Hyperfunctioning Parathyroid Research Articles

The role of 18F-FCH PET/CT in patients with uremic hyperparathyroidism compared with 99mTc-sestaMIBI SPECT/CT and ultrasonography

BackgroundThe aim of this study was to evaluate the diagnostic efficacy of 18F-fluorocholine (18F-FCH) PET/CT for uremic hyperparathyroidism (uHPT) compared to 99mTc-sestaMIBI SPECT/CT and ultrasonography (US).MethodsA total of 17 uHPT patients with stage 5 chronic kidney disease (CKD) were prospectively enrolled. All patients underwent US, 99mTc-sestaMIBI SPECT/CT, and 18F-FCH within 2 months and received surgical treatment. Visual and quantitative methods were used for image analyses. Intraoperative localization and postoperative histological results of the reference standard as well as the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the three modalities were analyzed using Pearson’s χ2 tests. In addition, the diagnostic efficacy of 18F-FCH PET/CT for uHPT was evaluated. The relationships between PET parameters and laboratory parameters were assessed using the Spearman correlation coefficient.ResultsA total of 63 parathyroid hyperplasia lesions were resected in 17 uHPT patients, and 53 lesions were detected using 18F-FCH PET/CT with no false-positive results. The sensitivity, specificity, accuracy, PPV, and NPV were 84.13%, 100%, 86.49%, 100%, and 52.38%, respectively. In comparison, the corresponding values for 99mTc-sestaMIBI SPECT/CT and US were 63.49%, 90.91%, 67.57%, 97.56%, and 30.30% and 61.90%, 81.82%, 64.86%, 95.12%, and 27.27%, respectively. The volume of hyper-functioning parathyroid glands was significantly different between lesions positive in 18F-FCH PET/CT and negative in 18F-FCH PET/CT (mean volume 1.36 ± 0.55 cm3 vs. 0.83 ± 0.26 cm3; P = 0.019). US misidentified intrathyroidal parathyroid hyperplasia as thyroid nodules in three patients, while 18F-FCH PET correctly identified the anatomy. No significant associations were observed between PET parameters and laboratory parameters in uHPT.Conclusion18F-FCH PET/CT was more sensitive and accurate for uHPT than 99mTc-sestaMIBI SPECT/CT and US, and had better preoperative diagnostic efficacy, particularly for lesions diagnosed as a thyroid nodule by US.

18F-Fluorocholine PET/CT Imaging of Brown Tumors in a Patient With Severe Primary Hyperparathyroidism

Brown tumors are rare skeletal anomalies occurring in patients with hyperparathyroidism and exposing patients to pathological fractures. We report the case of a 26-year-old woman with severe primary hyperparathyroidism (calcemia, 2.9 mmol/L; parathyroid hormone, 59 pmol/L) who underwent F-fluorocholine (FCH) PET/CT before parathyroidectomy. FCH PET localized the hyperfunctioning parathyroid gland and showed multiple foci in correspondence with bone lytic lesions on CT. Those lesions were not visible on the Tc-MIBI dual-phase scintigraphy. The pathology of one of the FCH-positive bone lesions corresponded to a brown tumor related to hyperparathyroidism.

Optimisation du protocole d’acquisition de la TEP à la fluorocholine dans la détection des lésions parathyroïdiennes

18F-Fluorocholine (FCH) PET/CT shows very promising potential for detection of hyperfunctioning parathyroid tumors. However, the optimal time to perform imaging after FCH administration has not yet been determined and protocols are highly variable. The aim of this study was to qualitatively and quantitatively compare 5, 10, 15, 20 and 60min post-injection acquisition times in patients with primary hyperparathyroidism and equivocal traditional imaging. Thirty-one patients were included. Two observers retrospectively analyzed the five protocols. Any focal increase in FCH uptake was localized and graded on a discrete gradation scale between 1 and 5 to assess the likelihood of hyperfunctioning parathyroid tumors. Gold standard was histopathological findings for the 11 operated patients. Regarding quantitative analysis, ratio of SUVmax of parathyroid foci on SUVmean of thyroid background (as signal-to-noise ratio) were compared between protocols. After injection of 2.5MBq/kg, FCH PET performed 60min post-injection (2min) had the best sensitivity and specificity by lesion (92% and 100% respectively and the best signal-to-noise ratio (median of 2). We suggest performing PET scan 60min after injection, associated with early acquisition so as not to miss a wash-out hyperfunctioning parathyroid tumors.

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.

Parathyroid imaging with 18F-fluorocholine PET/CT as a first-line imaging modality in primary hyperparathyroidism: a retrospective cohort study

Background18F-fluorocholine (FCH) PET/CT is a promising technique for visualizing hyperfunctioning parathyroid glands in hyperparathyroidism. It is still under debate whether to use this technique as a first-line imaging modality or to use it when conventional techniques such as 99mTc-sestamibi scintigraphy or ultrasonography are inconclusive. This study evaluates FCH PET/CT as a first-line modality.MethodsPatients with primary hyperparathyroidism, referred between June 2015 and December 2018 for FCH PET/CT as a first-line imaging method, were included in this study. Baseline characteristics, clinical data, scan results, and type of treatment were recorded. The rate of correct detection was calculated on a per patient-based and a per lesion-based analysis. The reference standard comprised histopathological results, intraoperative response to parathyroidectomy, and clinical follow-up.ResultsTwo hundred and seventy-one patients were included, of which 139 patients underwent parathyroidectomy, 48 were treated with calcimimetics, and 84 patients received further follow-up without active treatment. In the surgically treated group, a single adenoma was suspected in 127 scans, double adenoma in three scans, and one scan showed evidence of three hyperfunctioning glands. In eight scans, no lesions were visualized. A total of 154 parathyroid glands were surgically removed. The rate of correct detection was calculated at 96% and 90%, on a per patient-based and per lesion-based analysis, respectively.ConclusionThis retrospective study in a large cohort shows high detection rates of FCH PET/CT in primary hyperparathyroidism, which is in accordance to literature. The use of FCH PET/CT as a first-line imaging modality in preoperative planning of parathyroid surgery may therefore be a suitable choice.

Parkinsonism as an Atypical Manifestation of Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) occurs as a result of hyperfunctional parathyroid glands resulting in an elevation of serum calcium levels. The association between hypoparathyroidism and parkinsonism have been frequently reported in the literature, while evidence of hyperparathyroidism associated with parkinsonism is rare. The present study reports a case of a patient that had PHPT and developed symptoms of parkinsonism. A 75-year-old female patient with a history of diabetes mellitus, dyslipidemia, and systemic arterial hypertension presented to the emergency room due to unexplained drowsiness. Her serum calcium at the time was 14.2 mg/dL. A cervical ultrasound was performed, and the presence of a 2.5 × 1.9-cm nodule in the left lower parathyroid region was identified. Three days later, scintigraphy with the use of sestamibi showed an increased capture of the marker in the same region, suggesting parathyroid hyperfunction. During hospitalization, the patient developed symptoms of parkinsonism. A left inferior parathyroidectomy was performed, with normalization of serum calcium levels and a remission of drowsiness, in addition to a significant improvement in parkinsonian symptoms. The patient remained free of parkinsonism over 3 years of follow up. Parathyroidectomy can provide a significant remission of parkinsonism in a patient with PHPT. Even though it is rare, the relation between parkinsonism and PHPT exists.

Transoral Endoscopic Parathyroidectomy Vestibular Approach (TOEPVA)—Choosing the Right Patient

Parathyroidectomy is the surgical treatment for primary hyperparathyroidism. A single parathyroid adenoma is the most common cause of primary hyperparathyroidism (PHPT) making it amenable to a focused surgery whereby the putative hyperfunctional parathyroid gland is excised. Parathyroid surgery, like thyroid surgery, is typically performed through a cervical incision usually measuring 4–5 cm. Though most surgical scars heal well over time, the presence of a scar may affect a patient’s quality of life (Goldfarb and Casillas, Thyroid. 26(7):923–32, 2016; Choi et al., Ann Dermatol. 26(6):693–9, 2014). Surgeons may perceive scars differently and more favorably than patients. Variables such as scar length do not always correlate with patient satisfaction (Arora et al., Int J Surg. 25:38–43, 2016; Toll et al., Eur Arch Otorhinolaryngol. 269(1):309–13, 2012; Linos et al., Surgery 153(3):400–7, 2013). Remote access approach to the parathyroid: Remote access approaches such as transoral and axillo-bilateral-breast approaches have been proposed to access the suspected hyperfunctional parathyroid gland similar to the thyroid to avoid a scar in the neck (He et al., J Laparoendosc Adv Surg Tech. 25(4):311–3, 2015). Transoral endoscopic thyroidectomy vestibular approach (TOETVA) for thyroidectomy introduced by Anuwong is gaining popularity as a remote access approach with feasibility demonstrated by several groups (Dionigi et al., J Endocrinol Invest. 40(11):1259–63, 2017; Russell et al., Thyroid. 28(7):825–829, 2018; Anuwong et al., Surg Endosc. 32(1):456–65, 2018). Focused parathyroid surgery may also be completed via this approach (TOEPVA) (Sasanakietkul et al., Surg Endosc. 31(9):3755–63, 2017).

Role of routine frozen sections for parathyroid exploration in a resource poor setting

Removal of parathyroid is recommended for patients suffering from hypercalcemia due to excess parathyroid hormone levels. There are several causes for a hyperfunctioning parathyroid gland out of which parathyroid adenoma is the most common pathological entity. There is great variation in the number and location of parathyroid glands. Hence, intra-operative confirmation of parathyroid tissue makes it easier for the surgeon to be confident of the outcome of the procedure and assure the patient of a permanent cure. A descriptive cross sectional study was done in a cohort of 26 patients who presented with elevated total serum calcium and parathyroid hormone concentrations. Intra-operative frozen section diagnoses were correlated with routine histological studies and post-operative parathyroid hormone concentration. The majority of patients were diagnosed as having parathyroid adenoma (88.46%). Three out of 26 patients (11.53%) had parathyroid hyperplasia involving more than one gland. Sensitivity and specificity of intraoperative frozen section diagnosis was 100%. There was a statistically significant association (p In the light of the discussion on parathyroid surgery it is apparent that frozen sections play a pivotal role in resource poor settings, when facilities for novel intra-operative imaging studies such as sestamibi scan and single-photon emission computed tomography are limited. The participants of the study have been followed up during last 5 years with no evidence of residual disease or recurrence up to date.

VueBox® perfusion analysis of contrast-enhanced ultrasound (CEUS) examinations in patients with primary hyperparathyroidism for preoperative detection of parathyroid gland adenoma.

Aim of this study was to firstly describe reproducible, objective perfusion parameters of contrast-enhanced ultrasound (CEUS) kinetics of parathyroid gland adenoma (PA) using perfusion analysis software (VueBox®, Bracco, Italy). Thereby the efficiency of quantitative CEUS for characterization of PA should be evaluated comparing US to postoperative histopathological findings after PA resection. 42 patients with symptoms/lab work suggestive of pHPT presented a parathyroid gland lesion in B-mode US, which was consequently analyzed by dynamic CEUS. CEUS was performed by one experienced examiner after i.v.-injection of max. 2.4 ml sulphurhexaflouride microbubbles saving digital DICOM cine loops (up to 25 s) and images. PA were evaluated during arterial, venous and late phase (up to 3 min.) for perfusion characterization. A retrospective, blinded VueBox® perfusion analysis of arterial phase of 28/42 PA was performed by a second, independent examiner placing 3 ROIs manually in the PA (center, rim of PA, surrounding thyroid gland tissue) to objectify findings. US findings were correlated to postoperative histology after PA resection. Out of 42 patients with PA findings in CEUS, perfusion analysis could be performed in 28/42 cases only as some CEUS cine loops had too much moving. In three cases the second examiner could not detect PA retrospectively, in 25 cases PA were characterized correctly resulting in a sensitivity rate of 89.3 %. VueBox® perfusion analysis confirmed that PA present a persisting hypervascularization of the rim with higher TTP (mean 7.93 s centrally, 8.36 s rim-sided), mTT (mean 56.6 s centrally, 64.5 s rim-sided) and lower PE (mean 10542.93 rm2 centrally, 8909.21 rm2 rim-sided) peripherally followed by a central wash-out during later phases. RT was comparable in all defined regions. VueBox® analysis of parathyroid gland CEUS examinations seemed to be a valuable tool for quantification of a PA's perfusion and can help to detect and localize hyperfunctional parathyroid glands prior to surgery.

Prevalence of Thymic Parathyroids in Primary Hyperparathyroidism During Radioguided Parathyroidectomy.

Background:Radioguided surgery has been an effective tool for identifying hyperfunctioning parathyroid glands during routine parathyroidectomy for hyperparathyroidism. The purpose of this study was to examine the role of radioguided surgery for the identification of intrathymic parathyroid glands.Material and Methods:Between March 2001 and February 2018, 2291 patients underwent parathyroidectomy by 1 surgeon for primary hyperparathyroidism. Of these patients, 158 (7%) were identified to have an ectopic intrathymic parathyroid gland. All patients underwent radioguided parathyroidectomy. Ex vivo radionuclide counts were used to confirm parathyroid excision with specimen radioactivity of >20% of the background level.Results:The mean age was 56 ± 1 years with 74% of the patients being female. Preoperatively, 122 patients underwent sestamibi scan, which correctly identified the affected gland 61% of the time. Mean background radionuclide count was 208 ± 7, mean ex vivo radionuclide count was 127 ± 9, with ex vivo counts of removed glands >20% in all patients. All ectopic parathyroid glands were successfully identified using gamma probe. Ex vivo counts found to be significantly higher in patients with adenomas. Patients with parathyroid adenomas also were older in age and had higher preoperative calcium levels. While 10% of patients with primary hyperparathyroidism have hyperplasia, 42% of patients with thymic parathyroids had hyperplasia.Conclusions:Radioguided parathyroidectomy is useful in detecting ectopic parathyroid glands in the thymus. Patients with hyperplasia disproportionately have clinically significant thymic parathyroid glands.

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.

Parathyroid Imaging by 18F-Fluorocholine PET/CT in Patients With Primary Hyperparathyroidism and Inconclusive Conventional Methods: Clinico-Pathological Correlations

(18)F-fluorocholine positron emission tomography/computed tomography (FCH) was performed after inconclusive neck ultrasound and (99)Tc-sestaMIBI SPECT (MIBI) scintigraphy in patients with primary hyperparathyroidism (PHPT) to localize abnormal parathyroid glands before surgery. The results were retrospectively evaluated and compared to postoperative histopathological findings. 13 patients with PHPT were enrolled (mean age 64.3 years, preoperative calcium 2.74 mmol/l and parathyroid hormone 114.6 ng/l). FCH localized hyperfunctioning parathyroid glands in 12 patients of 13 (per patient sensitivity 92 % and positive predictive value (PPV) 100 %). Fourteen parathyroid lesions (11 adenomas, 3 hyperplastic glands) were resected with a mean size of 11.9 mm (per lesion sensitivity 93 % and PPV 81 %). Four adenomas and one hyperplastic gland were composed of only chief cells, whereas five lesions contained both chief and oxyphil cells. In three patients an exclusively oxyphil adenoma was found, surprisingly with negative MIBI scintigraphy in spite of a high mitochondria content in the oxyphil parathyroid cells. 12 of 13 patients had thyroid disease. In our limited study sample, FCH correctly identified parathyroid adenomas and/or hyperplastic glands in 92 % of patients with previously inconclusive conventional imaging. Unlike MIBI, FCH successfully localized small, hyperplastic and multiple hyperfunctioning parathyroid glands, irrespective of their histopathological composition.

Ectopic tissue of the thyroid gland and the parathyroid glands

Ectopic thyroid tissue results from developmental defects of the early stages of thyroid embryogenesis, in which the median thyroid anlage descends from the floor of the mouth to its final pre-tracheal position. The most common sites of ectopic thyroid tissue are accordingly in the area of the floor of the mouth and in the course of the thyroglossal duct. Rare localizations are intrathoracic (mediastinal, cardiac, pulmonary) and sub-diaphragmatic (including the adrenals, liver, gall bladder, and gastrointestinal tract). The most important differential diagnosis of ectopic thyroid is metastasis of differentiated thyroid carcinoma.By contrast, the term parathyroidectopy is not uniformly defined. Usually, the cervical-central localizations are referred to as "positional variants" (with the exception of the maxillary sinus and high parapharyngeal), whereas the cervical-lateral localizations (carotid sheath, vagus nerve) and those below the brachiocephalic and mediastinal positions (extraligamentary, aortopulmonary window, paravagal) and other rare localizations are classified as "ectopic parathyroid tissue". Parathyroidectomy is very common (in autopsy studies in 28 to 42.8% of all humans). In the context of primary hyperparathyroidism (pHPT), there is aprevalence of 6.3 to 16% of ectopic hyperfunctional parathyroid tissue (predominantly adenomas), which play an important role in the surgical treatment of pHPT.

PETC/CT with 18F-Choline localizes hyperfunctioning parathyroid adenomas equally well in normocalcemic hyperparathyroidism as in overt hyperparathyroidism.

Identification of pathologic parathyroid glands in primary hyperparathyroidism, traditionally based on neck ultrasound (US) and/or 99mTc-Sestamibi scintigraphy, can be challenging. PET/CT with 18F-Fluorocholine (18F-FCH) might improve the detection of pathologic parathyroid glands. We aimed at comparing the diagnostic performance of 18F-FCH-PET/CT with that of dual-phase dual-isotope parathyroid scintigraphy and neck US. Thirty-four consecutive patients with primary hyperparathyroidism were prospectively enrolled, 7 had normocalcemic hyperparathyroidism, and 27 had classic hypercalcemic hyperparathyroidism. All patients underwent high-resolution neck US, dual-phase dual-isotope 99mTc-Pertechnetate/99mTc-Sestamibi scintigraphy, and 18F-FCH-PET/CT. In the whole patients' group, the detection rates of the abnormal parathyroid gland were 68% for neck US, 71% for 18F-FCH-PET/CT, and only 15% for 99mTc-Sestamibi scintigraphy. The corresponding figures in normocalcemic and hypercalcemic hyperparathyroidism were 57 and 70% for neck US, 70 and 71% for 18F-FCH-PET/CT, and 0 and 18% for 99mTc-Sestamibi scintigraphy, respectively. In the 17 patients in whom the abnormal parathyroid gland was identified, either at surgery or at fine needle aspiration cytology/biochemistry, the correct detection rate was 82% for neck US, 89% for 18F-FCH-PET/CT, and only 17% for 99mTc-Sestamibi scintigraphy. 18F-FCH-PET/CT can be considered a first-line imaging technique for the identification of pathologic parathyroid glands in patients with normocalcemic and hypercalcemic hyperparathyroidism, even when the parathyroid volume is small.

Challenging pre-surgical localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism: the added value of 18F-Fluorocholine PET/CT.

To evaluate the added value of 18F-Fluorocholine (18F-FCH) PET/CT in presurgical imaging of patients with primary hyperparathyroidism (HPT) and challenging localization of the hyper-functioning parathyroid glands. We included 27 consecutive patients with primary HPT (19 F; median age: 58 years), with either (i) non-conclusive pre-surgical localization with 99mTc-sestaMIBI scintigraphy and neck ultrasonography (US), (ii) recurrence of previously operated HPT, or (iii) familiar HPT with a suspicion of multiple gland disease. Histological findings and resolution of HPT were considered as the gold standard. 18F-FCH PET/CT was positive in 24/27 patients. Twenty-one patients underwent surgery with 27 resected lesions (14 adenomas, 11 hyperplastic glands, two hyper-functioning histologically normal glands), with resolution of HPT in 19/21 patients (90%). 18F-FCH PET/CT localized 22 lesions in 17/21 patients (per patient: sensitivity 81%, positive predictive value (PPV) 94%; per gland: sensitivity 76%, PPV 85%, specificity 91%, negative predictive value (NPV) 86%). 18F-FCH PET/CT found eight lesions which were undetectable on both 99mTc-sestaMIBI scintigraphy and US. In patients with a familial HPT and/or a multiple gland disease, sensitivity was 100 and 79% on a per-patient and a per-gland analysis respectively, while NPV was 63%. In six patients with a persistence or recurrence of previously treated HPT, 18F-FCH PET/CT localized all lesions, both in sporadic and familiar disease. 18F-FCH PET/CT is a promising modality in challenging pre-surgical localization of hyper-functioning parathyroid glands, such as inconclusive standard imaging, recurrence after surgery, or suspected multiple gland disease.

18F-choline PET/CT for parathyroid scintigraphy: significantly lower radiation exposure of patients in comparison to conventional nuclear medicine imaging approaches

Background. Parathyroid subtraction scintigraphy (PSS) is the most commonly used imaging method for localisation of hyperfunctioning parathyroid glands (HPGs) in primary hyperparathyroidism (PHP), a common endocrine disorder. Hybrid (SPECT/CT) imaging with 99mTc-sestaMIBI (MIBI) at an early and delayed phase (dual-phase imaging) may be the most accurate conventional imaging approach, but includes additional radiation exposure due to added CT imaging. Recently, 18F-choline (FCH) PET/CT was introduced for HPG imaging, which can also be performed using the dual-phase approach. To date, no studies have compared organ doses and the effective dose (ED) from conventional subtraction scintigraphy, dual-phase MIBI SPECT/CT, and FCH PET/CT in the localisation of HPGs. Aim. In addition to the comparison of the diagnostic performance of FCH PET/CT and conventional scintigraphic imaging methods, the aim of the study was to measure the organ doses and the ED for conventional subtraction parathyroid imaging protocols, using dual-phase MIBI SPECT/CT as a potential conventional imaging method of choice and FCH dual-phase PET/CT as a potential future imaging method of choice for the localisation of HPGs. Materials, methods. Thirty-six patients referred for parathyroid imaging with a clinical indication of PHP underwent preoperative PSS and dual-phase SPECT/CT imaging with the addition of FCH PET/CT. The diagnostic performance of the imaging modalities was assessed by using histology results as a gold standard. Radiation exposure was calculated for the administered activities of radiopharmaceuticals using ICRP80 weighting factors and for CT exposure at hybrid imaging using dose-length products and the ImPACT CT Patient Dosimetry Calculator. Results. The diagnostic performance of FCH PET/CT was significantly better than that of conventional imaging modalities (sensitivity of 97% vs 64% and 46% for MIBI SPECT/CT and PSS, respectively, with comparable specificity of over 95% for all modalities). The highest radiation exposure was caused by conventional PSS (7.4 mSv), followed by dual-phase MIBI SPECT/CT (6.8 mSv). The radiation exposure was the lowest for dual-phase FCH PET/CT imaging (2.8 mSv). The added CT imaging for both hybrid approaches did not cause significant additional radiation exposure (1.4 mSv for MIBI SPECT/CT, additional 26.4% to overall exposure; 0.8 mSv for FCH PET/CT, additional 42.4% to overall exposure). Conclusion. In comparison to conventional scintigraphic imaging of HPGs, emerging hybrid (SPECT/CT, PET/CT) imaging techniques combine superior diagnostic performance with lower radiation exposure to patients.

Preoperative localization of parathyroid glands. Use of MRI, scintigraphy, and image fusion.

Minimally invasive resection of hyperfunctional parathyroid glands is an alternative to open surgery. However, it requires a precise preoperative localization. This study evaluated the diagnostic use of magnetic resonance (MR) imaging, parathyroid scintigraphy, and consecutive image fusion. 17 patients (9 women, 8 men; age: 29-72 years; mean: 51.2 years) with primary hyperparathyroidism were included. Examination by MRI used unenhanced T1- and T2-weighted sequences as well as contrast-enhanced T1-weighted sequences. (99m)Tc-MIBI scintigraphy consisted of planar and SPECT (single photon emission tomography) imaging techniques. In order to improve the anatomical localization of a scintigraphic focus, SPECT-data were fused with the corresponding MR-data using a modified version of the Express 5.0 software (Advanced Visual Systems, Waltham, MA). Results of image fusion were then compared to histopathology. In 14/17 patients, a single parathyroid adenoma was found. There were 3 cases with hyperplastic glands. MRI detected 10 (71%), scintigraphy 12 (86%) adenomas. Both modalities detected 1/3 patients with hyperplasia. Image fusion improved the anatomical assignment of the 13 scintigraphic foci in five patients and was helpful in the interpretation of inconclusive MR-findings in two patients. Both MRI and (99m)Tc-MIBI scintigraphy sensitively detect parathyroid adenomas but are less reliable in case of hyperplastic glands. In case of a scintigraphic focus, image fusion considerably improves its topographic assignment. Furthermore, it facilitates the evaluation of inconclusive MRI findings.

Clinical usefulness of intraoperative parathyroid hormone monitoring for primary hyperparathyroidism

PurposeThe availability of intraoperative parathyroid hormone (IOPTH) monitoring allows successful focused parathyroidectomy for primary hyperparathyroidism (pHPT). The objective of this study was to report our initial experience in IOPTH monitoring during parathyroid surgery for primary hyperparathyroidsim.MethodsBetween May 2011 and February 2013, 37 patients underwent focused parathyroidectomy due to pHPT. IOPTH monitoring based on Miami criteria was used to confirm complete excision of hyperfunctioning parathyroid gland during surgery. Medical records of patients were reviewed retrospectively.ResultsPreoperative mean maximal calcium level was 11.7 ± 0.9 mg/dL. Preoperative technetium (99mTc) sestamibi scan and ultrasonography identified 32 of 37 (86.5%) and 29 of 37 (78.4%) of abnormal parathyroid glands, retrospectively. Results of the 2 imaging modalities were discordant for 8 cases (21.6%). The mean pre-excision PTH level was 147.2 ± 201.5 pg/mL. At 5- and 10-minute post tumor resection, PTH levels were 65.3 ± 25.4 pg/mL and 47.5 ± 24.3 pg/mL, respectively. In all cases, IOPTH levels fell by at least 50% after removing all suspected abnormal glands. All patients had a successful return to normocalcemia after surgery (mean follow-up period: 60.2 ± 15.4 months).ConclusionSurgeon could confirm complete excision of abnormal hyperfunctioning parathyroid glands by IOPTH monitoring during surgery for pHPT. IOPTH monitoring can maximize performance of successful focused para thyroidectomy for pHPT, especially when preoperative imaging results are discordant.

Ectopic parathyroid adenoma: single-centre experience from India

Background: The commonest cause of primary hyperparathyroidism (PHPT) is hyperfunctional parathyroid adenoma (PA) (94%), parathyroid hyperplasia ( Methods: Between 2014 to 2017, seven of the 13 patients with PHPT, who had failed surgical and noninvasive localisation, were included in the study. Hybrid localisation technique positron emission tomography-Computed tomography (PET-CT) with tracer 11C-choline was used. Location of parathyroid adenoma was classified using Perrier classification, which uses, letters A-G to describe the exact location of the adenoma. A 50% drop in PTH levels as compared with pre-incision values was confirmed as a cure. Results: The biochemical and hormonal profile of the 7 (54%) patients with ectopic PA are (mean±SD) serum calcium (mg/dL), 25OH-D (ng/dL) and PTH (pg/mL) 11.36 ± 0.82; 22.82 ± 8.57; 205 ± 105 respectively. Three of the seven had renal stones. In all, seven patients of PA were localised using PET-CT using tracer 11C-choline. The profile of PA were two type-G (intrathyroidal), one type-C (posterior mediastinum), two type-F (superior mediastinum), one of type D (mid region of posterior surface of thyroid parenchyma at the junction of recurrent laryngeal nerve and the middle thyroid vein) and one type B. Conclusion: Ectopic PA is rare. In a biochemically and hormonally confirmed PHPT and in failed imaging localisation techniques/failed neck exploration one should look for ectopic PA. Newer hybrid techniques combined with newer tracer agents (PET-CT) will help in localization of PA. To the best of our knowledge this is the first report of series of ectopic PA from a single center from India.

Parathyroid surgery within an OMFS department: Indications and changes in service provision over a 10 year period

Intro: The standard of care for symptomatic hyperparathyroidism is surgical removal of all hyperfunctional parathyroid tissue. We reviewed one trust's activity in performing parathyroid surgery over a 10 year period. We looked at both indications for surgery and yearly trends in the number of cases carried out. All patients were treated within the Torbay and South Devon NHS Foundation Trust.