Updated guidelines on the preoperative staging of thyroid cancer

Ultrasonography-guided radiofrequency ablation vs. surgery for the treatment of solitary T1bN0M0 papillary thyroid carcinoma: A comparative study

OBJECTIVE

Ultrasonography-guided radiofrequency ablation (RFA) has been used to treat low-risk small papillary thyroid carcinoma (PTC) and yielded promising results. However, little research has been conducted on the application of RFA for the management of T1bN0M0 PTC. Therefore, this study was to compare the midterm outcome of RFA with that of surgery for the treatment of clinical solitary T1bN0M0 PTC.

DESIGN

This is a retrospective study.

PATIENTS

In total, 182 patients with solitary T1bN0M0 PTC between April 2014 and May 2019 were treated with RFA or surgery (n = 91/group).

MEASUREMENTS

The primary end points were local tumour progression and complication rates. Local tumour progression were defined as: (a) new or persistent PTC confirmed by core needle biopsy; (b) cervical lymph node metastasis (LNM) confirmed by core needle biopsy or surgery; (c) ablation zone increased in the RFA group.

RESULTS

In the RFA group, local tumour progression was seen in four patients (4.4%, three persistent PTC and one LNM). In the surgery group, two patients (2.2%) developed LNM; no new or persistent PTC was confirmed. There was no significant difference between the two groups in local tumour progression. Permanent hypoparathyroidism was observed in four patients (4.4%) in the surgery group, while no major or minor complications were observed in the RFA group.

CONCLUSIONS

Ultrasonography-guided RFA is feasible and safe for treating solitary T1bN0M0 PTC, so it may be considered an alternative to surgery in select patients, especially those who are ineligible for or refusal of surgery.

Long-Term Follow-Up Results of Ultrasound-Guided Radiofrequency Ablation for Low-Risk Papillary Thyroid Microcarcinoma: More Than 5-Year Follow-Up for 84 Tumors

Background: Despite reports describing favorable short-term results for thermal ablation of thyroid cancer, there remains a need to evaluate long-term results because of its indolent characteristics. The purpose of this study was to evaluate the long-term efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC) over a follow-up period of more than five years. Methods: From a cohort of patients under surveillance after US-guided RFA for primary low-risk PTMC, those with a record of follow-up data of more than five years were selected for this study. Before RFA, all patients underwent US and computed tomography to evaluate the PTMC and the presence of neck metastasis. RFA was performed using thyroid-dedicated electrodes. Follow-up US was performed 6 and 12 months after initial RFA, and then every 12 months. The status of ablated tumors was evaluated according to volume reduction, local tumor progression, newly developed cancers, lymph node (LN) or distant metastasis, and delayed surgery during follow-up. Complications during the procedure and follow-up period were evaluated. Results: A total of 84 nodules from 74 patients were included in this study. All patients tolerated RFA, and the mean follow-up duration was 72 months. After RFA, complete disappearance rates of 98.8% and 100% were achieved at 24 and 60-month follow-up, respectively. Additional ablations were performed in 13 of 84 tumors. The mean number of RFA sessions was 1.2. There were four newly developed cancers in three patients, and these were also treated with RFA and completely disappeared. During the follow-up period, there was no local tumor progression, no LN or distant metastasis, and no patients underwent delayed surgery. The major complication rate was 1.4% (1/74), and there was no delayed complication or procedure-related death. Conclusions: RFA is effective for treating low-risk PTMC patients, without occurrence of local tumor progression, LN or distant metastasis, delayed complications, procedure-related death, or delayed surgery over more than five years of follow-up.

A methylomics-associated nomogram predicts recurrence-free survival of thyroid papillary carcinoma

Background

Thyroid papillary carcinoma (TPC) is the most common type of thyroid cancer (TC). The prognosis of TPC patients with tumor‐cell metastasis is poor. Therefore, this study aims to develop a model for predicting TPC patients' recurrence‐free survival (RFS).

Methods

We included 546 TPC patients who were clinically and pathologically diagnosed with TPC. The methylation biomarkers that associate with RFS were explored. These 546 samples were divided into training dataset (first 70%) and validation dataset (remaining 30%) randomly. The training dataset was used to identify prognostic biomarkers and construct risk prediction model, in addition, the validation dataset was used to verify the predictive performance of the model. We used Cox proportional hazard analysis and the least absolute shrinkage and selection operator (LASSO) Cox regression analysis to identify the significant predictive biomarkers, and establish the relapse risk prediction model from the identified biomarkers.

Results

A 6‐DNA methylation signature yielded a high evaluative performance for RFS. The Kaplan‐Meier analysis indicated that the 6‐DNA methylation signature could significantly distinguish the high‐ and low‐risk patients in training, validation and entire sets. In addition, a nomogram was constructed based on risk score, metastasis status and residual tumor status, and C‐index, receiver operating characteristic (ROC) and the calibration plots analysis which demonstrated the good performance and clinical utility of the nomogram.

Conclusions

The results suggested that the 6‐DNA methylation signature is the independent prognostic marker for RFS and functioned as a significant tool for guiding the clinical treatment of TPC patients.

US-Guided Radiofrequency Ablation for Low-Risk Papillary Thyroid Microcarcinoma: Efficacy and Safety in a Large Population

OBJECTIVE

To evaluate the efficacy and safety of radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC) in a large population.

MATERIALS AND METHODS

Cases of 152 biopsy-proven PTMCs from 133 patients who had undergone RFA for PTMC between May 2008 and January 2017 were included in this study. All patients were either of high surgical risk or refused to undergo surgery. They were followed up for at least 6 months after initial RFA. Ultrasonography (US) and computed tomography were performed to evaluate the PTMC and the presence of neck metastasis before treatment. RFA was conducted using an internally cooled thyroid-dedicated electrode system. Follow-up US was performed at 1 week, and 2, 6, and 12 months, after the initial RFA, and then at every 6-12 months. We evaluated serial changes of ablated tumors, newly developed cancers, lymph node (LN) or distant metastasis and complications.

RESULTS

Complete disappearance was found in 91.4% (139/152) of ablated tumors. Among the 13 tumors in patients who did not show complete disappearance, no tumor displayed any regrowth of the residual ablated lesion during the follow-up period. The mean follow-up period was 39 months. During the follow-up period, there were no local recurrence, no LN or distant metastasis, and no newly developed thyroid cancers. No patients were referred to surgery. The overall complication rate was 3% (4/133) of patients, including one voice change. There were no life-threatening complications or procedure-related deaths.

CONCLUSION

Our results suggest that RFA is an effective and safe option for treating low-risk PTMC patients who are of high surgical risk or refuse surgery.

The Impact of Arterial Phase on the Detection of Cervical Lymph Node Metastasis From Papillary Thyroid Carcinoma: A Quantitative Evaluation on Multiphasic Computed Tomography

OBJECTIVE

The purpose of this study was to assess the diagnostic performance of multiphasic computed tomography (CT) in the discrimination of metastatic lymph nodes (LNs) of papillary thyroid cancer by using quantitative parameters.

METHODS

This study enrolled 272 pathologically proven metastatic and benign LNs. Multiphasic CT was utilized by using nonenhanced, arterial (25-second delay), and venous (80-second delay) phases. Mean tissue attenuation values (MAVs) of metastatic and benign LNs were measured, and normalized MAV (common carotid artery and paraspinal muscle) and wash-in and wash-out percentages were also calculated.

RESULTS

The arterial phase showed the highest diagnostic performance in differentiation (area under the curve ± standard error, 0.97 ± 0.02; 95% confidence interval, 0.94-1.0; P < 0.001). Cutoff values for MAVs, normalized MAVs, and wash-in and wash-out percentages to predict metastatic LNs were calculated as 109 HU, 0.33, 1.93, 122.5, and -5.6 (sensitivity: 93.4%, 93.3%, 90.4%, 94.1%, and 97.8%, and specificity: 99.3%, 90.4%, 98.5%, 92.6%, and 99.3%, respectively).

CONCLUSIONS

Early-phase enhanced CT and the use of quantitative parameters derived from multiphasic CT improve the detection of cervical lymph node metastasis from papillary thyroid cancer.

Diagnostic value of computed tomography combined with ultrasonography in detecting cervical recurrence in patients with thyroid cancer

BACKGROUND

To determine the diagnostic role of CT added to ultrasound for the diagnosis of recurrent differentiated thyroid cancer (DTC) and to evaluate potential benefits for patients.

METHODS

A total of 193 patients with recurrent DTC were retrospectively included. The diagnostic performances of ultrasound and combination of ultrasound and CT (ultrasound/CT) in detecting recurrence were compared. Benefits of CT were assessed based on the presence of any recurrence detected only with additional CT.

RESULTS

In detecting cervical recurrence, ultrasound/CT showed higher sensitivity (P = .001) and lower specificity (P < .001) than ultrasound alone, overall resulting in higher area under the curve (P < .001). Seventy-nine patients (40.9%) benefited from additional CT in detecting recurrence.

CONCLUSION

For reoperation of cervical recurrence in patients with DTC, addition of CT to ultrasound offers better surgical planning by enhancing detection of recurrent cancers that were overlooked with ultrasound alone.

Great veins invasion in follicular thyroid cancer: single-centre study assessing prevalence and clinical outcome

PURPOSE

Great veins invasion is considered as a rare and prognostically unfavourable event in thyroid cancer. However, current knowledge about this issue is mainly based on single case reports. Follicular thyroid cancer (FTC) represents the histotype with the most pronounced angioinvasive feature. This study is aimed at assessing the actual prevalence of great veins invasion in FTC and providing information about prognosis and the proper clinical management of these patients.

METHODS

Clinico-pathological and radiological data of patients with thyroid cancer undergoing thyroidectomy in our institution were retrospectively retrieved. Inclusion criteria were as follows: (a) histological diagnosis of FTC; (b) instrumental and histological evidence of great veins invasion and (c) documented follow-up entirely performed at our institution. Pre-surgical assessment of great veins status was performed in all patients by means of Doppler ultrasonography.

RESULTS

Out of 637 patients operated from 2003 to 2013, four subjects, all affected with FTC, showed great veins involvement (0.62% of the overall cohort and 7.85% of the FTC group). One of them was lost at follow-up. All three patients with available follow-up were subjected to aggressive surgery obtaining a complete eradication of neck disease. All of them achieved the 5-year survival target (60, 63 and 96 months of survival for patients 1, 2 and 3, respectively).

CONCLUSIONS

Great veins invasion may not be uncommon in FTC and preoperative detection and characterisation of such condition may optimise surgical approach and improve survival.

Evolving management considerations in active surveillance for micropapillary thyroid carcinoma

PURPOSE OF REVIEW

To summarize developments on active surveillance for micropapillary thyroid cancers, with a focus on strategies for optimal risk stratification and caveats that currently limit adoption.

RECENT FINDINGS

Observational trials encompassing thousands of active surveillance patients worldwide have increasingly demonstrated the viability of active surveillance for small, low-risk thyroid cancers. Collectively, these data have established that with proper patient selection and strict monitoring, more than 85% of such cases remain indolent no meaningful clinical growth over at least 10 years. Moreover, to date no cases of symptomatic progression or distant metastasis have been reported, and that delayed treatment when needed has not led to unresectable disease or higher risk of complications. Deeper investigation to better predict clinical progression is necessary to improve patient selection, given concerns regarding patient anxiety, age eligibility, and underestimation of true disease extent.

SUMMARY

Compelling data from ongoing trials support active surveillance as a first-line management option for micropapillary thyroid carcinomas. Proper risk stratification and strict monitoring protocols will be necessary to sustain the excellent results achieved to date. Broad adoption of active surveillance will require further education, collaboration, and equipoise between physicians and patients to optimize such individualized treatment plans.