Sestamibi SPECT/CT versus SPECT only for preoperative localization in primary hyperparathyroidism: a single institution 8-year analysis.

BACKGROUND: Primary hyperparathyroidism is caused by single gland disease in 85% of cases and by multiglandular disease in 15%. Our aim was to discover if the addition of computed tomography acquisition/fusion on a hybrid scanner to traditional dual-phase single-photon emission tomography improves localization accuracy. METHODS: A prospective database was queried for the perioperative data of patients with sporadic primary hyperparathyroidism who had initial exploration from 2006-2014 with ≥6 month follow-up to define anatomy. Prior to 2010, patients had single-photon emission tomography (n = 633); after 2010, they had single-photon emission tomography/computed tomography (n= 755). RESULTS: In 1,388 patients, the rates of single gland disease (P=.8), bilateral exploration (P=.4), and negative imaging (145 patients, P=.33) were equal between imaging cohorts. In 1,186 patients with single gland disease, the positive predictive value of single-photon emission tomography/computed tomography was somewhat greater (90% vs 85%) and the accuracy of single-photon emission tomography/computed tomography was superior (83% vs 77%, P=.02). In the 202 patients with multiglandular disease, 20% had negative imaging results with no difference by type (single-photon emission tomography/computed tomography 17%, single-photon emission tomography 23%, P=.3), but single-photon emission tomography/computed tomography was more accurate (36%) than single-photon emission tomography (22%, P=.04) in predicting multiglandular disease. CONCLUSION: In a large cohort study of patients with sporadic primary hyperparathyroidism undergoing parathyroidectomy, positive single-photon emission tomography/computed tomography results provided more reliable operative guidance than single-photon emission tomography for both single gland disease and multiglandular disease.

18F-FDG PET/CT in patients with suspected recurrent or metastatic well-differentiated thyroid cancer.

UNLABELLED: PET using 18F-FDG has been shown to effectively detect various types of cancer by their increased glucose metabolism. The aim of this study was to evaluate the use of coregistered PET and CT (PET/CT) in patients with suspected thyroid cancer recurrence. METHODS: After total thyroidectomy followed by radioiodine ablation, 61 consecutive patients with elevated thyroglobulin levels or a clinical suspicion of recurrent disease underwent 18F-FDG PET/CT. Of these, 59 patients had negative findings on radioiodine (131I) whole-body scintigraphy (WBS). Fifty-three of the 61 patients had both negative 131I WBS findings and elevated thyroglobulin levels. PET/CT images were acquired 60 min after intravenous injection of 400-610 MBq of 18F-FDG using a combined PET/CT scanner. Any increased 18F-FDG uptake was compared with the coregistered CT image to differentiate physiologic from pathologic tracer uptake. 18F-FDG PET/CT findings were correlated with the findings of histology, postradioiodine WBS, ultrasound, or clinical follow-up serving as a reference. The diagnostic accuracy of 18F-FDG PET/CT was evaluated for the entire patient group and for those patients with serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL. RESULTS: Thirty patients had positive findings on 18F-FDG PET/CT; 26 were true-positive and 4 were false-positive. In 2 patients, increased 18F-FDG uptake identified a second primary malignancy. 18F-FDG PET/CT results were true-negative in 19 patients and false-negative in 12 patients. The overall sensitivity, specificity, and accuracy of 18F-FDG PET/CT were 68.4%, 82.4%, and 73.8%, respectively. The sensitivities of 18F-FDG PET/CT at serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL were 60%, 63%, and 72%, respectively. Clinical management changed for 27 (44%) of 61 patients, including surgery, radiation therapy, or chemotherapy. CONCLUSION: Coregistered 18F-FDG PET/CT can provide precise anatomic localization of recurrent or metastatic thyroid carcinoma, leading to improved diagnostic accuracy, and can guide therapeutic management. In addition, the findings of this study suggest that further assessment of 131I WBS-negative, thyroglobulin-positive patients by 18F-FDG PET/CT may aid in the clinical management of selected cases regardless of the thyroglobulin level.

Use of intraoperative nuclear imaging leads to decreased anesthesia time and real-time confirmation of lesion removal.

BACKGROUND: Lymphatic mapping to guide sentinel lymph node biopsy (SLNB) typically requires lymphoscintigraphy prior to surgery. In young pediatric patients, this process often requires intubation in the nuclear medicine suite followed by transport to the operating room (OR). METHODS: We reviewed 14 pediatric cases in which a portable nuclear imaging camera was utilized to perform the entirety of the SLNB in the OR. RESULTS AND CONCLUSION: This method, utilizing intraoperative nuclear imaging, helped to confirm removal of the sentinel lymph node in real time, decreased anesthesia time, and avoided transport of a sedated or intubated child. LEVEL OF EVIDENCE: III.

FDG PET CT assessment of treatment response after yttrium-90 ibritumomab tiuxetan radioimmunotherapy.

Yttrium-90 ibritumomab tiuxetan (Zevalin; IDEC Pharmaceuticals Corp., San Diego, CA) is the first radioimmunotherapy agent approved by the U.S. Food and Drug Administration (FDA) for treatment of non-Hodgkin lymphoma. In a randomized clinical trial comparing Zevalin with rituximab, the overall response rate was 80% and 56%, respectively. Response was determined by assessing the size of lymph nodes on CT scans. FDG PET has been well accepted as an accurate imaging study for staging non-Hodgkin lymphoma and evaluating response to treatment. Simultaneous FDG PET and CT imaging (PET CT) provides coregistered functional PET images with anatomic CT images. We describe 2 cases of non-Hodgkin lymphoma treated in which response was followed using PET CT.

Biliary pleural fistula detected by hepatobiliary scintigraphy.

A biliary pleural fistula is a rare complication secondary to trauma, infection, malignancy, biliary disease, malignancies, or percutaneous procedures. Its presence may be suggested by the development of a right pleural effusion in a patient with such history and can be confirmed with a hepatobiliary scan or endoscopic retrograde cholangiopancreatography. Patients are treated with antibiotics and the fistula usually spontaneously closes. If after 2 weeks the fistula persists, percutaneous drainage, sphincterotomy, or biliary stent placement can be performed to promote healing of the fistula. In complicated cases, open thoracic surgery or video-assisted thoracic surgery may be required.

Fortuitous detection of papillary carcinoma of the thyroid with F-18 FDG positron emission tomography in a patient with non-Hodgkin lymphoma.

Use of F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) in patients with known thyroid cancer is well documented, but the role of this imaging modality in the initial workup of a thyroid nodule has not been defined. The incidental finding of a hypermetabolic focus in the thyroid on F-18 FDG PET in patients with a variety of primary malignancies is reported. Based on the authors' literature search, this is the first documented case of a thyroid cancer resulting from papillary carcinoma detected in a patient with a history of non-Hodgkin lymphoma.

Surgeon volume and adequacy of thyroidectomy for differentiated thyroid cancer.

INTRODUCTION: We aimed to determine influence of surgeon volume on (1) frequency of appropriate initial surgery for differentiated thyroid cancer (DTC) and (2) completeness of resection. METHODS: We reviewed all initial thyroidectomies (Tx; lobectomy and total) performed in a health system during 2011; surgeons were grouped by number of Tx cases per year. For patients with histologic DTC ≥ 1 cm, surgeon volume was correlated with initial extent of the operation, and markers of complete resection including uptake on I(123) prescan, thyrotropin-stimulated thyroglobulin levels, and I(131) dose administered. RESULTS: Of 1,249 patients who underwent Tx by 42 surgeons, 29% had DTC ≥ 1 cm without distant metastasis. At a threshold of ≥ 30 Tx per year, surgeons were more likely to perform initial total Tx for DTC ≥ 1 cm (P = .01), and initial resection was more complete as measured by all 3 quantitative markers. For patients with advanced stage disease, a threshold of ≥ 50 Tx per year was needed before observing improvements in I(123) uptake (P = .004). CONCLUSION: Surgeons who perform ≥ 30 Tx a year are more likely to undertake the appropriate initial operation and have more complete initial resection for DTC patients. Surgeon volume is an essential consideration in optimizing outcomes for DTC patients, and even higher thresholds (≥ 50 Tx/year) may be necessary for patients with advanced disease.

Unsuspected pneumonia detected by increased lung uptake on 111In-ibritumomab tiuxetan scan.

99Y-ibritumomab tiuxetan (Zevalin) is a CD20-targeted radioimmunotherapy for the treatment of B-cell non-Hodgkin lymphoma approved by the FDA in 2002. The acquisition of an 111In ibritumomab tiuxetan scan (bioscan) to confirm normal biodistribution before treatment with 99Y-ibritumomab tiuxetan was initially required in the United States until November 2011. This is the first documented example of abnormal biodistribution due to unsuspected pneumonia detected by increased lung uptake on the bioscan. The pneumonia was treated and resolved before 99Y Zevalin, avoiding potential harm and indicating that a screening chest x-ray may be appropriate when a bioscan is not performed.

Thyroid: nuclear medicine update.

Nuclear medicine has been used in the evaluation and treatment of benign and malignant thyroid disease since the discovery of iodine 131 ((131)I) in the 1930s. Although traditional methods of imaging are routinely used, recent advancements such as SPECT/CT and PET/CT have greatly enhanced the ability of nuclear medicine to accurately detect and localize. Guidelines for the management of thyroid cancer continue to evolve, treatment regimens selected should balance the long-term risk of disease recurrence and cumulative risks of radiation exposure, and physicians should be aware of these updates and guidelines when caring for patients with thyroid disease.