarction via multimodality fusion imaging: methodology, validation, and preliminary clinical application.

The precise assessment of myocardial infarction (MI) is crucial both for therapeutic interventions in old MI and the development of new and effective techniques to repair injured myocardium. A novel method was developed to assess left ventricular (LV) quantitatively infarction through three-dimensional (3D) multimodality fusion based on computed tomography angiography (CTA) and technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) single-photon emission computed tomography (SPECT) images. This study sought to develop a 3D quantitative method for MI for pre-clinical study and clinical application. Three months after the MI models were established in 20 minipigs, CTA and SPECT images were acquired separately, which were then aligned automatically with the constraints of the shape and the whole heart and LV myocardium position. Infarct ratios were quantified based on the 3D fusion images. The quantitative assessment was then experimentally validated via an ex vivo histology analysis using triphenyl-tetrazolium-chloride staining and subsequently applied to post-MI patients (n=8). The location of an infarct identified by the SPECT was consistent with that identified by an ex vivo heart in a 3D space. Infarct size determined by CTA-SPECT was correlated with infarct size assessed by triphenyl-tetrazolium-chloride pathology {27.6% [interquartile range (IQR) 17.1-34.7%] vs. 24.1% (IQR 14.7-32.5%), r2=0.99, P<0.01}. In clinical cases, the CTA-SPECT 3D fusion quantitative results were significantly correlated with the quantitative perfusion SPECT results (r=0.976, P<0.01). The proposed 3D fusion quantitative assessment method provides reliable and intuitive evaluations of infarction. This novel quantification technique enables whole heart quantification for the pre-operation evaluation and post-diagnosis management of old MI patients. It could also be applied to the design of 3D-printed cardiac patches.