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Background The detection of parathyroid adenomas by 99mTc-labelled hexakis 2-methoxyisobutyl isonitrile (sestamibi) scintigraphy is influenced by several factors, including tumour size and serum level of parathyroid hormone (PTH). This study examined the relationship between sestamibi accumulation and multidrug resistance (MDR)-related P-glycoprotein (P-gp) expression in a large series of surgically excised parathyroid tumours. Methods Seventy-eight patients underwent dual-phase sestamibi imaging before parathyroidectomy. Expression of P-gp within tumour cells was assessed by immunohistochemistry. Tumour size was measured and the ellipsoid volume calculated. Scan results were analysed in relation to preoperative serum levels of calcium and PTH, P-gp expression and tumour volume. Results Sixty-four of the 78 sestamibi scans were positive and 14 negative. Smaller adenomas (less than 0·5 cm3) were more likely to be sestamibi negative than larger lesions (P = 0·006). Ten of 14 adenomas with negative imaging showed strong P-gp membrane positivity and 45 of 64 lesions with a positive scan did not show P-gp membrane expression, indicating a significant association between high P-gp membrane immunoreactivity and negative sestamibi result (P = 0·006). Conclusion These data suggest an association between P-gp membrane expression and false-negative sestamibi scan result. Inhibition of the P-gp transmembrane pump using MDR modulators may therefore improve the sensitivity of sestamibi scintigraphy.

Solitary adenomas have been shown to be responsible for almost 90% of cases of primary hyperparathyroidism. The purpose of this study was to determine the utility of sestamibi scanning pre-operatively to guide minimally invasive video-assisted (MIVA) parathyroidectomy. We reviewed 40 patients who underwent parathyroidectomy between 2003 and 2004. All patients underwent a pre-operative sestamibi scan. Thirty-three (82%) patients had a localized solitary adenoma on sestamibi scan. Of these patients 29 underwent attempted MIVA parathyroidectomy. MIVA parathyroidectomy was successful in 22 patients. When pre-operative sestamibi scanning was correlated with pathological diagnosis it was shown to have a sensitivity of 82% and positive predictive value of 94%. Pre-operative sestamibi scan localization of a parathyroid adenoma offers a 94% positive predictive value for adenoma location. This facilitates MIVA parathyroidectomy to be used effectively to treat primary hyperparathyroidism in the majority of patients.

The sestamibi scan (MIBI) and ultrasound (US) are used for preoperative localization of parathyroid adenoma (PTA), with sensitivity as high as 90%. We developed 4-dimensional magnetic resonance imaging (4D MRI) as a novel tool for identifying PTAs. Eleven patients with PTA were enrolled. 4D MRI from the mandible to the aortic arch was used. Optimization of the timing of image acquisition was obtained by changing dynamic and static sequences. PTAs were identified in all except 1 patient. In 9 patients, there was a complete match between the 4D MRI and the US and MIBI, as well as with the operative finding. In 1 patient, the adenoma was correctly localized by 4D MRI, in contrast to the US and MIBI scan. The sensitivity of the 4D MRI was 90% and after optimization, 100%. Specificity was 100%. We concluded that 4D MRI is a reliable technique for identification of PTAs, although more studies are needed.

Background:The role of routine intra-operative parathyroid hormone monitoring for sporadic primary hyperparathyroidism is contentious. Satisfactory results can be achieved in high-volume centres. The results of low-volume hospitals are rarely studied.Methods:A retrospective, non-comparative study was conducted. From November 2002 to October 2012, 105 patients with clinically sporadic primary hyperparathyroidism underwent focused parathyroidectomy without intra-operative parathyroid hormone monitoring. Single adenoma was localised on pre-operative ultrasonography or sestamibi scan. The cure rate, surgical complication rate and pathology findings were evaluated.Results:Most of the operations (63.8 per cent) were performed under local anaesthesia. All but two patients (98.1 per cent) were cured after surgery. There was only one case of double adenomas. No recurrent hyperparathyroidism was observed after a mean follow up of 56.9 months. Surgical complications comprised two cases (1.9 per cent) of transient vocal fold palsy and one case (1.0 per cent) of permanent vocal fold palsy. Seven patients (6.7 per cent) suffered temporary hypocalcaemia.Conclusion:Satisfactory results of focused parathyroidectomy without routine intra-operative parathyroid hormone monitoring for appropriately selected primary hyperparathyroidism cases can be attained in a low-volume hospital.

Summary Haemorrhage of a parathyroid adenoma is a rare clinical presentation. This report describes a previously fit and well 54-year-old woman who presented with acute neck swelling and pain with an overlying ecchymosis. Admission laboratory tests revealed a raised parathyroid hormone and hypercalcaemia. A computed tomography (CT) scan showed widespread anterior cervical haemorrhage and a lesion at the inferior pole of the left thyroid gland. A working diagnosis of spontaneous haemorrhage from a parathyroid adenoma was made. As she was haemodynamically stable, she was treated conservatively with a period of observation in hospital to monitor for signs of neck organ compression. Follow-up imaging with CT, ultrasound and sestamibi confirmed the likely source of haemorrhage as a parathyroid nodule with significant vascularity. The diagnosis was confirmed on histopathological analysis after elective surgical exploration of the neck 6 months after her presentation. This revealed a benign parathyroid adenoma with evidence of acute and chronic bleeding. The patient made a full recovery with immediate normalisation of her biochemistry post-operatively. Despite developing a hoarse voice in the immediate post-operative period, this resolved completely within 1 month. This case report provides further evidence to support a minimal delay for elective surgery after conservative management to reduce the risks associated with recurrent bleeding. Learning points Haemorrhage of a parathyroid adenoma should be a differential for all cases of acute cervical swelling or ecchymosis with no precipitating factor. The clerking should identify any risk factors for endocrine disease. Blood tests to screen for abnormal parathyroid biochemistry should be performed on admission. Detailed imaging of the neck is essential to identify the source of haemorrhage and risk of compression to vital neck organs. Conservative management is a suitable option for patients who remain haemodynamically stable but all should undergo a period of observation in hospital. Conservatively managed patients should be considered for definitive surgical exploration within a month of presentation to avoid the risks of recurrent bleeding.

Objective To determine whether preoperative sestamibi scanning facilitates the desired outcome of successful completion of minimally invasive parathyroidectomy (MIP) and also to analyze the results in patients with underlying concurrent thyroid disease. Methods We undertook a retrospective analysis by review of medical records of 133 parathyroidectomies for sporadic primary hyperparathyroidism with preoperative sestamibi scanning during a 26-month period at our medical center. Results Of the 133 patients with preoperative sestamibi scanning, 106 were candidates for MIP, and 86 had positive scans showing a localized focus of uptake. MIP, with use of intraoperative parathyroid hormone level monitoring, was successfully completed in 70 patients; the other 16 patients required conversion to bilateral neck exploration. Another 20 patients with negative sestamibi scans (no localized focus of uptake) also underwent MIP. The surgeon used ultrasonography or subtle, nondiscrete sestamibi scan findings to decide on this approach. In this group, 65% of patients had successful completion of MIP, in comparison with 81% (95% confidence interval, 72% to 89%) in the group with positive scans (P = 0.13). Subgroup analysis of patients with underlying concomitant thyroid abnormalities showed successful completion of MIP in 39 of 51 (76%), in comparison with 31 of 35 patients (89%) without thyroid abnormalities (P = 0.16). Conclusion In patients with sporadic primary hyperparathyroidism, finding a localized focus of uptake on a preoperative sestamibi scan facilitates successful completion of MIP. In patients with underlying thyroid disease, positive sestamibi scans are still useful in completing MIP, but more patients in this group require conversion to bilateral neck dissection. (Endocr Pract. 2006;12:615-621)

Background Localization of hyperfunctioning parathyroid glands in patients with previous cervical operations is not always successful with noninvasive methods such as ultrasound, sestamibi scan, or magnetic resonance imaging. The aim of our study was to evaluate the results of selective venous sampling (SVS) of intact parathyroid hormone (PTH) in patients undergoing surgery for primary (75%) or secondary (25%) hyperparathyroidism (HPT). Methods Between January 2000 and January 2006, SVS for PTH was performed in 51 consecutive patients with persistent or recurrent HPT or patients with previous cervical explorations. The results of SVS were compared with those of noninvasive localization studies. Results Successful surgical treatment was achieved in 47 of 51 patients (92%). SVS had a sensitivity of 83.3% for the correct localization of a parathyroid adenoma (79.5%) or hyperplastic parathyroid glands (91.6%). False-positive or indeterminate results of SVS were found in 6% and 2%, respectively, of the patients. Ultrasound detected enlarged parathyroid glands with a sensitivity of 33.3%, and sestamibi scan with a sensitivity of 57.1%. Conclusions Compared with noninvasive localization studies, SVS for PTH yielded the best results for recurrent or persistent HPT and for patients with previous neck explorations. SVS is strongly recommended in reoperative surgery for HPT with indeterminate results of noninvasive methods.

Primary hyperparathyroidism is a rare cause of acute pancreatitis. Five consecutive patients with acute or recurrent acute pancreatitis and primary hyperparathyroidism were included. All patients had elevated serum calcium on admission and high levels of circulating parathyroid hormone. Both ultrasonography and Sestamibi scan was used to localize parathyroid adenoma. Except for one, all patients underwent parathyroidectomy and postoperative histology was consistent with parathyroid adenoma. One patient died while on treatment. Metabolic causes of acute pancreatitits, though uncommon, are important as early recognition helps management and prevents recurrence.

A rare case of double lipoadenomas of parathyroid glands with hyperparathyroidism is described. A 56-year-old woman was referred for management of diabetes. Work up revealed: serum Calcium (Ca) =11.9 mg/dl, glomerular filtration rate (GFR) = 103 ml/min/m2, parathyroid hormone (PTH) = 60 pg/ml, Phosphorus = 3.0 mg/dl, 25 hydroxy vitamin D (25 OH D) =16.5 ng/ml, 24 h urine Calcium =179 mg/day. Parathyroid sestamibi scan showed increased activity in the left thyroid and right thyroid lobe. Single photon emission computed tomography demonstrated uptake in inferior left and right thyroid lobes. Her serum calcium following successful bilateral parathyroidectomy was 9.3 mg/dl. Pathology showed double parathyroid lipoadenomas. After surgery, her serum Calcium and PTH normalized to 9.8 mg/dl and 32 pg/ml respectively. Lipoadenoma has been described as a very rare lesion of the parathyroid gland and is most commonly non-functional. PubMed search failed to reveal any case of hyperparathyroidism due to double parathyroid lipoadenomas.

The present study evaluated sestamibi scan-directed parathyroidectomy with intraoperative parathyroid hormone (PTH) assessment (ioPTH). The preoperative sestamibi scintigraphies were compared with the intraoperative findings for 103 patients undergoing first exploration for sporadic primary hyperparathyroidism (pHPT). Data were collected prospectively. Ninety-nine patients (96%) were cured. Patients with persistent pHPT (n = 4) all had an incorrect scintigram as well as an insufficient decline of ioPTH. At operation, 90 patients (87%) had solitary parathyroid adenoma; 12 patients had multiglandular disease. In one patient no enlarged parathyroid gland was found. Overall 77 of 118 abnormal glands (65%) were correctly identified by sestamibi scintigraphy. The sensitivity for localizing a single parathyroid adenoma was 80%. Patients with incorrect scintigrams had a higher proportion of upper pole adenomas than patients with correct scans. High glandular weight and high level of serum PTH were important factors for detectability. Sestamibi scintigraphy did not predict multiglandular disease. However, the use of ioPTH identified 8 of the 9 patients with a positive scan (a solitary focus) and multiglandular disease. In contrast, false-negative ioPTH led to four unnecessary bilateral explorations in the 63 patients with a scan-identified adenoma. With the help of ioPTH, a focused parathyroidectomy was accomplished in 43% of scan-negative patients with a solitary adenoma. In conclusion, sestamibi scintigraphy is an acceptable method for localizing a solitary parathyroid adenoma. However, the technique alone does not reliably predict multiglandular disease. Potentially the failure rate in scan-directed parathyroidectomy could increase, with up to 10% of patients without ioPTH.

Background The aim of this study was to determine the ability of localizing studies and rapid intraoperative parathyroid hormone (PTH) to predict the success of a limited approach in patients who then underwent bilateral exploration. Methods Preoperative sestamibi-iodine subtraction scan and neck ultrasonography (US) were used to direct a focal (1-gland) and unilateral (1-sided) parathyroid exploration by using rapid intraoperative PTH determinations in 350 patients with sporadic primary hyperparathyroidism. Regardless of the findings, the contralateral side was then explored. Results A single gland was predicted by sestamibi in 290 patients (83%), US in 298 patients (85%), and concordance of both in 205 patients (59%). Unilateral parathyroid exploration, directed by these studies, would correctly identify single-gland disease in only 68%, 74%, and 79%, respectively. The addition of intraoperative PTH would increase the success rate to 73%, 77%, and 82%, respectively. The finding of 2 normal or 2 abnormal glands on 1 side would force bilateral exploration, and additional unsuspected pathology was found in 13%, 13%, and 9%, respectively. This failure rate would increase to 21%, 18%, and 15%, respectively, if the analysis assumed a focal rather than unilateral approach to the initial exploration. Conclusions Even in patients with concordant sestamibi and US scans, and an appropriate PTH drop, additional abnormal parathyroid glands were found on complete exploration in 15%. A bilateral approach offers the best opportunity for the long-term cure of primary hyperparathyroidism.

Background and aim Surgery for primary hyperparathyroidism (PHPT) due to a solitary parathyroid adenoma (PA) is moving from traditional bilateral neck exploration (BNE) towards the use of limited neck exploration. The aimof the present study was to define the efficacy of minimally invasive radioguided surgery (MIRS) in PHPT patients with a high probability of a solitary PA with particular regard to benefits achievable in elderly patients. Patients and methods The study population included a total of 266 consecutive PHPT patients who had undergone surgery at our centre between September 1999 and February 2003. Preoperative imaging consisted of [ 9 9 m Tc]pertechnetate/ 9 9 m Tc sestamibi ( 9 9 m TcO 4 /sestamibi) scintigraphy and neck ultrasound obtained in the same session. One hundred and eighty-seven patients from the whole series (75 of whom were older than 65 years) with a high scan/ultrasound probability of a solitary PA, a high PA sestamibi uptake, and a normal thyroid gland were selected for MIRS. The other 79 patients were selected for traditional BNE. The intra-operative technique was based on the injection of a low dose (37 MBq) of sestamibi in the operating theatre a few minutes before the beginning of intervention and on the use of a 11 mm collimated gamma probe. Results MIRS was successfully performed in 97.8% of all PHPT patients selected for this type of surgery and, in particular, in 100% of the subgroup (n=75) of elderly patients. MIRS required a mean operating time of 35 min and a mean hospital stay of 1.2 days; that is, approximately half of that required for traditional BNE. Moreover, local anaesthesia was successfully performed in 27 patients, 19 of whom were >65 years with concomitant invalidating diseases contraindicating general anaesthesia. No major surgical complications were recorded. Transitory hypocalcaemia was observed in 9% of cases treated with MIRS compared with 27% of patients treated with BNE. Conclusion MIRS can be accurately planned in elderly PHPT patients with a solitary PA on the basis of a 9 9 m TcO 4 /sestamibi scan and neck ultrasound. MIRS has been proven to be safe and effective in our experience, and allows a significant reduction of operating and recovery time, as well as the possibility of using local anaesthesia, especially in elderly patients with concomitant invalidating diseases.

Introduction: Re-operation for hyperparathyroidism (HPT) represents a challenge for experienced endocrine surgeons. The present study reviews the technical and pathological factors for failure of initial surgery and identifies strategies to approach re-operative parathyroidectomy. Methods: Clinical details, operation notes, pathology, localization studies and complications for re-operative cases performed by three surgeons were reviewed. Results: Over a 10-year period there were 40 re-operative cases with a 98% success rate. There were 31 patients with primary HPT, 21 with persistent primary (PP) and 10 with recurrent primary (RP). Multigland disease (MGD) was present in 19 of the 31 (61%) primary HPT cases. The culprit gland was ectopic in 14 cases, at a normal location in 10 and there was regrowth at previously excised sites or remnant disease in 10. There were nine patients with secondary HPT, four with persistent secondary (PS) and five with recurrent secondary (RS). The culprit gland was ectopic in five, at a normal location in four and regrowth at a previously excised site in two. Pre-operative investigations were employed in all cases and the most helpful were sestamibi scan (S) and selective venous sampling (SVS) for parathyroid hormone (PTH) concentration. True positive localizations for S was in 20 of 34 cases (59%), SVS in seven of nine (78%), computed tomography (CT) in seven of 17 (41%) and ultrasound scan (USS) in 10 of 28 (36%). Conclusions: Re-operative parathyroidectomy can be performed by experienced surgeons with a very high success rate and minimal complications.

Functioning parathyroid cyst is a rare cause of primary hyperparathyroidism. Surgeons can experience difficultly in diagnosing this condition during cervical exploration as it mimics a thyroid cyst. Preoperative localization by Sestamibi scan is limited by the volume of functioning parathyroid tissue in the cyst wall. Therefore, a high index of suspicion is required in order not to miss the abnormal parathyroid tissue. The diagnosis can be confirmed by intraoperative needle aspiration of the cyst fluid for parathyroid hormone and histological examination. A case of functioning parathyroid cyst localized by Sestamibi scan is presented.

To report the complementary use of video-assisted thoracoscopic surgery (VATS) and intraoperative 99mTc-sestamibi scanning for persistent secondary hyperparathyroidism due to a mediastinal supernumerary parathyroid gland.We describe a patient with recurrent secondary hyperparathyroidism attributable to a mediastinal parathyroid gland who underwent parathyroidectomy with use of VATS, intraoperative 99mTc-sestamibi scanning (gamma probe), and intraoperative monitoring of intact parathyroid hormone (iPTH).A 32-year-old man with chronic renal failure who had undergone a 4-gland parathyroidectomy with autotransplantation 14 years previously presented with symptomatic hypercalcemia. A preoperative single-photon emission computed tomographic (SPECT) sestamibi scan revealed a focus of mediastinal uptake, suggestive of an intrathymic gland. The patient underwent a cervical exploration, and the previously reimplanted parathyroid gland and the thymus were resected. iPTH levels failed to normalize, and the operation was terminated. A repeated SPECT scan again revealed an area of mediastinal uptake. Computed tomographic scan of the chest showed a mediastinal gland adjacent to the aortic arch. VATS and intra-operative sestamibi scanning aided in localization of the ectopic parathyroid gland. After removal of the hyperplastic gland, iPTH levels decreased appropriately.In reoperative parathyroidectomy involving mediastinal glands, VATS, complemented by gamma probe localization and iPTH monitoring, may be used to minimize the operative dissection needed to cure hyperparathyroidism.

Purpose The purpose of this study was to determine the value of the intraoperative gamma probe and the efficacy of dual-phase Tc-99m sestamibi imaging in patients with primary hyperparathyroidism. Methods Twenty-one patients with primary hyperparathyroidism were examined prospectively. Results of same-day dual-phase Tc-99m sestamibi scintigraphy and intraoperative gamma probe evaluations were compared with the intraoperative findings and histopathologic diagnoses. A 15-mm handheld gamma probe was used to measure gamma activity in the neck and upper mediastinum. Nuclear mapping by gamma probe showed a single quadrant of neck that emitted gamma radiation significantly greater than the other three quadrants, which correlated with the sestamibi scan. Results Dual-phase Tc-99m sestamibi scintigraphy determined and localized parathyroid lesions in 20 patients (sensitivity, 94%). Of the 20 parathyroid lesions removed, 15 were located in normal positions, whereas five were explored in ectopic sites (one within the thyroid, one in the anterior mediastinum, one in a retrotracheal position, one in the carotid sheath, and one in the retroesophageal region). Although the index of thyroid nodules varied from 15.8% to 22.9%, the index for parathyroid lesions was 77.3% to 112.8%. Conclusions These results confirm that parathyroid lesions, especially at ectopic sites, can be treated successfully in shorter operative times with minimal complications with the help of the intraoperative gamma probe.

Summary Functional parathyroid cysts are a rare cause of primary hyperparathyroidism and are often mistaken for thyroid cysts. Systemic lupus erythematosus (SLE) is also a very rare cause of hypercalcemia. We report the case of a 62-year-old woman, who was diagnosed with SLE 30 years ago, presenting with clinical and biochemical features of primary hyperparathyroidism. Laboratory investigation revealed increased serum calcium and parathyroid hormone (PTH) levels; neck ultrasonography (USG) revealed 40×34×26 mm cystic mass in the left lobe of thyroid gland. PTH level in the cysts was >2500 pg/ml, determined by USG-guided fine-needle aspiration (FNA). In this case, no evidence for potential pathogenic association between parathyroid cyst and SLE was uncovered. However, the recognition of this association is very important because the therapeutical strategy is completely different. Operative management is usually straightforward and alleviates symptoms and any biochemical abnormalities caused by the cyst. Learning points Functional parathyroid cysts are the rare cause of primary hyperparathyroidism and are often mistaken for thyroid cysts. SLE is also a very rare cause of hypercalcemia. Ultrasound-guided FNA of cystic fluid with assay for PTH level is an accurate method of differentiating parathyroid cyst from thyroid cyst. Appropriate management of functional parathyroid cysts is surgical excision.

Summary We report of a male patient aged 32 years who presented with primary hyperparathyroidism. Three parathyroid glands were resected. At the age of 46 years, nervus facialis irritation was noted, and an MRI scan incidentally revealed a non-functioning pituitary adenoma with affection of the chiasma opticum. The patient underwent transsphenoidal operation resulting in pituitary insufficiency postoperatively. At the same time, primary hyperparathyroidism reoccurred and a parathyroid adenoma located at the thymus was resected. The mother of the patient died early due to multiple tumors. The patient was suspected to have multiple endocrine neoplasia type 1 (MEN1) and genetic analysis was performed. In addition, on clinical examination, multiple exostoses were noticed and an additional genetic analysis was performed. His father was reported to have multiple osteochondromas too. MEN1 was diagnosed in the patient showing a novel heterozygote mutation c.2T>A in exon 2, codon 1 (start codon ATG>AAG;p.Met1?) of the MEN1 gene. In genetic mutational analysis of the EXT1 gene, another not yet known mutation c.1418-2A>C was found in intron 5 of the EXT1 gene (heterozygotic). In conclusion, we report novel mutations of the EXT1 and the MEN1 genes causing hereditary multiple osteochondromas and MEN1 in one patient. Learning points It is important to ask for the patient's family history in detail. Patients with MEN1 are characterized by the occurrence of tumors in multiple endocrine tissues and nonendocrine tissues, most frequently parathyroid (95%), enteropancreatic neuroendocrine (50%), and anterior pituitary (40%) tissues. Familiar MEN1 has a high degree of penetrance (80–95%) by the age over 50; however, combinations of the tumors may be different in members of the same family. Patients with EXT1 gene mutations should be monitored for possible transformation of bone lesions into osteochondrosarcoma.

Objective: Sestamibi scanning is performed to evaluate hyperparathyroidism; however, finding an adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma on a sestamibi scan is not common.Methods: A 49-year-old Caucasian female with increased thirst and urination and weight gain was referred for evaluation of primary hyperparathyroidism (pHPT). Her serum calcium and parathyroid hormone (PTH) levels were at the upper normal limit, and 24-hour urinary calcium was elevated. Sestamibi scan did not reveal a parathyroid adenoma, but showed increased uptake in the pituitary gland. Morning serum cortisol, 11 pm salivary cortisol levels, and 24-hour urinary free cortisol (UFC) levels were elevated on 2 occasions. Cortisol levels were only suppressed with an overnight 8-mg dexamethasone suppression test (DST) and not with 1- or 2-mg DST. Two magnetic resonance imaging (MRI) scans of the pituitary and pan-body computed tomography (CT) scan did not reveal an ACTH source. Inferior petrosal sinus sampling (IPSS) showed a central to peripheral ACTH ratio >3.0 with lateralization to the right, and an ACTH-producing corticotroph adenoma was then surgically confirmed.Results: We report the incidental discovery of an ACTH-secreting pituitary adenoma adenoma on a sestamibi scan in a patient with hyperparathyroidism.Conclusion: Pituitary incidentalomas on sestamibi scans performed to evaluate parathyroid abnormalities have been reported, but their secretory nature has not been studied. Further studies are therefore needed to clarify the role of sestamibi scanning in the diagnosis of imaging-negative pituitary Cushing disease.Abbreviations: ACTH adrenocorticotropic hormone DST dexamethasone suppression test pHPT primary hyperparathyroidism IPSS inferior petrosal sinus sampling MIBI methoxyisobutylisonitrile MRI magnetic resonance imaging PTH parathyroid hormone UFC urinary free cortisol

Objectives: In patients who have parathyroid adenoma, combination of ultrasonography and technetium Tc 99m sestamethoxyisobutylisonitrile scan (also called sestamibi or MIBI scan), which allows anatomic and functional information about parathyroid adenomas, is used commonly to maximize operative cure. The sensitivity of MIBI scan may be increased by adding single photon emission computed tomography (SPECT) and computed tomography (CT) as a combined MIBI-SPECT CT scan. We assessed the accuracy of ultrasonography and parathyroid MIBISPECT scan in detecting parathyroid adenoma and evaluated the potential benefit of the combined protocol of ultrasonography and MIBI-SPECT parathyroid scan. Methods: In 58 patients who had biochemical evidence of primary hyperparathyroidism, we retrospectively reviewed the preoperative ultrasonography and MIBI-SPECT scans. The results of these studies were correlated with surgical findings. Results: In the 58 patients, surgery showed that 43 patients (74%) had solitary parathyroid adenoma. The sensitivity, specificity and accuracy of MIBI-SPECT for parathyroid adenoma was (72%,80%,74%) and for ultrasonography (53%,60%,55%) respectively. The highest sensitivity is noted with the combination of MIBI-SPECT and ultrasonography (79%), . 9 adenomas (21%) were missed by both modalities. In the 20 adenomas that were missed by ultrasound 11 were detected by MIBI SPECT. Conclusion: The MIBI-SPECT had better performance than ultrasonography for parathyroid adenoma localization. The combined MIBI SPECT and ultrasonography has the highest sensitivity for parathyroid adenoma detection (79%). An alternative strategy may be to use MIBI-SPECT initially, and to proceed to ultrasonography only in patients with negative MIBI- SPECT. This may avoid many ultrasonography procedures.

Objectives: Objectives were to review our current experience with radio-guided parathyroid surgery and to compare various techniques of minimally invasive parathyroidectomy. Study Design: 1) To review our recent experience of radio-guided gamma probe localization during surgery for primary hyperparathyroidism and 2) to compare the intraoperative findings with the preoperative sestamibi scan. Methods: Analysis was made of the 10 most recent surgical procedures for primary hyperparathyroidism at a single institution to compare the operative localization with preoperative sestamibi scan and to determine the radioactivity in the tissue removed during surgery, such as parathyroid adenoma, normal parathyroid gland, thyroid tissue, or lymph nodes. Results: The sestamibi scan was able to localize the enlarged parathyroid gland in eight patients. Although gamma probe was helpful in localizing the parathyroid gland, the identification of an enlarged parathyroid gland was directly based on the preoperative findings of sestamibi scan. In the remaining two patients, the intraoperative gamma probe was not helpful. Conclusions: The major advantage of gamma probe in the series was to evaluate the radioactivity in the tissue that was removed and to determine whether it was an enlarged parathyroid gland, lymph node, thyroid tissue, or fatty tissue. The radio-guided surgery did not add substantially to the surgical procedure in patients in whom the sestamibi scan had localized the enlarged parathyroid gland preoperatively.

Objective To review the outcomes of 656 consecutive parathyroid explorations performed by a single surgeon and to compare the results of conventional and minimally invasive parathyroidectomy (MIP) techniques. Background Data Traditional surgery for primary hyperparathyroidism (HPTH) involves bilateral cervical exploration, which is usually accomplished under general endotracheal anesthesia. The MIP technique involves preoperative localization with sestamibi scans, surgeon-administered cervical block anesthesia, directed exploration through a small incision, intraoperative rapid parathyroid hormone assay, and discharge within 2 to 3 hours of surgery. Methods Six hundred fifty-six consecutive patients with primary HPTH underwent exploration between January 1990 and March 2001. Results MIP was used with ever-increasing frequency beginning in March 1998. Four hundred one procedures (61 %) were performed using the standard technique and 255 patients (39%) were selected for MIP. The success rate for the entire series was 98%, with no significant differences comparing traditional and MIP techniques. The overall complication rate of 2.3% reflects 3.0% and 1.2% rates in the standard and MIP groups, respectively. MIP was associated with approximately a 50% reduction in operating time, a sevenfold reduction in length of hospital stay, and a mean cost savings of $2,693 per procedure, which represents nearly a 50% reduction in total hospital charges. Conclusions A dramatic and sustained shift has occurred in the surgical treatment of primary HPTH: MIP has replaced traditional exploration for most patients.

Intrathymic parathyroid adenoma is a rare cause of persistent primary hyperparathyroidism. We encountered a case of intrathymic parathyroid adenoma, detected by computed tomographic scan and confirmed by Technetium-99 (Tc-99) Sestamibi scan and histology. The surgical approach included a median sternotomy and a large intrathymic parathyroid adenoma was identified and excised through the sternotomy. In this case, Tc-99 Sestamibi scan successfully localized a persistant abnormal tracer uptake in the mediastinum suggestive of mediastinal parathyroid adenoma. Although not recommended for routine preoperative evaluation, scintigraphy can be useful in the preoperative localization of ectopic parathyroid adenomas.

The aim of this study was to highlight our experience over a 15-year period in dealing with primary hyperparathyroidism (PHPT) due to a parathyroid tumor. Parathyroidectomy is the standard therapy for patients with PHPT. Our study included all patients with PHPT treated by parathyroidectomy at the Affiliated Cancer Hospital of Zhengzhou University, China. Between 1998 and 2013, a total of 107 patients were recruited. Their clinical data, presentation, laboratory examinations, imageological diagnoses and surgical approaches were analyzed retrospectively. Eighty-four cases (78.5%) were followed up. During a median follow-up period of 5.7 years, a total of 80 patients were without recurrence and metastasis. The main symptoms of PHPT patients were palpable neck mass, joint pains and pathological fracture. The high levels of preoperative parathyroid hormone (PTH) and serum calcium in PHPT patients decreased to below the normal upper limit within 3 days of surgery. The sensitivity of neck ultrasonography, sestamibi scanning, CT, MRI and the combination of three or four types of test were 86.0%, 90.4%, 80.8%, 79.6% and 96.1%, respectively. A 50% or greater drop in PTH levels within 20 min compared with the highest PTH levels before surgery occurred in 95/107 cases (88.8%). Transient hypocalcemia was the most common surgical complication. The ultrasonography and sestamibi scan is the most effective examination for parathyroid tumor. The 20 min PTH measurement appears to be extremely useful, and avoids unnecessary bilateral exploration.

Background Four-dimensional computed tomography (4D-CT) is often used for patients with primary hyperparathyroidism and non-definitive localization after Sestamibi scan (MIBI) and ultrasound (US), but may expose patients to unnecessary radiation, typically between 10 and 26 millisieverts (mSv). We hypothesize that a simpler two-phase CT protocol would have a similar sensitivity, specificity and accuracy to those published for 4D-CT, while exposing the patient to less radiation. Methods We reviewed 54 patients with primary hyperparathyroidism and non-definitive localization studies who had a two-phase CT between 2009 and 2012 at our tertiary referral center. Results The mean radiation dose of two-phase CT over the course of the study was 5.2 mSv (range 3.5 mSv–9.1 mSv). Two-phase CT had a 77% (CI = 65%–86%) sensitivity and an 87% (CI = 73%–95%) specificity to lateralize enlarged parathyroid glands to the correct side of the neck and a 58% (CI = 45%–68%) sensitivity and 91% (CI = 83%–94%) specificity to localize parathyroid tumors to the correct quadrant of the neck. The overall accuracy of two-phase CT to lateralize enlarged parathyroids was 81% (CI = 73%, 88%) and the accuracy to localize enlarged parathyroids was 79% (CI = 73%, 84%). Discussion As a second line investigation two-phase CT has a similar sensitivity, specificity and accuracy to those published for 4D-CT in patients with non-localized, enlarged parathyroids with less radiation exposure. Two-phase CT can help localize enlarged parathyroid glands not definitively identified using MIBI and US. Conclusion Two-phase CT allows clinicians to accurately identify enlarged parathyroid glands while exposing the patient to less radiation than 4D-CT.

Parathyroid sestamibi scan is routinely performed before parathyroid surgery. A large number of thyroid cancers take up 99mTc-sestamibi (MIBI). Since 2001, thyroid nodules discovered on sestamibi, nodules >2 cm, and/or with suspicious criteria were resected. The aim of this study was to evaluate the results of this policy. All patients operated on for hyperparathyroidism, with a MIBI and cervical ultrasonography (US) with a thyroid resection for nodule, were retrospectively included. From 2001 to 2013, 685 patients were operated on for hyperparathyroidism. Some 137 (85 % females) had both preoperative MIBI and cervical US and a thyroid resection. The mean age was 63.2 ± 12.8 years. Sixty-three patients had a total thyroidectomy and 74 a lobectomy. Thirty-six patients had a thyroid cancer. The median size of cancers was 6.5 mm (0.3–22 mm), and 23 (16.7 %) patients had microcarcinoma. Among the 137 patients, 44 (32 %) had a MIBI+ nodule including 22 cancers. Sixty-one percent of malignant nodules were MIBI+ (22/36). The median size of MIBI+ cancers was 15 mm (9–22 mm) versus 2 mm (0.3–17 mm) for MIBI− cancers (p = 0.03). Twenty-two percent of benign nodules were MIBI+ (22/101). Finally, the sensitivity, specificity, positive predictive value, and negative predictive value of MIBI were 61, 78, 50, and 85 %, respectively. Thyroid nodules incidentally discovered on MIBI in hyperparathyroidism patients should be resected.

Background: Primary hyperparathyroidism affects 1 in 700 individuals in the United States. A single adenoma is responsible in over 85% of cases. Surgery remains the most effective treatment. This study was designed to assess the feasibility of minimally invasive radioguided parathyroidectomy MIRP with confirmation of excision by ex vivo radioactivity alone. Methods: Seventy-five consecutive patients with primary hyperparathyroidism were prospectively studied. Following sestamibi scan, patients underwent unilateral neck exploration guided by a handheld gamma probe, which was also used to measure ex vivo radioactivity of excised tissue. Results: The sestamibi scan was positive in 88% of the patients. A small incision mean, 3.2 ± 0.3 cm was sufficient. Ectopic gland sites were localized in five patients with positive scans and single adenomas. Mean operative time was 48 minutes range, 15–125 minutes, with shorter procedures after the initial 20 cases mean, 24 vs. 72 minutes; P < .01. Radioguided parathyroidectomy was successful in 97%, with a mean follow-up of 11 months range, 1–26 months. As noted previously, adenomatous parathyroid glands contained more than 20% of the background radioactivity. Conclusions: MIRP is a feasible alternative to bilateral dissection with the advantages of guided dissection and rapid confirmation, and may become the procedure of choice for primary hyperparathyroidism.

Objective: To determine the value and correlation between sestamibi scan and methylene blue staining for localization of parathyroid glands in patients with primary hyperparathyroidism. Study Design: Nonrandomized convenience sample, followed prospectively. Methods: Twenty-three consecutive patients underwent 24 operations for primary hyperparathyroidism. All patients underwent preoperative technetium 99m-sestamibi planar scintigraphy, preoperative administration of 7.5 mg/kg methylene blue initiated within 60 minutes of surgical incision, and surgical neck exploration supervised by a single surgeon. Results: All patients were cured of hypercalcemia. Sensitivity for sestamibi and for methylene blue staining was 76% and 79%, respectively. Specificity for sestamibi and for methylene blue was 98% and 93%, respectively. Agreement between sestamibi and methylene blue was 96%. Conclusions: Sestamibi scanning and methylene blue staining are useful, complementary localizing tools for patients undergoing surgery for primary hyperparathyroidism. When used together, these studies decrease operative time, justify unilateral exploration in patients with parathyroid adenoma, and increase the ease of identification of hyperplastic parathyroid glands.

Background: Since 1996 new technologies have been brought to bear on the treatment of primary hyperparathyroidism. The Tc 99m sestamibi scan is useful in defining the location of a solitary adenoma, and used in combined with the gamma probe, it facilitates the removal of a solitary adenoma with a degree of accuracy and a cure rate previously not available. Intraoperative measurement of parathyroid hormone is also being used to judge immediately if the surgery has been successful. Methods: This is a retrospective review of all cases of primary hyperparathyroidism treated surgically at Group Health Cooperative, Seattle, Washington, from April 1997 until June 2000. Results: Of the 49 procedures in 47 patients, 44 had a sestamibi scan preoperatively. Fifteen patients had a combination of the sestamibi scan done on the day of surgery and the intraoperative use of the gamma probe. This has been labeled minimally invasive radioguided parathyroidectomy (MIRP). The procedures are divided into two groups. The 28 procedures before the advent of MIRP are labeled group A. The 22 procedures after the advent of MIRP are labeled group B. One patient with two procedures is represented in both groups. They are further differentiated into three groups in terms of surgical difficulty: routine, difficult, and complex. Eleven procedures are in the difficult category and 3 procedures are classified in the complex category. Since the start of MIRP on May 14, 1999, there have been 15 MIRPs and 7 procedures requiring a standard incision. Group A is compared with group B using a variety of parameters. Conclusions: The combination of the Tc 99m sestamibi scan on the day of surgery and the use of the gamma probe intraoperatively is a major advance in the treatment of primary hyperparathyroidism. A significant number of difficult and complex cases must still be treated with bilateral neck exploration, including patients with hyperplasia, double adenoma, carcinoma and patients with underlying thyroid pathology. There is a “surgery time” advantage to the surgeon who does more than 10 cases per year.

Aim: To evaluate the accuracy of Tc-99m sestamibi scintigraphy in pre-operative localization of a single parathyroid adenoma and to determine if neck exploration can be limited to the side of the adenoma. Methods: Over a period of 4 years, 30 patients with primary hyperparathyroid disease underwent surgical treatment in the form of unilateral neck exploration after localization by Tc-99m sestamibi scintigraphy. The scan findings were interpreted by one radiologist with a special interest in parathyroid imaging and the operative findings were correlated with scan findings. Results: Tc-99 sestamibi scan localized a single parathyroid adenoma in 29 patients. There was doubtful uptake of isotope in one patient. Unilateral cervical exploration confirmed isotope scan findings in 29 patients with a positive scan, and these were subsequently proven by histology. In the patient with doubtful sestamibi scan, bilateral neck exploration was undertaken and three enlarged glands were excised. All the three glands were reported to be abnormal, consistent with either adenomas or hyperplasia. All the patients were normocalcaemic after 6 months follow-up. Conclusions: Our results demonstrate that Tc-99m sestamibi scintigraphy is highly accurate in pre-operative localization of a single parathyroid adenoma when performed by an experienced radiologist. Unilateral cervical exploration, as directed by a positive Tc-99m sestamibi scintigram, seems to be a logical approach for the patients with primary hyperparathyroid disease due to solitary adenoma.

Background. In an effort to determine an efficient algorithm for the evaluation of patients with parathyroid adenomas in the reoperative setting, we explored the combination of using ultrasound scans (US) and sestamibi scintigraphy as the only preoperative imaging tests. Methods. We analyzed the outcomes of 62 consecutive patients who were treated between January 1995 and May 1999 and who were referred for persistent primary hyperparathyroidism after initial surgical exploration, at which time no abnormal parathyroid glands had been found. Although all patients underwent US, computed tomography scan, magnetic resonance imaging, and sestamibi scan, we analyzed the success of localization and reoperation using only the results of US and sestamibi scan. Results. Sixty-one patients (98%) underwent curative reoperations. The sensitivity, positive predictive value, and accuracy for US were 90%, 86%, and 84%, respectively; the corresponding values for sestamibi imaging were 78%, 94%, and 74%, respectively. In 58 of 62 cases (94%) preoperative US and/or sestamibi scan accurately identified the adenoma. In 3 patients for whom combined US and sestamibi scan were inaccurate, 1 adenoma was found by intraoperative US in the strap muscle; 1 adenoma was found by blind cervical thymectomy, and 1 adenoma was found by planned sternotomy that was based on computed tomography findings. Conclusions. This study supports an algorithm of obtaining US and sestamibi scan as the initial and perhaps only preoperative localization tests for patients with primary hyperparathyroidism after failed operation, at which time no abnormal glands had been found. (Surgery 2000;128:1103-10.)

Background: The role of imaging studies before parathyroidectomy has been extensively debated and recent advances in unilateral parathyroidectomy intensify this controversy. The purpose of this study was to review the parathyroidectomy experience of a single surgeon, looking at the role of sestamibi scans and a standard postoperative care regimen. Study Design: Retrospective review of office and hospital charts was completed on 90 patients with primary hyperparathyroidism who underwent parathyroidectomy from 1991 to 1998. Patient workup and outcomes were noted, as were results of preoperative imaging. True-positive scans visualized an abnormality ipsilateral to the adenoma found at operation. Statistics were performed using nonparametric testing and Student's t -test. Results: There were 21 male and 69 female patients, with an average age of 54 years (range 29 to 81). There were zero mortalities, three morbidities (3.3%), and three patients who had persistent hypercalcemia, yielding a 96.7% success rate. Sixty-seven patients underwent preoperative sestamibi scanning, with a sensitivity of 74% and positive predictive value of 89%. Operative time in imaged patients averaged 103 ± 49.9 minutes versus 121.5 ± 85.9 minutes for patients without sestamibi scans. Operating time differences were not statistically significant and a preoperative sestamibi scan did not affect the success of parathyroidectomy. Discharge on postoperative day 1 was accomplished in 80% of patients and 13% were discharged the next day. There was no morbidity from hypocalcemia. Conclusions: A preoperative sestamibi scan does not improve efficacy or decrease operating time for primary hyperparathyroidism when bilateral neck exploration is performed. A postoperative care protocol including oral calcium and vitamin D supplementation allows the majority of patients to be discharged on postoperative day 1 with excellent results.

To evaluate the comparative abilities of gated single photon emission computed tomography (SPECT) wall thickening, delayed thallium-201 (TI-201) SPECT, and F-18 fluorodeoxyglucose (FDG) SPECT in detecting myocardial viability, 23 patients with previous myocardial infarction and clinically suspected viability were studied. Each patient had at least 1 extensive fixed perfusion defect on rest/stress technetium-99m sestamibi SPECT. A total of 41 major vascular territories had fixed defects. The mean (±1 SD) left ventricular ejection fraction determined from gated perfusion SPECT was 26% ±11%. Wall thickening was assessed in a semiquantitative fashion by the regional increase in myocardial intensity during systole and was considered normal when a ≥20% increase was observed. Tl-201 SPECT was acquired 4 hours after resting tracer injection was administered. Viability was considered present when regional defect Tl-201 count density, determined by quantitative analysis, was

Objective To evaluate the efficacy of “double-phase” technetium-99m-sestamibi scanning in the localization of abnormal parathyroid tissue in patients with hyperparathyroidism. Methods We present a prospective review of patients with hyperparathyroidism seen at a university teaching hospital between June 1994 and May 1997. Twenty-four patients entered into the study underwent preoperative localization with double-phase technetium-99m-sestamibi. The nuclear medicine results were compared with the operative findings. Results The Tc-99m-sestamibi scan correctly identified the location of single parathyroid adenomas in 22 patients (100%). Of the other two patients, both with diffuse parathyroid hyperplasia, one had a negative sestamibi scan and one had only the two inferior parathyroid glands localized on the sestamibi scan. One patient with recurrent hypercalcemia, who previously underwent total parathyroidectomy and parathyroid autotransplantation into the left forearm, had activity localized to that forearm but not to the neck. Subsequently, hyperplastic parathyroid tissue was successfully removed from the transplantation site. Another patient, who had previously undergone two unsuccessful surgical explorations prompted by hyperparathyroidism, had sestamibi localization of an adenoma inferior and medial to the right submandibular gland. The third surgical exploration disclosed a large adenoma medial to the carotid artery, just below the angle of the jaw. In two elderly, debilitated women with positive scans, adenomas were removed with use of local anesthesia. Of 22 patients in whom long-term follow-up was available, 21 remained normocalcemic for a mean period of 11.4 ± 1.7 months postoperatively. One patient in whom hyperplastic parathyroid tissue had been removed from the left forearm had recurrence of hypercalcemia 1 year after operation. Conclusion Technetium-99m-sestamibi scanning is a reliable method for identifying parathyroid adenomas but not as helpful in localizing hyperplastic parathyroid glands. The precise localization of an adenoma simplifies surgical exploration and in selected patients may allow excision of the adenoma under local anesthesia. Tc-99m- sestamibi scanning has become the preferred method for noninvasive localization of abnormal parathyroid glands. (Endocr Pract. 1998;4:184-189)

In 1991, a National Institutes of Health Consensus Panel stated that preoperative localization for primary hyperparathyroidism is not cost effective. Since then, the sestamibi scan has been applied to parathyroid disease with excellent results, even allowing unilateral exploration under local anesthesia.A metaanalysis of the English literature over the past 10 years was performed to determine the collective sensitivity and specificity of sestamibi scanning to establish its utility in directing a unilateral procedure. The cost effectiveness of scanning all patients with sporadic primary hyperparathyroidism was examined by determining the costs of seven operative technique-dependent variables that could be reduced with a limited procedure.The average sensitivity and specificity of sestamibi were 90.7% and 98.8%, respectively, indicating its ability to guide an accurate unilateral exploration. The analysis of 6,331 patients showed that 87% had solitary adenomas. An average cost savings of $650 was demonstrated for a unilateral operation, which could be realized in as many as 90% (sestamibi sensitivity) of those with solitary adenomas.A preoperative sestamibi scan is specific enough in identifying solitary adenomas to allow unilateral exploration with a1% failure rate. The sensitivity of this scan suggests that 78% of all patients with sporadic primary hyperparathyroidism (90% of the 87% with solitary adenomas) are candidates for unilateral exploration. This rate is significantly higher than the 51% rate at which scanning all patients becomes cost effective.

Objectives. This study was designed to investigate whether left ventricular ejection fraction (LVEF) calculated from post-stress single-photon emission computed tomography (SPECT) reflects the basal value for LVEF or whether post-stress LVEF is reduced in some patients with stress-induced ischemia.Background. Automated programs are now commercially available for assessing global left ventricular (LV) function from post-stress technetium-99m sestamibi gated SPECT performed >15 min after completion of exercise.Methods. Eighty-one sequential patients who underwent a 2-day stress/rest sestamibi imaging protocol and showed perfusion defects on the post-stress tomogram underwent gated acquisition of the second-day rest tomogram. The post-stress and rest tomographic images were read for presence, location, severity and reversibility of defects by consensus of two to three experienced observers with the aid of circumferential count displays. Defects were scored as mild, moderate or severe and as completely or partially reversible or fixed, and a summed defect severity score was calculated. Of these 81 scans, 20 showed nonreversible perfusion defects (group 3), whereas 61 showed reversible perfusion defects. Post-stress and rest LVEF was calculated from the processed gated SPECT data. From 15 additional patients who underwent rest gated SPECT studies on separate days, serial reproducibility of LVEF values calculated from the gated SPECT data was determined to be ±5.2%. Coronary angiography was performed within 3 months of the scan without intervening events in 47 of 81 patients, including 39 of 61 with reversible perfusion defects.Results. In 22 (36%) of 61 patients with reversible perfusion defects, post-stress LVEF was >5% lower than that at rest (group 2), whereas in the remaining 39 patients, post-stress LVEF was either ±5% or greater than that at rest (group 1). Segmental chordal shortening analysis performed in group 2 studies showed that differences in chordal shortening between rest and post-stress were significantly greater in the reversible perfusion defect territories than in the nonischemic perfusion defect territories ([mean ± SD] 0.14 ± 0.14 vs. 0.02 ± 0.09, respectively, p < 0.0001). There were no significant differences among groups for any of the following variables: age, gender, previous myocardial infarction and type of stress. Time to imaging and stress and scan variables were correlated with the change in LVEF by univariate analysis, and the two variables that correlated significantly were the summed defect reversibility score on the scan and a left anterior descending coronary artery location of the scan defect. Only summed defect reversibility score was significant on multivariate analysis.Conclusions. When the only gated sestamibi scan is the post-stress scan, global and regional LV function will not represent basal LV function in all patients with stress-induced ischemia.

Background Despite the fact that primary hyperparathyroidism (HPTH) is the result of a single adenoma in 85% to 92% of cases and is cured following the removal of this one gland, many surgeons continue to perform a complete bilateral neck exploration for patients with primary HPTH. The advent of the sestamibi scan now enables the identification of patients with a single adenoma. Methods The use of preoperative sestamibi scanning followed immediately by minimally invasive parathyroidectomy using intraoperative nuclear mapping allows cure for primary HPTH in properly selected patients. Results Reports have shown that preoperative sestamibi scanning has a sensitivity of approximately 90% and a specificity of almost 100% in identifying patients with a single adenoma. Intraoperative mapping allows a limited dissection to be performed under local anesthesia in an outpatient setting in approximately 80% of all patients with primary hyperparathyroidism. The details of this new technique — patient selection, timing, use of the intraoperative nuclear probe, and surgical exploration — are described. Conclusions When selected appropriately, most patients with primary HPTH can be successfully treated through a minimally invasive technique.

Background: Various invasive and noninvasive localizing tests are available for the evaluation of primary hyperparathyroidism. The surgical success in primary intervention exceeds 90% without localization studies. However, localization tests are absolutely essential for re-exploration and in certain select circumstances, even in primary exploration. The traditional noninvasive localization studies include the sonogram, thalliumtechnetium scan, computed tomography (CT) scan, and magnetic resonance imaging (MRI). The purpose of this report is to review our recent experience with sestamibi scan. The sestamibi scan appears to be the most sensitive and accurate noninvasive test available today. Methods: Technetium 99m sestamibi has recently been used for parathyroid localization, in conjunction with iodine 123 subtraction. We have evaluated 24 patients with suspected primary hyperparathyroidism to study the role of technetium 99m sestamibi scan. T c -sestamibi was used either with or without iodine 123 for subtraction of thyroid activity. Results: None of these patients had renal failure or secondary hyperparathyroidism. Of 24 patients, the parathyroid adenoma was localized by scintigraphy in 19 patients. Twenty patients underwent surgical exploration. In 17 patients there was a complete correlation between the imaging study and the operative findings (positive predictive value, 89%). There were no false positives in this series. The interpretation of the parathyroid images was relatively easy; however, the depth of the adenoma could not be predicted, based on the scan alone. The largest adenoma weighed 2.7 g, the smallest, 700 mg. Conclusion: This newer radiopharmaceutical, technetium 99m sestamibi, appears to be quite useful and accurate in the preoperative localization of patients with primary hyperparathyroidism. Parathyroid enlargement can also be studied by sestamibi imaging alone if delayed imaging is performed.

Summary Aim: The aim of our study was to evaluate the possibility of intraoperative scintimetric detection of parathyroid adenomas with Tc-99m labelled tracers for its usefulness in dystopic or ectopic adenomas. Methods: 12 women with biochemically confirmed hyperparathyroidism were included in our study. After injection of 370 MBq Tc-99m tetrofosmin e.g. sestamibi, preoperative scintigraphy (double phase study and SPECT) was performed and T/NT ratios were evaluated for early, delayed and SPECT images. Surgery was performed using a handheld gamma-probe after preoperative injection of 555-925 MBq Tc-99m tetrofosmin e.g. sestamibi. Count rates (cts/10 sec) were measured and used for calculating in situ - and ex situ - T/NT ratios. Results: In 9 out of 12 patients, adenoma could be detected on static images. Mean T/NT ratios for Tc-99m tetrofosmin were 1.29 for early and 1.23 for delayed images, respectively 1.39 and 1.23 for early and delayed Tc-99m sestamibi scan. Three cases could only be detected with SPECT reconstruction. 11 of 12 parathyroid adenomas could be confirmed intra-operatively. Conclusion: SPECT with Tc-99m labelled cationic complexes showed advantages in detection, precise localization and contrast over static scintigraphy and should therefore be performed at least in cases with poor or no uptake on static images to avoid failures in detection of deeply sited, dislocated glands or adenomas with low uptake. Intraoperative localization and confirmation of parathyroid adenoma with Tc-99m-labelled cationic complexes and a gamma probe is possible and may be useful in case of dys- or ectopic adenoma by influencing surgical approach and operating time.

A 54-year-old woman was referred for imaging studies after presentation for palpitations and a palpable thyroid nodule. The patient underwent a dual-phase single-agent Tc-99m sestamibi scan followed later by a thyroid ultrasound at an outside hospital. The Tc-99m sestamibi scan showed a marked focus of activity separate from the thyroid bed in the inferior left neck. Thyroid ultrasound showed a dominant calcified nodule in the left lobe of the thyroid, measuring 1.3 cm, as well as 3-mm cystic lesions in both lobes of the thyroid. Also, an iodine-123 scan was performed showing a cold nodule in the left inferior thyroid. During surgery, the patient underwent a left thyroid lobectomy for an intrathyroidal parathyroid adenoma.

We report the case of a 54-year-old woman undergoing radioguided parathyroidectomy in whom four normal glands were identified on cervical exploration. The gamma probe was instrumental in guiding us to the adenoma in a fifth gland that was not visible and was localized to the parenchyma of the left lobe of the thyroid gland. Many surgeons do not advocate use of the gamma probe in minimally invasive parathyroidectomy and rely solely on focused exploration on the basis of a preoperative sestamibi scan and intraoperative rapid parathyroid hormone assays. This case, however, illustrates the utility of the gamma probe in parathyroid adenoma localization.

Primary hyperparathyroidism is a common condition due to either a parathyroid adenoma or, less commonly, parathyroid hyperplasia, whose treatment is essentially surgical. We have, therefore, assessed the accuracy of Tc-99m pertechnetate/Tc-99m sestamibi (methoxy-isobutyl isonitrile) imaging in the localization of adenomas and hyperplastic parathyroids. The clinical records of all patients who had Tc-99m pertechnetate/Tc-99m sestamibi imaging and parathyroid surgery at this hospital were reviewed. The technique used involves standard subtraction methodology with the addition of a novel change detection algorithm to optimize localization. Of 46 patients scanned in 48 patient episodes, 36 patients had adenomas; 28 (78%) were accurately localized to the correct quadrant, and 4 were correctly lateralized. Two patients with parathyroid carcinomas had their metastases correctly localized. Thus, in 34 of 38 (89.5%) of the scans, adenomas or carcinomas were able to be anatomically localized. Six patients presented with hyperplasia; 5 were diagnosed by sestamibi scans, and 3 of these accurately localized all hyperplastic glands. Four additional patients had known hyperplasia, of which 2 were rendered normocalcemic after removal of their sestamibi-positive glands; the other 2 had small second glands detected only at surgery. In patients with unknown pathology, imaging suggested that 6 patients had hyperplasia; this was correct in 5 cases (83%). Nine of the 12 scans in patients who had had previous parathyroid surgery accurately localized the tumors, 7 in the neck and 2 outside. We suggest that sestamibi imaging can help to distinguish hyperplasia from adenomatous disease; when imaging is required, we recommend it as the imaging modality of choice in all patients with primary hyperparathyroidism, especially in reoperated patients.

Background The intraoperative quick parathyroid hormone assay, the intraoperative gamma probe, and endoscopic parathyroidectomy are three very new techniques developed to facilitate parathyroid surgery. Some hospitals do not have the necessary equipment, and many, like ours, continue to operate in the time-honored way. Study design We performed a retrospective chart review of 34 such operations, done with the use of Sestamibi scans, but entirely without the newer modalities. Results Four-gland exploration was carried out on all patients. Operative times ranged from 15 to 165 minutes, with a mean of 47 minutes, and incision lengths ranged from 2 to 3 cm, with a mean of 2.8 cm. There was no mortality, no reoperation, and no vocal cord or recurrent laryngeal nerve injury. Our cure rate was 100%, as determined by a fall in postoperative calcium and parathormone levels. Conclusions In our view, the intraoperative parathyroid hormone assay, gamma probe, and endoscopic parathyroidectomy add an entirely unnecessary cost to an operation that can be completed satisfactorily with a preoperative Sestamibi scan and a thorough four-gland exploration.

The aim of this study was to evaluate the impact of intraoperative parathyroid hormone (PTH) monitoring on surgical strategy, intraoperative findings, and outcome in patients with negative sestamibi scintigraphy and with discordant imaging studies. We divided our 175 patients into 3 groups: group A was methoxyisobutylisonitrile (MIBI)-positive and ultrasonography positive and was concordant (114 patients), group B was MIBI-positive and ultrasonography-negative (50 patients), and group C was MIBI–-and ultrasonography-negative (11 patients). The overall operative success was 99.12% in group A, 98% in group B, and 90.91% in group C, with an incidence of multiglandular disease of 3.5% in group A, 12% in group B, and 9.09% in group C. Intraoperative PTH monitoring changed the operative management in 2.63% of patients in group A and 14% in group B. The use of intraoperative PTH achieves to obtain excellent results in the treatment of primary hyperparathyroidism in high-volume centers, even in the most difficult cases, during MIBI-negative and discordant preoperative imaging studies.

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

Background: The cost effectiveness of preoperative localization in cases of primary hyperparathyroidism has not been established. We analyzed the potential savings in operative time after localization with technetium 99m (99mTc) sestamibi scan. Methods: Thirty-three patients had localization of a solitary adenoma with99mTc-sestamibi. Measurement was made of the time required for adenomectomy, unilateral neck exploration (UNE), unilateral neck exploration and confirmation of one contralateral parathyroid gland (UNEC), or bilateral neck exploration (BNE). Results: The total operative time in minutes was 76.4 ± 18.8 for adenomectomy; 87.5 ± 20.4 for UNE; 105.6 ± 25.0 for UNEC; and 117.9 ± 26.7 for BNE. The time difference was significant between adenomectomy versus UNE, UNEC, and BNE. There were also significant time differences between UNE versus UNEC and BNE. Conclusions: The preoperative localization of a solitary parathyroid adenoma may optimize operative time with UNE, saving approximately 30 minutes.