Ultrasound-guided Ethanol Ablation Research Articles

Effect of Ultrasound-Guided Ethanol Ablation in Management of Benign Cystic Thyroid Nodules

Effect of Ultrasound-Guided Ethanol Ablation in Management of Benign Cystic Thyroid Nodules

Endoscopic ultrasound-guided ethanol ablation versus surgical resection of insulinomas.

Insulinoma is a rare tumor of the pancreas that can lead to hypoglycemia. To date, the standard therapy is surgical resection. After the first case report of successful endoscopic ultrasound-guided (EUS) ethanol injection 16 years ago, the need for establishing an alternative treatment method remains unchanged given the high morbidity rates of surgery and its unsuitability in some patients. Here, we provide retrospective data from 33 insulinoma patients that were treated at our center between 2010 and 2021. Of these, 9 patients were treated with EUS-guided ethanol injection and 24 underwent pancreatic surgery. The ethanol group was older (ethanol: mean ± SE 67.8±11.2 years vs. surgery: 52.3±15.7, p=0.014) with a higher Charlson Comorbidity Index (3.0 (1.0;4.0) vs. 1.0 (0.0;2.0), p=0.008). The lowest glucose values were similar between groups before (ethanol: 2.09±0.17 mmol/l vs. surgery: 1.81±0.08, p=0.158) and after (4.95±0.74 vs. 5.41±0.28, p=0.581) the respective treatments. Complications occurred more frequently in the surgery group (11 % vs. 54 %, p=0.026). One patient after prior partial pancreatectomy died postoperatively. The hospitalization time was significantly shorter in the ethanol group (4.78±0.78 days vs. 19.88±4.07, p<0.001). EUS-guided ethanol injection can be similarly effective for the treatment of hyperinsulinemic hypoglycemia compared with pancreatic surgery but seems to be associated with less severe complications. This implies the need for prospective randomized trials in insulinoma patients with a low risk for malignancy.

Ultrasound-guided ethanol ablation versus the Sistrunk operation as a primary treatment for thyroglossal duct cysts.

This study compared ethanol ablation (EA) with the Sistrunk operation (SO) with regard to feasibility, treatment efficacy, and cost-effectiveness. The goal was to evaluate whether EA could replace SO as a primary treatment modality for thyroglossal duct cysts (TGDCs). This retrospective case-control study included patients with TGDCs who were treated with either EA or SO between 2016 and 2022. The primary outcome variables evaluated were treatment efficacy (as measured by the volume reduction rate [VRR] and treatment success rate), complications, and cost-effectiveness. A total of 72 patients were enrolled, with 33 in the EA group and 39 in the SO group. The procedure or operation times for the EA and SO groups were 9 and 82 minutes, respectively (P<0.001). At the final follow-up appointment, the VRR was 94.1% for the EA group and 100.0% for the SO group (P<0.001). Treatment success was achieved for 32 patients (97.0%) in the EA group and for all 39 patients (100.0%) in the SO group (P=0.458). The overall complication rates were 0.0% and 17.9% in the EA and SO groups, respectively (P=0.013). The total costs, including all treatment procedures and follow-up ultrasound examinations, were $485 and $1,081.7 for the EA and SO groups, respectively (P<0.001). EA demonstrates superiority over SO in terms of feasibility, safety, and costeffectiveness, while maintaining comparable treatment efficacy. Despite the need for multiple treatment sessions in approximately one-quarter of patients, EA can serve as a primary treatment modality for selected patients with TGDCs, supplanting SO.

Ultrasound-Guided Ethanol Percutaneous Ablation Versus Rescue Surgery in Patients With Locoregional Recurrence of Papillary Thyroid Cancer.

Neck recurrence of papillary thyroid cancer (PTC) is frequently detected after initial surgery. The management of these lesions may include rescue surgery (RS) or minimally invasive techniques in selected patients, but comparative studies evaluating the effectiveness and safety of these techniques are lacking. In this paper, we compared ultrasound-guided ethanol ablation (EA) in selected patients to RS in a matched cohort. We retrospectively compared 41 patients and 41 matched PTC patients without known distant metastases, who underwent ultrasound-guided EA or RS (matched reference group), who had 63 and 75 thyroid bed and/or lymph node confirmed PTC recurrences during a median follow-up of 72.8 and 89.6 months, respectively. The primary outcome was time until structural recurrence, compared using Kaplan-Meier survival curves. The secondary outcomes included time until biochemical recurrence, plasma thyroglobulin (Tg) levels, American Thyroid Association (ATA) response-to-therapy categories by the last available observation, and treatment-derived complications in each group. No significant differences were found between the EA and RS groups for time until structural recurrence (log-rank test, P=0.94). The time until biochemical recurrence was also similar (P=0.51); and the plasma Tg concentration reduction and proportions of patients in the ATA reclassification categories were also similar. A significantly higher proportion of patients in the RS group presented treatment-derived complications (29.27% vs. 9.75%, P<0.05). In this retrospective analysis, the treatment of PTC neck recurrence with EA in selected patients was comparable to RS in a matched reference group for the long-term risk of structural or biochemical relapse, but with a lower risk of treatment-derived complications. These. support the effectiveness and safety of this minimally invasive technique in the management of selected patients with recurrent PTC.

Ultrasound-Guided Ethanol Ablation for Thyroglossal Duct Cyst: A Review of Technical Issues and Potential as a New Standard Treatment.

The thyroglossal duct cyst (TGDC) is the most common congenital neck mass, accounting for 70-75% of all congenital neck masses. Although the Sistrunk operation has been used as a standard of treatment, it is accompanied by a considerable surgical burden, including the need for general anesthesia, a visible surgical scar on the neck surface, and postoperative complications. Ultrasound-guided ethanol ablation (US-EA) is a minimally invasive and office-based technique that is widely used as a non-surgical treatment for several benign cystic lesions, particularly benign thyroid cysts. Recently, US-EA has also been gaining popularity as a good alternative for TGDC treatment, which is associated with high feasibility, a high safety profile, and favorable treatment outcomes. To our best knowledge, seven studies on the use of EA as a primary treatment option for TGDC have been published since 2011. Although these studies have reported promising results, there is a lack of consensus on several issues regarding the application of EA for TGDC, particularly its detailed techniques and role as a primary treatment. This article aims to provide a comprehensive review of EA for TGDC, addressing technical issues and its possible role as a new standard of treatment for TGDC.

Hypercalcaemia and delusions of blood poisoning: a parathyroid adenoma refractory to ultrasound-guided ethanol ablation

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Efficacy and predictive factors of endoscopic ultrasound-guided ethanol ablation in benign solid pancreatic tumors

Backgrounds and ObjectivesEndoscopic ultrasound-guided ethanol ablation (EUS-EA) has recently been introduced for the management of solid pancreatic tumors, including pancreatic neuroendocrine tumors (PNETs) and solid pseudopapillary tumors (SPTs). The study aims to evaluate the efficacy and predictive factors for response of EUS-EA in solid pancreatic tumors.MethodsBetween October 2015 and July 2021, 72 patients who underwent EUS-EA for solid pancreatic tumors were included. The study outcomes were to evaluate the efficacy of EUS-EA with complete remission (CR) and objective response, and their predictive factors.ResultsDuring follow-up, 47 patients were diagnosed with PNETs and 25 with SPTs. Eight cases reached CR and 48 reached objective response. When compared with SPTs, PNETs showed similar duration to reach CR (median not reached; p = 0.319), but shorter duration to reach objective response (PNETs: median 20.6 months, 95%CI 10.26–30.88; SPTs: median 47.7 months, 95%CI 18.14–77.20; p = 0.018). Ethanol dosage > 0.35 ml/cm3 shortened the duration to reach CR (median not reached; p = 0.026) and objective response (median 42.5 months, 95%CI 25.34–59.66 vs. 19.6 months, 95%CI 10.17–29.09; p = 0.006). CR had no significant predictive factors, but PNETs showed significant predictive factors for objective response (HR 3.34, 95%CI 1.07–10.43; p = 0.038). Twenty-seven patients experienced adverse events, and there were two severe cases.ConclusionEUS-EA for pancreatic solid lesions seems feasible as a local treatment for patients who refuse or are unfit for surgery. Additionally, PNETs seem to be the better candidate for EUS-EA.

Development and validation of a nomogram model for predicting residue of partially cystic thyroid nodules after ultrasound-guided ethanol and thermal ablation.

To develop and validate a nomogram model for predicting residue of partially cystic thyroid nodules (PCTNs) after ethanol and thermal ablation. From July 2015 to August 2022, a total of 97 patients (age 40.78 ± 12.61 years) with 107 treated benign PCTNs receiving ethanol and thermal ablation were enrolled. Pre-ablative laboratory test results and the ultrasound (US) and contrast-enhanced ultrasound (CEUS) features of lesions were collected. They were categorized into non-residue group and residue group according to the CEUS examination assessment after ablation. Univariate and multivariate logistic regression analysis were adopted to build a nomogram. The nomogram was validated by internal stratified fivefold cross-validation. The calibration, discrimination and clinical utility of the nomogram were investigated to assess the performance of the model. Residue was reported in 30 out of 107nodules (28.0%). Multivariate logistic regression analysis revealed initial volume (OR=1.12, 95%CI 1.06-1.19) and presence of septum (OR=3.19, 95%CI 1.09-9.36) were predictors of residue of PCTNs. The nomogram developed by the above factors showed good calibration and discrimination. The area under the curve (AUC), sensitivity and specificity of this model were 0.832, 86.7% and 68.8%, respectively. When applied to internal validation, the model revealed good generalizability with stratified fivefold cross-validation in the cohort (mean AUC = 0.821). The nomogram model has good performance for predicting the residue of PCTNs undergoing ethanol and thermal ablation. This could play a role in the decision of treatment and follow-up in clinical practice.

Ultrasound-Guided Ethanol Ablation as a Primary Treatment for Thyroglossal Duct Cyst: Feasibility, Characteristics, and Outcomes.

To evaluate the feasibility, characteristics, and outcomes of ultrasound-guided ethanol ablation (US-EA) as a primary treatment for thyroglossal duct cysts (TGDCs). Prospective case series. Single center study. The inclusion criteria were as follows: (i) patients with TGDC aged ≥18 years, (ii) benign TGDC in imaging and cytological examinations, and (iii) patients' needfor nonsurgical scarless treatment. US-EA was used as the primary treatment strategy. The primary outcome variables were the volume reduction rate (VRR) and cosmetic score at the last follow-up. We enrolled 28 patients with TGDC. The median TGDC volume at baseline was 6.7 mL. The median procedure time of the US-EA was 6.5 minutes. The median volumes of the cyst aspirate and injected ethanol were 4.0 and 2.0 mL, respectively. Overall, 18, 8, and 2 patients underwent 1, 2, and 3 treatment sessions, respectively. There were no complications. The median VRR was 96.2%, and the treatment success rate was 96.4%. The World Health Organization cosmetic score decreased from 4 (baseline) to 1 (after treatment) in all patients. The subjective grade for cosmetic satisfaction was satisfactory or highly satisfactory in all patients. The VRR, treatment success rate, and the number of treatment sessions did not differ as functions of the characteristics of the TGDC, including the initial volume, septation, debris, or viscosity of the cyst fluid. US-EA was feasible, safe, and effective in patients with TGDC. Therefore, US-EA can be used as a primary treatment for TGDC, evading general anesthesia and surgical scar.

Safety and efficacy of ethanol ablation for benign thyroid cystic nodules: A single centre experience

Objective To evaluate and audit the safety and efficacy of ultrasound guided ethanol ablation for the treatment of benign thyroid cystic nodules with pressure and cosmetic symptoms. Methods Retrospective case series from November 2018 to March 2021, presented with symptomatic benign cystic thyroid nodules and treated with ethanol ablation. The major clinical outcomes were 6-month volume reduction rate and improvement in pressure symptom scores and cosmetic symptom score. All complications were evaluated. Results We studied thirty-seven consecutive cases with symptomatic benign thyroid cystic nodules. All cystic nodules were confirmed by FNAC to be benign. Seven out of thirty-seven cases received two sessions of ethanol ablation. The initial mean volume of cystic nodules was 17.93ml (range 1.11ml- 60.01ml). The mean volume of ethanol injected was 3.54ml (range 0.5ml-10.0ml). The mean volume at 6-month post ablation was 4.48ml (range 0ml- 60.15ml). The mean volume reduction rate at 6-month post ablation was 80.46%. The median procedure time was 15 minutes. Adverse events were noted in three cases including transient pain and haematoma. The mean pressure symptom score improved from 4.48 (pre-ablation)(range 0-10) to 1.20 (post-ablation)(range 0-5). The mean cosmetic symptomscores improved from 3.45 (pre-ablation) (range 1-4) to 1.37 (post-ablation)(range 1-3). There was one case with salvage hemithyroidectomy arranged. Conclusion Ultrasound guided ethanol ablation is a safe and feasible treatment for symptomatic benign thyroid cystic nodules in terms of volume reduction and symptomatic relief, it serves as an alternative to surgical resection.

Endoscopic Ethanol Ablation as Definitive Therapy for Suspected Insulinoma

Introduction: Hypoglycemia is defined as plasma glucose <70mg/dL, with autonomic and/or neuroglycopenic symptoms often occurring at levels less than 55mg/dL. Diagnostic workup of hypoglycemia unrelated to use of hypoglycemic agents is crucial as it is linked to increased mortality. After ruling out common culprits such as drugs (insulin, sulfonylureas), ethanol and malnutrition, further testing should be pursued for patients who meet the Whipple’s Triad: symptoms of hypoglycemia, documented low plasma glucose and relief of symptoms upon raising plasma glucose. We present the case of an 85-year old male with a suspected insulinoma who underwent endoscopic alcohol ablation as definitive therapy.Case: An 85-year-old male with a history of metastatic prostate cancer was found to have recurrent episodes of asymptomatic hypoglycemia with fasting plasma glucose levels as low as 50-60s during an unrelated inpatient admission. He had no history of diabetes mellitus or insulin use. On further investigation, he was noted to have recurrent falls, though these symptoms could not be temporally linked to documented hypoglycemia as the patient was not monitoring blood sugars at home. Further workup revealed fasting plasma glucose of 58mg/dL and negative sulfonylurea screen. Plasma C-peptide and fasting plasma insulin levels during an episode of hypoglycemia were elevated at 6.42ng/mL and 38uIU/mL respectively. IGF-II and insulin autoantibody testing was negative. Abdominal imaging revealed a 1.3cm hypervascular pancreatic head lesion consistent with a neuroendocrine tumor, concerning for an insulinoma in view of his lab findings. Surgical removal of this lesion was not within the patient’s goals of care. Attempts at medical management included escalating doses of prednisone and subcutaneous octreotide; however, he continued to have hypoglycemic episodes despite therapy. His cardiac history precluded the use of other medical therapies. After careful evaluation, he underwent ultrasound-guided ethanol ablation of his neuroendocrine tumor as potential definitive therapy, with successful resolution of hypoglycemic episodes noted during his post-procedural hospital stay.Discussion: Traditionally, insulinomas are primarily managed surgically. Poor surgical candidates can benefit from medical management including diazoxide, somatostatin analogs and verapamil among others. Ultrasound-guided ethanol ablation is a newer modality aimed achieving cure in selected patients, thus avoiding need for surgery. Our case highlights the challenges in management of insulinomas, especially in complicated patients like ours who are not surgical candidates and who may be resistant to medical therapy. Though there are not many studies on the long-term efficacy and outcomes with ethanol ablation of insulinomas, it appears to be a promising option and certainly deserves further study.

Re: Technical issues in ultrasound-guided ethanol ablation for thyroid lesions

Re: Technical issues in ultrasound-guided ethanol ablation for thyroid lesions

Endoscopic ultrasound-guided ethanol and radiofrequency ablation of pancreatic insulinomas: a systematic literature review.

Background:Insulinoma is the most common neuroendocrine neoplasm of the pancreas, characterised by hypoglycaemic symptoms. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) and ethanol ablation (EUS-EA) are novel methods for treating insulinoma.We aimed to perform a systematic review to assess the efficacy and safety of EUS-guided ablation techniques for pancreatic insulinomas.Methods:We systematically searched for articles detailing EUS-guided ablations of insulinomas. We performed a qualitative analysis and summarised data on the efficacy and safety of EUS-RFA and EUS-EA techniques.Results:In total, we identified 35 case reports and case series describing 75 patients with insulinomas treatment with EUS-guided ablation. Twenty-seven patients were treated with EUS-RFA, 47 patients with EUS-EA, and 1 patient received EUS-EA and EUS-RFA in the same session. In total, 84 insulinomas were ablated (EUS-RFA: 31, EUS-EA: 53). Most insulinomas were in the head of the pancreas (40%). The clinical success rate for EUS-guided ablation techniques was 98.5%. The median glucose level was 1.95 (Q1-Q3: 1.69–2.13) mmol/L before ablation compared to 6.20 (Q1-Q3: 5.30–7.05) mmol/L after treatment. The median insulin and C-peptide levels before and after RFA/EA were 230 (Q1–Q2: 120–257) pmol/L and 41 (Q1–Q2 35–42) pmol/L; 2077 (Q1–Q2 1644–2459) pmol/L and 819 (Q1–Q2 696–1072) pmol/L, respectively. There were eleven adverse events: seven abdominal pain, two mild acute pancreatitis, one necrotising acute pancreatitis and one local hematoma. All patients recovered, and there were no periprocedural deaths.Conclusions:EUS-guided ablation of insulinoma seems to be a safe and effective treatment and is an alternative to surgical resection in selected cases.

Ultrasound-guided ethanol ablation for cystic thyroid nodules: effectiveness of small amounts of ethanol in a single session

PurposeThe aim of this study was to evaluate the efficacy of ethanol ablation (EA) in the treatment of cystic thyroid nodules using low-dose ethanol regardless of the initial volume of the nodule or properties of the aspirate.MethodsSixty-one nodules in 60 patients were treated with EA from October 2013 to January 2020. In each patient, EA was performed only once, using less than 5 mL of ethanol (99.5%) instilled and removed completely after a few minutes of retention. Nodule volume, the symptom score, the cosmetic score, and complications were evaluated before and after treatment. The therapeutic success rate (TSR) and volume reduction rate (VRR) according to nodule volume and properties of the aspirate were evaluated. Therapeutic success was defined as the absence of any residual fluid or sufficient volume reduction (≥50%) with improvement of nodule-related symptoms.ResultsThe 61 nodules comprised 38 pure cysts and 23 predominantly cystic nodules. The initial nodule volume was 21.9±15.2 mL (range, 4.4 to 77.2 mL). The TSR was 88.5% (100% in pure cysts and 69.6% in predominantly cystic nodules, P<0.001). The TSR of pure cysts was 100% regardless of nodule volume and properties of the aspirate. In predominantly cystic nodules, the TSR and VRR gradually decreased as volume increased. One patient experienced arrhythmia during the procedure, but completely recovered without sequelae.ConclusionSingle-session EA using low-dose ethanol might be effective for the treatment of symptomatic cystic thyroid nodules regardless of the initial cyst volume and properties of the aspirate, especially in pure cysts.

Follow-up case report of an endoscopic ultrasound-guided ethanol ablation: An alternative option for the treatment of pancreatic insulinoma

Follow-up case report of an endoscopic ultrasound-guided ethanol ablation: An alternative option for the treatment of pancreatic insulinoma

Endoscopic ultrasound-guided ethanol ablation for the management of a symptomatic pancreatic insulinoma.

pancreatic insulinoma is a sporadic, usually benign, frequently solitary tumor that is smaller than 20 mm. When it is functioning, patients present with symptoms of hypoglycemia secondary to insulin hypersecretion. The diagnosis is clinical, with biochemical and radiological confirmation. Surgery is the management of choice, although endoscopic ultrasound-guided ablation is currently being developed. we present a prospective case series of pancreatic insulinoma patients with symptoms of severe hypoglycemia, who were treated with endoscopic ultrasound-guided ethanol ablation as an alternative to surgical management. technical and clinical success was achieved in all cases and there were no complications associated with the procedure. the treatment of symptomatic insulinoma by endoscopic ultrasound-guided ethanol ablation could be a safe and effective alternative to surgical management in non-surgical patients or those who refuse surgery.

Ultrasound-guided ethanol injection for the treatment of parathyroid adenoma: A prospective self-controlled study.

Background:Parathyroidectomy, the standard treatment of primary hyperparathyroidism (PHP) due to parathyroid adenoma, is not suitable for all patients. We evaluated the efficacy of ultrasound-guided ethanol ablation of parathyroid adenoma in a group of patients with PHP.Materials and Methods:In a prospective self-controlled trial, 39 patients with parathyroid adenoma, who were not candidates for surgery, were enrolled. Ethanol injections were performed by two experienced interventional radiologists under the guidance of real-time ultrasonography. Adenoma size changes were assessed at about 1 month later. Serum levels of parathyroid hormone, calcium, phosphate, 25-OH Vitamin D, and alkaline phosphatase were evaluated at the baseline, 1, 3, 6, and 12 months after the injections. The treatment effects on outcome variables were assessed by repeated measures analysis.Results:Volume of the adenomas decreased during the study period from 1.87±6.45 cm3 to 0.38± 0.48cm3 (P < 0.001). Corrected serum calcium levels decreased from 10.40 ± 0.96 mg/dl to 8.82 ± 0.58 mg/dl (P < 0.001), and remained stable during one year follow-up. Serum levels of parathyroid hormone decreased gradually from 129.85 ± 63.37 to 72.58 ± 53.86 pg/mL after 3 months and to 44.78 ± 28.04 pg/mL after 1 year (P < 0.001). Overall, 46% of the patients improved after 1 month of ethanol ablation therapy which increased to 84.5% during 1-year follow-up. No major complications were observed.Conclusion:The current study showed the efficacy of ultrasound-guided ethanol injection in PHP and may be considered as a suitable alternative treatment in patients who are not candidates for the surgery. It has also a good safety profile without major complications if performed by experienced hands.

Safety of endoscopic ultrasound-guided ethanol ablation for pancreatic cystic lesions: A single-center experience of 214 patients

Endoscopic ultrasound-guided ethanol ablation (EUS-EA) for pancreatic cystic lesions (PCLs) has been used in recent years as a feasible treatment modality for low malignant probability PCLs or patients considered high-risk for surgery. The present study aimed to confirm the safety of EUS-EA and to find predictive factors for adverse event (AE). A retrospective review was performed from the prospectively maintained database of patients who underwent EUS-EA for PCLs from June 2006 to April 2018 at Seoul National University Hospital. The primary outcomes of the study were the rates of AEs and severe AEs by EUS-EA. The secondary outcome was the predictive factors of AEs including acute pancreatitis and abdominal pain. A total of 214 patients were evaluated and the diagnoses of PCLs according to cystic fluid analysis and clinical features were as follows: serous cystic neoplasm (32.2%), mucinous cystic neoplasm (26.6%), branch duct type intraductal papillary mucinous neoplasm (BD-IPMN) (29.4%), and pseudocyst (11.7%). Three patients (1.4%) experienced severe AEs. Overall, AEs occurred in 71 (33.2%) patients. BD-IPMN (OR: 2.87; 95% CI: 1.05-7.84; P = 0.040), multilocular cysts (OR: 3.59; 95% CI: 1.09-11.85; P = 0.036), suspected ethanol leakage during procedure (OR: 10.68; 95% CI: 1.98-57.53; P = 0.006), and sticky cystic fluid (OR: 3.83; 95% CI: 1.20-12.24; P = 0.024) were predictive factors for post-procedural acute pancreatitis. PCLs of uncinate process (OR: 2.99; 95% CI: 1.22-7.35; P = 0.017) and PCLs with exophytic portion (OR: 3.70; 95% CI: 1.96-7.01; P<0.001) were predictive factors for post-procedural abdominal pain. EUS-EA is a safe procedure with a very low rate of severe AEs. It seems possible to predict the AEs according to the features of the procedure and PCLs.

Malignant conversion and peritoneal dissemination after endoscopic ultrasound-guided ethanol ablation in intraductal papillary mucinous neoplasm of the pancreas.

With the increasing detection of pancreatic cysts, many centers have applied endoscopic ultrasound-guided pancreatic cyst ablation (EUS-PCA), even in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas based on early promising outcomes. However, long-term effects of ethanol ablation have been rarely reported, especially regarding oncologic outcomes. We report eight cases of malignancy conversion after EUS-PCA in patients with IPMNs who had worrisome features. Moreover, two patients showed tumor spillage or peritoneal seeding (carcinomatosis) after EUS-PCA. Endoscopic ultrasound-guided pancreatic cyst ablation must not be performed as a treatment for IPMNs, considering adverse results such as tumor spillage and the lack of oncological therapeutic effect.

MON-553 Nerve Injury after Ethanol Ablation of Thyroid Cancer Metastases to the Neck

Background Thyroid cancer often recurs in the neck. Well-differentiated thyroid cancer metastasizes to the neck in about 40%, and recurs after surgery in about 20%-30%. Surgery is the treatment of choice, with biochemical remission in 21-66%, but some patients are poor surgical candidates or refuse surgery, and permanent nerve injury and hypoparathyroidism are substantial complications. The 2018 National Comprehensive Cancer Network (NCCN) guidelines state that in select patients with unresectable, non-radioiodine-avid, and progressive disease, local therapies such as ultrasound guided ethanol ablation (EA) can be considered. Recent systematic reviews have confirmed the efficacy and safety of EA, and show that this minimally invasive therapy compares favorably to surgical resection in non-randomized studies. Objectives To determine the rate, type, and outcomes of nerve injury after EA for neck metastases from thyroid cancer. Methods IRB approval was obtained. Retrospective review of medical records of all EA performed from March 2004 through August 2018. Data collected included sex, age, histologic type of thyroid cancer, date of all EA sessions, and number of tumor sites injected per EA session. Nerve injury was defined as a neurologic deficit with immediate onset after ethanol injection that lasted beyond the effect of local anesthetic. Diagnosis was made based on symptoms and functional deficit as described during follow up phone calls or visits. Confirmatory laryngoscopy was not performed. Results During the 14 year period 104 patients received EA; 64 females with mean age 60 (range 23-90) and 40 males with mean age 54 (range 24-85). A total of 298 sites were treated (lymph nodes and local extra-nodal recurrence) in 169 ethanol injection sessions (mean 1.8, range 1-7). Histologic diagnosis was papillary in 89.4% (classic 87, follicular variant 4, tall cell variant 2), medullary 6 (5.8%), and follicular 4.8% (follicular 1, Hurthle cell variant 4). Recurrent laryngeal nerve (RLN) deficit occurred in 2, superior laryngeal nerve (SLN) deficit in 1 and sympathetic deficit in 1. Nerve injury occurred in 4/104 patients (3.8%), 4/169 EA sessions (2.4%), and 4/298 EA sites (1.3%). All EA with nerve injury were in level VI, including a very deep injection associated with the sympathetic chain injury. The dysphonia from two RLN injuries recovered fully at 1 week and at 3 months. One SLN injury had no hoarseness but could not project a loud voice while singing with his church choir and recovered in 1 month. The one patient with ptosis recovered almost completely, did not notice any residual problems, but physical examination demonstrated a subtle difference in palpebral elevation 1 year after EA. Conclusion Nerve injuries after EA are infrequent and most resolve completely within 3 months.