Background: The purpose of this study was to examine the utility of remnant uptake on postoperative radioiodine scans as an oncologic indicator after thyroidectomy for differentiated thyroid cancer (DTC). Methods: We conducted a retrospective review of patients undergoing total thyroidectomy for DTC and subsequent radioactive iodine (RAI) treatment. Of the eight surgeons included, three were considered high volume, performing at least 20 thyroidectomies per year. Patients with distant metastases at diagnosis or poorly differentiated variants were excluded. To control for the effect of varying RAI doses, the remnant uptake was analyzed as a ratio of the percentage uptake to the dose received (uptake to dose ratio [UDR]). Multivariate logistic regression was used to determine the influence of UDR on recurrence. Results: Of the 223 patients who met inclusion criteria, 21 patients (9.42%) experienced a recurrence. Those with a recurrence had a 10-fold higher UDR compared with those who did not (0.030 vs. 0.003, p = 0.001). Similarly, patients with increasing postoperative thyroglobulin measurements (0.339 vs. 0.003, p < 0.001) also had significantly greater UDRs compared with those with stable thyroglobulin. The UDRs of high-volume surgeons were significantly smaller than low-volume surgeons (0.003 vs. 0.025, p = 0.002). When combined with other known predictors for recurrence, UDR .10], p = 0.041) was significantly associated with recurrence. High-volume surgeons maintained a low level of permanent complications across all UDRs, whereas low-volume surgeons had greater permanent complications associated with higher uptake. Conclusions: Remnant uptake is a useful postoperative oncologic quality indicator that can predict a patient's risk of disease recurrence and indicate the completeness of resection.

Background Current post-operative thyroid replacement dosing is weight-based with adjustments made following TSH values. This method can lead to significant delays in achieving euthyroidism and often fails to accurately dose over and underweight patients. Our aim was to develop an accurate dosing method that utilizes patient BMI data. Study Design A retrospective review of a prospectively collected thyroid database was performed. We selected adult patients undergoing thyroidectomy with benign pathology who achieved euthyroidism on thyroid hormone supplementation. BMI and euthyroid dose were plotted and regression was used to fit curves to the data. Statistical analysis was performed using STATA 10.1 (StataCorp, College Station, TX). Results 122 patients met inclusion criteria. At initial follow-up, only 39 patients were euthyroid (32%). 53% of patients with a BMI>30 were overdosed, while 46 % of patients with BMI<25 were under-dosed. The line of best fit demonstrated an overall quadratic relationship between BMI and euthyroid dose. A linear relationship best described the data up to a BMI of 50. Beyond that, the line approached 1.1 mcg/kg. A regression equation was derived for calculating initial levothyroxine dose (mcg/kg/day = −0.018*BMI +2.13 {F statistic =52.7, root mean squared error of 0.24}). Conclusion The current standard of weight based thyroid replacement fails to appropriately dose underweight and overweight patients. BMI can be used to more accurately dose thyroid hormone using a simple formula.

BACKGROUND Many patients with primary hyperparathyroidism (PHPT) present with less severe biochemical parameters. The purpose of this study was to compare the presentation, operative findings, and outcomes of these patients with “mild” PHPT to patients with “overt” disease. METHODS A retrospective review of a prospectively collected parathyroid database was performed to identify cases of PHPT undergoing an initial neck operation. Patients were classified as mild when either the preoperative calcium or PTH was within the normal limits. Comparisons were made with the student’s t-test, Chi-squared test, or Wilcox on rank-sum test where appropriate. Kaplan-Meier estimates were plotted for disease-free survival and compared by the log-rank test. RESULTS Of the 1,429 patients who met inclusion criteria, 1,049 were classified as overt and 388 (27.1%) were mild. Within the mild group, 122 (31.4%) presented with normocalcemic PHPT and 266 (68.6%) had a normal PTH. The two groups had similar demographics and renal function. Interestingly, the mild group had more than double the rate of kidney stones (3.1% vs. 1.3%, p = 0.02). The mild group was less likely to localize on sestamibi scan (62.4% vs. 78.7%, p<0.01). Intraoperatively, more mild patients exhibited multigland disease (34.3% vs. 14.1%, p<0.01). When examining intraoperative PTH (IoPTH) kinetics where single adenomas were excised, the IoPTH fell at a rate of 6.9 pg/min in mild patients compared to 11.5 pg/min in the overt group (p<0.01). Accordingly, 62.2% of patients in the overt group and 53.3% in the mild group were cured at five minutes post-excision (p<0.01). There was no difference in the rates of persistence or recurrence between the groups, and disease-free survival estimates were identical (p = 0.27). CONCLUSIONS Patients with mild PHPT were more likely to have multigland disease and a slower decline in IoPTH, but these patients can be successfully treated with surgery.

Introduction Persistent or recurrent hyperthyroidism after treatment with radioactive iodine (RAI) is common, and many patients require either additional doses or surgery before they are cured. The purpose of this study was to identify patterns and predictors of failure of RAI in patients with hyperthyroidism. Methods We conducted a retrospective review of patients treated with RAI from 2007–2010. Failure of RAI was defined as receipt of additional dose(s) and/or total thyroidectomy. Using a Cox proportional hazards model, we conducted univariate analysis to identify factors associated with failure of RAI. A final multivariate model was then constructed with significant (p < 0.05) variables from the univariate analysis. Results Of the 325 patients analyzed, 74 patients (22.8%) failed initial RAI treatment. 53 (71.6%) received additional RAI, 13 (17.6%) received additional RAI followed by surgery, and the remaining 8 (10.8%) were cured after thyroidectomy. The percentage of patients who failed decreased in a step-wise fashion as RAI dose increased. Similarly, the incidence of failure increased as the presenting T3 level increased. Sensitivity analysis revealed that RAI doses < 12.5 mCi were associated with failure while initial T3 and free T4 levels of at least 4.5 pg/mL and 2.3 ng/dL, respectively, were associated with failure. In the final multivariate analysis, higher T4 (HR 1.13, 95% CI 1.02–1.26, p=0.02) and methimazole treatment (HR 2.55, 95% CI 1.22–5.33, p=0.01) were associated with failure. Conclusions Laboratory values at presentation can predict which patients with hyperthyroidism are at risk for failing RAI treatment. Higher doses of RAI or surgical referral may prevent the need for repeat RAI in selected patients.

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