Effectiveness of various thermal ablation techniques for the treatment of nodular thyroid disease--comparison of laser-induced thermotherapy and bipolar radiofrequency ablation

US-CT fusion-guided percutaneous radiofrequency ablation of large substernal benign thyroid nodules

The aim of the present study was to assess feasibility, safety and outcome of ultrasound (US) guided percutaneous radiofrequency (RF) ablation of large substernal benign thyroid nodules assisted by US-computed tomography (CT) fusion imaging and real-time virtual needle tracking (VT) system. Thirty patients (18 females, mean age 56 y, range 32-76 y) with 35 benign nonfunctioning thyroid nodules (mean volume ± SD 26.8 ± 7.6 mL; range 20-38mL) were selected for CT-US fusion guided RF ablation. Nodules' volume was evaluated before treatment and during 12-months follow-up. Complications' rate was also evaluated. US-CT fusion imaging with VT system was feasible in all cases (feasibility 100%) and it was always possible to complete the procedure as planned (technical success 100%). Minor complications occurred in 2/30 cases (6.6%). No major complications occurred. 50% volume reduction (technique efficacy) was achieved in 93% cases, with a significant mean volume reduction at 12 months follow-up (68.7 ± 10.8%), (p < .001). The VT system could be useful in thyroid nodules ablation procedures assistance being able to track the RF electrode tip even when this is obscured by the bubbles produced by the ablative process. The combination of fusion imaging with VT assisted RF ablation represents a safe, non-surgical treatment option for patients with large substernal benign thyroid nodules.

Can local ablative techniques replace surgery for locally advanced pancreatic cancer?

In the treatment of pancreatic ductal adenocarcinoma (PDAC) the best chance at long term survival or cure has to date always included the complete surgical removal of the tumor. However, locally advanced pancreatic cancer (LAPC), about 25% of all newly diagnosed PDAC, is defined by its primary technical unresectability due to infiltration of visceral arteries and absence of metastasis. Induction therapies, especially FOLFIRINOX treatment, together with technical surgical advancement have increased the numbers for conversion to secondary resectability. Recent data on resections after induction therapy show promising, almost doubled survival compared to palliative treatment. Yet, around 70% of LAPC remain unresectable after induction therapy, often due to persistent local invasion. As locally ablative techniques are becoming more widely available this review examines their possible applicability to substitute for surgery in these cases which we propose to group under the new term "Inconvertible LAPC". The need for defining this novel subgroup who might benefit from ablative treatment is based on the findings in our review that high-level evidence on ablative techniques for PDAC is largely lacking and the latest effective, harmonized treatment guidelines for LAPC are not often incorporated in these studies. The "inconvertible LAPC" label requires persistent unresectability after staging and induction therapy of LAPC according to current guidelines followed by liberal indication for aggressive surgical exploration at a center equipped for extended pancreatic resections. Ideally, this specification of a new, distinct patient group will also put it in the spotlight more, hopefully prompt more trials designed to generate robust evidence and optimize transferability of study results.

Discontinuous moving shot technique for conformal thermal ablation in an ex vivo porcine liver model

PURPOSE

We aimed to determine the ablation characteristics of discontinuous moving shot technique (DMST) in microwave ablation (MWA), radiofrequency ablation (RFA) and laser ablation (LA), and analyze the differences compared with fixed electrode technique (FET) in an ex vivo porcine liver model.

METHODS

FET was defined as the ablation needle remaining fixed during ablation. In DMST, ablation needle moved backward for a fixed distance twice along the long axis during ablation. Four moving distances (0.5 cm, 0.75 cm, 1 cm and 2 cm) were used in DMST. Long-axis diameter (LAD) and short-axis diameter (SAD) of ablation zones were measured. The ratio of LAD/SAD was calculated.

RESULTS

The shape and size of ablation zones were different between DMST and FET. Compared with FET, DMST could achieve greater LAD when the moving distance became long enough. In MWA with DMST, SAD decreased with the extension of moving distance and finally became smaller than the SAD in FET. While in LA and RFA, the change of moving distance did not affect SAD significantly.

CONCLUSION

In MWA, RFA and LA, the characteristics of ablation zone of DMST were different from that of FET. This unique ablation technique may be suitable for conformal thermal ablation.

Efficacy and safety of radiofrequency ablation for benign thyroid nodules in patients with previous thyroid lobectomy

Background

Radiofrequency ablation (RFA) is recommended for the treatment of benign thyroid nodules. However, data on the clinical role of RFA for benign thyroid nodules in patients with history of thyroid lobectomy are insufficient. The purpose of this study was to evaluate the efficacy and safety of radiofrequency ablation (RFA) for benign thyroid nodules in patients who had previously undergoing thyroid lobectomy.

Methods

From May 2015 to October 2018, a total of 20 patients (19 females, 1 male, mean age 49.50 ± 14.26 years, range 22–74 years) with 20 benign thyroid nodules (mean volume 15.04 ± 21.17 ml, range 0.40–69.67 ml) who had undergone previous thyroid lobectomy were included in this retrospective study. Patients were followed up at 3, 6, 12 months after RFA and every 12 months thereafter by ultrasound, clinical evaluation and thyroid function. Volume, volume reduction rate (VRR), symptom score and cosmetic score were evaluated.

Results

During the mean follow-up time of 21.24 ± 16.41 months, the mean nodule volume decreased significantly from 15.04 ± 21.17 ml to 1.29 ± 1.17 ml (P = 0.018) with a mean VRR of 85.41 ± 12.17%. Therapeutic success was achieved in a single session for all thyroid nodules. The symptom score (P = 0.001) and cosmetic score (P = 0.001) were both significantly reduced at the last follow-up. The levels of free triiodothyronine (fT3), free thyroxine (fT4) and thyroid stimulating hormone were not significantly different at the last follow-up from those prior to treatment (all P > 0.05). No life-threatening complications or sequelae occurred after RFA.

Conclusions

As a minimally invasive modality, RFA was a safe, effective, and thyroid function-preserving option for patients with symptomatic benign thyroid nodules after a previous lobectomy.

Radiofrequency Thermoablation On Ex Vivo Animal Tissues: Changes on Isolated Swine Thyroids

The use of Radiofrequency thermoablation (RFA) for treating large thyroid nodules is limited by the modest efficiency of the available systems in terms of volume of the ablation zones (AZs). This increases the risk of incomplete ablation of the nodule. Systems employing perfused electrodes have been developed to increase the volume of the AZ. Aim of this study is to compare the size of the AZ induced by RFA systems using internally cooled perfused vs. non-perfused electrodes in swine thyroids. RFAs were performed on 40 freshly isolated swine thyroids using both systems. The perfused system was tested using 0.9% saline, 7% and 18% hypertonic saline solutions. Energy delivery to the tissue was stopped when tissue conductivity dropped (real life simulations) and after an established time of 20 seconds (controlled duration). Following RFA, thyroids were transversally and longitudinally cut. Photographs were taken for macroscopic morphometry of the ablated zones before and after formalin fixation, to evaluate tissue shrinkage. Microscopic morphometry was performed on PAS stained sections. In real life simulation experiments, gross morphometry revealed that AZs produced with electrodes perfused using 7.0% saline are larger compared to isotonic saline. Microscopically, all the conditions tested using the perfused system produced larger AZs compared to non-perfused system after 20 seconds of RFA. In conclusion, the perfusion with 7.0% NaCl solution increased the electrical conductivity of the tissue in real life simulations, resulting in larger ablated areas compared to the use of isotonic saline.

A Prospective Intervention Trial on Tailored Radiofrequency Ablation of Uterine Myomas

Background and Objective: Investigating the use of radiofrequency myolysis (RFM) for the treatment of fibroids through less invasive access by combining transvaginal ultrasound, hysteroscopy and laparoscopy. Materials and Methods: Fifty-four premenopausal women with 106 symptomatic uterine myomas. Patients underwent RFM in three ways: Vaginal Ultrasound-guided RFM (VU-RFM), Laparoscopic RFM (L-RFM) and Hysteroscopic-RFM (H-RFM). The mean patient age was 43 years; 52 symptomatic uterine myomas were subserosal, 44 intramural and 10 submucosal. The outcomes evaluated at 1 and 12 months after RFM were myoma size (volume-diameter), "Uterine Fibroid Symptom and Quality of Life (UFS-QOL)" questionnaire and a 10-point Visual Analogue Scale (VAS). The therapy was completed with a single ablation in all patients, no complication was registered. The average number of fibroids treated per intervention was two with the use of different accesses: 64/106 VU-RFMs (60.4%), 32/106 L-RFMs (30.2%) and 10/106 H-RFMs (9.4%). Results: Volume and diameter of fibroids were significantly reduced by, respectively, 51.3% and 20.1% in the first 30 days post-intervention (p < 0.001) up to a maximum of 73.5% and 37.1% after the second follow-up visit at 12 months (p < 0.001). A similar trend was shown in terms of disability with a progressive and significant reduction of symptoms (menorrhagia, dysmenorrhea, dyspareunia and pollakiuria) demonstrated by percentage variation of UFS-QOL Symptom Severity and VAS scores to -74.3% and -45.3% as well as -84.9% and -74.3%, respectively, at 1 and 12 months after RFM (p < 0.001). An overall improvement in the quality of life was also demonstrated by a significant increase in the UFS-QOL total score of +38.2% in the first 30 days post-intervention up to +44.9% after the second follow-up visit at 12 months (p < 0.001). The overall average surgery time of the RFM for each patient was 48 minutes, and the time to treat each fibroid by Vaginal Ultrasound-guided RFM (23 min) was found to be significantly less than those of laparoscopy or hysteroscopy (respectively 35 and 34 min) (p < 0.05). An electromagnetic virtual needle tracking system (VNTS) was successfully tested during the RFM procedures, and real-time contrast-enhanced ultrasound (CEUS) has proven to be effective in determining the duration of myolysis through the identification of eventual residual areas of enhancement within the fibroids. Conclusion: Radiofrequency can be considered a minimally invasive and safe procedure for the treatment of uterine myomas through the customization and possible combination of transvaginal, laparoscopic or hysteroscopic accesses. The standardization of the ablation technique with pre-intervention biopsy and new technologies such as VNTS and CEUS spares healthy uterine tissue and may change the future management of symptomatic uterine fibroids.

Percutaneous laser ablation for benign thyroid nodules: a meta-analysis

Purpose

To evaluate percutaneous laser ablation in treating benign thyroid nodules, we conducted a meta-analysis based on summarizing existing researches.

Materials and Methods

A literature search for clinical trial was performed in PubMed, Cochrane Library and Excerpt Medica Database. The qualities of included studies were evaluated. We calculated the indexes with mean difference. Heterogeneity and publication bias were tested and explored. We performed subgroup analyses and sensitivity analysis further.

Results

A total of 19 researches and 2137 patients were included in this meta-analysis. The pooled estimates of nodule volume were statistically significant after percutaneous laser ablation for 1 month, 3 month, 6month, 12month, 24month and 36month(P < 0.05). The pooled estimate of thyroid-stimulating hormone was statistically significant after percutaneous laser ablation for 1 and 12 month (P = 0.008 and P = 0.03). The pooled estimate of free triiodothyronine was no statistically significant after percutaneous laser ablation for all follow-up intervals. The pooled estimate of free tetraiodothyronin was statistically significant after percutaneous laser ablation1 month (P = 0.004). The pooled estimate of thyroglobulin was statistically significant after percutaneous laser ablation 24 month (P = 0.04). The heterogeneity was found and the source of heterogeneity was explored in nodule volume for 6 and 12 month. No publication bias was found.

Conclusions

This meta-analysis demonstrated that percutaneous laser ablation was safe and useful in shrinking benign thyroid nodules volume, improving thyroid function, relieving symptoms of pressure and esthetic, especial for hyper-vascular benign thyroid nodules. Larger number of high-quality prospective studies still needs to be performed.

Treatment efficacy and safety of ultrasound-guided percutaneous bipolar radiofrequency ablation for benign thyroid nodules

OBJECTIVE

To evaluate the therapeutic efficacy and safety of ultrasound-guided percutaneous bipolar radiofrequency ablation (BRFA) of benign thyroid nodules by comparison with a matched untreated control group.

METHODS

The therapeutic efficacy and safety in 35 patients who were subjected to a single session of ultrasound-guided percutaneous BRFA (Group A) for benign thyroid nodules were compared with those in 35 untreated patients (Group B) with benign nodules. The benign nature of all the nodules was confirmed by ultrasound-guided fine-needle aspiration biopsy (FNAB), and all the patients had normal thyroid functions. BRFA was performed with a bipolar electrode (CelonProSurge 150-T20) with an output power of 20 W. Nodule volume, thyroid function and clinical symptoms of all the patients were compared before treatment and during follow-up.

RESULTS

In Group A, the BRFA procedures were completed with a mean time of 10.02 ± 3.30 min (range, 5.47-16.03 min) and with a mean total energy deposition of 10.747 ± 3704 J (range, 5510-17.770 J). The procedures were tolerated well in all the patients without causing any major complications. At the 6-month follow-up, all of the nodule volume decreased significantly (from 8.81 ± 8.66 to 1.59 ± 1.55 ml, p < 0.001) in Group A, whereas the nodule volume increased from 6.90 ± 3.77 to 7.87 ± 3.95 ml in Group B (p < 0.001). All (100%) the 35 nodules in Group A had volume reduction ratios (VRRs) of >50%, among which 3 (8.57%) had VRRs >90%. In Group A, the clinical symptoms of the patients who had symptoms before BRFA disappeared, whereas in Group B, the patients had no resolution of clinical symptoms at the 6-month follow-up.

CONCLUSION

Ultrasound-guided percutaneous BRFA seems to be an effective and safe method for the treatment of benign thyroid nodules. It may gain a wide use in clinical practice.

ADVANCES IN KNOWLEDGE

Based on the comparable efficacy and clinical symptoms between the BRFA and untreated groups, the technique of BRFA can be used as an effective and safe method for the treatment of benign thyroid nodules.

Advances in nonsurgical treatment of benign thyroid nodules

Ethanol ablation has traditionally been used for treatment of cystic thyroid nodules. Laser ablation and radiofrequency ablation were introduced later and used for treatment of solid thyroid nodules. However, how to select the best treatment modality among the different techniques has, so far, not been determined and causes confusion in clinical practice. Therefore, the necessity for a proper guideline regarding the choice of the preferable treatment modality has been suggested as the use of nonsurgical treatment for benign thyroid nodules has been increasing. This article provides an up-to-date review of nonsurgical treatment of benign thyroid nodules focusing on how to select the best treatment modality according to the composition of thyroid nodules based on the clinical evidence.

Percutaneous radiofrequency ablation of benign thyroid nodules assisted by a virtual needle tracking system

Our aim was to assess the feasibility and outcome of ultrasound (US)-guided percutaneous radiofrequency (RF) ablation of benign thyroid nodules assisted by a real-time virtual needle tracking (VT) system. Forty-five patients (34 females, mean age ± standard deviation (SD): 44 ± 16 y, range: 29-68 y) with 45 benign non-functioning thyroid nodules (mean volume ± SD: 13.5 ± 6.7 mL, range: 12-22 mL) underwent VT-assisted US-guided RF ablation. Nodule volume was evaluated before treatment and during 6-mo of follow-up. Complication rates and patient satisfaction after treatment were also evaluated. By use of the VT system, the tip of the RF electrode was identified during all ablation procedures. The overall mean volume reduction and complication rate were 72.6 ± 11.3% and 2.5%, respectively. Overall satisfaction at the 6-mo follow-up was rated by patients as positive in 42 cases (93%). The VT system could be useful in thyroid nodule ablation procedures because it is able to track the RF electrode tip even when the tip is obscured by the bubbles produced by the ablative process. VT-assisted RF ablation can be a tolerable, non-surgical treatment for patients with benign non-functioning thyroid nodules.

Short-term effects of radiofrequency shrinkage treatment for anterior cruciate ligament relaxation on proprioception

OBJECTIVE

Radiofrequency (RF) shrinkage is used in anterior cruciate ligament (ACL) reconstruction. The present study investigated the therapeutic effects of RF on ACL relaxation and the probable influencing factors.

METHODS

Patients with ACL relaxation were included. Participants were randomly divided into two groups: a treatment group, in which patients were treated with RF shrinkage (RF group); a control group, in which patients received conventional surgical treatment. Thermal shrinkage was performed on ACL using an ArthroCare® CAPSure® wand. Lysholm scores, proprioceptive testing and Tegner activity scores were evaluated before and after treatment (at 6 and 12 months).

RESULTS

A total of 38 patients were included. The mean ± SD Lysholm score of those in the RF group at 12 months' post-treatment was significantly higher than in controls. The angle of deviation of the knee joint in RF group was significantly larger than in the control group at 6 months' post-treatment.

CONCLUSIONS

RF shrinkage treatment for ACL laxity could improve knee scores, and may affect proprioception and recovery of activity after surgery.

Use of radiofrequency ablation in benign thyroid nodules: a literature review and updates

Successful thermal ablation using radiofrequency has been reported in various tumors including liver or kidney tumors. Nonsurgical minimally invasive ablative therapy such as radiofrequency ablation (RFA) has been reported to be a safe and efficient treatment option in managing symptomatic cold thyroid nodules or hyperfunctioning thyroid nodules. Pressure and cosmetic symptoms have been shown to be significantly improved both in the short and long terms after RFA. For hyperfunctioning thyroid nodules, RFA is indicated for whom surgery or radioiodine are not indicated or ineffective or for those who refuse surgery or radio-iodine. Improvement of thyroid function with decreased need for antithyroid medications has been reported. Complication rate is relatively low. By reviewing the current literature, we reported its efficacy and complications and compared the efficacy of RFA relative to other ablative options such as ethanol ablation and laser ablation.