Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Pathological examination occasionally reveals incidental central lymph nodes metastasis (iLNM) after thyroidectomy for patients with papillary thyroid cancer (PTC) who did not undergo compartment-orientated lymphadenectomy. We aimed to investigate the risk of recurrence for patients with iLNM. METHODS:We conducted a retrospective review of all patients undergoing total thyroidectomy for PTC (January 2000 to January 2010). Patients with distant metastases, central- or lateral neck dissection and pre-operative suspicious lymph nodes (by ultrasound or clinical examination) were excluded. The association between iLNM and recurrent disease was investigated using Kaplan-Meier survival estimates and Cox proportional hazards analysis. RESULTS:225/1000 patients had incidental nodes after total thyroidectomy for PTC. 183 were node-negative and 42 had iLNM. Mean age was 46 years and 201 (89%) were women. Mean number of resected nodes was 2.3. Disease recurred in 8/183 (4.4%) of patients with N0 versus 7/42 (17%) with iLNM. After adjusting for other factors, iLNM was independently associated with recurrent disease (hazard ratio = 4.01 [95% CI 1.21-13.3]). CONCLUSIONS:Positive incidental lymph nodes are independently associated with recurrent disease in patients with PTC. These patients should therefore be monitored more carefully.

Purpose To investigate the performance of flourine 18 (¹⁸F) fluorocholine (FCH) positron emission tomography (PET)/magnetic resonance (MR) imaging in patients with hyperparathyroidism and nonlocalized disease who have negative or inconclusive results at ultrasonography (US) and technetium 99m (^99mTc) sestamibi scintigraphy. Materials and Methods This study was approved by the institutional review board. Between May and December 2015, 10 patients (mean age, 70.4 years; range, 58-82 years) with biochemical primary hyperparathyroidism and inconclusive results at US and ^99mTc sestamibi scintigraphy were prospectively enrolled. All patients gave informed consent. Directly after administration of 3 MBq/kg of FCH, PET imaging was performed, followed by T1- and T2-weighted MR imaging before and after gadolinium enhancement. Intraoperative localization and histologic results were the reference standard for calculating sensitivity and positive predictive value. The Wilcoxon rank test was used to calculate the mean difference in maximum standardized uptake value (SUV_max) between abnormal parathyroid uptake and physiologic thyroid uptake. The Wilcoxon rank-sum test was performed. Results MR imaging alone showed true-positive lesions in five patients and a false-positive lesion in one patient. FCH PET/MR imaging allowed correct localization of nine of 10 adenomas (90% sensitivity), without any false-positive results (100% positive predictive value). One patient had four-gland hyperplasia, of which three hyperplastic glands were not localized. The median SUV_max of the nine preoperatively identified adenomas was 4.9 (interquartile range, 2.45-7.35), which was significantly higher than the SUV, 2.7 (interquartile range, 1.6-3.8), of the thyroid (P = .008). Conclusion FCH PET/MR imaging allowed localization of adenomas with high accuracy when conventional imaging results were inconclusive and provided detailed anatomic information. More patients must be examined to confirm our initial results, and the accuracy of FCH PET/MR imaging for localization of glands in patients with four-gland hyperplasia remains to be investigated. ^© RSNA, 2017.

BACKGROUND:Catecholamine excess in patients with pheochromocytoma often results in impaired glucose tolerance, leading to diabetes mellitus. Little data are available on the long-term effect of surgery on diabetes. OBJECTIVE:The primary aim of this study was to determine the likelihood of diabetes cure after surgery, while secondary objectives were to determine risk factors for development of diabetes preoperatively and persistence of diabetes postoperatively. METHODS:All patients undergoing surgery for pheochromocytoma from 1996 to 2015 were retrospectively reviewed to identify those with a preoperative diagnosis of diabetes. Demographic and diabetes-specific data were collected. Median follow-up was 52.1 months. RESULTS:Overall, 153 patients underwent surgery. Diabetes was seen in 36 (23.4%) patients. Eight patients met the exclusion criteria and were removed from the final analysis, while 22 (78.6%) patients had complete resolution of diabetes. Four patients remained on medication with improved control. Overall, 93.0% of patients had improvement of their diabetes; two patients did not improve. Patients with large, symptomatic tumors were more likely to develop preoperative diabetes, and diabetes was more likely to persist in patients who had an elevated body mass index (BMI). CONCLUSIONS:Diabetes was found concurrently with pheochromocytoma in 23% of patients, more often in those with large, symptomatic tumors. The majority of patients had long-term resolution of diabetes after successful resection; however, some patients may continue to require treatment of diabetes after operation, especially those with a higher BMI.

PURPOSE/OBJECTIVE:To perform a systematic review and meta-analysis of the sensitivity and positive predictive value (PPV) of CT for preoperative parathyroid localization in patients with primary hyperparathyroidism (pHPT), and subsequently compare the different protocols and their performance in different patient groups. MATERIALS AND METHODS/METHODS:We performed a search of the Embase, Pubmed and Cochrane Library databases to identify studies published between January 1, 2000 and March 31, 2016 investigating the diagnostic value of CT for parathyroid localization in patients with biochemical diagnosis of pHPT. Performance of CT was expressed in sensitivity and PPV with pooled proportion using a random-effects model. Factors that could have affected the diagnostic performance were investigated by subgroup analysis. RESULTS:Thirty-four studies evaluating a total of 2563 patients with non-familial pHPT who underwent CT localization and surgical resection were included. Overall pooled sensitivity of CT for localization of the pathological parathyroid(s) to the correct quadrant was 73% (95% CI: 69-78%), which increased to 81% (95% CI: 75-87%) for lateralization to the correct side. Subgroup analysis based on the number of contrast phases showed that adding a second contrast phase raises sensitivity from 71% (95% CI: 61-80%) to 76% (95% CI: 71-87%), and that adding a third phase resulted in a more modest additional increase in performance with a sensitivity of 80% (95% CI: 74-86%). CONCLUSION/CONCLUSIONS:CT performs well in localizing pathological glands in patients with pHPT. A protocol with two contrast phases seems to offer a good balance of acceptable performance with limitation of radiation exposure.

BACKGROUND AND OBJECTIVES/OBJECTIVE:We investigated the rate, stage, and prognosis of thyroid cancer in patients after solid-organ transplantations, and compared this to the general population. METHODS:We performed a retrospective review of patients who developed thyroid cancer after a solid-organ transplantation between January 1988 and December 2013 at a high volume transplant center. Standardized Incidence Ratio's (SIR) were calculated. Additionally, a systematic review of the literature was performed. RESULTS:A total of 10,428 patients underwent solid organ transplantation. Eleven patients (11.4 per 100,000 person-years) developed thyroid cancer: six men and five women with a mean age at diagnosis of thyroid cancer of 58 years. Ten patients underwent surgery and had stage I thyroid cancer. One patient had recurrent disease after a mean follow-up time of 78 months. The SIR varied between 0.75 and 2.3. Seventeen studies were included in the systematic review with a SIR ranging from 2.5 to 35. CONCLUSION/CONCLUSIONS:Rate of thyroid cancer is not significantly higher in patients who underwent solid organ transplantation compared to general population. Stage at presentation and prognosis also appear to be similar to that of the general population. Post-transplant screening for thyroid cancer remains debatable; however, when thyroid cancer is discovered, treatment should be similar to that of non-transplant patients. J. Surg. Oncol. 2017;115:105-108. © 2017 Wiley Periodicals, Inc.

BACKGROUND:The management of low-risk micropapillary thyroid cancer <1 cm in size has come into question, because recent data have shown that nonoperative active surveillance of micropapillary thyroid cancer is a viable alternative to hemithyroidectomy. We conducted a cost-effectiveness analysis to help decide between observation versus operation. METHODS:We constructed Markov models for active surveillance and hemithyroidectomy. The reference case was a 40-year-old patient with recently diagnosed, low-risk micropapillary thyroid cancer. Costs and health utilities were determined using extensive literature review. The willingness-to-pay threshold was set at $100,000/quality-adjusted life year gained. Deterministic and probabilistic sensitivity analyses were performed to account for uncertainty in the model's variables. RESULTS:Active surveillance is dominant (less expensive and more quality-adjusted life years) for a health utility <0.01 below that for disease-free, posthemithyroidectomy state, or for a remaining life expectancy of <2 years. For a utility difference ≥0.02, the incremental cost-effectiveness ratio (the ratio of the difference in costs between active surveillance and hemithyroidectomy divided by the difference in quality-adjusted life years) for hemithyroidectomy is <$100,000/QALY gained and thus cost-effective. For a utility difference of 0.11-the reference case scenario-the incremental cost-effectiveness ratio for hemithyroidectomy is $4,437/quality-adjusted life year gained. CONCLUSION:The cost-effectiveness of hemithyroidectomy is highly dependent on patient disutility associated with active surveillance. In patients who would associate nonoperative management with at least a modest decrement in quality of life, hemithyroidectomy is cost-effective.

BACKGROUND:The recently published 2015 American Thyroid Association guidelines recognize lobectomy as a viable alternative for low-risk cancers and advise more conservative use of radioactive iodine. Some factors indicating adjuvant treatment with radioactive iodine (and therefore completion total thyroidectomy), however, only can be found upon pathologic investigation. METHODS:We performed a retrospective analysis including patients with American Thyroid Association low- and low-to-intermediate risk well-differentiated thyroid cancer 1-4 cm. We evaluated how often radioactive iodine would be indicated and compared this with our historic rate. A subanalysis was performed to determine the rate of completion total thyroidectomy necessary, based on the indications for adjuvant radioactive iodine therapy. RESULTS:A total of 394/1,000 (39.4%) patients were included for final analysis. Adjuvant radioactive iodine would have been favored in 101/394 (25.6%) of patients, which is 2.5 times less than was given in our historic cohort. Completion total thyroidectomy to enable adjuvant radioactive iodine would have been recommended in 29/149 (19.5%) patients preoperatively eligible for lobectomy. CONCLUSION:Despite the tightened regulations for radioactive iodine, about 20% of patients with apparently "low-risk" well-differentiated thyroid cancer who are eligible for lobectomy may need completion total thyroidectomy because of pathologic findings for which radioactive iodine use is listed as considered or favored by the current guidelines.

BACKGROUND:Primary hyperparathyroidism is the most common manifestation of multiple endocrine neoplasia type 1 (MEN1). Guidelines advocate subtotal parathyroidectomy (STP) or total parathyroidectomy with autotransplantation due to high prevalence of multiglandular disease; however, both are associated with a significant risk of permanent hypoparathyroidism. More accurate imaging and use of intraoperative PTH levels may allow a less extensive initial parathyroidectomy (unilateral clearance, removing both parathyroids with cervical thymectomy) in selected MEN1 patients with primary hyperparathyroidism. METHODS:We performed a retrospective cohort study at a high-volume tertiary medical center including patients with MEN1 and primary hyperparathyroidism, who underwent STP or unilateral clearance as their initial surgery from 1995 to 2015. Unilateral clearance was offered to patients who had concordant sestamibi and ultrasound showing a single enlarged parathyroid gland. For both the groups, we compared rates of persistent/recurrent disease and permanent hypoparathyroidism. RESULTS:Eight patients had unilateral clearance and 16 had STP. Subtotal parathyroidectomy patients were younger (37 vs 52 years). One patient in each group had persistent disease. One (13 %) unilateral clearance and five (31 %) STP patients had recurrent hyperparathyroidism after a mean follow-up of 47 and 68 months (p = 0.62). No unilateral clearance patients and two of 16 SPT patients had permanent hypoparathyroidism (p = 0.54). CONCLUSIONS:Some MEN1 patients with primary hyperparathyroidism who have concordant localizing studies may be selected for unilateral clearance as an alternative to STP. For appropriately selected MEN1 patients, unilateral clearance can achieve similar results as STP and has no risk of permanent hypoparathyroidism, and may facilitate possible future reoperations.