Meta-Analysis of the Application Effect of Different Modalities of Thermal Ablation and Surgical Treatment in Papillary Thyroid Microcarcinoma

Abstract

Background: Papillary thyroid microcarcinoma (PTMC) refers to papillary thyroid carcinoma (PTC) with a maximum diameter of 10 mm. Thermal ablation, including radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA), has been applied in the treatment of benign thyroid nodules and captured extensive attention. At present, the application of thermal ablation in PTMC has been extensively reported, but outcomes such as volume reduction rate (VRR), complete remission rate (CRR), and adverse reaction rate (ARR) vary considerably. Therefore, this meta-analysis was performed to evaluate the safety and efficacy of different treatment methods of PTMC.

Methods: We did a systematic review and network meta-analysis. We searched PubMed, EMBase, and Cochrane-Library from the date of inception to January 10, 2022, to retrieve the VRR, CRR, and ARR of MWA, RFA, LA and surgical treatment of PTMC, and a meta-analysis was performed using the R meta-package. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, and sensitivity analyses, cumulative meta-analyses, and publication bias were also performed. Relevant literature was retrieved with keywords; the eligible cohort studies were screened based on the established inclusion and exclusion criteria.

Results: A total of 1515 patients were included in the 12-month follow-up. The overall VRR was 86.25% (95% CI: 77.89, 94.60), and the VRR was RFA > WMA > LA, but the differences were not significant. A total of 1483 patients were included in the last follow-up. The overall VRR was 99.41% (95% CI: 99.11, 99.72), and the VRR was RFA > WMA > LA, but the differences were not significant. A total of 1622 patients showed complete remission at the last follow-up, and the overall CRR was 0.63 (95% CI: 0.46, 0.79). The CRR was RFA > LA > WMA, but the differences were not significant. A total of 1883 patients had adverse reactions at the last follow-up, and the overall ARR was 0.06 (95% CI: 0.03, 0.08). The ARR at the last follow-up was RFA = Surg < LA < WMA. The ARR of the RFA and Surg subgroups was significantly lower than that of the WMA subgroup.

Conclusions: Similar good efficacy and safety profiles were observed in WMA, RFA, LA, and surgical treatment in PTMC, among which RFA showed the best volume reduction, complete remission rate, and adverse reaction reduction. However, there is a slight bias in the limited literature included in this study, and we did not conduct or refer to mechanistic studies to confirm its specific mechanism of action. Clinicians are advised to use their discretion in the choice of treatment.

Figure 1

The flowchart of literature enrolled.

Figure 2

Quality assessment of included literature.

Figure 3

VRR forest map at 12 months after different thermal ablation methods. The 12-month follow-up VRR of the three thermal ablation methods was RFA > WMA > LA, and the differences were not significant. Note: WMA = microwave ablation; RFA = radiofrequency ablation, LA = laser ablation; VRR = volume reduction rate.

Figure 4

VRR forest map at last follow-up with different thermal ablation methods. The last follow-up VRR of the three thermal ablation methods was RFA > WMA > LA, but the difference was not significantly significant. Note: WMA = microwave ablation; RFA = radiofrequency ablation, LA = laser ablation; VRR = volume reduction rate.

Figure 5

CRR forest map at last follow-up with different thermal ablation methods. The CRR of the three thermal ablation methods at the last follow-up was RFA > LA > WMA, and the differences were not significant. Note: WMA = microwave ablation; RFA = radiofrequency ablation; LA = laser ablation; CRR = complete remission rate.

Figure 6

ARR forest plot at last follow-up with different thermal ablation methods. The final ARR of the four treatments RFA = Surg LA WMA follow-up, and the ARR of the RFA and Surg subgroups were considerably lower than WMA subgroups, because the distinction was statistically significant. Note: WMA = microwave ablation; RFA = radiofrequency ablation; LA = laser ablation; ARR = adverse reaction rate.

Figure 7

Inclusion funnel plot. All funnel plots were considerably asymmetric, and Egger's test findings revealed strong heterogeneity in all studies.