Background: Some researchers have achieved favorable efficacy in the treatment of primary papillary thyroid microcarcinoma (PTMC) using microwave ablation (MWA). However, as PTMC is a slowly progressing disease, a long follow-up period is required to confirm treatment efficacy. Our study aim was to investigate the long-term efficacy and safety of ultrasound (US)-guided MWA in PTMC. Methods: In this study, 41 patients with thyroid masses (41 nodules) were diagnosed with PTMC by fine-needle aspiration or core needle biopsy. They underwent US-guided MWA. Preablation ultrasonic images of the thyroid nodules were collected, and the volumes were measured. The patients had follow-up at 1, 3, 6, and 12 months in the first year and every 6 months from the second year on, after MWA. The volume reduction rates (VRRs) of the thyroid nodules were analyzed. Results: In total, 40 of 41 nodules were completely ablated by MWA. After 60 months of follow-up, the volume significantly decreased from a median of 55.78 mm ³ (quartile: 21.50, 112.20 mm ³ ) to 0 mm ³ (0, 0 mm ³ ) ( p < 0.001), with a VRR of 99.37% ± 4.02%. Two patients developed hoarseness after ablation; one recovered within 10 minutes, and the hoarseness in the other patient resolved 2 months after the ablation. No recurrence, metastatic cervical lymph nodes, or distal metastasis was found during the follow-up period. Conclusions: In this five-year follow-up, MWA presented favorable efficacy with satisfactory safety for the treatment of PTMC. It should be considered an alternative therapy to surgery and active surveillance for solitary PTMC.

Carbon nanotubes (CNTs), as advanced nanotechnology with specific properties and structures, have presented practical drug delivery properties. Ginsenoside Rg3 is a component of puffed ginseng and demonstrates anti-cancer activities. To explore the effect of CNTs-loaded Rg3 (Rg3-CNT) on the PD-1/PD-L1 signaling and the development of triple-negative breast cancer (TNBC). Our data revealed that Rg3 inhibited the cell viability of TNBC cells, in which Rg3-CNT further enhanced this effect in the system. Similarly, the colony formation of TNBC cells was decreased by Rg3, while Rg3-CNT could reinforce its effect in the cells. Besides, the treatment of Rg3 induced apoptosis of TNBC cells, in which Rg3-CNT treatment further increased the phenotype in the cells. Remarkably, Rg3-CNT, but not Rg3, attenuated PD-L1 expression in TNBC cells. Rg3-CNT decreased the PD-L1 upregulation induced by interferon-γ (IFN-γ) in breast cancer cells. Importantly, Rg3-CNT was able to reduce PD-1 expression in activated T cells. Specifically, Rg3-CNT reduced the PD-1/PD-L1 axis in a T cell/triple-negative TNBC cell co-culture system. Moreover, the levels of IFN-γ, interleukins-2 (IL-2), interleukins-9 (IL-9), interleukins-10 (IL-10), interleukins-22 (IL-22), and interleukins-23 (IL-23) were significantly stimulated in the activated T cells, while the treatment of Rg3-CNT could reverse these phenotypes in the cells. Rg3-CNT attenuated the TNBC cell growth in vivo. The Rg3-CNT improved the anti-cancer effect of Rg3 toward TNBC by inhibiting the PD-1/PD-L1 axis. Our finding provides new insights into the mechanism by which Rg3-CNT attenuates the development of TNBC. Rg3-CNT may be applied as the potential therapeutic strategy for immunotherapy of TNBC.

Objective: To compare the safety and efficacy of ultrasound-guided thermal ablation and conventional thyroidectomy for benign thyroid nodules (TNs) by performing a systematic review and meta-analysis. Methods: We searched PubMed, Embase, Web of Science and Cochrane Library databases for clinical trials from the date of their inception to 1 April 2019. Two investigators independently examined the trials to select qualified studies, extracted relevant information and assessed the risk of bias according to the Cochrane Collaboration checklist (Oxford, UK). The primary study outcomes were safety (hoarseness, hypothyroidism and postoperative pain) and efficacy (symptom improvement, postoperative cosmetic effects and hospitalization time). This study is registered with PROSPERO (CRD42019125643). Results: Seven studies involving 1289 patients were included. The results demonstrated that the incidences of hoarseness [odds ratio (OR) 0.33, 95% confidence interval (95% CI) (0.14, 0.79)], hypothyroidism [risk difference (RD) −0.31, 95% CI (−0.34, −0.28)] and postoperative pain [OR 0.35, 95% CI (0.25, 0.49)] were lower, and the hospitalization time was shorter [standard mean difference (SMD) −4.01, 95% CI (−4.22, −3.81)], in the thermal ablation group than in the conventional thyroidectomy group, and postoperative cosmetic effects were better [relative risk (RR) ratio 1.12, 95% CI (1.01, 1.24)] (p < 0.05). For symptom improvement, the difference was not statistically significant. Conclusions: This study shows that for benign TNs, ultrasound-guided thermal ablation may have potential advantages in terms of safety, cosmetic effects and shorter hospitalization time compared with conventional thyroidectomy, while symptom improvement is the same.

Objective: To report more than 5-year outcomes of ultrasound-guided thermal ablation (TA) for patients with solitary low-risk papillary thyroid microcarcinoma (PTMC) in a large multicenter cohort. Background: TA, including radiofrequency ablation (RFA) and microwave ablation (MWA) have been used in patients with low-risk PTMC who refuse surgery or active surveillance. However, its clinical value remains controversial. Materials and Methods: This retrospective multicenter study included 474 patients with solitary low-risk PTMC treated with TA (357 for RFA; 117 for MWA) from 4 centers and followed up for at least 5 years. Disease progression including lymph node metastasis and recurrent tumors, volume reduction rate (VRR), tumor disappearance rate, complications, and delayed surgery were assessed. RFA and MWA outcomes were compared using propensity score matching. Results: During the median follow-up period of 77.2 months, disease progression incidence, lymph node metastasis, and recurrent tumors rates were 3.6%, 1.1%, and 2.5%, respectively. Age below 40 years old, male sex, Hashimoto thyroiditis, and tumor size were not independent factors associated with disease progression by Cox analysis. The median VRR was 100% and 471 tumors disappeared radiographically. Eight patients experienced transient voice change (1.7%) which recovered within 3 months. None of the patients underwent delayed surgery because of anxiety. After 1:1 matching, no significant differences were found in the disease progression, VRR, tumor disappearance rate, or complications between RFA and MWA subgroups. Conclusion: This multicenter study revealed that TA was an effective and safe treatment for patients with solitary low-risk PTMC, which could be offered as a treatment option for the management for low-risk PTMC.

Objectives: The short-term effects of microwave ablation (MWA) for the treatment of benign thyroid nodules (BTNs) were satisfactory in previous studies. However, as a slowly progressing disease, the long-term efficacy of MWA for BTNs at present is not clear. Our study aim was to assess the long-term results of MWA for BTNs after a 48-month follow-up.Methods: From June 2015 to September 2017, 148 patients had 148 BTNs. All patients were from the China-Japan Union Hospital of Jilin University. Careful ultrasound examinations were performed 1 day, 1 month, 3 months, 6 months, 12 months, and every 6 months after MWA. The volume, volume reduction rate (VRR), recurrence rate of the ablated area and thyroid function were recorded.Results: The mean volumes of the 148 nodules were 15.6 ± 9.4 cm³ (range: 1.3-48.9 cm³) and 0.6 ± 0.6 cm³ (range: 0-3.5 cm³) before and 48 months after MWA, respectively, with a nodule VRR of 96.9 ± 2.5% (range: 90.4-100%). Two patients (1.35%) had recurrence after MWA. Compared with thyroid function before MWA, no significant variation was observed after MWA. Five patients experienced complications (3.38%): two patients (1.35%) had bleeding, two patients (1.35%) had ear pain and toothache during MWA, and one patient (0.68%) had hoarseness after MWA. No cases of oesophageal injury, tracheal injury, infection, skin burns, etc., were reported during or after MWA.Conclusions: Based on a long-term follow-up, MWA is an effective method for treating BTNs and is expected to be a potential first-line treatment.