Central node dissection in papillary thyroid carcinoma in the era of near-infrared fluorescence

A prospective cross-sectional study on hypocalcemia after total thyroidectomy in patients with Graves' disease: insights on secondary hyperparathyroidism

PURPOSE

To investigate the parathyroid function and calcium (Ca) levels in the secondary hyperparathyroidism (SHPT) state in patients with Graves' disease.

METHODS

We examined 31 consecutive patients with Graves' disease without chronic kidney disease, who were treated with total thyroidectomy. The patients were divided into a normal parathyroid hormone (PTH) group (NPTH group; n = 19) with a PTH level ≤ 65 pg/mL, and a secondary hyperparathyroidism group (SHPT group; n = 12), with a PTH level > 65 pg/mL. The PTH and Ca-related parameters were examined and the risk factors for postoperative hypocalcemia were analyzed.

RESULTS

The preoperative Ca level was significantly lower (2.24 ± 0.06 vs. 2.31 ± 0.07 mmol/L, p < 0.05) in the SHPT group than in the NPTH group. The reduction in PTH, 1,25-dihydroxyvitamin D (1,25(OH)2D), and Ca levels from the preoperative day to the next morning was significantly greater in the SHPT group than in the NPTH group (p < 0.05). When intraoperative factors were included, the decrease in the PTH level alone was significant. SHPT was a significant factor in determining the extent of PTH reduction.

CONCLUSIONS

Hyperfunctioning parathyroid glands in the SHPT state were more susceptible to postoperative PTH reduction, which, combined with low preoperative Ca levels, increased the risk of postoperative hypocalcemia in patients with Graves' disease.

The Oncologic Outcomes of Bilateral Central Lymph Node Dissection in Unilobar Papillary Thyroid Cancer and Its Risks: A Prospective Cohort Study

Background Indications for performing a prophylactic central neck dissection (pCND) in papillary thyroid cancer (PTC) remain controversial. Thyroidectomy and central neck dissection (CND) are often recommended in all cases with proven differentiated thyroid cancer (DTC) and clinically positive lymph nodes (LNs), as well as in high risk for micro-metastasis patients with T3-T4 tumors or established metastatic nodes in the lateral compartments. Aims The aims of this study were to ascertain the role of performing bilateral central LN dissection in unilobar PTC in improving the oncological outcomes and outline the risks involved. Methods This was a department-based, prospective cohort study. We included all 20 patients who had unilobar PTC and underwent total thyroidectomy with bilateral CND. A postoperative histopathological analysis was used to identify metastatic central LNs. Results Twenty total thyroidectomies plus bilateral CNDs were performed, of which 10 were prophylactic bilaterally (those with N0), and all 20 were prophylactic on the contralateral side of PTC. Conventional risk factors (age, tumor size, and extrathyroidal extension) were not associated with performing a pCND. The presence of unilobar PTC by preoperative FNAC was the only factor associated with performing bilateral CND. Positive ipsilateral LNs were retrieved in 55% of CNDs, while positive contralateral LNs were retrieved in only 15% of the patients. Conclusions The incidence of contralateral cervical LN metastasis in patients with unilateral PTC is low, while there is clear evidence of postoperative morbidity from routine contralateral CND in unilobar PTC. Contralateral CND in patients with unilobar PTC may be reserved for high-risk patients: males, those aged ≤45 years, tumors larger than 1.0 cm, and cases with extrathyroidal extension and micro-calcification on ultrasound.

Significant role of 1,25-dihydroxyvitamin D on serum calcium levels after total thyroidectomy: a prospective cohort study

Introduction

Although active vitamin D (VD) has been used both preoperatively and postoperatively to prevent hypocalcemia risk in patients undergoing total thyroidectomy, the role of 1,25-dihydroxyvitamin D (1,25(OH)2D) has not been examined. This study comprehensively investigated the effects of 1,25(OH)2D on calcium (Ca) concentrations after total thyroidectomy.

Methods

Serum Ca, parathyroid hormone (PTH), and 1,25(OH)2D levels were measured in 82 patients with thyroid disease before and after surgery.

Results

Serum Ca, PTH, and 1,25(OH)2D levels decreased significantly on the morning of the first postoperative day. Notably, the decrease in 1,25(OH)2D concentration was significantly lower than that of PTH concentration (10.5 ± 33.4% vs. 52.1 ± 30.1%, p<0.0001), with 28% of patients showing increases in 1,25(OH)2D. The only factor predicting a postoperative 1,25(OH)2D decrease was a high preoperative 1,25(OH)2D concentration. Postoperative 1,25(OH)2D concentrations, as well as the magnitude and rate of decrease from preoperative levels, showed strong positive correlations with preoperative 1,25(OH)2D concentrations (p<0.0001 for all three variables) but not with PTH concentrations. These findings suggest that 1,25(OH)2D concentrations after thyroidectomy were more strongly dependent on preoperative concentrations than on the effect of PTH decrease and were relatively preserved, possibly preventing sudden severe postoperative hypocalcemia. A high 1,25(OH)2D level was the most important preoperative factor for hypocalcemia (<2 mmol/L; p<0.05) on the first postoperative day; however, only PTH decrease was statistically significant (p<0.001) when intraoperative factors were added. In the PTH >10 pg/mL group, the decrease in 1,25(OH)2D levels was significantly associated with postoperative hypocalcemia (p<0.05). Similarly, in the PTH levels >15 pg/mL group, a decrease in 1,25(OH)2D concentration was a significant factor, and the amount of PTH decrease was no longer significant.

Conclusion

1,25(OH)2D plays an important role in preventing sudden, severe hypocalcemia due to decreased PTH levels after total thyroidectomy, whereas high preoperative 1,25(OH)2D levels are a significant risk factor for postoperative hypocalcemia. Optimizing preoperative protocols to adjust Ca, PTH, and 1,25(OH)2D levels to improve the management of patients undergoing total thyroidectomy and to prevent extreme intraoperative PTH decreases may reduce the risk of hypocalcemia.

Development and validation of a nomogram for preoperative prediction of ipsilateral cervical central lymph node metastasis in papillary thyroid cancer: a population-based study

Background

The incidence of papillary thyroid cancer (PTC) has increased dramatically, and it is susceptible to cervical lymph node metastasis (LNM), predominantly in the ipsilateral cervical central lymph node metastasis (CLNM). Ipsilateral cervical CLNM affects patients' surgical options and survival rates. In this study, we integrated multiple factors to establish a nomogram-based preoperative prediction model of ipsilateral cervical CLNM in PTC.

Methods

Data were retrospectively collected from 609 patients with PTC admitted to Peking University International Hospital, all of whom underwent ipsilateral cervical lymph node dissection. They were randomly divided into a modeling set and validation set in the ratio of 7:3. Binary logistic regression was used to analyze independent risk factors for ipsilateral cervical CLNM in PTC and to construct a nomogram model. The performance of nomogram CLNM prediction was evaluated by the receiver operating characteristic (ROC) curve and calibration curve.

Results

Binary Logistic Regression showed that age, history of osteoporosis, complicated by Hashimoto's thyroiditis, enlarged lymph nodes in the central neck, and extrathyroidal extension were risk factors for ipsilateral cervical CLNM. Combining these five independent risk factors, a nomogram prediction model was developed. In the modeling set, the area under the curve (AUC) of the nomogram ROC was 0.782 [95% confidence interval (CI): 0.730-0.833], and the sensitivity and specificity of the model were 0.761 and 0.763, respectively, with a well-calibrated curve fit. Moreover, the model presented better discrimination than any of the independent risk factors. The nomogram performed well in the validation set (AUC 0.753; 95% CI: 0.648-0.858).

Conclusions

A non-invasive, and accurate nomogram prediction model for ipsilateral cervical CLNM of PTC was established. It can help physicians identify patients with a high risk of ipsilateral cervical CLNM of PTC preoperative for individualized treatment.

Impact of near-infrared fluorescence imaging plus indocyanine green fluorescence on postoperative hypoparathyroidism rates after total thyroidectomy and central neck lymph node dissection

BACKGROUND

Patients with thyroid carcinoma often undergo cervical lymph node dissection, which is associated with high rates of both transient and permanent postoperative hypoparathyroidism. The impact of near-infrared fluorescence imaging + indocyanine green (ICG) fluorescence on postoperative hypoparathyroidism rates after total thyroidectomy and central neck lymph node dissection was evaluated.

METHODS

All patients undergoing surgery between January 2019 and March 2023 were included and divided into three groups: a control group (parathyroid glands identified visually), a near-infrared fluorescence imaging alone group, and a near-infrared fluorescence imaging + ICG fluorescence group. The primary outcome was the transient and permanent postoperative hypoparathyroidism rates. Secondary outcomes were: length of surgery and number of parathyroid glands identified, inadvertently resected, and autotransplanted.

RESULTS

A total of 131 patients were included in the study (47 in the control group, 45 in the near-infrared fluorescence imaging alone group, and 39 in the near-infrared fluorescence imaging + ICG fluorescence group). The transient hypoparathyroidism rate was 48.9% in the control group, 37.8% in the near-infrared fluorescence imaging alone, and 5.1% in the near-infrared fluorescence imaging + ICG fluorescence group (P < 0.0001), while the permanent hypoparathyroidism rate was 8.5% in the control group, 2.2% in the near-infrared fluorescence imaging alone group, and 0% in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.096). The number of parathyroid glands identified was 159 of 188 in the control group, 165 of 180 in the near-infrared fluorescence imaging alone group, and 149 of 156 in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.002). Inadvertent resection of parathyroid glands occurred for 29 of 188 in the control group, 15 of 180 in the near-infrared fluorescence imaging alone group, and 7 of 156 in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.002), with subsequent parathyroid gland autotransplantation for 2 of 29 in the control group, 2 of 15 in the near-infrared fluorescence imaging alone group, and 3 of 7 in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.040). There was no difference in the median operating time between groups.

CONCLUSION

The use of near-infrared fluorescence imaging + ICG fluorescence decreased both transient and permanent hypoparathyroidism rates in patients undergoing total thyroidectomy and central neck lymph node dissection.