Adrenalectomy Improves Body Weight, Glucose, and Blood Pressure Control in Patients With Mild Autonomous Cortisol Secretion: Results of an Randomized Controlled Trial by the Co-work of Adrenal Research (COAR) Study.

OBJECTIVE: To assess the metabolic effects of adrenalectomy in patients with mild autonomous cortisol secretion (MACS). BACKGROUND: Despite retrospective studies showing the association of adrenalectomy for MACS with beneficial metabolic effects, there have been only 2 randomized prospective studies with some limitations to date. METHODS: A prospective, multicenter study randomized 132 patients with adrenal incidentaloma without any features of Cushing syndrome but with serum cortisol >50 nmol/L after a 1 mg overnight dexamethasone suppression test into an adrenalectomy group (n = 66) or control group (n = 66). The primary outcomes were changes in body weight, glucose, and blood pressure (BP). RESULTS: Among the 118 participants who completed the study with a median follow-up duration of 48 months (range: 3-66), the adrenalectomy group (n = 46) exhibited a significantly higher frequency of improved weight control, glucose control, and BP control (32.6%, 45.7%, and 45.7%, respectively) compared with the control group (n = 46; 6.5%, P = 0.002; 15.2%, P = 0.002; and 23.9%, P = 0.029, respectively) after matching for age and sex. Adrenalectomy [odds ratio (OR) = 10.38, 95% CI = 2.09-51.52, P = 0.004], body mass index (OR = 1.39, 95% CI = 1.08-1.79, P = 0.010), and cortisol after a 1 mg overnight dexamethasone suppression test levels (OR = 92.21, 95% CI = 5.30-1604.07, P = 0.002) were identified as independent factors associated with improved weight control. Adrenalectomy (OR = 5.30, 95% CI = 1.63-17.25, P = 0.006) and diabetes (OR = 8.05, 95% CI = 2.34-27.65, P = 0.001) were independently associated with improved glucose control. Adrenalectomy (OR = 2.27, 95% CI = 0.87-5.94, P = 0.095) and hypertension (OR = 10.77, 95% CI = 3.65-31.81, P < 0.001) demonstrated associations with improved BP control. CONCLUSIONS: adrenalectomy improved weight, glucose, and BP control in patients with MACS.

Preoperative prediction of metastatic pheochromocytoma and paraganglioma using clinical, genetic, and biochemical markers: A cohort study.

BACKGROUND: The prevalence of metastatic pheochromocytoma and paraganglioma (PPGL) is approximately 15%-20%. Although there are indicators to assess metastatic risks, none of them predict metastasis reliably. Therefore, we aimed to develop and validate a scoring system using clinical, genetic, and biochemical risk factors to preoperatively predict the metastatic risk of PPGL. METHODS: In the cross-sectional cohort (n = 180), clinical, genetic, and biochemical risk factors for metastasis were identified using multivariate logistic regression analysis, and a novel scoring system was developed. The scoring system was validated and compared with the age, size of tumor, extra-adrenal location, and secretory type (ASES) score in the longitudinal cohort (n = 114). RESULTS: In the cross-sectional cohort, pseudohypoxia group-related gene variants (SDHB, SDHD, or VHL), methoxytyramine >0.16 nmol/L, and tumor size >6.0 cm were independently associated with metastasis after multivariate logistic regression. Using them, the gene variant, methoxytyramine, and size of tumor (GMS) score were developed. In the longitudinal cohort, Harrell's concordance index of the GMS score (0.873, 95% confidence interval [CI]: 0.738-0.941) was higher than that of the ASES score (0.713, 95% CI: 0.567-0.814, p = 0.007). In the longitudinal cohort, a GMS score ≥2 was significantly associated with a higher risk of metastasis (hazard ratio = 25.07, 95% CI: 5.65-111.20). A GMS score ≥2 (p < 0.001), but not ASES score ≥2 (p = 0.090), was associated with shorter progression-free survival. CONCLUSION: The GMS scoring system, which integrates gene variant, methoxytyramine level, and tumor size, provides a valuable preoperative approach to assess metastatic risk in PPGL.

Enhancement on CT for preoperative diagnosis of metastatic lymph nodes in thyroid cancer: a comparison across experience levels.

OBJECTIVES: To investigate the diagnostic performance and interobserver agreement of quantitative CT parameters indicating strong lymph node (LN) enhancement in differentiated thyroid cancer (DTC), comparing them with qualitative analysis by radiologists of varying experience. MATERIALS AND METHODS: This study included 463 LNs from 399 patients with DTC. Three radiologists independently analyzed strong LN enhancement on CT. Qualitative analysis of strong enhancement was defined as LN cortex showing greater enhancement than adjacent muscles on the arterial phase. Quantitative analysis included the mean attenuation value (MAV) of LN on arterial phase (LNA) and venous phase (LNV), LNA normalized to the common carotid artery (NAVCCA), internal jugular vein (NAVIJV), and sternocleidomastoid muscle (NAVSCM), attenuation difference [AD; (LNA - MAVSCM)], and relative washout ratio [((LNA - LNV)/LNA) × 100]. The interobserver agreement and diagnostic performance of the quantitative and qualitative analyses were evaluated. RESULTS: Interobserver agreement was excellent for all quantitative CT parameters (ICC, 0.83-0.94) and substantial for qualitative assessment (κ = 0.61). All CT parameters except for LNV showed good diagnostic performance for metastatic LNs (AUC, 0.81-0.85). NAVCCA (0.85, 95% CI: 0.8-0.9) and AD (0.85, 95% CI: 0.81-0.89) had the highest AUCs. All quantitative parameters except for NAVIJV had significantly higher AUCs than qualitative assessments by inexperienced radiologists, with no significant difference from assessments by an experienced radiologist. CONCLUSION: Quantitative assessment of LN enhancement on arterial phase CT showed higher interobserver agreement and AUC values than qualitative analysis by inexperienced radiologists, supporting the need for a standardized quantitative CT parameter-based model for determining strong LN enhancement. CLINICAL RELEVANCE STATEMENT: When assessing strong LN enhancement in DTC, quantitative CT parameters indicating strong enhancement can improve interobserver agreement, regardless of experience level. Therefore, the development of a standardized diagnostic model based on quantitative CT parameters might be necessary. KEY POINTS: Accurate preoperative assessment of LN metastasis in thyroid cancer is crucial. Quantitative CT parameters indicating strong LN enhancement demonstrated excellent interobserver agreement and good diagnostic performance. Quantitative assessment of contrast enhancement offers a more objective model for the identification of metastatic LNs.

Comparison of TERT and 5-Hydroxymethylcytocine immunohistochemistry in various thyroid carcinomas.

Telomerase reverse transcriptase (TERT) promoter mutation is associated with an aggressive clinical course in thyroid carcinomas. Therefore, detection of TERT promoter mutation is essential for proper patient management. 5-Hydroxymethylcytosine (5hmC) is an epigenetic marker involved in the DNA demethylation pathway, and its loss has been observed in various tumors. Loss of 5hmC has also been reported in thyroid carcinomas and is presented as a possible predictive biomarker for TERT promoter mutation and worse prognosis. This study evaluated the expression of TERT and 5hmC by immunohistochemistry (IHC) in 105 patients (44 in the TERT mutant group and 61 in the TERT wild group) with various thyroid carcinomas. H-scores were calculated using an image analyzer. The median H-scores of TERT IHC were significantly higher in the TERT mutant group than in the TERT wild group (47.15 vs. 9.80). The sensitivity and specificity of TERT IHC for predicting TERT promoter mutations were 65.9 and 65.7 %, respectively. Regardless of TERT promoter mutation status, the 5hmC H-scores were markedly lower in all subtypes of thyroid carcinomas compared to those in their normal counterparts. Significant differences in 5hmC H-scores were observed between N0 and N1 in total thyroid carcinomas, but not within the papillary thyroid carcinoma subgroup. In conclusion, TERT and 5hmC IHC have limitations in predicting the presence of TERT promoter mutations. The expression of 5hmC was downregulated in various thyroid carcinomas compared to that in normal and benign lesions, but comprehensive further studies are required to elucidate the role of 5hmC in thyroid carcinomas.

Safety and feasibility of single-port surgery for posterior retroperitoneal adrenalectomy using the da Vinci SP robotic system: a retrospective cohort study.

BACKGROUND: This study demonstrates our experience of single-port robotic posterior retroperitoneal adrenalectomy (RPRA) using the da Vinci SP robot system and evaluates its technical feasibility and surgical outcomes. METHODS: We conducted a retrospective analysis of 250 RPRAs, including 117 conventional 3-port RPRAs, 103 reduced 2-port RPRAs, and 30 single-port RPRAs. Each RPRA type was compared by analyzing 30 patients in the early phase of surgery. RESULTS: All patients who underwent single-port RPRA showed excellent surgical outcomes. Age, sex, BMI, and tumor location site did not significantly differ between the three groups. In the early phase, the size of the adrenal tumor was similar between three groups, and it tended to increase as the number of ports increased (p < 0.001). The mean operation time was shorter for patients who underwent single-port RPRA than those who underwent RPRA types (p < 0.001). The numeric rating scale score did not significantly differ between the groups on most days. No major complications were observed, and no patients were converted to open surgery or required additional port insertion. CONCLUSION: Single-port RPA using the da Vinci SP robotic system showed the effectiveness of the surgical procedure and improved cosmetic outcomes for patients, while also enabling surgeons to perform operations with greater ease and convenience. Therefore, single-port RPRA could be a good alternative option for the treatment of adrenal tumors in selected situations.

Prognosis of Patients with 1-4 cm Papillary Thyroid Cancer Who Underwent Lobectomy: Focus on Gross Extrathyroidal Extension Invading Only the Strap Muscles.

BACKGROUND: This study was designed to evaluate the prognostic implication of gross extrathyroidal extension (ETE) invading the strap muscles after thyroid lobectomy in patients with 1-4 cm papillary thyroid cancer (PTC). METHODS: This retrospective cohort study included patients with 1-4 cm PTC who underwent thyroid lobectomy from 2005 to 2012. Overall, 595 patients were enrolled after excluding patients with aggressive variants of PTC, gross ETE into a major neck structure, and lateral cervical lymph node (LN) metastasis. We evaluated the risk factors for structural recurrence after lobectomy in 1-4 cm PTC. RESULTS: Seventy-eight patients (13.1%) had gross ETE invading only the strap muscles. During the median follow-up period of 7.7 years, structural recurrence was confirmed in 35 patients (5.9%). The presence of gross ETE was an independent risk factor for structural recurrence (hazard ratio 2.54, 95% confidence interval 1.19-5.44; p = 0.016). Subgroup analysis of patients with gross ETE showed that 11 and 47 patients had low- and intermediate-risk LN metastasis, respectively. A significant difference in recurrence-free survival was observed according to the degree of cervical LN metastasis (p = 0.03). Those without LN metastasis or low-risk LNs had a 75% lower risk of recurrence when compared with those with both gross ETE and intermediate-risk LNs. CONCLUSION: Gross ETE and intermediate-risk cervical LN metastasis were associated with a significantly high risk of recurrence after lobectomy in patients with 1-4 cm PTC. Completion thyroidectomy would be considered in this subgroup of patients but not in all patients with gross ETE invading only the strap muscles.

Indices of ACTH-stimulated adrenal venous sampling as predictors of postsurgical outcomes in primary aldosteronism.

OBJECTIVE: This study aimed to investigate the impact of indices of adrenal venous sampling (AVS) on postsurgical outcomes in patients with primary aldosteronism (PA). DESIGN AND PATIENTS: This retrospective study determined biochemical and clinical outcomes based on ACTH-stimulated AVS parameters (lateralisation index [LI], contralateral ratio [CLR], and ipsilateral ratio [ILR]) in 251 patients with PA at 3 months after surgery. RESULTS: Modified complete biochemical success was achieved in 8 of 12 (66.7%) patients with LI = 3-4, 39 of 47 (83.0%) with LI = 4-10, and 155 of 169 (91.7%) with LI ≥ 10 (p = .004 for trend). Modified complete biochemical success was achieved in 29 of 38 (76.3%) patients with CLR ≥ 1 and ILR ≤ 2, 73 of 86 (84.9%) with CLR = 0.25-1 and ILR > 2, and 100 of 104 (96.2%) with CLR < 0.25 and ILR > 2 (p = .001 for trend). After adjusting for confounders, modified complete biochemical success was associated with an LI ≥ 10 (odds ratio [OR] = 6.32; 95% confidence interval [CI] = 1.33-29.93) using LI = 3-4 as a reference and combined CLR < 0.25 and ILR > 2 (OR = 11.49; 95% confidence interval [CI] = 2.49-53.01) using combined CLR ≥ 1 and ILR ≤ 2 as a reference. Using combined CLR ≥ 1 and ILR ≤ 2 as a reference, complete clinical success was associated with combined CLR < 0.25 and ILR > 2 (OR = 3.10; 95% CI = 1.03-9.28) and combined CLR = 0.25-1 and ILR > 2 (OR = 4.92; 95% CI = 1.64-14.76). CONCLUSION: LI ≥ 10 may be appropriate for achieving biochemical success. With ILR > 2, CLR < 0.25, and CLR < 1 may be appropriate for achieving biochemical and clinical success, respectively.

Risk factors for metastasis in indeterminate lymph nodes in preoperative patients with thyroid cancer.

OBJECTIVES: To investigate the relevance of clinical and sonographic features as indicators of metastasis in indeterminate lymph node (LN), to determine possible indications for fine-needle aspiration (FNA). METHODS: Consecutive patients who underwent US-guided FNA for sonographic indeterminate LNs from differentiated thyroid carcinoma between January 2014 and December 2018 were retrospectively reviewed. Indeterminate LNs were defined as LNs which had neither an echogenic hilum nor hilar vascularity in the absence of any suspicious finding in accordance with the Korean Society of Thyroid Radiology (KSThR) guidelines. Univariate and multivariate logistic regression analyses were performed to identify significant risk factors related to malignancy of indeterminate LNs. RESULTS: Of the 236 LNs in 212 patients enrolled in this study, 67 LNs (28.3%) were metastatic. The multivariate logistic regression analysis showed that the long diameter of LNs has a negative association with metastasis in indeterminate LNs and the sonographic features of extrathyroidal extension (ETE) and nonparallel orientation of the primary tumor are associated with metastasis in indeterminate LNs. The sensitivity and positive predictive value were increased when FNA was performed for LNs with primary tumors showing ETE or nonparallel orientation than when FNA was performed for LNs larger than 5 mm (59.7% and 40.4% vs. 11.94% and 15.69%). CONCLUSIONS: The size of LNs has a negative association with metastasis in indeterminate LNs. Performing FNA for indeterminate LNs in patients whose primary tumor shows ETE or a nonparallel orientation can improve the diagnostic performance and decrease the rate of unnecessary FNA. KEY POINTS: • The size of lymph nodes was negatively related to the risk of metastasis in indeterminate lymph nodes. • Extrathyroidal extension and a nonparallel orientation of the primary tumor were suggested as sonographic features predicting metastasis in indeterminate lymph nodes. • The routine practice of FNA for large indeterminate lymph nodes detected during preoperative evaluation of thyroid cancer should be discouraged.

Sonographic assessment of minor extrathyroidal extension of papillary thyroid microcarcinoma involving the posterior thyroid capsule.

OBJECTIVES: This study aimed to determine sonographic features and clinical significance of minor extrathyroidal extension (ETE) to the posterior thyroid capsule in papillary thyroid microcarcinoma (PTMC) patients. METHODS: We retrospectively reviewed the records of 506 PTMC patients consisting of 151 patients with minor ETE and 355 patients without ETE. Significant clinicoradiologic features associated with ETE were identified by logistic regression analyses. The diagnostic performance of sonographic features, including the presence of capsular abutment, capsular abutment degree (< 25%, 25-50%, ≥ 50%), and protrusion, were assessed for the diagnosis of posterior minor ETE. Interobserver agreement was calculated. RESULTS: PTMC patients with posterior minor ETE were more likely to have lymphovascular invasion and lateral neck lymph node metastasis (OR = 2.636, 95%CI: 1.754, 3.963 and OR = 2.897, 95%CI: 1.069, 7.848). Regarding the diagnostic performance, the capsular abutment yielded the highest sensitivity (81.5%), followed by ≥ 25% abutment, protrusion, and ≥ 50% abutment (57.0%, 21.9%, and 4.6%, respectively), with similar levels of diagnostic accuracy (71.3-75.1%). The specificity was highest for the sonographic feature of ≥ 50% abutment (99.7%), followed by protrusion, ≥ 25% abutment, and capsular abutment (97.8%, 82.0%, and 68.7%, respectively). Abutment assessment had a moderate interobserver agreement (K = 0.705), and abutment degree and protrusion assessment had a fair and slight interobserver agreement (K = 0.553 and 0.287). CONCLUSIONS: Sonographic features of posterior capsular abutment are sensitive and reliable for diagnosis of posterior minor ETE and are associated with lymphovascular invasion and lateral neck lymph node metastasis in PTMC patients. The assessment of posterior minor ETE is important for considering candidates for active surveillance among PTMC patients. KEY POINTS: • PTMC patients with posterior minor ETE were more likely to have lymphovascular invasion and lateral neck lymph node metastasis. • Sonographic features of posterior capsular abutment are sensitive and reliable for the diagnosis of posterior minor ETE. • The assessment of posterior minor ETE is important for considering candidates for active surveillance among PTMC patients.

The association between the type of anesthesia and hemodynamic instability during pheochromocytoma surgery: a retrospective cohort study.

BACKGROUND: Pheochromocytoma often carries a risk for perioperative hemodynamic instability (HDI). The aim of this study is to evaluate the risk factors of intraoperative HDI during minimally invasive posterior retroperitoneal adrenalectomy (PRA) for pheochromocytoma. MATERIALS AND METHODS: This retrospective study analyzed the prospectively collected data of 172 patients who underwent laparoscopic PRA or robotic PRA for pheochromocytoma between January 2014 and December 2020 at a single tertiary center. The patients were divided into two groups according to the intraoperative hypertensive event of systolic blood pressure (> 160 mmHg). The clinical manifestations and perioperative hemodynamic conditions were analysed. RESULTS: In the multivariate logistic regression analysis, the tumor size (> 3.4 cm) [OR 3.14, 95% confidence intervals (CI) (1.48-6.64), p = 0.003], type of preoperative alpha-blocker (selective type) [OR 3.9, 95% CI (1.52-10.02), p = 0.005], preoperative use of beta-blockers [OR 3.94, 95% CI (1.07-14.49), p = 0.039] and type of anesthesia [total intravenous anesthesia (TIVA) vs. balanced anesthesia (BA)] [OR 2.57, 95% CI (1.23-5.38), p = 0.012] were determined as independent risk factors of intraoperative hypertensive events during minimally invasive adrenalectomy. CONCLUSIONS: The type of anesthesia was independently associated with intraoperative HDI along with larger tumor size, type of preoperative alpha-blocker and the use of preoperative beta-blockers. TIVA increased the risk of intraoperative hypertensive events compared with BA. Thus, the consideration of the type of anesthesia prior to adrenal surgery for pheochromocytoma along with the use of preoperative non-selective alpha-blockers may be beneficial in minimizing the risk of intraoperative HDI.

Comparison Between Familial and Sporadic Non-medullary Thyroid Carcinoma: A Retrospective Individual Risk Factor-Matched Cohort Study.

BACKGROUND: This study aimed to compare clinicopathologic features and outcomes between patients with familial non-medullary thyroid carcinoma (FNMTC) and patients with sporadic non-medullary thyroid carcinoma (SNMTC) after performing individual risk factor-matching. Additionally, the study evaluated a dynamic risk stratification (DRS) system to validate its usefulness for familial-type thyroid carcinoma. METHODS: After individual risk factor-matching, 286 patients remained in the FNMTC group, and 858 patients were assigned to the SNMTC group consisting of papillary thyroid carcinoma (PTC). The prognostic outcomes were compared between the two groups in a matched cohort. RESULTS: During the mean follow-up period of 142 months, recurrences were experienced by 64 patients in the sporadic group (7.5%) and 29 patients in the familial group (10.1%). In the multivariate analysis, the independent risk factors for recurrence were primary tumor size (p = 0.033), gross extrathyroidal extension (p = 0.001), and lymph node metastasis (p < 0.001). The independent risk factors did not include family history alone (p = 1.101) or the number of affected family members (p = 0.122 for 2 members and p = 0.625 for ≥ 3 members). In this matched-cohort study, the DRS system was well adjusted in the FNMTC and SNMTC groups. Moreover, the proportion of DRS categories and the recurrence rate in each DRS category were similar between the familial and sporadic groups. CONCLUSIONS: Family history did not present a statistically significant association with a poor prognosis for PTC patients. With a family history of PTC alone, less aggressive treatment could be considered. In this matched cohort, DRS was adjusted well and could be useful in predicting prognosis, even for PTC patients with a family history of PTC.

Clinical implications of age and excellent response to therapy in patients with high-risk differentiated thyroid carcinoma.

BACKGROUND: Patients with American Thyroid Association (ATA) high-risk differentiated thyroid carcinoma (DTC) have poor clinical outcomes. This study aimed to evaluate the clinical implications of age and response to therapy classification in patients with ATA high-risk DTC. DESIGN AND PATIENTS: This study included 222 patients with high-risk DTC who initially underwent therapy between 2000 and 2010 in a single tertiary center in Korea. We evaluated the prognostic parameters associated with progression-free survival (PFS) and disease-specific survival (DSS) with a focus on age and achieving an excellent response (ER). RESULTS: During the median follow-up period of 11.3 years, disease progression was detected in 77 patients (34.7%), and disease-specific mortality was reported in 31 patients (14.0%). Older age (≥55 years) and not achieving ER (not-ER) were independent risk factors associated with PFS (age, p < .001; not-ER, p < .001) and DSS (age, p < .001; not-ER, p = .015). Of the 74 patients in the ER group, 7 (9.5%) displayed disease progression and 1 (1.4%) died from DTC. There were no significant differences in PFS and DSS according to age in the ER group. However, older patients had significantly worse PFS and DSS than younger patients in the not-ER group (p = .002 and p < .001, respectively). CONCLUSIONS: Response to therapy classification is important for predicting PFS and DSS in patients with high-risk DTC. Patients in the ER group had a relatively good prognosis, but disease progression occurred in 9.5% of patients. Age was a key predictor of both PFS and DSS in high-risk patients who did not achieve ER.

Efficacy of radiofrequency ablation for recurrent thyroid cancer invading the airways.

OBJECTIVES: To evaluate the efficacy of radiofrequency ablation (RFA) in patients with recurrent thyroid cancer invading the airways. METHODS: We reviewed patients who had undergone RFA for recurrent thyroid cancer in the central compartment after total thyroidectomy between January 2008 and December 2018. All tumors were classified according to their association with the laryngeal structure and trachea. The volume reduction rate (VRR) and complete disappearance rate were calculated, and their differences were determined relative to the association between the tumor and trachea. Complication rates associated with RFA were evaluated. RESULTS: The study population included 119 patients with 172 recurrent tumors. Mean VRR was 81.2% ± 55.7%, with 124 tumors (72.1%) completely disappearing after a mean follow-up of 47.9 ± 35.4 months. The complete disappearance rate of recurrent tumors not in contact with the trachea was highest, followed by tumors forming acute angles, right angles, and obtuse angles with the trachea, and tumors with intraluminal tracheal invasion (p value < 0.001). The overall complication rate was 21.4%. CONCLUSIONS: RFA is effective and safe for the local control of recurrent tumors in the central neck compartment after total thyroidectomy, even for tumors invading the airways, and may be considered an alternative to surgical resection. The inverse relationship between RFA efficacy and airway invasion suggests that early RFA may benefit patients with recurrent tumors in the central neck compartment. KEY POINTS: • RFA achieved a mean VRR of 81.2% ± 55.7% and complete disappearance of 124 tumors (72.1%) after a mean follow-up of 47.9 ± 35.4 months. • The complete disappearance rate of recurrent tumors not in contact with the trachea was the highest, followed by tumors forming acute angles, right angles, and obtuse angles with the trachea, and tumors with intraluminal tracheal invasion. • Stent-assisted RFA may be a good alternative for palliative treatment of recurrent tumors with intraluminal tracheal invasion.

Treatment Efficacy of Radiofrequency Ablation for Recurrent Tumor at the Central Compartment After Hemithyroidectomy.

OBJECTIVE. The aim of this study was to evaluate the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) for recurrent tumor in the central compartment after hemithyroidectomy. MATERIALS AND METHODS. The medical records of patients who underwent RFA for recurrent tumor after hemithyroidectomy between January 2008 and December 2018 were reviewed. Eight patients who underwent RFA for 10 recurrent tumors after hemithyroidectomy were included in our study population. Patients underwent follow-up US 1, 6, and 12 months after treatment and annually thereafter. The tumor volume reduction rate (VRR) was calculated as follows: VRR = ([initial volume - final volume] × 100) / initial volume. All patients were advised to undergo contrast-enhanced CT after tumor ablation. Complete tumor disappearance was defined as no visible treated tumor on follow-up US or CT. RESULTS. Mean tumor VRR was 97.8% ± 7.0% (SD) (range, 77.8-100%). Complete tumor ablation was achieved for all 10 recurrent tumors. Complete disappearance was confirmed in nine recurrent tumors, and one recurrent tumor showed a VRR of 77.8% on US but there was no enhancement on CT. All eight patients achieved no evidence of disease during mean follow-up of 33.0 months. RFA was tolerated by all patients; there were no major complications or procedure-related deaths. One patient experienced transient voice change during RFA. CONCLUSION. RFA can be considered to be an effective and safe alternative treatment method for recurrent tumor in the central compartment after hemithyroidectomy.

Modified risk stratification based on cervical lymph node metastases following lobectomy for papillary thyroid carcinoma.

OBJECTIVE: Evidence for American Thyroid Association (ATA) risk stratification stems largely from studies involving patients undergoing total thyroidectomy. We aimed to assess the risk of recurrence according to the present ATA risk stratification system in patients who underwent lobectomy. DESIGN: Retrospective cohort study. PATIENTS: Patients who underwent thyroid lobectomy for 1-4 cm-sized papillary thyroid carcinoma (n = 571). MEASUREMENTS: Disease-free survival (DFS) was compared according to the ATA risk stratification, and specific lymph node (LN) characteristics were evaluated to modify the ATA criteria with a higher predictability for recurrence. RESULTS: Based on the ATA risk stratification, 439 patients (61.1%) were classified into intermediate- or high-risk group, and consideration for completion thyroidectomy is suggested by ATA guidelines for these patients. However, no significant differences were found in DFS among the low-, intermediate- and high-risk groups (P = .9). In contrast, when patients were stratified according solely to the LN criteria from the ATA risk stratification, only 127 patients (22.2%) had intermediate risk (intermediate-N1a) and exhibited significantly poorer DFS than those with N0 disease (P = .035). Modifying the intermediate-N1a criteria by adding the extranodal extension (ENE) status and omitting the clinical nodal disease enabled the subclassification of 19 patients (3%) with a high risk for recurrence. CONCLUSIONS: The present study suggests that risk stratification based solely on LN metastases is more reasonable for predicting structural persistence/recurrence following lobectomy than that based on the overall ATA criteria. Considering the ENE status can assist in selecting patients with a high risk of recurrence to minimize further treatments.

Safety and feasibility of reduced-port site surgery for robotic posterior retroperitoneal adrenalectomy.

BACKGROUND: Minimally invasive surgery, such as laparoscopic adrenalectomy and robotic adrenalectomy, has become a treatment of choice for benign adrenal tumors. Efforts are ongoing to minimize the invasiveness of the procedure and to reduce the number of port sites. The primary endpoint of this study was the safety and feasibility of a reduced-port site technique for robotic posterior retroperitoneal adrenalectomy (RPRA). METHODS: This study retrospectively analyzed 74 RPRAs performed by a single surgeon, including 30 conventional three-port site early-phase RPRAs, 30 three-port site late-phase RPRAs, and 14 reduced-port site RPRAs. Reduced-port site RRPA was defined as using two port sites: one for a multi-glove port and one for an additional side port. The clinicopathological features and surgical outcomes were compared in these three groups. RESULTS: No major complications were observed following RPRA in the three groups of patients. Operation time, pain score, and hospital stay did not differ significantly among these three groups. CONCLUSIONS: RPRA using a reduced-port site system was safe and feasible and may be a good alternative to conventional three-port site RPRA for benign adrenal tumors in certain situations.

Usefulness of a 3D-Printed Thyroid Cancer Phantom for Clinician to Patient Communication.

BACKGROUND: Thyroid glands and surrounding structures are very complex, and this complexity can pose a challenge for clinicians when explaining and communicating to the patient the details of a proposed surgery for thyroid cancer. A three-dimensional (3D) thyroid cancer model could help and improve this communication. METHODS: A 3D-printed phantom of a thyroid gland and its presenting cancer was produced from segmented head and neck contrast-enhanced computed tomography (CT) data from a patient with thyroid cancer. The phantom reflects the complex anatomy of the arteries, veins, nerves, and other surrounding organs, and the printing materials and techniques were adjusted to represent the texture and color of the actual structures. Using this phantom, patients and clinicians completed surveys on the usefulness of this 3D-printed thyroid cancer phantom. PARTICIPANTS: patients (n = 33) and clinicians (n = 10). RESULTS: In the patient survey, the patients communicated that the quality of understanding of their thyroid disease status was enhanced when clinicians explained using the phantom. The clinicians communicated that the 3D phantom was advantageous for explaining complex thyroid surgery procedures to patients, and that the 3D phantom was helpful in educating patients with relatively poor anatomical knowledge. CONCLUSIONS: Using 3D printing technology, we produced a CT-based 3D thyroid cancer phantom, and patient and clinician surveys on its utility indicated that it successfully helped educate patients, providing them with an improved understanding of the disease.

Clinical Significance of Gross Invasion of Strap Muscles in Patients With 1- to 4-cm-Sized Papillary Thyroid Carcinoma Undergoing Lobectomy.

BACKGROUND: Given the emerging evidence supporting the lack of prognostic significance of gross extrathyroidal extension invading only strap muscles (strap-gETE), this study investigated whether lobectomy is feasible for patients with strap-gETE. METHODS: A retrospective cohort study was conducted with 636 patients who had 1- to 4-cm-sized papillary thyroid carcinoma (PTC) treated with thyroid lobectomy. Patients with gross invasion of perithyroidal organs other than strap muscles or synchronous distant metastasis were excluded from the study. Disease-free survival (DFS) was compared according to the presence of strap-gETE. RESULTS: Strap-gETE was present in 50 patients (7.9%), with the remaining 586 patients (92.1%) showing no evidence of gETE. During the median follow-up period of 7.4 years, 6% of the patients with strap-gETE and 5.1% of the patients without gETE experienced structural persistent/recurrent disease (p = 0.99). No differences in DFS were observed between the two groups (hazard ratio [HR], 1.24; 95% confidence interval [CI], 0.38-4.08; p = 0.720). After adjustment for five major risk factors (age, gender, tumor size, multifocality, and cervical lymph node metastasis status) in the multivariate analysis, the presence of strap-gETE did not exhibit an independent role in the development of structural persistent/recurrent disease (HR 1.05; 95% CI 0.24-4.53, p = 0.950). CONCLUSIONS: Strap-gETE did not increase the risk of structural persistent/recurrent disease for the patients who underwent lobectomy for 1- to 4-cm-sized PTC. The study data support the limited role of strap-gETE in clinical outcomes and may broaden the indications for lobectomy for patients with PTCs.

Malignancy risk of initially benign thyroid nodules: validation with various Thyroid Imaging Reporting and Data System guidelines.

OBJECTIVE: Some authors have found little or no diagnostic benefit from repeated biopsy of benign thyroid nodules. However, to our knowledge, integration of Thyroid Imaging Reporting and Data System (TIRADS) guidelines with one biopsy for sufficient benign thyroid nodule diagnosis has not been previously described. We investigated malignancy rate and probability by using various malignancy stratification systems in initially biopsy-proven benign nodules and sought to determine their clinical relevance in management of benign thyroid nodules. METHODS: This retrospective study collected 6762 thyroid nodules from 6493 consecutive patients who underwent biopsy between January 2013 and December 2013. The initial biopsy with ≥1 year of follow-up was used as the gold standard for benign diagnosis. For our study purpose, we analyzed 2747 (57.0%, 2747 of 4822, 532 women, 2111 men; 229 malignant and 2518 benign) thyroid nodules diagnosed by initial biopsy with 28.2 ± 9.1 (range, 12-41) months of follow-up. We calculated the malignancy probability of thyroid nodules by using various malignancy risk stratification systems. RESULTS: The overall calculated thyroid malignancy rate was 8.3% (229 of 2747). Initially biopsy-proven benign nodules exhibited a ≤3.0% malignancy probability when assessed as "low suspicion" by Korean-TIRADS (K-TIRADS), "low suspicion" by the ATA guideline, and "very probably benign" by the French TIRADS guideline and gave a score of ≤3 by the web-based TIRADS. CONCLUSION: When initially biopsy-proven benign nodules exhibit a "low suspicion" US pattern and low malignancy probability, as stratified by various TIRADS guidelines, imaging surveillance instead of second biopsy is warranted. KEY POINTS: • One biopsy is sufficient for initially biopsy-proven benign nodules. • Repetitive biopsy is necessary for imaging-pathology mismatched nodules. • Scoring risk stratification permits personalized management.

Radiofrequency ablation of primary thyroid carcinoma: efficacy according to the types of thyroid carcinoma.

OBJECTIVE: To evaluate the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) according to the types of thyroid carcinoma, particularly in patients with a high-surgical risk. MATERIALS AND METHODS: Eight patients with nine tumours of pathologically proven papillary and anaplastic carcinoma were treated by US-guided RFA. Patients with primary thyroid carcinoma were divided into three groups; group (1) Anaplastic carcinoma, group (2) papillary macrocarcinoma, and group (3) papillary microcarcinoma. We evaluated changes in clinical symptoms, tumour volume and local tumour recurrence/metastasis after RFA. Patients were followed up at 1, 6 and 12 months and annually thereafter. RESULTS: Among nine tumours, one anaplastic carcinoma was treated three times and the other anaplastic carcinoma and one papillary macrocarcinoma were treated twice. Group 3 were treated once. The initial mean tumour volume was 107.9 ± 78.6 (with neck bulging), 126.9 (with neck bulging) and 0.16 ± 0.08 mL (without cosmetic or symptomatic problems) in groups 1-3, respectively. Group 1 showed no improvement in clinical symptoms or neck bulging after RFA, whereas group 2 demonstrated a decreased tumour volume measuring 0.7 mL with improved neck bulging. In group 3, mean volume decreased measuring 0.07 ± 0.12 mL. No local tumour recurrence or metastatic lesion was detected during the mean follow-up of 19.3 months in papillary carcinomas. No major complications were encountered. CONCLUSIONS: In patients with primary thyroid carcinoma, RFA achieved excellent local tumour control for papillary macro- and microcarcinoma; however, its clinical effect on anaplastic carcinoma was questionable.