Value of radiofrequency ablation for treating locally recurrent thyroid cancer: a systematic review and meta-analysis for 2-year follow-up.

PURPOSE: To evaluate the safety and efficacy of radiofrequency ablation (RFA) in treating locoregional recurrent thyroid cancer (LRTC) after a 2-year follow-up time. METHODS: PubMed, Embase and Cochrane Library were searched from inception until 20 September 2022 to find studies reporting the safety and efficacy of RFA in LRTC patients after a 2-year follow-up. Two radiologists performed the data extraction and methodological quality assessment according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: We analyzed 6 studies, 229 LRTC patients with 319 locally recurrent tumors were treated with RFA. The mean follow-up time of each study was ≥24 months. The pooled changes in the largest diameter and volume were 7.22 mm (95% confidence interval (CI), 6.35-8.09 mm) and 164.28 mm3 (95% CI, 87.78-240.77 mm3), respectively; the pooled volume reduction rate was 95.03% (95% CI, 87.56-102.49%). The total complete disappearance rate after treatment was 92% (95% CI, 83-100%). The pooled decrease of serum thyroglobulin levels was 0.02 ng/ml (95% CI, -0.00-0.04 ng/ml). The pooled proportion of recurrence rate was 6% (95% CI, 0-13%). The pooled complication rate was 5% (95% CI, 0-10%). The major complications were voice change and hoarseness, only one patient developed permanent vocal cord paralysis; minor complications were cough and pain. CONCLUSIONS: Ultrasound-guided RFA is an effective and safe treatment for LRTC based on 2-year follow-up results.

Current guidelines for the application of radiofrequency ablation for thyroid nodules: a narrative review.

Background and Objective: Thyroid nodules are frequently incidentally found on physical exam or imaging for an unrelated work-up. Although surgery remains the gold standard for treating symptomatic benign and/or malignant thyroid nodules, radiofrequency ablation (RFA) has emerged as a minimally invasive treatment option for high risk patients and those who decline surgery. The novel application of RFA to treat thyroid disease was originally described for symptomatic, benign thyroid nodules. Since then, several studies have tried to expand its indication to treat primary and recurrent well-differentiated thyroid cancer. The high success rates and the low complication profile, has allowed for quick adoption of RFA as a treatment option for well-selected patients with benign thyroid nodules and locoregional recurrent thyroid malignancy. As such, multidisciplinary guidelines and consensus statements were developed to standardize indications, techniques, outcome measures, and follow-up to ensure the best patient care. This article summarizes the current indications and recommendations to help guide clinicians on how best to effectively and safely utilize RFA to treat thyroid disease. Methods: A PubMed/MEDLINE search between 2000-2022 using a combination of "radiofrequency ablation", "RFA", "thyroid nodule", and "guidelines" was conducted. The inclusion criteria were articles published in English which offered recommendations on RFA use for thyroid nodules. Key Content and Findings: For symptomatic, benign thyroid nodules, RFA is effective at significantly reducing nodule volume. For large nodules, multiple RFA sessions may be needed to achieve clinically significant volume reduction. Patients undergoing RFA for autonomously functioning thyroid nodules may see symptomatic relief but success rates are variable. RFA may serve a curative or palliative role in recurrent well-differentiated thyroid cancers. There is little data describing the use of RFA for primary well-differentiated thyroid cancer >1 cm and the role of RFA for thyroid microcarcinomas remains controversial. Conclusions: RFA is a safe minimally invasive technique and may be considered, in appropriate circumstances, a first-line treatment option for benign thyroid nodules. Practices adopting RFA will likely increase as more clinicians become familiar with this technique, highlighting the importance of developing standardized guidelines.

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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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. RESULTS: support the effectiveness and safety of this minimally invasive technique in the management of selected patients with recurrent PTC.

Long-term results of radiofrequency ablation for locally recurrent papillary thyroid carcinoma.

OBJECTIVE: To evaluate the long-term efficacy and safety of ultrasound-guided radiofrequency ablation (RFA) for treating locally recurrent papillary thyroid cancer (PTC). METHODS: This retrospective study involved 32 patients with pathologically confirmed locally recurrent PTC. The ablation zone was assessed by contrast-enhanced ultrasound (CEUS) after RFA. At baseline, 6 and 12 months and every 6 months or 12 months thereafter, the following results were recorded: recurrence rate, largest diameter, volume, volume reduction rate (VRR) of recurrent lesions, serum thyroglobulin (Tg) level and complications. RESULTS: 58 recurrent lesions in 32 patients were successfully ablated with RFA. The mean follow-up time was 73.19 ± 12.68 months (range, 60 to 98 months). At the last follow-up, almost all ablated lesions disappeared completely, and only one lesion showed scar-like changes. Nine (28.13%) patients developed new locally recurrent tumors; they were successfully treated with repeat RFA sessions. No new recurrent lesions were found during the follow-up. The largest diameter and volume of recurrent lesions decreased from 13.71 ± 6.48 mm and 520.43 ± 627.85 mm3 to 0 each at the end of observation period (p < .001). The average VRRs at 6, 12, 24, 36, 48, 60 months and last follow-up after RFA were 54.17%, 72.90%, 82.28%, 89.30%, 92.57%, 96.60%, 96.88%, 98.14% and 100% respectively. The median of serum Tg level was decreased from 1.48 ng/mL to 0.00 ng/mL (p < .05). No complications were reported during the follow-up. CONCLUSIONS: US-guided RFA is an effective and safe option for treating locally recurrent PTC in selected patients, with favorable long-term outcomes.

2022 Taiwan clinical multicenter expert consensus and recommendations for thyroid radiofrequency ablation.

Radiofrequency ablation (RFA) is a minimally invasive management strategy that has been widely applied for benign and recurrent malignant thyroid lesions as an alternative to surgery in Taiwan. Members of academic societies for specialists in interventional radiology, endocrinology, and endocrine surgery collaborated to develop the first consensus regarding thyroid RFA in Taiwan. The modified Delphi method was used to reach a consensus. Based on a comprehensive review of recent and valuable literature and expert opinions, the recommendations included indications, pre-procedural evaluations, procedural techniques, post-procedural monitoring, efficacy, and safety, providing a comprehensive review of the application of RFA. The consensus effectively consolidates advice regarding thyroid RFA in clinical practice for local experts.

Successful localization of abnormal parathyroid tissue with ultrasound-guided methylene blue dye injection before surgery for metastatic or recurrent thyroid cancers and parathyroid adenomas.

OBJECTIVES: A surgery to be performed on a previously operated neck includes difficulties such as increased risk of complications and prolonged operation time. The aim of the present study is to analyze the benefit of pre-anesthetic ultrasound-guided injection of methylene blue into parathyroid adenomas and abnormal lymph nodes to simplify their safe and satisfactory extraction. METHODS: We analyzed the case series records of 14 patients who were operated for reoperative neck surgery due to recurrent thyroid cancer (8 patients) and parathyroid adenoma (6 patients) and in the technique; 0.2 ml of a 1:5 dilution of 1 % methylene blue solution was injected directly onto the target during real-time ultrasound guidance before the operating room. RESULTS: In adenomas, ultrasound-guided methylene blue injection was successfully applied in all cases, an average of 33.1 min before entering the operating room (range = 28-38 min). There were no complications related to dye injection. For patients with recurrent thyroid tumors, preoperative ultrasound-guided methylene blue injection was successfully applied in all patients, on average 27.5 min before entering the operating room (range = 20-35 min). No complications occurred due to dye injection. The blue stained lesion was easily identified during surgery. CONCLUSIONS: We analyzed the feasibility of the injection process, the certainty of defining pathological lymph nodes, and the complications of the procedure. Preoperative administration of methylene blue preserved its intraoperative efficacy and maintained the easy the detection of reoperative or primary pathologies. The present study suggest that methylene blue dye injection is a safe, sufficient, and quietly effective method for identifying recurrent tumors and parathyroid adenomas in scarred reoperative neck surgeries. Our cases had comparatively short operative times and lower complication rates.

The Treatment of Thyroid Cancer With Radiofrequency Ablation.

In the past decade, there has seen been a shift from treating all thyroid cancer surgically, to favoring less aggressive approaches for low-risk thyroid cancer. Surgery was historically the treatment of choice for most thyroid cancer. Active surveillance has emerged as an alternative for low-risk thyroid cancer in select patients. This approach has been accepted worldwide, and sound evidence supports its oncological safety in carefully selected patients. However, not all patients want to undergo lifelong monitoring, and some patients may wish to treat their cancer in a minimally invasive manner. Thermal ablation has developed as a minimally invasive alternative to surgery and active surveillance for well selected patients with thyroid malignancy. Herein, we review the role of thermally ablative techniques, specifically radiofrequency ablation, for the treatment of small primary thyroid cancers, recurrent thyroid cancer, and lymph node metastases.

Outcome of 18f-Fluorodeoxyglucose Positron Emission Tomography (PET)-Directed Resections in Differentiated Thyroid Carcinoma (DTC): Experience in a Developing Country.

The aim of this study was to assess the accuracy of 18F-fluorodeoxyglucose positron emission tomography (18-FDG-PET scan) in localizing the disease in differentiated thyroid carcinoma patients undergoing re-operations. This is a retrospective analysis of a prospectively maintained data (December 2007 to December 2016). The patients included had elevated serum thyroglobulin (Tg) levels and negative iodine uptake (TENIS) and planned for re-operation with one or more accessible site of metastasis detected on FDG-PET scan. Clinical details, FDG-PET/CT findings, operative findings, histology, pre-, and post-operative Tg levels were recorded. Thirty-two patients were included. The mean age of the patients was 46.8 ± 15.8 years (M:F = 1:1.6) and mean pre-operative Tg value was 247.6 ± 92.3 ng/ml. FDG-PET disclosed a total of 77 hot spots in these 32 patients, 56 of which were surgically explored and resections performed. Patient- and lesion-based positive predictive value (PPV) of FDG-PET in detecting recurrent/metastatic DTC lesions was 87.5 and 71%, respectively. Remaining cases had granulomatous or nonspecific inflammatory lesions. A total of 12.5% of recurrent DTC patients explored could achieve biochemical cure. All these had disease confined to neck. Remaining patients continued to have high serum Tg level, though it fell substantially in majority of patients. False positive scans are frequent in regions with high prevalence of inflammatory diseases. Hence, FDG-PET directed re-operations should be taken up judiciously.

Piperlongumine, a Potent Anticancer Phytotherapeutic, Induces Cell Cycle Arrest and Apoptosis In Vitro and In Vivo through the ROS/Akt Pathway in Human Thyroid Cancer Cells.

Thyroid cancer (TC) is the most common endocrine malignancy, and its global incidence has steadily increased over the past 15 years. TC is broadly divided into well-differentiated, poorly differentiated, and undifferentiated types, depending on the histological and clinical parameters. Thus far, there are no effective treatments for undifferentiated thyroid cancers or advanced and recurrent cancer. Therefore, the development of an effective therapeutic is urgently needed for such patients. Piperlongumine (PL) is a naturally occurring small molecule derived from long pepper; it is selectively toxic to cancer cells by generating reactive oxygen species (ROS). In this study, we demonstrate the potential anticancer activity of PL in four TC cell lines. For this purpose, we cultured TC cell lines and analyzed the following parameters: Cell viability, colony formation, cell cycle, apoptosis, and cellular ROS induction. PL modulated the cell cycle, induced apoptosis, and suppressed tumorigenesis in TC cell lines in a dose- and time-dependent manner through ROS induction. Meanwhile, an intrinsic caspase-dependent apoptosis pathway was observed in the TC cells under PL treatment. The activation of Erk and the suppression of the Akt/mTOR pathways through ROS induction were seen in cells treated with PL. PL-mediated apoptosis in TC cells was through the ROS-Akt pathway. Finally, the anticancer effect and safety of PL were also demonstrated in vivo. Our findings indicate that PL exhibits antitumor activity and has the potential for use as a chemotherapeutic agent against TC. This is the first study to show the sensitivity of TC cell lines to PL.

Update of Radiofrequency Ablation for Treating Benign and Malignant Thyroid Nodules. The Future Is Now.

Thermal and chemical ablation are minimally invasive procedures that avoid removal of the thyroid gland and target symptomatic nodules directly. Internationally, Radiofrequency ablation (RFA) is among one of the most widely used thermal ablative techniques, and is gaining traction in North America. Surgery remains the standard of care for most thyroid cancer, and in the right clinical setting, Active Surveillance (AS) can be a reasonable option for low risk disease. Minimally invasive techniques have emerged as an alternative option for patients deemed high risk for surgery, or for those patients who wish to receive a more active treatment approach compared to AS. Herein, we review the literature on the safety and efficacy of RFA for treating benign non-functioning thyroid nodules, autonomously functioning thyroid nodules, primary small low risk thyroid cancer (namely papillary thyroid cancer) as well as recurrent thyroid cancer.

The Utility of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Differentiated Thyroid Cancer Patients with Biochemical Recurrence and Negative Whole-Body Radioiodine Scintigraphy and Evaluation of the Possible Role of a Limited Regional Scan.

PURPOSE OF THE STUDY: 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is used in the management of recurrent differentiated thyroid cancer (DTC) patients presented with rising thyroglobulin (Tg) or anti-Tg antibody (Atg) levels and negative whole-body I-131 scan (WBS). We aimed to evaluate the utility of regional or limited PET/CT in a large population preset with variable Tg/(ATg) levels. MATERIALS AND METHODS: In a retrospective study, we analyzed 137 PET/CT done on DTC patients presented with raised Tg/Atg and negative WBS. Retrospective evaluation of other available clinical information was done. RESULTS: One hundred and thirty-seven patients aged 8-72 years (41 ± 17.7 years) were included in the study. Eighty-nine (64.9%) patients had positive findings on 18F-FDG PET-CT. It included thyroid bed recurrence, cervical, mediastinal lymphadenopathy, lung, and bone lesions. In addition, 36 patients had metabolically inactive lung nodules detected on CT. Serum Tg and female sex were the only predictors for a positive PET scan. In most (97.1%) of the patients, the disease was limited to the neck and thoracic region. CONCLUSIONS: PET/CT is an excellent imaging modality for evaluating DTC patients presented with biochemical recurrence. It not only finds the disease in more than 80% of the patients but also detects distant metastatic disease, which precludes regional therapies. Lesions were noted mostly in the neck and thoracic region with very few distant skeletal metastases (4/137 patients). In most of the patients, routine vertex to mid-thigh imaging could be avoided.

Comparison of efficacy and complications between radiofrequency ablation and repeat surgery in the treatment of locally recurrent thyroid cancers: a single-center propensity score matching study.

PURPOSE: To compare the efficacy and complication rates of radiofrequency ablation (RFA) and repeat surgery in the treatment of locally recurrent thyroid cancers. MATERIALS AND METHODS: A total of 221 patients with locally recurrent thyroid cancers who underwent either RFA (n = 96) or repeat surgery (n = 125) between March 2008 and March 2017 were retrospectively enrolled (range of follow-up, 1-10 years). Each cohort consisted of 70 patients after propensity score adjustment. Patients with more than three recurrent lesions were excluded. The primary and secondary end points were recurrence-free survival and complication rates, respectively. Recurrence-free survival curves were compared via the log-rank test. The complications-voice changes, hypocalcemia, and immediate procedural complications-were compared between the groups. In addition, pretreatment serum thyroglobulin (Tg) levels and those at the last follow-up were also compared between the two groups to examine therapeutic efficacy. RESULTS: After propensity score matching, both groups showed no significant differences in baseline characteristics. The recurrence-free survival rates were comparable between the RFA and surgery groups (p = .2). There were no significant differences in mean serum Tg levels and their mean decrease after treatment between the groups (p = .891 and p = .963, respectively). Immediate procedural complications and voice changes also showed no significant between-group differences (p = .316, p = .084, respectively). Hypocalcemia occurred only in the repeat surgery group (n = 18). Overall complications were significantly more frequent in the repeat surgery group (RFA, n = 7; surgery, n = 27; p < .001). CONCLUSION: RFA may be an effective and safe alternative to repeat surgery in the treatment of a small number of locally recurrent thyroid cancers.

Management strategy for nerve damage during radiofrequency ablation of thyroid nodules.

OBJECTIVE: The aim of this study was to introduce a management strategy for nerve damage occurring during radiofrequency ablation (RFA). METHODS: From January 2016 to October 2017, 17 patients who experienced the symptoms of nerve damage during RFA were enrolled in this study. If damage to nerves was suspected during RFA, ablation was stopped immediately, and a cold solution of 5% dextrose was injected directly into the space where the nerves were located until symptoms improved. Patients were followed up after the procedure until symptoms had resolved. The clinical data of patients who received a cold dextrose solution injection for nerve damage were compared with those who did not receive such an injection. RESULTS: Of 17 patients who experienced nerve damage, 12 received an injection of cold dextrose solution shortly after the emergence of symptoms. While resolution of symptoms was seen in all 17 patients, the mean time to recovery was significantly faster in the 12 patients who received treatment with an injection of cold dextrose solution than in those patients who did not receive such a treatment (p value = .041). CONCLUSIONS: In the event of thermal damage to adjacent nerve structures during RFA, the direct injection of a cold dextrose solution is a simple and effective treatment that can result in rapid symptom resolution.

Prognostic implication of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in patients with recurrent papillary thyroid cancer.

BACKGROUND: Fluorine-18 fluorodeoxyglucose positron emission tomography/CT (18 F-FDG PET/CT) has been widely accepted as an effective method for detecting recurrent papillary thyroid cancer (PTC) in patients with increased serum thyroglobulin (Tg) or Tg antibody (TgAb) levels and negative whole-body scintigraphy (WBS) results. The role of WBS as a diagnostic tool in detecting recurrence has relatively decreased recently. However, only a few studies have examined the usefulness of 18 F-FDG PET/CT for evaluating patients with recurrent PTC, regardless of the WBS results. The purpose of this analysis was to evaluate the diagnostic value and prognostic role of 18 F-FDG PET/CT for patients with recurrent PTC, irrespective of their WBS results. METHODS: Sixty-six patients with locoregional recurrent PTC who underwent 18 F-FDG PET/CT and neck CT within 6 months before surgical treatment were included in this retrospective analysis. Imaging findings were compared with postoperative histopathologic results. The diagnostic values of 18 F-FDG PET/CT and neck CT were compared according to the serum Tg and TgAb levels and cervical levels. Each patient's status at the last follow-up was also reviewed, and survival probabilities were estimated using the Kaplan-Meier plot. RESULTS: The sensitivity, specificity, and diagnostic accuracy of 18 F-FDG PET/CT for the entire patient group were 38.5%, 90.2%, and 58.3%, respectively. The corresponding neck CT values were 55.0%, 85.7%, and 66.7%, respectively. According to the serum Tg and TgAb levels, except for the specificity, most diagnostic values of 18 F-FDG PET/CT were worse than those of the neck CTs, with or without statistical significance. For the high maximum standardized uptake value (SUVmax) group (SUVmax >10) and the low SUVmax group, the median locoregional disease-free survival times were 33.3 months and 81.8 months, respectively (P < .001). CONCLUSION: The diagnostic value of 18 F-FDG PET/CT for localizing recurrent lesions was worse than that of the neck CT, irrespective of the WBS results. However, patients with a higher SUVmax showed a significantly worse prognosis than did those with a lower SUVmax. Therefore, we suggest that, in patients with recurrent PTC, 18 F-FDG PET/CT should be considered for prognostication rather than diagnosis.

Long-Term Outcomes of Lateral Neck Dissection in Patients with Recurrent or Persistent Well-Differentiated Thyroid Cancer.

BACKGROUND: Well-differentiated thyroid carcinoma (WDTC) has a high predilection for regional metastatic spread. Rates for WDTC lateral neck recurrence are reported to be as high as 24% in patients after initial thyroidectomy, lateral neck surgery, and adjuvant radioactive (RAI) iodine treatment. The objective of the study was to evaluate the efficacy, safety, and long-term outcome of comprehensive lateral neck dissection (LND) of levels II-V for recurrent or persistent WDTC in a tertiary referral center. METHODS: This study retrospectively analyzed the standardized approach of LND for recurrent WDTC in the lateral neck compartment. Survival was analyzed by Cox regression analysis. RESULTS: Three hundred and seven patients underwent 429 LND for cytopathology-confirmed lateral neck recurrent WDTC at the University of Texas MD Anderson Cancer Center between 1994 and 2012. The vast majority (90%) of patients were originally treated elsewhere. Multilevel lateral neck dissection had been originally performed in 80% of patients, with 17% having undergone at least two previous operations. Two hundred and sixty-seven (87%) patients had previous RAI. The most common levels of recurrence were levels III and IV (33% and 33%, respectively). Postoperative complications were seen in 7% of patients. Median follow-up was 7.2 years. In-field lateral neck control was 96% at 10 years. Overall lateral neck regional control, overall survival (OS), and disease-specific survival (DSS) at 10 years was 88%, 78%, and 91%, respectively. When stratifying by age (<24 years, 24-50 years, and >50 years), OS and DSS was significantly better in patients <50 years (OS: p < 0.001; DSS: p < 0.001). However, there was worse overall lateral neck control in the younger group (<24 years; p = 0.04). Regional recurrence after salvage LND occurred within a median time interval of 20.0 months (2.9-121.3 months), of which 2% (8/429) developed in-field lateral neck recurrences. Of those with any lateral neck recurrence after salvage LND, 24/30 (80%) patients successfully underwent another LND, resulting in an ultimate 98% lateral neck regional control rate. CONCLUSIONS: Expert comprehensive LND of levels II-V is associated with few perioperative complications and results in very high in-field regional control rate and ultimate lateral neck control in recurrent/persistent WDTC.

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

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.

Use of thyroglobulin as a tumour marker.

It is worthwhile to measure serum thyroglobulin (TG) level in thyroid cancer before subjecting patients to surgery for two reasons. Firstly, if the level is high, it may give a clue to the local and metastatic tumour burden at presentation; secondly, if the level is normal, it identifies the patients who are unlikely to show rising TG levels in the presence of thyroid cancer. Those who have high serum TG before surgery will show up recurrence as rising serum TG during the postoperative period. Those who do not have high serum TG before surgery will not show up rising serum TG in the presence of recurrent disease. In the latter situation, normal TG level gives only a false reassurance regarding recurrence of disease. Nevertheless, rising serum TG during the postoperative period must be interpreted cautiously because this could be due to the enlargement of non-cancerous residual thyroid tissue inadvertently left behind during surgery.

Complications encountered in ultrasonography-guided radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers.

OBJECTIVES: To evaluate the complication rates and describe the possible complications of ultrasonography-guided radiofrequency ablation (RFA) of benign thyroid nodules (BTN) and recurrent thyroid cancers (RTC), and to compare the complication rates between BTN and RTC. METHODS: This retrospective study reviewed 875 patients who underwent RFA for BTN (746 patients; 83.5%) or RTC (129 patients; 14.7%). Medical records were reviewed for all types of complications occurring during and after the RFA procedure. The baseline characteristics and the complication rates of BTN and RTC were compared. RESULTS: The overall complication rate was 3.5% (31/875), and the major complication rate was 1.6% (14/875). The major complication rate of RTC was significantly higher than that of BTN (5.4% vs. 0.9%, P = 0.002), while there were no significant differences in the minor complications rate. New complications, such as Horner syndrome, spinal accessory nerve injury, and complications due to lidocaine toxicity, were also revealed. CONCLUSIONS: Various complications of RFA may occur in both BTN and RTC, although the complication rate is low. To understand the broad spectrum of complications and minimise the complications and sequela, the suggested technical tips and cervical anatomy are essential. KEY POINTS: • The overall complication rate was 3.5% (31/875). • The major complication rate was 1.6% (14/875). • The major complication rate of RTC was significantly higher than BTN. • There were only four patients showing persistent symptoms (0.5%). • Unreported new complications were also demonstrated.

Impact of combined FDG-PET/CT and MRI on the detection of local recurrence and nodal metastases in thyroid cancer.

BACKGROUND: Suspected recurrence of thyroid carcinoma is a diagnostic challenge when findings of both a radio iodine whole body scan and ultrasound are negative. PET/CT and MRI have shown to be feasible for detection of recurrent disease. However, the added value of a consensus reading by the radiologist and the nuclear medicine physician, which has been deemed to be helpful in clinical routines, has not been investigated. This study aimed to investigate the impact of combined FDG-PET/ldCT and MRI on detection of locally recurrent TC and nodal metastases in high-risk patients with special focus on the value of the multidisciplinary consensus reading. MATERIALS AND METHODS: Forty-six patients with suspected locally recurrent thyroid cancer or nodal metastases after thyroidectomy and radio-iodine therapy were retrospectively selected for analysis. Inclusion criteria comprised elevated thyroglobulin blood levels, a negative ultrasound, negative iodine whole body scan, as well as combined FDG-PET/ldCT and MRI examinations. Neck compartments in FDG-PET/ldCT and MRI examinations were independently analyzed by two blinded observers for local recurrence and nodal metastases of thyroid cancer. Consecutively, the scans were read in consensus. To explore a possible synergistic effect, FDG-PET/ldCT and MRI results were combined. Histopathology or long-term follow-up served as a gold standard. For method comparison, sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated. RESULTS: FDG-PET/ldCT was substantially more sensitive and more specific than MRI in detection of both local recurrence and nodal metastases. Inter-observer agreement was substantial both for local recurrence (κ = 0.71) and nodal metastasis (κ = 0.63) detection in FDG-PET/ldCT. For MRI, inter-observer agreement was substantial for local recurrence (κ = 0.69) and moderate for nodal metastasis (κ = 0.55) detection. In contrast, FDG-PET/ldCT and MRI showed only slight agreement (κ = 0.21). However, both imaging modalities identified different true positive results. Thus, the combination created a synergistic effect. The multidisciplinary consensus reading further increased sensitivity, specificity, and diagnostic accuracy. CONCLUSIONS: FDG-PET/ldCT and MRI are complementary imaging modalities and should be combined to improve detection of local recurrence and nodal metastases of thyroid cancer in high-risk patients. The multidisciplinary consensus reading is a key element in the diagnostic approach.