High-intensity focused ablation (HIFU) of single benign thyroid nodule rarely alters underlying thyroid function

Abstract

Background: High intensity focused ultrasound (HIFU) is a promising ablation technique for benign thyroid nodules. However, its effect on underlying thyroid function remains unknown. We aimed to evaluate the 6?months changes in serum thyroid stimulating hormone (TSH) and free thyroxine (FT4) after HIFU treatment.

Methods: Eighty-three consecutive patients who underwent single HIFU ablation for symptomatic benign thyroid nodule were analysed. Eligible patients had serum TSH and FT4 checked before treatment (baseline), 1 week, 3 and 6 months following HIFU treatment. Primary endpoints were hypothyroidism (FT4?<?12?pmol/L) and hyperthyroidism (FT4?>?23?pmol/L) in the 6?months following treatment. To express extent of nodule ablation relative to the total gland volume, an ablation volume ratio was calculated by [(Ablated nodule volume/total thyroid volume)/(total thyroid volume)]?×?100.

Results: Relative to baseline, 1-week serum TSH significantly dropped (from 1.16 to 0.76 mIU/L, p?<?0.001) while 1-week serum FT4 significantly rose (from 16.0?to 17.8?pmol/L, p?<?0.001). However, 3- and 6-months TSH and FT4 did not changed significantly from baseline (p?>?0.05). No patients developed hyperthyroidism while one (1.4%) developed hypothyroidism (FT4?=?11?pmol/L) at 3 months and 6 months. Interestingly, this patient had a previous lobectomy and an ablation volume ratio of 64.00%.

Conclusions: Hypothyroidism following single HIFU ablation occurred rarely (1.4%) and resulted in little clinical relevance. Given that only one patient developed hypothyroidism following single HIFU ablation, it remains unclear how patients with different amount of parenchyma and relative extent of ablation may affect subsequent thyroid function.     

The percentage of serum thyroglobulin rise in the first-week did not predict the eventual success of high-intensity focussed ablation (HIFU) for benign thyroid nodules

Abstract

Background: Given that high-intensity focussed ultrasound (HIFU) of benign thyroid nodules often causes a massive release of thyroglobulin (Tg) into the circulation, we hypothesised a greater initial Tg rise may result in a greater nodule shrinkage 6?months after ablation.

Methods: One hundred and five patients who underwent HIFU for symptomatic benign thyroid nodule from 2015 to 2016 were analysed. Serum Tg and anti-Tg autoantibody were checked on treatment day (baseline) and 4?d after treatment. The % of Tg rise?=?[serum Tg on day-4 – baseline serum Tg]/[baseline serum Tg] * 100 while the nodule shrinkage as measured by volume reduction ratio (VRR)?=?[baseline volume – volume at 6-month]/[baseline volume] * 100. Treatment success was defined as VRR?>50%.

Results: At 6-month, the mean VRR was 62.2?±?25.0% and 59 (76.6%) patients had treatment success. The mean baseline Tg level increased from 292.8?±?672.7?ng/mL to 2022.7?±?1759.8?ng/mL in the first-week. The % of Tg rise did not significantly correlate with either 3-month or 6-month VRR (p?=?0.920 and p?=?0.699, respectively). The mean % of Tg rise in the first week was not different between those with and without 6-month treatment success (368.2% vs. 1068.7%, p?=?0.381). No clinical factors significantly correlated with treatment success.

Conclusions: There was an almost seven-fold increase in the mean Tg level 4?d after HIFU ablation. The % of Tg rise in the first week did not appear to correlate with the 6-month nodule shrinkage or treatment success.     

High intensity focused ultrasound (HIFU) ablation of benign thyroid nodule is safe and efficacious in patients who continue taking an anti-coagulation or anti-platelet agent in the treatment period

Background: High intensity focused ultrasound (HIFU) ablation is a promising treatment for benign thyroid nodules but because bleeding complications can occur following any intervention to the thyroid gland, the safety and efficacy of HIFU ablation were evaluated in patients who continued taking an anti-coagulation or anti-platelet agent during treatment.

Methods: From 2015 to 2017, 303 patients who underwent a single-session ablation for a benign thyroid nodule were analyzed. The primary study endpoint was thyroid bleeding, intra-lesional or peri-thyroidal hematoma or neck bruising diagnosed within 4?days of the treatment. Other endpoints included treatment-related complications, extent of nodule shrinkage and symptom score. Nodule volume was estimated by ultrasound. Extent of nodule shrinkage (by volume reduction ratio) (VRR)=?[Baseline volume – volume at 6-month]/[Baseline volume]?×?100. Obstructive symptom score (by 0– 10 visual analog scale, VAS) was evaluated after treatment.

Results: Twelve patients continued taking an anti-coagulation or anti-platelet agent while the other 291 patients did not during treatment. No patients in either group suffered active thyroid bleeding, intralesional/pericapsular hematoma or subcutaneous neck bruising in the first 4?days of treatment. Complication rate and the 6-month VRR were comparable between the two groups (0.0% vs. 1.7%, p?=?1.000 and 55.96% vs. 61.29%, respectively, p?=?.073).

Conclusions: HIFU ablation is a feasible treatment in patients who continue to take an anti-coagulation or anti-platelet agent during treatment and might be preferable in patients who continuously require an anti-coagulation or anti-platelet agent for one reason or another during treatment.     

Local thyroid tissue ablation by high-intensity focused ultrasound: Effects on thyroid function and first human feasibility study with hot and cold thyroid nodules

Objective: The aim of this study was to assess whether high-intensity focused ultrasound (HIFU), a new and promising method for the treatment of benign hot and cold thyroid nodules using thermal ablation, has an impact on thyroid function, and to evaluate its feasibility in outpatient settings. Additionally, a possible difference in the treatment of solid and complex thyroid nodules was evaluated. Method: Ten patients with one thyroid nodule each (six cold and four hot nodules) underwent HIFU in January 2014. Four nodules were solid and six nodules were complex. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobulin (hTg) and additionally antibodies against hTg (TAK), TSH receptors (TRAK) and thyroid peroxidase (TPO) were measured at enrolment and 24?h after the HIFU treatment. The pre- and post-thyroglobulin reduction was measured to evaluate the scale of ablation. In addition, patients’ pain was recorded on a numeric rating scale from 0 to 10. Results: The HIFU treatment did not affect thyroid function, since hormone levels stayed stable (p?p?p?Conclusion: HIFU is a safe and effective method to treat benign, solid, complex, hot and cold thyroid nodules preserving thyroid function. Further developments of the system are needed to gain suitability for daily use.     

Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up

Purpose The aim of this study was to evaluate the decrease of benign thyroid nodules after bipolar radiofrequency ablation (RFA) in a 3-month follow-up using a multiple overlapping shot technique (‘MOST’).

Methods A total of 18 patients with 20 symptomatic benign thyroid nodules (17 cold nodules, 3 hyperfunctioning nodules) were treated in one single session by bipolar RFA. Bipolar ablation was performed using MOST. The nodule volumes were measured prior to ablation and 3 months after the procedure using ultrasound. The population consisted of either solid (>80% solid tissue within the volume of interest), complex, or cystic nodules (<20% solid tissue within the volume of interest).

Results Bipolar RFA resulted in a highly significant (p?<?0.0001) decrease of nodule volume (ΔV), median 5.3?mL (range 0.13–43.1?mL), corresponding to a relative reduction in mean of 56?±?17.9%. Median initial volume was 8?mL (range 0.48–62?mL); 3 months after ablation a median volume of 2.3?mL (range 0.3–32?mL) was measured. Nodule growth ≥50% occurred in 70% (14 nodules). At the follow-up no complications such as infections, persisting pain, nerve injuries or immunogen stimulation occurred. Patients with cold nodules (15) remained euthyroid, with hyperfunctioning nodules either euthyroid (2) or latent hypofunctional (1).

Conclusion The use of bipolar RFA is an effective, safe and suitable thermoablative technique to treat benign thyroid nodules. Combined with the multiple overlapping shot technique it allows sufficient ablation.     

Laser ablation is more effective for spongiform than solid thyroid nodules. A 4-year retrospective follow-up study

Purpose: Laser ablation (LA) is used as therapeutic modality for reducing the volume of large benign thyroid nodules. The aim of this retrospective study was to assess the efficacy of LA therapy in patients with benign non-functioning thyroid nodules in a 4-year follow-up and evaluate whether different compactness of nodules may influence the final shrinkage.

Patients and methods: Fifty-six euthyroid patients (42 females; mean age 54.7?±?11.7 years) with benign cold thyroid solitary nodules or a dominant nodule within a multinodular goitre underwent LA between July 2009 and March 2012. Nodule volume, thyroid function test and ultrasound were monitored at baseline, and at 3, 6 and 12 months after the procedure, then annually.

Results: With a mean baseline volume of 15.7?±?11.7?mL, nodule volume decreased by 55.5% (6.5?±?5.7?mL) 4 years after LA (p?p?=?.04) and became even more significant up to 48 months (p?=?.001).

Conclusions: The LA technique succeeded in reducing thyroid nodules by about 50% at 4 years, but was more effective for spongiform than solid nodules.     

Nodule size as predictive factor of efficacy of radiofrequency ablation in treating autonomously functioning thyroid nodules

Context: No defined pre-treatment factors are able to predict the response to radiofrequency ablation (RFA) of an autonomously functioning thyroid nodule (AFTN).

Objective: Primary endpoint was to evaluate the success rate of RFA to restore euthyroidism in a cohort of adult patients with small solitary AFTN compared with medium-sized nodules. Secondary endpoints included nodule volume reduction and rate of conversion from hot nodules to cold using scintiscan.

Methods: This was a 24-month prospective monocentric open parallel-group trial. Twenty-nine patients with AFTN were divided into two groups based on thyroid volume: 15 patients with small nodules (<12?mL) in group A and 14 patients with medium nodules (>12?mL) in group B. All patients underwent a single session of RFA and were clinically, biochemically, and morphologically evaluated at baseline and at 1, 6, 12 and 24 months after treatment.

Results: After RFA, there was greater nodule volume reduction in group A compared with group B (p?p?=?0.01), 12 (p?=?0.005), and 24?months (p?p?p?Conclusions: A single session of RFA was effective in restoring euthyroidism in patients with small AFTNs. Nodule volume seems to be a significant predictive factor of the efficacy of RFA in treating AFTN.     

Factors related to recurrence of the benign non-functioning thyroid nodules after percutaneous microwave ablation

Purpose: To determine the factors affecting the recurrence of the solitary benign thyroid nodules (BTN) after microwave ablation (MWA).

Materials and methods: Between January 2013 and January 2015, a total of 110 patients with at least one solid thyroid nodule (solid component ≥?80%) were enrolled. MWA was performed under continuous ultrasound (US) guidance. Before and during the follow-up, the thyroid nodule volume, thyroid function and cosmetic complaints were evaluated. Recurrence is defined by the new blood flow in the total ablation area or/and >?50% increase in nodule volume.

Results: Almost all thyroid nodules were significantly decreased in size after MWA. After 12 months, the average volume of thyroid nodules was decreased from 12.6?±?15.1 to 3.2?±?5.7?ml. Of the total 110 patients, 16 cases had recurrence 12 months after MWA, and these patients had a larger initial volume than that of the non-recurrence patients (11.6?±?14.9 vs. 23.9?±?12.5, p?p?p?p?Conclusions: The US-guided MWA results in a satisfactory long-term outcome of the patients with a benign solitary thyroid nodule. We identified three risk factors for recurrence: initial volume, vascularity and the energy per 1?ml reduction in nodular volume.     

Radiofrequency ablation of benign thyroid nodules: depicting early sign of regrowth by calculating vital volume

Abstract

Objective: We evaluated long-term follow-up results of radiofrequency ablation of benign thyroid nodules to analyse the role of marginal vital tissue on nodule regrowth.

Materials and methods: We reviewed the medical records of 54 patients who underwent radiofrequency ablation between June 2008 and November 2013 with pressure symptoms, and/or cosmetic problems. All patients were followed up at least 12?months on three occasions. To evaluate an early sign of regrowth, three types of nodule volumes (total volume, ablated volume and vital volume) were measured and calculated using ultrasonography. Regrowth was defined as a more than a 50% increase in the total volume and vital volume increase was defined as a more than 50% increase compared to the previously reported smallest volume on ultrasonography.

Results: The mean follow-up period was 39.4?±?21.7 (range, 13–87) months. Vital volume increases occurred in 31 nodules (57.4%) and there was regrowth in 13 nodules (24.1%). The mean timing of the vital volume increase was 27.5?±?18.5?months, and for regrowth it was 39.9?±?17.5?months. Vital volume increase tended to precede regrowth.

Conclusion: Vital volume increase tended to occur earlier than regrowth and might be an early sign of regrowth in following-up after the radiofrequency ablation of benign thyroid nodules.     

Vocal cord paresis following single-session high intensity focused ablation (HIFU) treatment of benign thyroid nodules: incidence and risk factors

Abstract

Background: Vocal cord paresis (VCP) may occur following high intensity focused ultrasound (HIFU) of thyroid nodules. We hypothesised its occurrence relates to the distance of the focus point (FP) of the HIFU beams from the recurrent laryngeal nerve (RLN) and the thermal power that this point received. Their relationships were examined.

Methods: One hundred and three patients who underwent HIFU for symptomatic benign thyroid nodule from October 2015 to March 2017 were analysed. All treatment images were captured and were later watched by 2 reviewers to identify three FPs closest to the tracheoesophageal groove (TEG) on transverse sonographic view. TEG was taken as the RLN position. After identifying these FPs, their distance (mm) from the TEG, thermal power (W) used and depth from skin (mm) were recorded. These parameters were compared between those with and without VCP. VCP was defined as a cord with reduced or no movement.

Results: Four (3.9%) patients suffered from a unilateral VCP afterwards but they all recovered fully within 6?weeks. There were no significant differences in baseline characteristics and treatment efficacy between the two groups. The distance from TEG (OR?=?1.706, 95%CI?=?1.001 to 2.915, p?=?0.050) was the only significant factor for VCP. None of the other variables including thermal power were significant.

Conclusions: The incidence of VCP was 3.9% (4/103) and they completely recovered within 6?weeks. The distance between the FP and the TEG was the only related factor for VCP. The safe distance between FP and TEG should be ≥1.1?cm.     

Percutaneous microwave ablation of thyroid nodules: effects on thyroid function and antibodies

Abstract

Purpose: Microwave ablation (MWA) is a new minimally invasive method for thermal ablation of benign thyroid nodules with promising results. The aim of this study was to investigate whether MWA has an impact on thyroid function. Materials and methods: Thirty patients with a total of 34 benign thyroid nodules underwent MWA between January 2013 and July 2014. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobuline (Tg) and additionally antibodies against Tg (anti-Tg), thyrotropin receptors (TRAb) and thyroid peroxidase (anti-TPO) were measured at enrolment, 24?h after MWA, as well as at the 3-month and 6-month follow-up. Moreover, the nodule volume was evaluated to determine effectiveness. Results: Serum TSH, T4, T3 and Tg levels did not change significantly at the 3-month or 6-month follow-up (p?>?0.05); thyroid function was not affected by MWA. Antibody levels did not change significantly either; however, two patients developed antibodies after treatment. A volume reduction of 51.4% or 7.85?mL could be demonstrated after 3 months and a reduction of 55.8% or 14.0?mL after 6 months. Slight complications such as mild pain during the ablation or superficial haematomas emerged. The development of Graves’ disease and mild Horner’s syndrome were observed as more severe side effects. Conclusions: The data suggest MWA as an alternative for the treatment of benign thyroid nodules. While first results for preservation of thyroid function are positive, further measurements of laboratory data and especially antibodies are necessary.     

A comparison of laser with radiofrequency ablation for the treatment of benign thyroid nodules: a propensity score matching analysis

Abstract

Purpose: To compare technique efficacy and safety of laser ablation (LA) and radiofrequency ablation (RFA) in treatment of benign thyroid nodules.

Materials and methods: Institutional review board approval was obtained, and patients’ consent was waived. 601 nodules were treated from May 2009 to December 2014 at eight centres, 449 (309 females, age 57?±?14?years) with LA and 152 (107 females, age 57?±?14?years) with RFA. A matched cohort composed of 138 patients from each group was selected after adjustment with propensity score matching. Factors influencing volume reduction at 6 and 12?months and complications were evaluated.

Results: No significant differences were observed in the baseline characteristics between groups after propensity score matching adjustment. Mean nodule reduction at 6 and 12?months was ?67?±?19% vs. ?57?±?21% (p?<?0.001)???70?±?19% vs. ?62?±?22% (p =?0.001) in LA group and in RFA group, respectively. Nodules with volume?>30?mL had significantly higher percentage volume reduction at 6 and 12?months (?69?±?19 vs. ?50?±?21, p?=?0.001) and (?73?±?18 vs. ?54?±?23 8, p?=?0.001) in the LA group than in the RFA group, respectively. In both groups, operator’s skills affected the results. Major complications occurred in 4 cases in each group (p?=?0.116)

Conclusions: LA and RFA showed nearly similar outcome but LA was slightly more effective than RFA in large nodules. Operator’s skills could be crucial in determining the extent of nodule volume reduction regardless of the used technique.     

Benign thyroid nodules treatment using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA)

Purpose: To evaluate the reduction over time of benign thyroid nodules treated using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA) by the same equipe.

Materials and methods: Ninety patients (age 55.6?±?14.1 years) underwent ablation for benign thyroid nodule causing compression/aesthetic dissatisfaction from 2011. Fifty-nine (age 55.8?±?14.1 years) underwent RFA and 31 (age 55.2?±?14.2 years) PLA, ultrasound guided. Technical success, complications, duration of ablation and treatment, energy deployed, volumetric percentage reduction at 1, 6 and 12 months were derived. A regression model for longitudinal measurements was used with random intercept and random slope. Values are expressed as mean?±?standard deviation or N (%).

Results: Technical success was always obtained. No major complications occurred. Mean ablation time was 30.1?±?13.8 vs. 13.9?±?5.9?min (p?Conclusions: RFA and PLA are similarly feasible, safe and effective in treating benign thyroid nodules when performed by the same equipe. RFA is faster than PLA but require significantly higher energy.     

Ultrasound-guided percutaneous microwave ablation versus surgery for papillary thyroid microcarcinoma

Background: Papillary thyroid microcarcinoma (PTMC) has high incidence and low disease-specific mortality. However, active surveillance is not accepted by most patients owing to high physical or psychological pressures. The emergence of ablation technologies is supplanting traditional surgery. Our goal was to compare the clinical outcomes of microwave ablation (MWA) and surgery for T1aN0M0 PTMC.

Methods: A total of 92 consecutive patients with T1aN0M0 PTMC were studied retrospectively. Forty-six patients had been treated with MWA, and the other 46 had undergone surgery. MWA was performed using extensive ablation extending from the nodule’s lower pole to the upper pole. Surgery was performed by total thyroidectomy or thyroid lobectomy. We compared the two groups in terms of mean length of stay, cost, mean blood loss, surgical incision, operating room (OR) time, quality of life (QOL) assessment, complications, and therapeutic efficacy over a follow-up period of 42 months.

Results: The mean length of stay, cost, mean blood loss, surgical incisions, OR time, and complications in the MWA group were significantly lower than those of the surgery group. The QOL after MWA was higher than it was after surgery. The nodule volume decreased significantly from 53.61?±?48.43?mm³ to 4.84?±?6.55?mm³ (p?Conclusions: MWA may be considered a minimally invasive alternative to surgery for solitary T1aN0M0 PTMC with low incidence of complications and good therapeutic effect.     

Microwave ablation compared to thyroidectomy to treat benign thyroid nodules

Objective: Benign thyroid nodules occur commonly but only require treatment when symptomatic. Surgical treatment, once routine, has been replaced by newer technologies, such as microwave ablation (MWA). The aim of this study was to assess the efficacy, tolerability and cost of MWA compared to surgery to treat benign thyroid nodules.

Methods: After obtaining ethical approval and informed consent, a prospective trial was conducted with 52 patients who had symptomatic benign thyroid nodules. Patients were randomly assigned to receive MWA or surgical treatment. The volume reduction ratio (VRR), thyroid function, complications, HRQoL, costs and some parameters were compared.

Results: MWA reduced mean nodule volume by 72.3% at 3 months, 84.5% at 6 months and 92.4% at 12 months as effective as surgery in inactivating nodules, and thyroid dysfunction did not occur during 12-month follow-up for those receiving MWA. Although both MWA and surgery were safe, patients undergoing MWA had fewer cases of complications and rarely reported pain. The MWA group was superior to the surgery group in length of stay, postoperative scar length and the operation time. Compared to patients who underwent surgery, those who underwent MWA had better general health and mental health scores at 6 months and 12 months. The mean total cost of the MWA group was lower than that of the surgery group.

Conclusion: MWA can significantly reduce nodule volume and nodule-related symptoms with more rapid recovery, more pleasing esthetic outcomes, less physiologic disruption and less expense compared to the surgery.     

High-intensity focused ultrasound in the treatment of breast fibroadenomata (HIFU-F trial)

Background: High-intensity focussed ultrasound (HIFU) is a non-invasive ablative technique utilising the application of high frequency ultrasound (US) pressure waves to cause tissue necrosis. This emerging technology is currently limited by prolonged treatment times. The aim of the HIFU-F trial was to perform circumferential HIFU treatment as a means of shortening treatment times.

Methods: A prospective trial was set up to treat 50 consecutive patients ≥18?years of age. Eligible patients possessed symptomatic fibroadenomata, visible on US. Patients ≥25?years of age required histological confirmation of the diagnosis. Primary outcome measures were reduction in treatment time, reduction in volume on US after 12?months and complication rates.

Results: HIFU treatment was performed in 51 patients (53 treatments) with a mean age of 29.8?years (SD 7.2?years) and a diameter of 2.6?cm (SD 1.4?cm). Circumferential ablation reduced treatment times by an estimated 19.9?min (SD 25.1?min), which is a 29.4% (SD 15.2%) reduction compared with whole lesion ablation. Volume reduction of 43.2% (SD 35.4%; p?t-test) was observed on US at 12?months post-treatment. Local complications completely resolved at 1 month apart from skin hyper-pigmentation, which persisted in nine cases at three months, six cases at 6 months and six at 12?months.

Conclusion: Circumferential HIFU treatment for breast fibroadenomata is feasible to reduce both lesion size and treatment time. HIFU is a non-invasive alternative technique for the treatment of breast fibroadenomata.

ISRCTN registration: 76622747     

Safety of radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: a systematic review and meta-analysis

Abstract

Objective: We performed a systematic review and meta-analysis to evaluate the safety of radiofrequency ablation (RFA) for the treatment of benign thyroid nodules and recurrent thyroid cancers.

Materials and methods: Ovid-MEDLINE, EMBASE, and Library of Cochrane databases were searched up to 12 July 2016 for studies on the safety of RFA for treating benign thyroid nodules or recurrent thyroid cancers. Pooled proportions of overall and major complications were assessed using random-effects modelling. Heterogeneity among studies was determined using the χ² statistic for the pooled estimates and the inconsistency index I².

Results: A total of 24 eligible studies were included, giving a sample size of 2421 patients and 2786 thyroid nodules. 41 major complications and 48 minor complications of RFA were reported, giving a pooled proportion of 2.38% for overall RFA complications [95% confidence interval (CI): 1.42%–3.34%] and 1.35% for major RFA complications (95% CI: 0.89%–1.81%). There were no heterogeneities in either overall or major complications (I²?=?1.24%–21.79%). On subgroup analysis, the overall and major complication rates were significantly higher for malignant thyroid nodules than for benign thyroid nodules (p?=?0.0011 and 0.0038, respectively).

Conclusions: RFA was found to be safe for the treatment of benign thyroid nodules and recurrent thyroid cancers.     

Microwave ablation induces a lower systemic stress response in patients than open surgery for treatment of benign thyroid nodules

Objective: In this study, we compared the systemic stress response induced by microwave ablation with that induced by conventional open surgery for treatment of benign thyroid nodules.

Methods: A total of 108 patients with benign thyroid nodules were randomly assigned to receive ultrasound-guided thyroid microwave ablation (microwave group, n?=?57) and conventional open thyroid surgery (open group, n?=?51). Body temperature, white blood cell (WBC) counts, visual analogue scale (VAS) scores for pain, and serum levels of high sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6) and cortisol were measured at 24?h before operation and at 8?h, 24?h and 48?h after operation.

Results: No significant between-group differences were observed with respect to preoperative body temperature, VAS scores, WBC counts, serum hs-CRP, IL-6 and cortisol levels. Patients in the open group exhibited higher body temperature at 24?h after operation and higher WBC counts at both 24?h and 48?h after operation, as compared to those in the microwave group. As compared with microwave ablation, open surgery was associated with significantly higher VAS scores, and significantly higher serum levels of hs-CRP, IL-6 and cortisol at all postoperative time-points (8?h, 24?h and 48?h).

Conclusion: Microwave ablation induces a lower systemic stress response than open surgery for treatment of benign thyroid nodules.     

High intensity focused ultrasound in the treatment of breast fibroadenomata: results of the HIFU-F trial

Objectives: Breast fibroadenomata (FAD) are the most common breast lumps in women. High intensity focused ultrasound (HIFU) is a non-invasive ablative technique that can be used to treat FAD but is associated with prolonged treatment times. In the HIFU-F trial, we evaluated the change in volume over time with circumferential HIFU treatment of FAD and compared this to no treatment.

Methods: Patients ≥18 years, diagnosed with symptomatic, palpable FAD, visible on ultrasound (US) were recruited. Twenty patients were treated using US-guided HIFU under local anaesthesia. Another 20 participants underwent an US 6 months after diagnosis. Outcome measures included: reduction in treatment time compared to whole lesion ablation; feasibility to achieve a 50% reduction in volume after 6 months; decrease in volume compared to a control group and reduction in symptoms.

Results: Circumferential ablation reduced the mean treatment time by 37.5% (SD 20.1%) compared to whole lesion ablation. US demonstrated a significant mean reduction in FAD volume of 43.5% (SD 38.8%; p?=?0.016, paired t-test) in the HIFU group compared to 4.6% (SD 46.0%; p?=?0.530) in the control group after 6 months. This mean reduction in FAD volume between the two groups was significant in favour of the HIFU group (p?=?0.002, grouped t-test). Pre-treatment pain completely resolved in 6 out of 8 patients 6 months post-treatment.

Conclusion: Circumferential HIFU ablation of FAD is feasible, with a significant reduction in pain and volume compared to control participants. It provides a simple, non-invasive, outpatient-based alternative to surgical excision for FAD.     

Sonographic measurement of thyroid nodule changes after microwave ablation: relationship between multiple parameters

Objective: Microwave ablation (MWA) is an effective technique for the treatment of benign thyroid nodules. The aim of this study was to investigate whether it is necessary to study changes in variables other than the volume reduction between follow-up intervals. This study also introduced the index R (S_surface/V) to explore whether it could reflect features of shape between follow-up intervals.

Materials and methods: A total of 236 complex benign thyroid nodules in 230 patients who underwent MWA in our department from October 2013 to February 2017 were included. The D_max, volume (V), volume reduction ratio (VRR) and index R (S_surface/V) parameters were evaluated before treatment and postoperatively at 1, 3, 6 and >12?months. Multiple comparisons of these parameters were performed between the baseline and each follow-up period for the entire patient group and subgroups based on diameter and volume.

Results: All of the thyroid nodules underwent a significant decrease in size after MWA. The mean decrease in the volume of the thyroid nodules was from 17.40?±?22.52?mL to 1.31?±?2.71?mL, with a mean percent decrease of 0.90?±?0.15% after 12?months. Index R increased over time from 2.55?±?1.08 to 8.10?±?5.01, which increased the effectiveness of shape parameterisation between the follow-up periods after the three-month time point, regardless of the initial volume size. For the nodules with a baseline D_max?≤?3.4?cm, the V, VRR and index R demonstrated similar capabilities in the evaluation of efficiency before the six-month follow-up visit.

Conclusions: Long-term follow-up emphasises changes in the shape and spatial structure of complex benign thyroid nodules, rather than size variations, after effective MWA. Index R, which is the surface area to volume ratio, can also reflect the shape change to some degree.