Vascular and interventional radiology radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: literature review

<italic>In vitro</italic> heat insulation efficacy of 5% dextrose versus 0.9% saline during radiofrequency ablation

PURPOSE

This study compared the efficacy of heat insulation between 5% dextrose and 0.9% saline in radiofrequency ablation (RFA). Accordingly, temperature variations and maximum temperatures were assessed at identical distances and heat field distributions.

METHODS

Cubes of porcine liver tissue, measuring 10 mm across, were selected to precisely align the ablation boundary with the tissue boundary. An 18-gauge electrode with a 7-mm tip was inserted into each cube (10 per group) in a stainless-steel cup containing 40 mL of 5% dextrose or 0.9% saline. Fixed ablation was performed for 3 minutes using continuous mode at 30 W, simulating the typical thermal environment during thyroid RFA. Real-time temperature measurements were recorded by sensors positioned 0, 1, 3, and 5 mm from the cube's edge. A comparative analysis was conducted to assess the maximum temperature, temperature variation, and duration of temperatures exceeding 42℃.

RESULTS

In both groups, the temperature curve declined with increasing distance from the edge of the ablated tissue. However, 0.9% saline exhibited higher maximum temperatures at 1, 3, and 5 mm compared to 5% dextrose (1 mm: 44.55°C±5.25°C vs. 34.68°C±3.07°C; 3 mm: 39.64°C±2.53°C vs. 29.22°C±2.21°C; 5 mm: 38.86°C±2.14°C vs. 28.74°C±2.51°C; all P<0.001). Considering a nerve injury threshold of 42°C, the 0.9% saline also displayed a greater proportion of samples reaching this temperature and a longer duration of temperatures exceeding it (P<0.05).

CONCLUSION

The heat insulation efficacy of 5% dextrose at 1-5 mm exceeds that of 0.9% saline at identical distances and in a common thermal environment during thyroid RFA.

Brazilian Consensus on the Application of Thermal Ablation for Treatment of Thyroid Nodules: A Task Force Statement by the Brazilian Society of Interventional Radiology and Endovascular Surgery (SOBRICE), Brazilian Society of Head and Neck Surgery (SBCCP), and Brazilian Society of Endocrinology and Metabolism (SBEM)

There is increasing interest in ultrasound-guided ablation treatments for thyroid diseases, including benign and malignant ones. Surgeons, radiologists, and endocrinologists carry out these treatments, and various organizations within these specialties have recently released multiple international consensus statements and clinical practice standards. The aim of the present consensus statement is to provide guidance, cohesion, and standardization of best practices for thermal ablation procedures of thyroid nodules. The statement includes the indications for these procedures, preprocedural evaluations, technical aspects of the procedures, posttreatment care, follow-up, complications, and training recommendations. This document was written by a panel of specialists from the Brazilian Society of Interventional Radiology and Endovascular Surgery (SOBRICE), the Brazilian Society of Head and Neck Surgery (SBCCP), and the Brazilian Society of Endocrinology and Metabolism (SBEM). The statement does not aim to provide criteria for assessing the capability of specialists to perform the procedure. Instead, it aims to promote the standardization of best practices to reduce potential adverse outcomes. Additionally, it strives to enhance the delivery of high-quality care and the widespread adoption of these technologies on a national level. The recommendations collectively serve as a guidebook for applying best practices in thyroid ablation.

Quality appraisal of clinical practice guidelines for the use of radiofrequency ablation in the treatment of thyroid nodules and cancer

INTRODUCTION

Radiofrequency ablation (RFA) has gained significant recent global interest in the treatment of benign thyroid nodules and thyroid cancer. It is a relatively new, minimally invasive, thermal ablation technique that is an alternative to surgery. Several clinical practice guidelines (CPGs), consensus statements, and recommendations currently exist for the use of RFA in the treatment of benign thyroid nodules and thyroid cancers. These documents have considerable variability amongst them, and to date, their quality and methodologic rigor have not been appraised.

OBJECTIVE

To identify and perform a quality appraisal of clinical practice guidelines for RFA in the treatment of benign thyroid nodules and thyroid cancer using the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool.

METHODS

A comprehensive literature search was performed in MEDLINE (via PubMed), EMBASE, and SCOPUS databases from inception to November 1, 2021. Four reviewers independently evaluated each guideline using the AGREE II instrument. Scaled domain scores were generated and the threshold used for satisfactory quality was >60%. Additionally, intraclass correlation coefficients (ICCs) were calculated to determine level of agreement between reviewers.

RESULTS

Seven guidelines were selected for final evaluation based on inclusion/exclusion criteria. Two guidelines were classified "high" quality, one "average" quality, and the rest "low" quality. The "Clarity and Presentation" (65.68 ± 26.1) and "Editorial Independence" (61.32 ± 25.8) domains received the highest mean scores, while the "Applicability" (32.14 ± 22.8) and "Rigor of Development" (45.02 ± 29.8) domains received the lowest mean scores. ICC statistical analysis showed high magnitude of agreement between reviewers with a range of (0.722-0.944).

CONCLUSION

Reflecting upon our quality appraisal, it is evident that the quality and methodologic rigor of RFA guidelines can be improved upon in the future. Our findings also elucidate the existing variability/discrepancies amongst guidelines in the indications and use of RFA.

Efficacy on radiofrequency ablation according to the types of benign thyroid nodules

Percutaneous radiofrequency ablation (RFA) has been recommended as minimally invasive treatment for patients with symptomatic benign thyroid nodules (BTNs) because of the large number of clinical applications. This retrospective observational study sought to evaluate the clinical outcomes of RFA for BTNs. From 2014 to 2019, a sample size of 1289 patients treated by RFA were 262 ones with solid nodules and 1027 ones with cystic-solid nodule, respectively. The efficacy including the nodule maximal diameter reduction ratio (MDRR), the volume reduction ratio (VRR) and the cosmetic scores reduction ratio (CSRR). The results of the nodule MDRR and VRR in the cystic-solid nodule group were significantly better than those in the solid nodule group at the 3rd and 6th month, and the CSRR in the two groups showed statistically significant difference at the 3rd month. In a word, RFA is an effective method for symptomatic benign solid or cystic-solid nodules. The achieved MDRR and VRR in the cystic-solid nodule group were significantly better than those in the solid nodule group at the 3rd and 6th month.

Elastography for the differential diagnosis of malignant versus benign testicular lesions: a meta-analysis

PURPOSE

The aim of this study was to evaluate the value of elastography in the differential diagnosis of benign versus malignant testicular lesions.

METHODS

The PubMed, Cochrane Library, and Embase databases were searched for relevant studies. The diagnostic accuracy of elastography was evaluated using pooled sensitivity, specificity, likelihood ratio, post-test probability, diagnostic odds ratio, and by summarizing the area under the hierarchical summary receiver operating characteristic (HSROC) curve.

RESULTS

Seven studies with 568 lesions were included. The pooled sensitivity and specificity were 87% (95% confidence interval [CI], 81% to 92%) and 81% (95% CI, 65% to 90%), respectively. The pooled estimates of the positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 4.48 (95% CI, 2.37 to 8.47), 0.16 (95% CI, 0.10 to 0.25), and 28.11 (95% CI, 11.39 to 69.36), respectively. The area under the HSROC curve was 90% (95% CI, 88% to 93%).

CONCLUSION

Elastography is useful for assessing the stiffness of testicular lesions and for differentiating benign from malignant lesions. Elastography can be an effective supplement to conventional ultrasonography.

Efficacy and safety of radiofrequency ablation in the treatment of low-risk papillary thyroid carcinoma: a review

Ultrasound-guided radiofrequency ablation (RFA) has recently been used for the treatment of thyroid carcinomas. In this study, we aimed to evaluate the efficacy and safety of RFA for treating low-risk papillary thyroid carcinomas (PTCs). We searched the MEDLINE and the SCOPUS databases up to December 29, 2020, for studies assessing the efficacy and safety of RFA in the management of low-risk PTCs. Data on volume reduction ratio (VRR), complete disappearance, carcinoma recurrence, and complication frequency were collected. Thirteen studies with a total of 1389 patients and 1422 tumors were included in the synthesis of this study. Mean VRR varied between 47.8 and 100%, with most studies reporting a ratio of 98.5-100%. The ratio of complete disappearance ranged between 33.7 and 100%, although studies with a prolonged follow-up period reported a frequency of 56-100%. The tumor progression/recurrence frequency was 0-4.5%. Complications occurred in 45 patients (3.2%). Mild-moderate pain and cervical discomfort were the most common complications and no life-threatening complications were reported. Based on these data, we suggest that ultrasound-guided RFA can serve as an efficacious and safe alternative for the treatment of low-risk PTC in patients who are unable or unwilling to receive surgical therapy.

Comparison of ultrasound guided percutaneous radiofrequency ablation and open thyroidectomy in the treatment of low-risk papillary thyroid microcarcinoma: A propensity score matching study

PURPOSE

The aim of this study was to evaluate the efficacy, safety and costs of ultrasound guided percutaneous radiofrequency ablation (RFA) versus open thyroidectomy for treating low-risk papillary thyroid microcarcinoma (PTMC) by using propensity score matching (PSM).

PATIENTS AND METHODS

157 patients who underwent RFA and 206 patients who underwent surgery for low-risk PTMC were included in the study. The patients were followed up at 1, 3, 6, 12 months after treatment, and every half year thereafter. A 1:1 PSM method was applied to balance the pretreatment data of the two groups. In the matched group (133 patients for each), the operative time, length of hospital stay, hospitalization expenses, cosmetic results, complications were assessed and compared between two groups.

RESULTS

At last follow-up, 39 tumors (29.3%) in the RFA group completely disappeared. Between the well-matched groups, no local recurrence, lymph node metastasis or distant metastases were detected in either group during the follow-up period. After matching, the operation time and hospitalization time in RFA group were shorter than those in surgery group (both P <  0.05). The average hospitalization expense of the patients in RFA group was cheaper than that in surgery group (P <  0.05). Moreover, the cosmetic score was found to be higher in RFA group than that observed in surgery group (P <  0.05).

CONCLUSIONS

RFA may be an effective and safe method for treating low-risk PTMC with a superior advantage of being low-cost and having a shorter operation time and hospital stay versus surgery.

The texture analysis as a predictive method in the assessment of the cytological specimen of CT-guided FNAC of the lung cancer

The lung cancer is the principle cause of the worldwide deaths and its prognosis is poor with a 5-year overall survival rate. Computed tomography (CT) gives many information about the prognosis, but the problem is the subject interpretation of the findings. Thanks to the computer-aided diagnosis/detection (CAD), it is possible to reduce the second opinion. "Radiomics" is an extension of CAD and overlaps the quantitative imaging data of the CT texture analysis (CTTA) with the clinical information, increasing the power and precision of the decision going through the personalized medicine. The aim of this study is to describe the role of the radiomics in the characterization of the pulmonary nodule. For this study, we retrospectively analyzed the images of the 87 NSCLC patients with a waiver of informed consent from the Institutional Review Board (IRB) at the Campania University "Luigi Vanvitelli" of Naples. All tumors were semiautomatically segmented by a radiologist with 10 years of experience using three diameters (AW Server 3.2). The examinations were acquired using 128 MDCT (GSI CT, GE) with a peak tube voltage of 120 kVp, tube current of 100 or 200 mA, and rotation times of 0.5 or 0.8 s. To confirm the imaging results, the FNAC was performed and for every nodule the following parameters were extracted: the presence of the solid component (named = 1), papillary component (named = 2), and mixed component (named = 3). Feature calculation was performed using the HealthMyne software and Integrated Platform That Enables Better Patient Management Decisions For Oncology. The radiologist uses the Rapid Precise Metrics (RPM)™ functionality to identify a lesion with the algorithm and these methods are put to work. The correlation between each feature and the tumor volume was calculated using a two-step cluster statistical analysis. In this retrospective study, in one year from 2018 to 2019 20 patients with lung adenocarcinoma confirmed with FNAC were enrolled. The pathologic results were subdivided into three categories: the solid architecture (group 1), papillary architecture (group 2), and mixed architecture (group 3). Nine lesions resulted with component 1, seven patients with component 2, and 3 patients with component 3. Eight females and 12 males with a median age 61 and 15 years (mean ± SD = 67.4 ± 9.7 years, range 39-73 years) were enrolled. The two results suggest, with p < 0.05, that the GGO variable is a good discriminating estimator of the kurtosis variable: GGO = "no" implies a high kurtosis value, while GGO = "yes" implies a low value. The numerous data obtained from the automatic analysis allow to have a fertile ground on which to develop a new concept of medicine which is precision medicine. The limit of this study is the poor sample. In the future, in order to have a more mature and consolidated discipline, it is necessary to increase the large scale of observations with further studies to establish the rigorous evaluation criteria. In order for radiomics to mature as a discipline in the future, it will be necessary to develop studies that consolidate its role to standardize the collected data.

Preliminary results in unresectable cholangiocarcinoma treated by CT percutaneous irreversible electroporation: feasibility, safety and efficacy

Cholangiocarcinoma (CC) accounts for about 3% of the gastrointestinal and 10-25% of all hepatobiliary malignancies. It arises from the epithelium of the bile duct and it can be classified in intrahaepatic (ICC), perihilar (PCC) and distal (DCC) cholangiocarcinoma, depending on the anatomical location. About 50-60% of the cases are PCC. Early detection is very difficult for the lack of symptoms, and most of the patients are not resectable at the time of diagnosis. IRE is a non-thermal ablation technique that determines cellular apoptosis by electrical impulses without involving extracellular matrix like MW or RF ablation (MWA and RFA). The aim of our study is to demonstrate the safety, feasibility and efficacy of this procedure in the treatment of cholangiocarcinoma according to our experience. From 2015 to 2019, fifteen patients with unre-sectable perhilar and intrahepatic colangiocarcinoma (7 female and 8 male, mean age 69.2) were referred to our department to be enrolled in our prospective study that was approved by local Ethical Committee. Eight lesions were defined iCC and seven of them pCC. Six patients had biliary STENT and four external percutaneous transhepatic biliary drainage (PTBD). The IRE procedure was performed to expert radiologist (G.B.) under CT guidance using the Nanoknife IRE device (Angiodynamics, Queensbury, NY). The data before and after treatment were compared using Wilcoxon Rank Test and the survival outcome was evaluated using Kaplan Meyer Test. All procedures performed under CT guidance have been successfully completed. Treated lesions were located seven perhilar and eight intrahepatic sites and showed a mean volume 66.3 (SD 70.9; IC ranged from 5.57 to 267.20 cm³). No major complications were observed. From 30 to 90 days, the mortality rate was around 0%. Progression of the disease in all cases were not observed. Only one patient was reported increase of the Ca19-9 without sign of pancreatitis and bile obstruction. The imaging follow-up showed the local disease control with a decrease of the entire volume of the lesion and a further reduction of the densitometric values. From the comparison between the mean volumes for each group (before and after treatment), the Wilcoxon Rank test demonstrated the statistical significant difference with a p value < 0.01. On the contrary, it is believed that this results encouraging in considering the IRE procedure the safe, feasible and effective method in the treatment of the CC.

Delayed enhancement in differential diagnosis of salivary gland neoplasm

Background

Multi-phasic Computed Tomography (CT) evaluation allows to study the enhancement features of parotid gland masses. The aim of our study was to evaluate the role of delayed enhancement in the characterization of different histologic types of parotid tumours.

Methods

Forty-eight patients (22 male and 26 female) with at least one parotid gland tumor, were included in our study. Multi-phase CT images were obtained before and 30, 120 s and 8 minutes after intravenous contrast injection. The images were evaluated by two radiologists for lesion enhancement degree. A quantitative assessment was performed using a region of interest on each lesion and density changes between different phases were compared. The tumoral enhancement ratio was calculated between the 8 minutes delayed and the early (30 s) phase. The pathological diagnosis was confirmed in all patients after surgery.

Results

All patients had unilateral lesion for a total of 48 lesions. Twenty-eight were pleomorphic adenomas, 15 Warthin's tumours and 5 carcinomas. All Warthin tumours showed a rapid contrast enhancement at the early phase (30 sec) followed by a progressive wash-out during the delayed scans. Most of pleomorphic adenomas (89.2%) showed the highest density at the 8-minutes delayed phase. Malignant tumours showed slower contrast enhancement and 3 out of 5 (60%) showed a marked decrease at the 8 minutes delayed phase while the remaining 2 (40%), did not show any density reduction. The tumoral enhancement ratio was significantly different between Warthin tumours and pleomorphic adenomas and between Warthin's and malignant tumours.

Conclusions

Multi-phasic CT examination with 8 minutes delayed acquisition has shown to be useful in parotid gland lesion differentiation.

Ultrasound imaging classifications of thyroid nodules for malignancy risk stratification and clinical management: state of the art

Assessing the risk of malignancy in the thyroid with ultrasound (US) is crucial in patients with nodules, as it can aid in selecting those who should have a fine-needle aspiration (FNA) biopsy performed. Many studies have examined whether the US characteristics of thyroid nodules are useful indicators of histological malignancy. Overall, these investigations have identified a few US features that are significantly more frequent in malignant thyroid nodules which can be coalesced into a defining set to be used as an indicator of a higher risk of malignancy. Despite these efforts, none of these classifications have been widely adopted worldwide, and there are still conflicting recommendations from different institutions. Understanding the role and appropriate utilization of these systems could facilitate the effective interpretation and communication of thyroid US findings among referring physicians and radiologists. In this comprehensive review, we outline the major US classification systems of thyroid nodules published in the last few years.

Does multiparametric US improve diagnostic accuracy in the characterization of small testicular masses?

Background

Recent advances in ultrasonography (US) have produced new innovative techniques for the non-invasive assessment of testicular masses. The aim of this study was to investigate the diagnostic performance of multiparametric US, including gray-scale, Color-power Doppler and real-time elastography (RTE) analysis, in the characterization of testicular lesions.

Methods

Fifty-four patients (median 42.2 years; range, 10-64 years) with testicular lesions detected with gray-scale US and power Doppler US were evaluated with RTE. The tissue elasticity was assessed in all lesions. Hard lesions were suspected of being malignant while testicular lesions with normal or decreased tissue stiffness (soft lesions) were considered benign. Intraoperative findings were the standard of reference. Sensitivity, specificity, negative predictive value, positive predictive value, and diagnostic accuracy were calculated for each US method and in combination.

Results

Forty-six of the 54 lesions (85.2%) were testicular malignant tumors. Thirty-five out of 46 (76%) were ≥2 cm [seminomas (n=18), mixed seminomatous and/or nonseminomatous tumors (n=9), embryonal carcinomas (n=2), immature teratomas (n=3) and Leydig cell tumors (n=3)] while the remaining 11 tumors were <2 cm [seminomas (n=5), mixed germinal cells tumors (n=2), immature teratomas (n=2) and Leydig cell tumors (n=2)]. Eight out of 54 lesions (14.8%) were benign lesions (orchitis n=2, dermoid cyst n=1, adrenal rest n=1, papillary cystadenoma n=1, sclero-hyaline nodule n=1, focal fibrosis n=1 and post-traumatic focal fibrosis n=1). RTE showed the presence of hard pattern in 40 out of 46 (87%) malignant tumors and in 2 out of 8 (25%) of benign lesions. The combination of gray-scale US, Color-power Doppler and RTE aided a sensitivity of 100%, a specificity of 83%, a negative predictive value of 100%, a positive predictive value of 91% and accuracy of 90%.

Conclusions

RTE demonstrated to increase the diagnostic accuracy of conventional US in the characterization of testicular lesions providing additional information on tissue stiffness. The multiparametric US evaluation has proven to increase the diagnostic performance in the characterization of testicular lesions.

Comparative study on operative trauma between microwave ablation and surgical treatment for papillary thyroid microcarcinoma

AIM

To compare the effect and postoperative trauma of ultrasound-guided percutaneous microwave ablation and surgical resection in the treatment of papillary thyroid microcarcinoma (PTMC).

METHODS

Eighty-seven patients with PTMC treated at Fudan University affiliated Shanghai Fifth People’s Hospital were enrolled as subjects. The patients were divided into a microwave ablation group (41 cases) and a surgical group (46 cases). The operative time, intraoperative blood loss, length of hospital stay, serum C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), thyroid-related hormonal changes, and complications 7 d and 30 d after surgery were observed.

RESULTS

The operative time, intraoperative blood loss, and length of hospital stay in the surgical group were significantly higher than those in the microwave ablation group (P < 0.05). The levels of CRP, IL-6, and TNF-α in the surgical group were significantly higher than those in the microwave ablation group (P < 0.05). The free triiodothyronine (FT3) and free thyroxin (FT4) levels in the surgical group were significantly lower than those in the microwave ablation group (P < 0.05). However, the postoperative thyroid stimulating hormone (TSH) level was significantly higher than that in the microwave ablation group (P < 0.05). There were significant interactions between the FT3, FT4, and TSH 7 d and 30 d after operation and the treatment methods (P < 0.05). There was no significant difference in the complications between the two groups (P > 0.05).

CONCLUSION

Microwave ablation for papillary microcarcinoma of the thyroid gland has less trauma to the body, quicker recovery, and no scars. It can effectively shorten the length of hospital stay and improve the quality of life of patients.

Cooled tip radiofrequency ablation of benign thyroid nodules: preliminary experience with two different devices

Background

Thyroid nodules are very common in general population. Even if benign, they may require a treatment in case of symptoms or cosmetic concerns. In the last years, minimally invasive treatments alternative to surgery have been developed, in particular ultrasound (US) guided radiofrequency ablation (RFA).

Methods

Twenty-four patients (9 males; 15 females; mean age 57.9 years) were treated and divided in two groups (A and B) according to the RFA needle used (18 gauge needle, AMICA; 17 gauge needle, COVIDIEN). Nodules and patients characteristics, together with procedural data were registered pre-treatment and at 1-month follow-up. US visibility of the needle, volume of the nodules, symptoms and cosmetic concerns, complications were registered.

Results

Visibility of the needle was not significantly different in the two groups (P=0.0787). At 1 month the mean volume of the nodules dropped from 37.1 to 25 mL in group A and from 23.2 to 15.4 mL in group B; shrinkage rate (36.9% and 39.5%, respectively) was not significantly different (P=0.3137). Symptoms decreased from 3.1 to 1.4 in group A and from 4 to 1.6 in group B: no significant differences in reductions were observed (P=0.3305). Cosmetic score decreased from 3.7 to 3.4 in group A and from 3.9 to 3.6 in group B: no significant differences in reductions were observed (P=0.96). Total complication rate (18.2% in group A vs. 23.1% in group B) did not showed significant differences (P=0.5049).

Conclusions

The two systems used in our study resulted equivalent in terms of US needle visibility, efficacy, symptom/cosmetic relief, safety. More patients and a longer follow-up are necessary to confirm our results.

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 < .001) at the 42-month follow-up, exhibiting a percentage volume reduction of 81.33 ± 36.87%. No recurrence or metastasis occurred in either group during the follow-up period.

CONCLUSIONS

MWA may be considered a minimally invasive alternative to surgery for solitary T1aN0M0 PTMC with low incidence of complications and good therapeutic effect.

Interventional radiology of the thyroid gland: critical review and state of the art

Thyroid nodules are a common incidental finding during a routinely ultrasound (US) exam unrelated to the thyroid gland in the healthy adult population with a prevalence of 20-76%. As treated before with surgery, in the last years new minimally invasive techniques have been developed as an alternative to surgery. The aim of this review, based on newly revised guidelines, is to provide some information regarding the basic principles, indications, materials, techniques, and results of mini-invasive procedures or treatments for thyroid nodules. We performed a narrative review including both newest and representative papers and guidelines based on the different procedures of ablation techniques developed in the last years for the diagnosis and the treatment of thyroid nodules. All examined papers referred very good results in term of volume nodule reduction, improvement in related symptoms and cosmetic problems, with a very low rate of complications and side effects for all the minimally invasive technique analyzed. Obviously, some differents between technique based on different kind of thyroid nodules and different indication were found. In conclusion, many thyroid nodules nowadays could be treated thanks to the advent of new mini-invasive technique that are less expensive and present a lower risk of major complications and side effects compared to surgery.

Statement and Recommendations on Interventional Ultrasound as a Thyroid Diagnostic and Treatment Procedure

The recently published guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on interventional ultrasound (INVUS)-guided procedures summarize the intended interdisciplinary and multiprofessional approach. Herewith, we report on recommendations for interventional procedures for diagnosis and treatment of the thyroid gland.

Pathological processes and therapeutic advances in radioiodide refractory thyroid cancer

While in most patients with non-medullary thyroid cancer (TC), disease remission is achieved by thyroidectomy and ablation of tumor remnants by radioactive iodide (RAI), a substantial subgroup of patients with metastatic disease present tumor lesions that have acquired RAI resistance as a result of dedifferentiation. Although oncogenic mutations in BRAF, TERT promoter and TP53 are associated with an increased propensity for induction of dedifferentiation, the role of genetic and epigenetic aberrations and their effects on important intracellular signaling pathways is not yet fully elucidated. Also immune, metabolic, stemness and microRNA pathways have emerged as important determinants of TC dedifferentiation and RAI resistance. These signaling pathways have major clinical implications since their targeting could inhibit TC progression and could enable redifferentiation to restore RAI sensitivity. In this review, we discuss the current insights into the pathological processes conferring dedifferentiation and RAI resistance in TC and elaborate on novel advances in diagnostics and therapy to improve the clinical outcome of RAI-refractory TC patients.

Minimally invasive local ablative therapies in combination with radioiodine therapy in benign thyroid disease: preparation, feasibility and efficiency - preliminary results

PURPOSE

Initial studies of combinations of radioiodine therapy (RIT) and local ablative procedures for the treatment of thyroid nodules have shown promising results. The goal of this study was to evaluate the effectiveness of RIT combined with radiofrequency ablation (RFA) in patients with goitres and to determine which ablative procedure is the most suitable for a combined therapy.

METHODS

Thirty patients with goitres were divided into two subgroups. A test group of 15 patients received combined therapy (RIT + RFA) and a control group of 15 patients received RIT mono therapy. All patients underwent assessments including ultrasound, laboratory evaluation (T3, T4, TSH, TG, TPOAb, TgAbTRAb) and scintigraphic imaging with Tc-99m-Pertechnetate. The 3-month volume reduction was used to evaluate therapy effectiveness.

RESULTS

Combined therapy (subgroup 1) resulted in a significant (p < 0.05) thyroid volume reduction (22.3 ± 54 ml/32.2 ± 58.2%) with better performance (p > 0.05) than the control group (20.2 ± 32.2 ml/29.6 ± 42.1%). All patients became euthyroid after treatment. No major discomfort or complications occurred. A review of the literature investigating combinations of other local ablative procedures with RIT was performed to determine the most promising combination.

CONCLUSIONS

The present study confirms the positive experiences with the combined therapy of RIT and local ablative procedures shown in the current literature and approves this approach for the treatment of goitres with RFA + RIT. These findings, when confirmed by further studies, should expand the indication of combined therapy as a minimally invasive alternative to surgery.

A rare case of persistent hypoglossal artery associated with contralateral proximal subclavian stenosis

The persistent hypoglossal artery is rare vascular anomalies. We report the case of a 50-year old man with right hypoglossal artery, ipsilateral hypoplasic internal carotid artery, associated with left proximal subclavian stenosis with subclavian steal syndrome. Power-Doppler-Ultra-Sonography spectral images obtained after the patient exercised the left arm showed mid-systolic deceleration with retrograde late-systolic velocities. A Computed Tomography Angiography demonstrated a proximal stenosis of the left SA, a mild right ICA hypoplasia and an anomalous artery arising from right ICA at C2-C3 level, entering the cranium via the hypoglossal canal and joining the basilar artery. Usually the presence of PHA may be completely asymptomatic, and detected as an incidental finding by CTA or MRA, but in our case its diagnosis is extremely important because it is often the only vessel supplying blood to the basilar trunk and posterior circulation.

Ultrasound-navigated radiofrequency ablation of thyroid nodules with integrated electromagnetic tracking: comparison with conventional ultrasound guidance in gelatin models

PURPOSE

A thyroid-like gelatin model was used to determine potential superiority of a new navigation system for ultrasound (US)-guided electrode insertion called EchoTrack, featuring a US probe with an integrated electromagnetic field generator, in comparison with conventional US when performing radiofrequency ablation.

METHODS

In order to compare 20 navigated ablations with 20 ablations under conventional US guidance, a thyroid-like gelatin model was used. In each group, 10 in-plane and 10 out-of-plane punctures were performed. Metal seeds measuring 8.5 [Formula: see text] 1.8 mm served as ablation targets. The number of redirections until final electrode placement, targeting accuracy and electrode placement time were measured.

RESULTS

The number of redirections could be significantly ([Formula: see text]) reduced from 2.7 ± 1.3 in the conventional group to 0.2 ± 0.5 in the EchoTrack group. Accuracy increased from 3.9 ± 4.7 to 2.0 ± 1.9 mm. The total placement time increased from 39 ± 20.5 to 79.2 ± 26 s.

CONCLUSIONS

EchoTrack is able to reduce the redirections needed to place the electrode in comparison with conventional US and provides high placement accuracy. Our new navigation system has high potential to reduce the risk of harming critical structures and to improve guidance during ablation of difficult nodules, as treatment planning as well as the safety of out-of-plane punctures are improved.

Microwave ablation for thyroid nodules: a new string to the bow for percutaneous treatments?

BACKGROUND

Thyroid nodules are a fairly common finding in general population and, even if most of them are benign, a treatment can be however necessary. In the last years, non surgical minimally invasive techniques have been developed to treat this pathology, starting from percutaneous ethanol injection (PEI), to laser ablation (LA), radiofrequency ablation (RFA) and, most recently, microwave ablation (MWA).

METHODS

We reviewed all medical literature searching in pubmed.gov the terms "microwave" & "thyroid". We found three original studies concerning MWA treatment, for a total of 263 patients (mean age 51.0 years; range, 15-80 years; male to female ratio 2.55) and 522 nodules.

RESULTS

A total of 522 nodules (338 solid, 22 cystic, 162 mixed) in 263 patients were treated. Studies have shown a mean reduction in volume of thyroid nodules ranging from 45.9% to 65%. No study reported a significant and definitive change in laboratory parameters, except for one case (Heck et al.). No studies have reported major complications after procedure.

CONCLUSIONS

MWA is a new, promising technique among the minimally invasive treatments of thyroid nodules. Actually, the larger diameter of MW antenna seems to be the major limiting factor in the use of this technique. More studies are necessary to evaluate feasibility, safety and efficacy of the procedure.

Laser Thermal Ablation of Thyroid Benign Nodules

Thermal ablation therapies for benign thyroid nodules have been introduced in recent years to avoid the complications of traditional methods such as surgery. Despite the little complications and the reportedly acceptable efficacy of thermal ablation methods, quite few medical centers have sought the potential benefits of employing them. This paper provides an introduction to the literature, principles and advances of Percutaneous Laser Ablation therapy of thyroid benign nodules, as well as a discussion on its efficacy, complications and future. Several clinical research papers evaluating the thermal effect of laser on the alleviation of thyroid nodules have been reviewed to illuminate the important points. The results of this research can help researchers to advance the approach and medical centers to decide on investing in these novel therapies.

Surgical management of pleomorphic adenoma of parotid gland in elderly patients: role of morphological features

The neoplasms of the salivary glands account for 2% of head and neck tumors and the most common form is the Pleomorphic adenoma (PA). Parotid gland is affected from 80% to 90% of cases. In elderly these tumors occur mostly in females. These benign tumors are composed of epithelial and myoepithelial cells that are arranged with various morphological patterns and subtypes. The classification of these tumors is also based on the amount and nature of the stroma. In literature there is an almost complete consensus that, in the major salivary glands, PAs are enclosed by a layer of fibrous tissue often called "capsule" but there is disagreement about the form, extension and thickness of this layer. The treatment is surgical and there are two main different surgical approaches: an enucleation (local dissection) or so-called subtotal superficial parotidectomy and lateral or superficial total parotidectomy. Histopathological characteristics of PAs especially of capsular alterations such as thin capsule areas, capsule-free regions, capsule penetration, satellite nodules and pseudopodia in the different subtypes are important for the choice of surgical treatment and the first explanation for tumor recurrence. In our study we describe a morphological features of 84 cases of pleomorphic adenoma of parotid gland from elderly patients treated by a surgical "enucleation like" method called nucleoresection.