Michael Tamilia

Same-day discharge after total thyroidectomy: the value of 6-hour serum parathyroid hormone and calcium levels.

The purpose of this study was to determine whether patients who undergo total thyroidectomy will have postoperative hypocalcemia develop when they reach the critical 6‐hour serum levels defined as parathyroid hormone (PTH) ≥28 ng/L and simultaneous corrected calcium ≥2.14 mmol/L.

Postoperative parathyroid hormone level as a predictor of post-thyroidectomy hypocalcemia.

OBJECTIVES To evaluate levels of parathyroid hormone following total thyroidectomy in order to ascertain its ability to predict postoperative hypocalcemia. To establish standardized criteria permitting the safe discharge of total thyroidectomy patients within 13 hours of surgery. METHODS This is a prospective study in which parathyroid hormone levels were tested in 54 consecutive patients who underwent total thyroidectomy. Levels were measured postoperatively at 6, 12, and 20 hours. Corrected calcium levels were also measured at 6, 12, and 20 hours in accordance with the preexisting protocol. RESULTS Statistical analysis demonstrates that patients with corrected calcium levels greater than or equal to 2.14 mmol/L and parathyroid hormone levels greater than or equal to 28 ng/L at 12 hours post-thyroidectomy can be discharged without further need for calcium monitoring. The analysis also demonstrates that patients with 12-hour parathyroid hormone levels less than or equal to 20 ng/L are at significant risk of developing hypocalcemia. CONCLUSION Parathyroid hormone levels in conjunction with corrected calcium values are accurate predictors of the calcium trends of post-thyroidectomy patients. Implementation of this protocol can result in shorter hospital stays for the majority of post-thyroidectomy patients, which can translate into substantial cost savings for the health care system.

Benefits Resulting from 1-and 6-Hour Parathyroid Hormone and Calcium Levels After Thyroidectomy

OBJECTIVE: Previous studies have established the efficacy of post-thyroidectomy hypocalcemia monitoring using parathyroid hormone (PTH) and corrected calcium levels at 1 and 6 hours. The goal of this study was to measure the impact of managing patients based on the above findings with respect to: duration of hospital stays, rates of transient hypocalcemia, number of blood tests, cost savings, and discharge from the hospital as early as 8 hours post-thyroidectomy without compromising safety. STUDY DESIGN AND SETTING: This is a prospective study involving 95 total thyroidectomy patients using historical data as controls. The previous protocol was modified in that all blood tests ceased for patients meeting the 6-hour critical level of PTH ≥ 28 ng/L and simultaneous corrected calcium ≥ 2.14 mmol/L (8.56 mg/dL). Furthermore, patients with 1-hour PTH levels ≤ 8 ng/L were prophylactically treated with calcium and vitamin D supplementation. RESULTS: This study demonstrates lower rates of transient hypocalcemia from 28% to 9% (OR = 4.13, P = 0.016), a 10-hour reduction in mean hospital stay, and fewer blood tests (23 vs 15) for patients undergoing total thyroidectomy since the implementation of the new protocol. Furthermore, the experimental protocol resulted in an average cost savings of

Incidence and histopathological behavior of papillary microcarcinomas: Study of 429 cases

766 per patient. CONCLUSIONS: The new algorithm resulting from PTH and corrected calcium monitoring at 1 and 6 hours post-thyroidectomy has led to significant cost savings for our institution. It has also translated into greater patient satisfaction as a result of fewer blood tests, a lower incidence of transient hypocalcemia, and significantly shorter hospital stays.

Serum thyroglobulin predicts thyroid remnant ablation failure with 30 mCi iodine-131 treatment in patients with papillary thyroid carcinoma.

Objective We aim to present papillary microcarcinoma (PMC) incidence at a university teaching hospital, to compare characteristics of PMC in relation to size, and to assess for significant difference in PMC incidence among patients with non-PMC thyroid malignancies. Materials and Methods Pathology results were reviewed for consecutive total thyroidectomies between 2002 and 2007 (n = 860). Statistical significance was calculated using χ2 or, when unavailable, Fisher exact test. Results PMC was found in 429 cases, which is 49.9 percent of all total thyroidectomies. In PMC ≥5 mm, 25.1 percent had extrathyroidal extension vs 9.1 percent for <5 mm (P < 0.001). When 4 mm is used as a threshold, P value was 300–fold smaller. Incidence in patients with any non-PMC thyroid malignancy was 51.6 percent against 47.2 percent in all other patients (P = 0.203). Conclusions In this study, PMC was found in 49.9 percent of patients, which, to our knowledge, is higher than any other reported incidence. A threshold of ≥4 mm was more significant than 5 mm for carrying increased risk for extrathyroidal spread. There was no significant difference in PMC incidence in patients with malignant vs benign disease.

Body Mass Index in the Evaluation of Thyroid Cancer Risk

BackgroundMost patients with differentiated thyroid cancer are treated with radioiodine (131-I) after thyroidectomy. The characteristics predictive of successful remnant ablation with low activities of 131-I are ill defined and could help stratify patients into those who should receive higher activities. MethodsIn a case series of 193 consecutive patients with papillary thyroid cancer who underwent total thyroidectomy and received 30 mCi (1110 MBq) of 131-I, we assessed the percentage of successful radioremnant ablation as defined by a composite of scintigraphic and biochemical endpoints. Clinical, histological, scintigraphic, and biochemical covariables were analyzed to identify associations with treatment failure. ResultsSuccessful radioremnant ablation with low-activity 131-I was obtained in 78% of the entire cohort of patients. The presence of limited microscopic extrathyroidal extension, nodal micrometastases, or an elevated stimulated ablation was associated with failure to ablate the remnant. While accounting for other factors in a multivariable analysis, patients with an ablation thyroglobulin of at least 6 &mgr;g/l were at a more than five times greater risk (P<0.001) to fail 30 mCi 131-I remnant ablation. ConclusionThe majority of patients with papillary thyroid carcinoma experienced successful ablation. However, elevated–stimulated ablation thyroglobulin levels were strongly predictive of ablation failure, suggesting that this biochemical marker correlates with a more aggressive tumor profile and identifies those patients who might benefit from additional therapy.

The role of sentinel lymph node biopsy in differentiated thyroid carcinoma.

BACKGROUND Obesity has been linked to numerous diseases including thyroid cancer, but the exact nature of the relationship, especially with respect to patients with thyroid nodules, remains unclear. The objective of this study was to evaluate the impact of body mass index (BMI) on thyroid cancer risk in a population of patients with indeterminate cytology on fine-needle aspiration biopsy (FNAB). METHODS A total of 253 consecutive patients with indeterminate thyroid nodule FNABs who underwent total thyroidectomy in a tertiary care teaching hospital between 2002 and 2007 were reviewed. Height and weight reported on the anesthesia summary were recorded for each patient. Malignancy rates were calculated for the underweight, normal, overweight, and obese groups stratified according to their BMI. Subanalyses according to age and sex were also performed. RESULTS The risk of malignancy tended to be lower in obese patients compared to patients with BMIs in the underweight, normal, and overweight ranges (52% vs. 61%, p = 0.195). In men, a BMI classified as obese was associated with a significantly lower rate of malignancy (36% vs. 72%, p = 0.003). Women older than 45 years were a subgroup in which higher malignancy rates were associated with obesity (65% vs. 54%, p = 0.293). Conversely, in men over the age of 45 years and women under 45 years, a BMI in the obesity range was linked to a lower incidence of malignancy (20% vs. 68% p = 0.009 and 36% vs. 68% p = 0.043, respectively). When older women were excluded from the population studied, the rate of malignancy in obese patients was 36% versus 70% in nonobese patients (p = 0.002) with an associated reduction of 5% in the risk of malignancy per increased unit of BMI. CONCLUSIONS For patients with FNAB results of indeterminate significance, a higher BMI correlates with lower rates of thyroid malignancy for all patients except women over the age of 45 years.

Postoperative parathyroid hormone levels in conjunction with corrected calcium values as a predictor of post-thyroidectomy hypocalcemia : Review of outcomes 1 year after the implementation of a new protocol

OBJECTIVE To determine whether sentinel lymph node (SLN) biopsy can accurately predict central compartment metastasis in patients with differentiated thyroid carcinoma. DESIGN Prospective clinical study. SETTING Academic tertiary care center. PATIENTS Ninety-eight patients (82 women and 16 men; mean age, 48.3 years) underwent a total thyroidectomy and central compartment dissection. INTERVENTION Peritumoral injection of methylene blue dye, 1%, followed by SLN biopsy. MAIN OUTCOME MEASURES The final pathology report established the presence of metastasis among SLNs and lymph nodes that did not stain blue (non-SLNs [NSLNs]). RESULTS Differentiated thyroid carcinoma was found in 75 of 98 patients (77%). Seventy of 75 patients with differentiated thyroid carcinoma presented with SLNs and/or NSLNs within the central compartment. Fifteen of 70 patients had metastasis-positive SLNs, while 55 had metastasis-negative SLNs. Six of 15 patients with positive SLNs also had positive NSLNs. No patients with negative SLNs were found to have positive NSLNs. Sentinal lymph node status was a highly significant predictor of NSLN result (Fisher exact test, P < .001). The accuracy, sensitivity, specificity, and positive and negative predictive values of SLN biopsy were 87%, 100%, 86%, 40%, and 100%, respectively. CONCLUSIONS To our knowledge, this is the largest series of SLN biopsy in patients with differentiated thyroid carcinoma. Our experience suggests that this is an accurate and noninvasive means to identify subclinical lymph node metastasis. Because negative SLNs correlate strongly with a negative central compartment (100% in this study, P < .001), this technique can be used as an intraoperative guide when determining the extent of surgery necessary in cervical level VI.

Cost savings associated with post-thyroidectomy parathyroid hormone levels

OBJECTIVES To determine the effectiveness of post-thyroidectomy parathyroid hormone (PTH) levels in conjunction with corrected calcium values as predictors of patients at risk of developing hypocalcemia. METHODS This is a follow-up study reviewing the results of a newly implemented post-thyroidectomy algorithm. The changes in management from the previous protocol involve decision making based on the 12-hour corrected calcium and PTH levels, as well as the 1-hour PTH value. The study involved 120 patients separated into two groups: 60 prior to implementation of the protocol and 60 following the implementation of the protocol. Patients having completion thyroidectomy, neck dissections, or parathyroidectomy were excluded. RESULTS Since the implementation of the new protocol, there has been a reduction in the rate of transient hypocalcemia (25% to 12%; p = .059), fewer blood tests (23 to 15 per patient), and earlier patient discharges. CONCLUSIONS The new algorithm is effective in detecting patients who are not at risk of developing hypocalcemia at 12 hours. This has led to significant cost savings at our institution. Moreover, calcium supplementation based on the 1-hour PTH level has coincided with a reduction in cases of transient hypocalcemia.

Female Gender as a Risk Factor for Transient Post-Thyroidectomy Hypocalcemia

OBJECTIVES: A 1-hour post-thyroidectomy parathyroid hormone (PTH) level of ≤8 ng/L is predictive of patients who will develop hypocalcemia and guides early supplementation with calcium and vitamin D. However, most hypocalcemic patients fail to meet this criterion. The goal of this study was to determine whether PTH ≤ 15 ng/L could be used as a better predictor of hypocalcemia. STUDY DESIGN, SUBJECTS, AND METHODS: This retrospective study involved 270 thyroidectomy patients (2004-2006). PTH and calcium levels, length of admission, supplementation, and rates of hypocalcemia were recorded. RESULTS: Forty-three percent (26/60) of patients developing hypocalcemia met the PTH ≤ 8 ng/L cut-off. In contrast, 80% (48/60) of patients developing hypocalcemia had a PTH ≤ 15 ng/L. Two point two percent of patients had a 1-hour PTH ≤ 15 ng/L and failed to develop hypocalcemia, for a specificity of 97%. CONCLUSIONS: A 1-hour PTH cut-off of ≤15 ng/L for prophylactic supplementation should allow the prevention of the majority of cases of hypocalcemia, leading to significant cost savings by shortening hospital stays.