Technetium-99m Sestamibi Scan Research Articles

6634 Dual-Mediated PTH And Osteolytic Hypercalcemia In Metastatic Endometrial Carcinoma

Abstract Disclosure: C.K. Persaud: None. D.J. Beckman: None. Background: Hypercalcemia of malignancy occurs in 20-30% of advanced stage cancer patients. Etiologies include parathyroid hormone-related peptides (PTHrP)-mediated, osteolytic metastases-mediated, overproduction of 1,25-dihydroxycholecalciferol, and rarely parathyroid hormone (PTH)-mediated. PTH-mediated hypercalcemia of malignancy is rare and occurs through ectopic PTH production or primary hyperparathyroidism. We report a rare case of both PTH-mediated and osteolytic-mediated hypercalcemia in the setting of malignancy. Clinical Case: A 57-year-old female with history of endometrial cancer and multiple solid organ metastasis, presented with two weeks of progressive poor oral intake, nausea, emesis, and right flank pain. On hospital admission, she had a serum calcium of >20.1 mg/dL (8.6-10.2), PTH of 203 pg/mL (15.0-65.0), and creatinine of 1.7 mg/dL (0.7-1.2, baseline 1.3). Non-contrasted CT chest/abdomen/pelvis noted increased size of known right adrenal metastasis, new left adrenal metastasis, periaortic lymphadenopathy, and scattered nodules in the subcutaneous tissues of the abdomen and chest, however bone metastasis were not noted. Patient’s hypercalcemia was treated with zoledronic acid, calcitonin, cinacalcet, and eventually denosumab due to difficulty controlling hypercalcemia. Additional labs obtained during evaluation included ionized calcium >2.5 nmol/L (1.12-1.32), PTHrP <2.0 pmol/L (<2.0), 1,25-dihydroxycholecalciferol <10 pg/mL (21-65). Patient’s right adrenal metastasis biopsy one month prior to admission was subsequently stained for PTH and was negative. Technetium-99m sestamibi scan was obtained for localization of parathyroid adenoma or carcinoma. The scan did not localize, however did show numerous new lytic lesions in the skull, spine, sternum, rib cage, and right humerus. Patient’s hospital course was complicated by progressively worsening renal function, anemia, and thrombocytopenia. Patient was discharged to a long-term acute rehab facility off hypercalcemia treatment with a corrected calcium of 10.0 mg/dL. Conclusion: PTH-mediated hypercalcemia is a rare cause of hypercalcemia of malignancy. PTH levels are typically low or low-normal in osteolytic mediated hypercalcemia. Generally, if PTH is elevated in hypercalcemia, an alternate etiology is not evaluated. This case highlights a rare dual-mediated hypercalcemia of malignancy. The patient’s PTH level elevation was discordant with her high degree of hypercalcemia and prolonged treatment course. She was subsequently found to have widespread bone metastases contributing to hypercalcemia. While multiple etiologies of hypercalcemia can be rare, it is important to evaluate for all contributing causes, especially with additional clinical conditions, such as malignancy. Presentation: 6/3/2024

The Correlation of Reverse Redistribution Pattern with Coronary Angiography: A Conundrum Revisited

Abstract Objective The reverse redistribution (RR) pattern is a phenomenon whose etiology, pathophysiology, and clinical implications are not well understood. The studies examining this pattern date back to days when timely coronary interventions and anti-ischemic therapies were not widely used, so we aimed to reinvestigate any relationship between RR and coronary angiography (CA) findings in today's contemporary clinical settings. Methods All patients with an RR pattern on the Tc99m-MIBI (technetium-99m sestamibi) scan between 2021 and 2023 were screened. Information on demographics, history of acute coronary syndrome, revascularization, comorbidities, and risk factors was collected. The CA findings were compared to RR regions. The physician's decision in the case of the RR pattern was grouped. Results In a total of 67 patients (men 83%, aged 63.6 ± 10.5), the RR pattern was most commonly seen in the inferior-posterior wall (n = 41, 31.3%), followed by the apex (n = 19, 14.5%) and anterior (n = 12, 9.2%). Most patients with RR pattern had normal/nonobstructive coronary angiograms (61.1%, n = 22); significant stenoses in 1, 2, and 3 vessels were present in 19.4% (n = 7), 13.8% (n = 5), and 5.5% (n = 2) of patients, respectively. There was no correlation between the regions of the RR pattern and significant stenosis detected on CA (p = 0.6, p = 0.5, p = 0.6, respectively, for left anterior descending artery, circumflex artery, and right coronary artery). Conclusion In this study, no evidence of a relationship between RR patterns and CA findings was found. The 60% of the patients with RR pattern had normal/nonobstructive coronaries, so the decision to proceed with CA should not be made based solely on this finding.

Clinical, Biochemical and Surgical Outcomes of Primary Hyperparathyroidism in the Present Era: A Prospective Study From a Tertiary Care Hospital.

Introduction Primary hyperparathyroidism (PHPT) has undergone a considerable change from being symptomatic to asymptomatic.This is the first large study from North Indiato study the clinical and biochemical features and surgical outcomes in thepresent era. Study design This is across-sectional study that was conducted in the Department of Endocrinology (SKIMS) from February 2021 to December 2022, in which 103 patients diagnosed with PHPT were included. Evaluation included measurement of total calcium, phosphorus,alkaline phosphate, intact parathyroid hormone, 25-hydroxy vitamin, 24-hour urinary calcium, radiological survey of hands and skull, Dual Energy X-ray absorptiometry, and ultrasonography (USG) of the abdomen. USG neck and technetium-99m sestamibi scans were usedfor preoperative localization; however, in cases of discordance between these investigations or suspicions of multi-glandular disease, four-dimensional computerized tomography of the neck was used. Patients were subjected to surgery according to the guidelines and monitored post-surgeryfor complications like hypocalcemia and hungry bone syndrome and to document the cure. Results The mean age of patients was 42.8±14.73 years, with a female-to-male ratio of 4.4:1.The mean eGFR of patientswas 99.1±30.87 ml/min, with 55 (53.4%) of themhaving renal disease.Osteoporosis and fractures were present in 41 (39.8%) and 5 (4.8%) patients, respectively. Cholelithiasis and pancreatitis were present in 25 (24.3%) and 5 (4.9%) patients, respectively.Hypertension (HTN) and diabetes mellitus (DM) were the commonest comorbidities, which were present in 34 (33.1%) and 15 (14.5%) patients, respectively.Mean preoperative levels of calcium, phosphorus (PO4), alkaline phosphate (ALP), intact parathyroid hormone (iPTH), 25(OH)vitamin D, and 24-hour urinary calcium were 12.1 mg/dl, 2.35 mg/dl, 210.2 U/L, 332.9 pg/ml, 25.7 ng/ml, and 452.1 mg/day, respectively. The most commontype was right inferior parathyroid adenoma, present in45 cases (43.7%), followed by left inferior parathyroid adenoma in31 cases (30.1%). A total of 75 patients (72.8%) underwent minimally invasive parathyroidectomy, with 68 patients (90.7%) achieving a biochemical cure. The mean adenoma weight was 3.19±2.25 g. There was no statistically significant correlation (r) between preoperative biochemical parameters and adenoma weight. Conclusion Despite improvements in imaging and the easy availability of immunoassays for early diagnosis, renal disease continued to be the most common presentation, followed by skeletal involvement in our population. In developing countrieslike India, any patient presenting with nephrolithiasis or nephrocalcinosis, low bone mass, or fragility fractures should be evaluated for PHPT.

Atypical Parathyroid Adenoma in a Young Man

Patient is a 38-year-old man who developed sudden onset of pain in the upper left arm while carrying a case of water. The pain recurred periodically over the next few months. He presented to the emergency department where imaging showed a pathologic fracture in the proximal left humerus through a lytic lesion. Laboratory testing showed: calcium 13.8 mg/dL (8.5–10.1 mg/dL), 25-OH vitamin D 8 ng/mL (31–100 ng/mL), parathyroid hormone 1583.1 pg/mL (18.5–88 pg/mL). Neck ultrasound showed a complex nodule in the left neck measuring 4.2 x 1.7 x 2.5 cm. Subsequent biopsy of the left arm lesion showed a Brown tumor. The patient was referred to endocrinology. There was concern for parathyroid carcinoma given the elevated parathyroid hormone and large neck lesion. Technetium-99m sestamibi scan showed a 4.1 x 2.6 x 2.5 cm mass posterior to the left thyroid lobe. He subsequently underwent left hemithyroidectomy and parathyroidectomy. Pathology revealed a 3.1 cm parathyroid mass with scattered fibrous bands, foci of prominent nucleoli and foci of sheet-like trabecular and spindled architecture. It was without necrosis, lymphovascular invasion, perineural invasion, increased mitotic activity, atypical mitoses or invasion into adjacent structures. Thus, it was classified as an atypical parathyroid adenoma.Primary hyperparathyroidism is the third most common endocrine disorder, but fewer than 2% occur as a result of an atypical parathyroid adenoma. Patients with an atypical parathyroid adenoma tend to have a more dramatic clinical presentation compared to those with classic adenoma. We see higher calcium and parathyroid hormone levels. Atypical parathyroid adenomas are classified as such due to other features which place the lesion at a higher risk for malignant behavior including higher mitotic activity, adherence to adjacent structures, banding fibrosis and a growth pattern that is either solid or trabecular. In contrast to parathyroid carcinoma, atypical parathyroid adenomas do not show invasion into the surrounding tissues or lymphatic/vascular vessels, and there should be no evidence of metastatic disease. The exact definition of an atypical parathyroid adenoma varies among institutions, and recognition of the defining features (or lack thereof) necessitates an experienced endocrine pathologist.Due to their uncertain malignant potential, patients with an atypical parathyroid adenoma should undergo routine surveillance for recurrence. Routine follow-up of calcium, parathyroid hormone and imaging is indicated to detect for recurrence. A CDC73 germline mutation is associated with recurrence compared to CDC73-negative patients. Parafibromin expression is also thought to play a role although studies so far have had discrepant results.

Correlation Between Technetium-99msestamibi Scans, Intraoperative Findings, and Histopathological Results in Primary and Tertiary Hyperparathyroidism

Correlation Between Technetium-99msestamibi Scans, Intraoperative Findings, and Histopathological Results in Primary and Tertiary Hyperparathyroidism

Serum Vitamin D Level Does not Affect The Sensitivity of Parathyroid Adenoma Localization Tests

The aim of the present study was to evaluate the predictive value of 25-hydroxyvitamin D, calcium and parathormone level, co-existence of thyroid nodule, thyroidectomy history and adenoma volume on the success of neck ultrasound (US) and technetium-99m sestamibi (MIBI) scan in primary hyperparathyroidism (PHP) patients. This study included 256 patients with PHP who underwent parathyroidectomy. 169 (%66) patients had vitamin D deficiency and 56 (%22) of patients had insufficiency. The sensitivity of US and MIBI studies showed no difference between vitamin D deficiency, insufficiency and replete groups (%80.5, %82 and %71 (p > 0.05) and %81, %84 and %71 respectively (p > 0.05)). Vitamin D level was not found to be an independent predictor of localization on either US or MIBI scan after adjusting for different variables (p > 0.05). Calcium level was found to be an independent predictor for US sensitivity (r2:0,033, p:0,032) and parathormone level for MIBI sensitivity (r2:0,05, p:0,025). The co-existence of nodular thyroid disease and history of thyroidectomy significantly decreased the sensitivity of US (%76 and %43). MIBI sensitivity was not impaired by nodular disease but the history of thyroidectomy also impaired the sensitivity of MIBI (%43). As a result vitamin D level does not affect the sensitivity of preoperative localization tests.

Follow up of Patients with Parathyroid Adenoma Detected by Parathyroid Scan

<p><strong><em>Background:</em></strong> Primary hyperparathyroidism (PHPT) is the third most endocrine disorder after diabetes and thyroid disease. The objective of this study was to observe the outcome of those patients who had positive parathyroid scan with Technetium-99m (<sup>99m</sup>Tc) sestamibi scan referred to National Institute of Nuclear Medicine & Allied Sciences (NINMAS) to perform parathyroid scan.<strong></strong></p><p><strong><em>Patients and Methods</em></strong><em>:</em> This longitudinal observational type of study was carried out at NINMAS, from January 2016 to December 2016. A total number of 43 hyperparathyroid patients who had positive parathyroid scan were included in this study during one year follow up period. There clinical status, biochemical profile & treatment history were evaluated Chi-quire and paired t-test were used to analyze the variables.</p><p><strong><em>Results:</em></strong><strong> </strong>Among 43 study patients, number of male patients was 26 (60.5%) and female patients were 17 (39.5%). The mean ± SD age was 42.44 ± 12.11 years and majority was in age group 41-50 years<strong>. </strong>It was observed that 40 (93.0%) patients were symptomatic and only 3 (7.0%) were asymptomatic. Regarding symptoms, majority (81.4%) patients had bone pain followed by renal stone (58.1%). More than half (55.8%) patient had abdominal pain or cramps. Twenty nine (67.4.0%) patients undergone operation and 14 (32.6%) patients did not receive operative treatment at the one year follow up period. Among 43 patients 29 (67.4%) were operated and all operated patients relieved their symptoms whereas patients 14 (32.6%) had not undergone operation and their symptoms persisted. There was strong statistical significant association (P<0.05) between operation and relief of symptoms. The biochemical profile of study patients showed that preoperative mean serum calcium level was 10.92±2.85 mg/dl which reduced after operation (7.53±2.75 mg/dl). The mean value of serum parathyroid hormone (PTH) level also reduced from 748±744.77 pg/ml to 171.61±168.23 pg/ml.</p><p><strong><em>Conclusion:</em></strong> Among all patients, 67.4% received operative treatment and were relieved from symptoms at one year follow up. Significant number of hyperparathyroid patients (32.6%) failed to receive operative treatment due to poor economic condition. More awareness is needed among physicians and patients about immediate operative treatment to alleviate their sufferings as well as to avoid crippling complications.</p><p>Bangladesh J. Nuclear Med. 20(2): 119-123, July 2017</p>

Highly specific preoperative selection of solitary parathyroid adenoma cases in primary hyperparathyroidism by quantitative image analysis of the early-phase Technetium-99m sestamibi scan.

Highly specific preoperative localizing test is required to select patients for minimally invasive parathyroidectomy (MIP) in lieu of traditional four-gland exploration. We hypothesized that Tc-99m sestamibi scan interpretation incorporating numerical measurements on the degree of asymmetrical activity from bilateral thyroid beds can be useful in localizing single adenoma for MIP. We devised a quantitative interpretation method for Tc-99m sestamibi scan based on the numerically graded asymmetrical activity on early phase. The numerical ratio value of each scan was obtained by dividing the number of counts from symmetrically drawn regions of interest (ROI) over bilateral thyroid beds. The final pathology and clinical outcome of 109 patients were used to perform receiver operating curve (ROC) analysis. Receiver operating curve analysis revealed the area under the curve (AUC) was calculated to be 0.71 (P=0.0032), validating this method as a diagnostic tool. The optimal cut-off point for the ratio value with maximal combined sensitivity and specificity was found with corresponding sensitivity of 67.9% (56.5-77.2%, 95% CI) and specificity of 75.0% (52.8-91.8%, 95% CI). An additional higher cut-off with higher specificity with minimal possible sacrifice on sensitivity was also selected, yielding sensitivity of 28.6% (18.8-38.6%, 95% CI) and specificity of 90.0% (69.6-98.8%, 95% CI). Our results demonstrated that the more asymmetrical activity on the initial phase, the more successful it is to localize a single parathyroid adenoma on sestamibi scans. Using early-phase Tc-99m sestamibi scan only, we were able to select patients for minimally invasive parathyroidectomy with 90% specificity.

일차성 부갑상선기능항진증으로 수술적 치료를 받은 환자들에 대한 임상적 고찰

Background and Objectives: To evaluate the accuracy of ultrasound (US), computed tomography (CT) and 99Tc sestamibi scan (MIBI) for preoperative localization of solitary parathyroid mass in patients with primary hyperparathyroidism and analyze our surgical outcomes. Materials and Methods: In a retrospective study of 57 consecutive patients with primary hyperparathyroidism, all patients underwent parathyroidectomy from Jan. 2003 through Dec. 2013. Patients were performed ultrasound, computed tomography and Technetium-99m ses-tamibi scan before surgery. We also reviewed serum calcium, serum parathyroid hormone (iPTH), associated symptoms and pathologic results through electronic medical records (EMR). Results: All 57 patients were enrolled and they had single solitary parathyroid mass. In final pathologic results, 45 patients had solitary parathyroid adenoma, 7 patients had nodular hyperplasia and 5 patients were diagnosed as parathyroid cancer. In adenoma and carcinoma as a single nodule, accuracy of US was 95.2% (40/42), CT was 91.7% (44/48), MIBI was 81.5% (31/38). The most common symptoms were general weakness and nausea. Interestingly, asymptomatic hypercalcemia, incidentaloma were over the half patients. Postoperative numbness was observed in 4 patients and they were treated with calcium supplementation but not persisted longer than 4th day postoperatively. Conclusions : Our results show that the combination of US, CT, MIBI has benefits for preoperative localization of parathyroid mass in primary hyperparathyroidism and parathyroidectomy was useful for patients with primary hyperparathyroidism. (J Clinical Otolaryngol 2017;28:205–210)

Use of a Technetium99m-Sestamibi Scan to Detect Ipsilateral Double Adenoma in a Patient with Primary Hyperparathyroidism: A Case Report

Patients with primary hyperparathyroidism generally have a single parathyroid adenoma that causes excessive excretion of parathyroid hormone. For about 2% to 15% of these patients, a double adenoma is present that involves one lesion on each side of the neck. We describe a case of double parathyroid adenoma causing asymptomatic hypercalcemia. A presurgical technetium99m (Tc99m) sestamibi scan suggested an ipsilateral double adenoma in the left thyroid lobe. An intraoperative parathyroid hormone assay confirmed its successful removal. Although double adenomas are not yet widely acknowledged, presurgical imaging and nuclear scans can help to localize multiple lesions, and intraoperative parathyroid hormone assays can confirm the diagnosis and cure.

Clinical and laboratory profile of primary hyperparathyroidism in Kashmir Valley: A single-center experience.

Background:Although primary hyperparathyroidism (PHPT) has become an asymptomatic disease in the West, in India, PHPT is still an uncommonly diagnosed, overtly symptomatic disease with skeletal, muscular, and renal manifestations.Aims:To describe the profile and surgical outcome of 78 consecutive PHPT patients over a period of two decades at a single center.Materials and Methods:All patients who underwent evaluation and surgery for PHPT from January 1996 to December 2015 were included. Evaluation included measurement of serum total calcium, inorganic phosphorus, alkaline phosphatase, intact parathyroid hormone, 25-hydroxy Vitamin D, 24 hour urinary calcium and radiological survey. Ultrasonography neck and technetium-99m sestamibi scan were used for preoperative localization.Results:A total of 78 patients were identified during the two decades of whom 29 patients were studied retrospectively and 49 patients prospectively. Mean age of patients was 44.72 ± 12.46, and male:female ratio was 1:6. The most common presenting features were nephrolithiasis and/or nephrocalcinosis (64.10%), bone pain (44.1%), abdominal pain (39%), constipation (26%), and myopathy (14.10%). Fractures were present only in 10.25%, and brown tumors in 6.41% patients. The cure rate in our series was 96.15%. The mean parathyroid gland weight was 2.05 ± 3.03 g. None of the 41 patients in whom long-term follow-up was available, had recurrence of PHPT.Conclusions:The profile of PHPT is changing with older age at presentation, and emergence of renal stone disease and decline in overt skeletal disease as common presentation. The parathyroid weight in our study resembles that reported from developed countries.

Intrathymic Parathyroid Adenoma

Introduction: Mediastinal parathyroid adenoma localization is a rare entity. We report a case of excision by manubriotomy of intrathymic parathyroid adenoma detected by Computed Tomography scan of the chest and neck and confirmed by Technetium-99 m-sestamibi scan (99 mTc-MIBI). Case Presentation: A 68 years old woman with history of hypercalcaemia, PTH elevation and operation for pathological fracture of the left femur 7 days before was presented to our service. The patient underwent manubriotomy and the adenoma was found within the right lobe of the thymus gland. Conclusion: The Technetium-99 m-sestamibi scan evaluation can be useful in the preoperative localization of ectopic parathyroid adenomas. The surgical approach by manubriotomy is privileged when the ectopic adenoma is in the upper part of anterior mediastinum.

Radiographic evaluation of non-localizing parathyroid adenomas

PurposePatients with primary hyperparathyroidism routinely undergo preoperative imaging to localize the abnormal gland to facilitate a guided parathyroidectomy. These techniques include neck ultrasound (US), dual phase planar technetium-99m (99mTC) sestamibi (MIBI) scans, single photon emission computed tomography (SPECT), combined SPECT/CT, and four dimensional CT scans (4D CT). Despite appropriate preoperative imaging, non-localization of abnormal glands does occur. This study aims to determine whether non-localization is the result of radiologic interpretive error or a representation of a subset of truly non-localizing parathyroid adenomas. Materials and methodsA retrospective study was performed; two senior radiologists reinterpreted the preoperative imaging (US and MIBI scans) of 30 patients with initially non-localizing studies. All patients underwent parathyroidectomy for primary hyperparathyroidism at a tertiary referral center. Both radiologists were blinded to the scores of his colleague. The results were compared for inter-reader reliability using Cohen’s kappa test. ResultsTwenty-nine of thirty nuclear studies were found to be negative on reinterpretation. The readers agreed in 86.67% of their observations, with a kappa (κ) value of 0.706 (SE=±0.131, 95% confidence interval for κ =0.449–0.962). One of eighteen ultrasounds had positive localizations on reexamination, however, the inter-observer agreement was only 55.6%, with a kappa value of 0.351 (SE=±0.139, and 95% confidence interval for κ =0.080–0.623). Overall, no statistically significant difference in preoperative and retrospective interpretation was found. ConclusionThis study identifies a subset of parathyroid adenomas that do not localize on preoperative imaging despite sound radiographic evaluation.

Persistent renal hyperparathyroidism caused by intrathyroidal parathyroid glands

Renal hyperparathyroidism usually occurs in chronic renal failure patients on regular dialysis. However, renal hyperparathyroidism resulting from intrathyroidal parathyroid glands is an uncommon condition. We herein present the case of a 35-year-old woman who has been on hemodialysis for 20 years. She had renal hyperparathyroidism with generalized weakness and bone pain for 2 years. The patient initially underwent parathyroidectomy at a local institution, during which two large parathyroid glands were resected from the right side (no parathyroid glands were found on the left side); however, the surgical procedure was unsuccessful, and the patient had persistent renal hyperparathyroidism after the operation. She was then transferred to our hospital and ectopic intrathyroidal parathyroid glands were localized by neck ultrasonography and technetium-99m sestamibi scans with single-photon emission computed tomography imaging preoperatively. A left thyroid lobectomy was performed and two intrathyroidal parathyroid glands were found. The patient recovered uneventfully and her symptoms resolved. Therefore, clinicians should be aware of the possibility of renal hyperparathyroidism resulting from intrathyroidal parathyroid glands in cases where the renal hyperparathyroidism persists after parathyroidectomy.

Parathyroid Adenoma in a Sixteen Year Old Male Presenting with Long-standing Non-specific Gastrointestinal Symptoms

A sixteen year-old male presented with a six-month history of intermittent morning nausea and epigastric pain. There was a ten-day history of non-bilious vomiting, anorexia, and weight loss. He admitted to binge drinking on weekends. He had pancreatitis at ten years of age. Both father and paternal grandfather had a history of renal stones. Physical examination revealed epigastric tenderness. Investigations: lipase 1534 (23-300U/L), PTH 11.5 (1.1-6.8pmol/L), calcium 2.93 (2.10-2.60mmol/L), ionized calcium 1.29 (1.09-1.25mmol/L), phosphorus 0.63 (0.8-1.45mmol/L). A technetium-99m sestamibi scan combined with single photon emission computed tomography revealed an 8 mm parathyroid adenoma in the lower right parathyroid region. The patient underwent right superior and inferior parathyroidectomies. Intraoperative PTH dropped precipitously from 15 to 1.4pmol/L, ionized calcium dropped from 1.32 to 0.97mmol/L. The patient did not develop hypocalcemia postoperatively. The pathology report confirmed the diagnosis of spontaneous parathyroid adenoma.

Suboptimal Awareness of Radiologic Dose Among Patients Undergoing Cardiac Stress Scintigraphy

Patients undergoing radiologic and nuclear medicine examination often receive little, if any, information related to the radiologic dose and consequent potential long-term cancer risk. This "economical with the truth" communication may violate basic patients' rights. We assessed the information perceived by patients on the radiation dose exposure during nuclear medicine examinations. We recruited 109 consecutive patients (66 male; aged 66 +/- 10 years) who were referred to the Nuclear Medicine laboratory of Sant'Orsola-Malpighi Hospital (Bologna University, Bologna, Italy) for a cardiac rest-stress technetium-99m sestamibi scan. This scan gives an effective dose of approximately 10 mSv, corresponding to a dose equivalent of 500 chest x-rays (European Commission Medical Imaging Guidelines 2001) and an estimated extra lifetime attributable risk of 1 cancer in 1,000 exposed subjects (Biological Effects of Ionizing Radiation VII Committee 2005). Radiation dose exposure was correctly identified by 21% of patients, with the remaining 79% underestimating the exposure by at least 500 times, considered to be zero by 11%, one-half of a chest x-ray by 23%, 1 chest x-ray by 35%, and "don't know" by 10%. The long-term cancer risk was correctly estimated by 27% of patients, with the remaining substantially underestimating the risk, considered to be "zero" by 30%, 1 in 1 million by 19%, 1 in 100,000 by 9%, and "don't know" by 10%. Patients undergoing common cardiac stress scintigraphy examinations involving significant radiation exposure have little or no awareness about nuclear medicine dose (and corresponding risk). This ineffective communication poses significant ethical concerns and possible vulnerability to legal suits against practitioners and prescribers, especially in case of inappropriate examinations.

Index of Suspicion

Index of Suspicion

Surgeon‐Performed Ultrasound for Preoperative Localization of Abnormal Parathyroid Glands in Patients with Primary Hyperparathyroidism

The introduction of portable ultrasound equipment enables surgeons to perform ultrasound examinations in a clinic setting. This study was undertaken to evaluate surgeon-performed ultrasound (SP-US) in patients with primary hyperparathyroidism (PHPT). Between July 2003 and March 2004, 65 patients with PHPT were evaluated with SP-US and 48 of these patients underwent parathyroid surgery. Among this group of 48 evaluable patients, 47 had preoperative imaging with technetium-99m sestamibi scanning (MIBI), and 12 had an additional ultrasound examination at an external radiology department (RP-US). All patients were cured of PHPT and the operative findings were used to determine the true status of the parathyroid glands of each patient. Twenty-four (50%) patients had concomitant thyroid nodules which were identified by SP-US, and 4 (8.3%) patients had simultaneous thyroid operations, 2 of which were for thyroid cancer. Considering data for all patients, SP-US had significantly higher sensitivity than MIBI or RP-US (60% vs. 46%, P = 0.013, and 60% vs. 11%, P = 0.004 respectively). Among the patients with a single adenoma, SP-US, MIBI, and RP-US had sensitivities of 83%, 63%, and 13% respectively. The specificities of all three imaging techniques were uniformly high and were not significantly different from each other. Surgeon-performed ultrasound is an accurate modality for localizing abnormal parathyroid glands in patients with PHPT, with results that compare favorably with other parathyroid imaging modalities.

Computed axial tomography–MIBI image fusion for preoperative localization in primary hyperparathyroidism

Background An imaging-guided unilateral surgical approach in patients with primary hyperparathyroidism (HPTH) requires reliable preoperative localization procedures. Using present imaging techniques, 60% to 80% of patients with primary HPTH can be treated successfully with limited surgery. Thus, further improvement of diagnostic accuracy is required. Computed axial tomography (CAT)–MIBI image fusion was introduced as a new technique for localizing enlarged parathyroid glands. We describe the new method and present its first results. Methods Six consecutive patients with primary HPTH underwent CAT–MIBI image fusion for preoperative parathyroid localization. CAT and technetium-99m–sestamibi scan were performed separately. The patient's head and neck were fixed with the noninvasive Vogele-Bale-Hohner Head Holder (VBH HeadFIX; Medical Intelligence, Schwabmünchen, Germany) and the BodyFIX (Medical Intelligence) vacuum cushion. Radiographic and scintigraphic markers were mounted at the head holder and the patient. CAT and MIBI images were fused by overlaying radiographic markers using a commercial software and workstation. Results In 5 patients, localization and dimension of the solitary adenomas were exactly predicted. In 1 patient with multiglandular disease (3 enlarged glands), CAT–MIBI image fusion was not able to predict multiple gland involvement. However, in a retrospective analysis of the localization study, the other two enlarged parathyroid glands could be correctly identified regarding their site and size. Conclusions First results of CAT–MIBI image fusion are promising. The new technique provides a higher image resolution and better delimitation of enlarged parathyroid glands and adjacent anatomic structures than conventional scintigraphic methods.

Parathyroid localization

Localization studies can help identify abnormal parathyroid glands resulting in morbidity at the time of parathyroid surgery. Currently employed techniques include radionucletatide studies, ultrasound, computed tomography, magnetic resonance imaging, and angiography. There are also some techniques, which help the surgeon intraoperatively. The most useful preoperative localization study to date has been the technetium-99m sestamibi scan. Localization studies can help identify abnormal parathyroid glands resulting in morbidity at the time of parathyroid surgery. Currently employed techniques include radionucletatide studies, ultrasound, computed tomography, magnetic resonance imaging, and angiography. There are also some techniques, which help the surgeon intraoperatively. The most useful preoperative localization study to date has been the technetium-99m sestamibi scan.