Predictors of malignancy for treatment direction in patients with nonfunctioning adrenal incidentaloma.

BACKGROUND: Adrenal incidentalomas (AI) are predominantly nonfunctional and benign, and their detection and differential diagnosis are aided by computed tomography (CT). A nonfunctioning adrenal incidentaloma (NFAI) usually requires regular follow-up; however, adrenalectomy may be necessary in certain patients. This study aimed to evaluate prognostic predictors to guide the treatment approach for AIs. METHODS: This retrospective, single-center study involved patients diagnosed with NFAI from January 2000 to December 2020. Patients were divided into surgery and observation groups. A subgroup analysis compared malignant and benign adenoma within the surgery group. RESULTS: A total of 307 patients were included, with 127 in the surgery group and 180 in the observation group. The surgery group displayed distinct morphological and malignant potential features in CT scans more frequently than the observational group did. The malignant subgroup exhibited more irregular borders on CT, and a higher number of patients with absolute washout under 60 % and relative washout under 40 % compared with the benign adenoma subgroup. Interestingly, within the surgery group, the mean tumor size was <4 cm for the both malignant and benign adenoma subgroups. CONCLUSIONS: Characterizing NFAI is important for appropriate treatment, as not all AIs have a favorable prognosis. CT findings associated with malignant potential, such as Hounsfield unit and washout values, were useful in determining the need for surgical treatment. However, the conventional criterion of a 4-cm size threshold for surgery was not a reliable malignancy predictor. Surgical resection should be considered for specific patient groups to ensure proper treatment over mere observation.

Radiofrequency Ablation for the Treatment of Benign Thyroid Nodules: 10-Year Experience.

Background: Longer follow-up after radiofrequency ablation (RFA) of benign thyroid nodules is needed to understand regrowth and other causes of delayed surgery and long-term complications. Methods: This retrospective study included consecutive patients treated with RFA for symptomatic benign nonfunctioning thyroid nodules between March 2007 and December 2010. RFA was performed according to the standard protocol. We followed up patients at 1, 6, and 12 months, then yearly, until August 2022, and calculated the volume reduction ratio (VRR) at each follow-up. We assessed the incidence of regrowth according to three published criteria, delayed surgery, and complications. The Kaplan-Meier method was used to evaluate the cumulative incidence of regrowth, and univariable and multivariable Cox regression analyses were performed to identify risk factors for regrowth. Results: This study included 421 patients (mean age, 47 ± 13 years; 372 women) with 456 nodules (mean volume, 21 ± 23 mL). The median follow-up period was 90 months (interquartile range, 24-143 months). The mean VRR was 81% at 2 years, 90% at 5 years, and 94% at ≥10 years. Overall regrowth was noted in 12% (53/456) of nodules and was treated with repeat RFA (n = 33) or surgery (n = 4) or left under observation (n = 16). Thyroid nodules with ≥20 mL initial volume had significantly higher risk of regrowth compared with nodules with <10 mL initial volume (hazard ratio, 2.315 [95% confidence interval, 1.183-4.530]; p = 0.014 on multivariable Cox regression analysis). Delayed surgery was performed in 6% (26/421) of patients because of regrowth and/or persistent symptoms (n = 4) or newly detected thyroid tumors (n = 22), one benign and 21 malignant. The overall complication rate was 2.4% (10/421), with no procedure-related deaths or long-term complications. Conclusion: RFA is safe and effective for treating benign thyroid nodules, with a high VRR at long-term follow-up. Regular follow-up after initial success is warranted because of the possibility of regrowth of ablated nodules and the need for delayed surgery in some patients.

Effectiveness of microvascular flow imaging for radiofrequency ablation in recurrent thyroid cancer: comparison with power Doppler imaging.

OBJECTIVES: To compare microvascular flow imaging (MVFI) and power Doppler ultrasonography imaging (PDUS) for detecting intratumoral vascularity in recurrent thyroid cancer both before and after radiofrequency ablation (RFA). METHODS: This retrospective study included 80 patients (age, 57 ± 12 years; 54 women) with 110 recurrent tumors who underwent RFA between January 2021 and June 2023. A total of 151 PDUS and MVFI image sets were analyzed (85 pre-RFA, 66 post-RFA). Two readers assessed vascularity on the images using a four-point scale with a 2-week interval between PDUS and MVFI to estimate inter-reader agreement. Intra-reader agreement was determined by reinterpreting images in reverse order (MVFI-PDUS) after a 1-month gap. Additionally, diagnostic performance for identifying viable tumors after RFA was assessed in 44 lesions using thyroid-protocol CT as a reference standard. RESULTS: MVFI demonstrated higher vascular grades than PDUS, both before (reader 1: 3.04 ± 1.15 vs. 1.93 ± 1.07, p < 0.001; reader 2: 3.20 ± 0.96 vs. 2.12 ± 1.07, p < 0.001) and after RFA (reader 1: 2.44 ± 1.28 vs. 1.67 ± 1.06, p < 0.001; reader 2: 2.62 ± 1.23 vs. 1.83 ± 0.99, p < 0.001). Inter-reader agreement was substantial (κ = 0.743) and intra-reader agreement was almost perfect (κ = 0.840). MVFI showed higher sensitivity (81.5%-88.9%) and accuracy (84.1%-86.4%) than PDUS (sensitivity: 51.9%, p < 0.01; accuracy: 63.6-70.5%, p < 0.04), without sacrificing specificity. CONCLUSION: MVFI was superior to PDUS for assessing intratumoral vascularity and showed good inter- and intra-reader agreement, highlighting its clinical value for assessing pre-RFA vascularity and accurately identifying post-RFA viable tumors in recurrent thyroid cancer. CLINICAL RELEVANCE STATEMENT: Microvascular flow imaging (MVFI) is superior to power-Doppler US for assessing intratumoral vascularity; therefore, MVFI can be a valuable tool for assessing vascularity before radiofrequency ablation (RFA) and for identifying viable tumors after RFA in patients with recurrent thyroid cancer. KEY POINTS: The value of microvascular flow imaging (MVFI) for evaluating intratumoral vascularity is unexplored. MVFI demonstrated higher vascular grades than power Doppler US before and after ablation. Microvascular flow imaging showed higher sensitivity and accuracy than power Doppler US without sacrificing specificity.

Tumor Growth Kinetics Based on Initial Tumor Volume Doubling Time in Active Surveillance of Low-Risk Papillary Thyroid Carcinoma.

Background: During active surveillance (AS) of low-risk papillary thyroid carcinomas (PTCs), the majority remain stable, while some exhibit either an increase or a decrease in tumor diameter or tumor volume (TV). We aimed to evaluate the clinical outcomes and relevant parameters influencing tumor growth kinetics of low-risk PTCs. Methods: This retrospective cohort study evaluated clinical parameters of 402 patients with low-risk PTC sized <2 cm, with a follow-up duration over 3 years. Changes in maximum tumor diameter, TV, and initial TV doubling time (i-TVDT) calculated within 3 years were assessed. A significant change in TV was defined as a change of 75% or more. Results: Of the 402 patients with low-risk PTC, 93.3% (375/402) were diagnosed with papillary thyroid microcarcinoma. During a median follow-up of 5 years, 3.4% (14/402) of patients developed new cervical lymph node (LN) metastasis, and 8.2% (33/402) experienced a maximal diameter increase of ≥3 mm. The i-TVDT of <5 years emerged as an independent risk factor for both maximal diameter growth and new LN metastasis (p < 0.001 and p = 0.04, respectively). Based on TV changes and i-TVDT during AS, we identified four statistically significant tumor kinetic patterns (p < 0.001): Stable (±75% change in TV), Rapid growth (TV increase >75% and i-TVDT <5 years), Slow growth (TV increase >75% and i-TVDT ≥5 years), and Shrinkage (TV decrease >75%). Most of the PTCs remained stable (67.7%), but 17.2% were rapidly growing, with a median onset of growth of 2.0 years. Slowly growing PTCs, comprising 10.9%, grew at a median of 4.3 years. A minority, 4.2%, exhibited shrinkage. In total, 115 (28.6%) patients underwent delayed surgery >12 months after initiating AS. The reasons for delayed surgery included patient preference (51/115, 44.3%), disease progression (31/115, 27.0%), and suspected disease progression, which was referred to as tumor growth not meeting the criteria of an increase of ≥3 mm in maximal tumor diameter (17/115, 14.8%). Conclusion: An i-TVDT of <5 years serves as an important prognostic indicator for disease progression, including tumor growth and new LN metastasis. The four tumor kinetic patterns based on TV changes and i-TVDT assist in guiding personalized decisions early in AS.

Exploring the Benefits of a Reduced-Port Approach in Robotic Posterior Retroperitoneoscopic Adrenalectomy: A Comparative Study of the Two-Port and Three-Port Techniques.

Background: Robotic adrenalectomy has become a surgical treatment option for benign and selected malignant adrenal diseases. We aimed to evaluate the eligibility of two-port robotic posterior retroperitoneoscopic adrenalectomy (PRA) as an alternative to the conventional three-port technique by comparing their surgical outcomes. Materials and Methods: This retrospective cohort study compared the clinicopathological factors and surgical outcomes among 197 patients who underwent two-port or three-port robotic adrenalectomy between 2016 and 2020 in a single tertiary center. For further evaluation, propensity score matching was performed to reduce the selection bias in population characteristics. Results: Patients were categorized by the number of ports (two-port group, 87; and three-port group, 110). The two-port group compared with the three-port group was significantly older (P = .006) and had a smaller mean tumor size (P = .003) and shorter mean operation time (P = .001). Upon comparing clinicopathologic characteristics according to adrenal disorders, for pheochromocytoma, the three-port group had a larger tumor size and a longer operation time. For Cushing's syndrome, the operation time was short and numeric rating scale pain score was significantly low in the two-port group. After propensity score matching, the two-port group had a short operation time and a significantly low postoperative pain score (P < .05). Predictive factors associated with prolonged operation time included male gender, an increased number of ports, and large tumor size. Conclusions: The two-port technique resulted in a shorter operation time and lower pain score compared with the three-port technique. The two-port technique may be a safe alternative to the conventional three-port technique for robotic PRA.

Silent pheochromocytoma in adrenal incidentaloma: unveiling clinical and radiological characteristics.

Purpose: Silent pheochromocytoma refers to tumors without signs and symptoms of catecholamine excess. This study aimed to clarify the clinical, radiological characteristics, and perioperative features of silent pheochromocytomas diagnosed after adrenalectomy for adrenal incidentaloma. Methods: Medical records of patients who underwent adrenalectomy for adrenal incidentaloma and were subsequently diagnosed with silent pheochromocytoma between January 2000 and December 2020 were retrospectively reviewed for demographic, diagnostic, surgical, and pathological findings. Results: Of the 130 patients who underwent adrenalectomy for incidentaloma, 8 (6.1%) were diagnosed with silent pheochromocytoma. Almost all patients had no hypertensive symptoms and their baseline hormonal levels remained within normal ranges. All patients exhibited tumor size >4 cm, precontrast Hounsfield unit >10, and absolute washout <60%. Intraoperative hypertensive events were noted in 2 patients (25.0%) in whom antiadrenergic medications were not administered. All patients in the intraoperative hypertensive event group exhibited atypical features on CT, whereas 83.3% of patients in the non-intraoperative hypertensive event group showed atypical features on CT imaging. Conclusion: Silent pheochromocytomas share radiological traits with malignant adrenal tumors. Suspicious features on CT scans warrant surgical consideration for appropriate treatment. Administering alpha-blockers can enhance hemodynamic stability during adrenalectomy in suspected silent pheochromocytoma cases.

Predictive factors for persistent hypercalcemia following parathyroidectomy in patients with persistent hyperparathyroidism after kidney transplantation: a retrospective cohort study.

BACKGROUND: Surgery for irreversible hyperparathyroidism is the preferred management for kidney transplant patients. The authors analyzed the factors associated with persistent hypercalcemia after parathyroidectomy in kidney transplant patients and evaluated the appropriate extent of surgery. MATERIALS AND METHODS: The authors retrospectively analyzed 100 patients who underwent parathyroidectomy because of persistent hyperparathyroidism after kidney transplantation at a tertiary medical center between June 2011 and February 2022. Patients were divided into two groups: 22 with persistent hypercalcemia after parathyroidectomy and 78 who achieved normocalcemia after parathyroidectomy. Persistent hypercalcemia was defined as having sustained hypercalcemia (≥10.3 mg/dl) 6 months after kidney transplantation. The authors compared the biochemical and clinicopathological features between the two groups. Multivariate logistic regression analysis was used to identify potential risk factors associated with persistent hypercalcemia following parathyroidectomy. RESULTS: The proportion of patients with serum intact parathyroid hormone (PTH) level is greater than 65 pg/ml was significantly high in the hypercalcemia group (40.9 vs. 7.7%). The proportion of patients who underwent less than subtotal parathyroidectomy was significantly high in the persistent hypercalcemia group (17.9 vs. 54.5%). Patients with a large remaining size of the preserved parathyroid gland (≥0.8 cm) had a high incidence of persistent hypercalcemia (29.7 vs. 52.6%). In the multivariate logistic regression analysis, the drop rate of intact PTH is less than 88% on postoperative day 1 (odds ratio 10.3, 95% CI: 2.7-39.1, P =0.001) and the removal of less than or equal to 2 parathyroid glands (odds ratio 6.8, 95% CI: 1.8-26.7, P =0.001) were identified as risk factors for persistent hypercalcemia. CONCLUSION: The drop rate of intact PTH is less than 88% on postoperative day 1 and appropriate extent of surgery for controlling the autonomic function were independently associated with persistent hypercalcemia. Confirmation of parathyroid lesions through frozen section biopsy or intraoperative PTH monitoring can be helpful in preventing the inadvertent removal of a parathyroid gland and achieving normocalcemia after parathyroidectomy.

Diagnostic consistency between computed tomography and adrenal vein sampling of primary aldosteronism: leading to successful curative outcome after adrenalectomy; a retrospective study.

BACKGROUND: Adrenal computed tomography (CT) is a useful tool for locating adrenal lesion in primary aldosteronism (PA) patients. However, adrenal vein sampling (AVS) is considered as a gold standard for subtype diagnosis of PA. The aim of this study was to investigate the consistency of CT and AVS for the diagnosis of PA subtypes and evaluate the concordance of surgical outcomes. MATERIALS AND METHODS: This retrospective study included 264 PA patients having both CT and AVS. Diagnostic consistency between CT and AVS was accessed, and clinical and biochemical outcomes were evaluated at 6 months after adrenalectomy. RESULTS: Of all, 207 (78%) had a CT unilateral lesion, 31 (12%) CT bilateral lesion, and 26 (10%) CT bilateral normal findings. Among the CT unilateral lesion group, 138 (67%) had ipsilateral AVS lateralization. For CT bilateral lesion and bilateral normal, AVS unilateral lateralization was found in 17 (55%) and 2 (8%), respectively. The consistency between CT lesion and AVS lateralization including CT unilateral with AVS ipsilateral, and CT bilateral lesion with AVS bilateral patients was 63.8% (152/238). Of 77 patients with available data out of 138 patients who underwent adrenalectomy with consistency between CT and AVS, the clinical success rate was 96%, for 17 inconsistency patients out of 22 patients who underwent adrenalectomy, the clinical success rate was 94% after adrenalectomy following the lateralization result of AVS. CONCLUSION: CT is a useful tool to diagnose the adrenal lesion in PA patients. However, AVS is more sufficient to detect the unilateral PA subtype, which could provide curable treatment to surgical candidates of PA such that AVS can identify patients with contralateral PA in CT unilateral lesion and unilateral PA in CT bilateral lesion. The surgical outcome was successful when an adrenalectomy was performed according to the AVS lateralization result.

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.

Contralateral Low-to-Intermediate Suspicion Nodule Is Not a Contraindication for Lobectomy in Patients with Papillary Thyroid Carcinoma.

Background: The optimal extent of surgery for unilateral papillary thyroid carcinoma (PTC) with contralateral nodules remains unclear. This study evaluated the long-term outcomes in a large cohort of patients with unilateral PTC and contralateral low-to-intermediate suspicious nodules who underwent lobectomy. Methods: This retrospective cohort study included patients with unilateral PTC who underwent lobectomy between January 2016 and December 2017 at Asan Medical Center in Korea. Patients were divided into two groups, those with and without contralateral nodules at the time of lobectomy: the Present group and the Absent group. All contralateral nodules observed at the time of surgery and during follow-up were evaluated. Results: The study cohort consisted of 1761 patients (1879 nodules), including 700 (39.8%) with and 1061 (60.2%) without contralateral nodules. The median size of the contralateral nodules was 0.5 cm. After a median follow-up of 59 months, the median growth of the contralateral nodules in the Present group was 0.1 cm (range, -3.4 to 4.7 cm). Of the contralateral nodules present at the time of lobectomy, 54.7% remained unchanged, decreased in size, or disappeared; whereas 14.8% increased ≥0.3 cm. Of the 700 patients with contralateral nodules, 20 (2.9%) were diagnosed with contralateral PTC. The 5-year contralateral PTC disease-free survival rates in patients with and without contralateral nodules were 98.2% and 99.3% (p = 0.003), respectively, whereas the 5-year recurrence-free survival rates did not differ significantly in these two groups. Of the 39 patients who underwent completion thyroidectomy, 2 (5.1%) experienced permanent hypocalcemia. Conclusions: Lobectomy may be a safe and feasible initial treatment option for patients with unilateral low-risk PTC and contralateral low-to-intermediate suspicious nodules.

Radiofrequency ablation of benign thyroid nodules: the value of anterolateral hydrodissection.

PURPOSE: This study aimed to evaluate the technical feasibility, efficacy, and safety of anterolateral hydrodissection (ALHD) in radiofrequency ablation (RFA) for benign thyroid nodules. METHODS: Between November 2019 and April 2020, 39 patients underwent 41 sessions of RFA with the ALHD technique to treat benign thyroid nodules. ALHD was performed with cold (0°C-4°C) 5% dextrose solution during RFA to minimize pain and secure sufficient safety margins from critical neck structures. The initial ablation ratio (IAR) was measured to assess the technique's efficiency. Ultrasound examinations, symptoms, and cosmetic scores were evaluated pre-procedure and at 6 and 12 months post-procedure. Procedure-related pain during RFA and complications were recorded. RESULTS: The mean index nodule volume was 20.5±21.6 mL. ALHD was technically feasible in all patients. The mean IAR was 90.7%±8.3%, and significant reductions in mean nodule volume were noted at 6- and 12-month follow-ups (P<0.001, 63.9%±19.0%, and 76.3%±18.9%, respectively). Symptom and cosmetic scores showed significant improvements at 6- and 12-month follow-ups (P<0.001). Pain during the procedure was well-controlled with ALHD in all patients. After the initial use of 5-10 mL of lidocaine at the start of the procedure, no further lidocaine injection was given to any patient. Transient voice change was observed in one patient, but the patient recovered spontaneously within 30 minutes. CONCLUSION: The ALHD technique was technically feasible and effective in all patients, achieving a mean IAR of 90.7%. The ALHD technique also had a pain-relieving effect, resulting in only low amounts of lidocaine administration being required during the procedure.

Short-term outcome of adrenal radiofrequency ablation of adrenal cysts: a single-center experience.

Percutaneous thermal ablation is a minimally invasive treatment for liver, kidney, lung, bone, and thyroid tumors. This treatment also has been used to treat adrenal tumors in patients, but there is no evidence for the efficacy of thermal ablation of adrenal cysts. The present study was performed to analyze the experience of a single center with percutaneous radiofrequency ablation (RFA) of adrenal cysts and to evaluate its efficacy. The present study enrolled all patients who underwent percutaneous RFA for unilateral adrenal cysts from 2019 to 2021. All patients underwent USG-guided percutaneous aspiration of cystic fluid, followed by RFA. A total nine patients with adrenal cysts were included in this study. All of them underwent technically successful percutaneous RFA, with no immediate complication. Follow-up CT 3 months after RFA showed that six of the nine adrenal cysts showed good responses, with reductions in cyst volume ranging from 86.4 to 97.9%. One patient had poor response in the cyst size (volume reduction rate 11.2%). She underwent secondary RFA with resulting that the cyst volume reduced by 91.1%. After a median follow-up period of 17.2 months, eight patients showed no evidence of regrowth. The patient, who showed evidence of regrowth, declined any other treatment and has been under regular surveillance. None of the nine patients developed adrenal insufficiency during the follow-up period. In conclusion, percutaneous RFA is a safe and effective minimally invasive treatment for adrenal cysts, suggesting that percutaneous RFA may be a good alternative option in selected patients.

Change of treatment modality and outcomes of adrenocortical carcinoma: a retrospective review of single tertiary center experience over 24 years.

Background: Adrenocortical carcinoma, a rare malignancy, has a poor prognosis, and the treatment modalities have not been well established. This study aimed to analyze the trend of treatment modalities and outcomes of patients with adrenocortical carcinoma. Methods: We retrospectively analyzed 94 patients with adrenocortical carcinoma between January 1995 and June 2020 for distributions according to the American Joint Committee on Cancer (AJCC) 8th edition tumor-node-metastasis (TNM) staging, the yearly trend of demographic features, differences in multidisciplinary treatment, and prognostic outcomes. Multidisciplinary treatment included any combination of treatment including surgery, mitotane, chemotherapy or radiation. Results: The mean age and tumor size were 48.9 years and 11.7 cm, respectively. Fifteen patients (16.0%) underwent surgery only, and 56 (59.6%) underwent surgery with additional multidisciplinary treatments. Initial curative treatment was performed in all patients with stage 1 (n=5), 33 patients with stage 2 (n=34, 97.1%), 12 patients with stage 3 (n=19, 63.2%), and 11 patients with stage 4 (n=36, 30.6%) (P<0.0001). Two patients (40.0%) with stage 1 presented recurrence. In stages 2, 3, and 4, 57.6%, 58.3%, and 90.9% of patients who received curative treatment had recurrences, respectively. The annual trend presented statistical differences in mitotane use that have been increasing recently (P<0.0001). Conclusions: Overall distribution of adrenocortical carcinoma stage was similar throughout the years. Although the rate of mitotane use in the treatment of patients with Adrenocortical carcinoma has increased over time, recurrences were common even after multidisciplinary curative treatment in all stages. The treatment effect and prognostic outcomes presented no promising progression even with adjuvant chemotherapy and mitotane use in addition to surgical treatment. Adrenocortical carcinoma still presented an extremely poor prognosis, and further prospective studies are needed.

Diagnostic Performance of Core Needle Biopsy for Characterizing Thyroidectomy Bed Lesions.

OBJECTIVE: Thyroidectomy bed lesions frequently show suspicious ultrasound (US) features after thyroid surgery. Fine-needle aspiration (FNA) may not provide definitive pathological information about the lesions. Although core-needle biopsy (CNB) has excellent diagnostic performance in characterizing suspicious thyroid nodules, no published studies have evaluated the performance of CNB specifically for thyroidectomy bed lesions. Therefore, we aimed to evaluate the diagnostic performance and safety of CNB for characterizing thyroidectomy bed lesions. MATERIALS AND METHODS: A total of 124 thyroidectomy bed lesions in 113 patients (79 female and 34 male; age, 23-85 years) who underwent US-guided CNB between December 2008 and December 2020 were included. We reviewed the US imaging features of the target lesions and the histories of previous biopsies. The pathologic results, diagnostic performance for malignancy, and complications of CNB were analyzed. RESULTS: All samples (100%) obtained by CNB were adequate for pathological analysis. Pathological analysis revealed inconclusive results in two lesions (1.6%). According to the reference standard, 50 lesions were ultimately malignant (40.3%), and 72 were benign (58.1%), excluding the two inconclusive lesions. The performance of CNB for diagnosing malignant thyroidectomy bed lesions in the 122 lesions had a sensitivity of 98.0% (49/50), a specificity of 100% (72/72), positive predictive value of 100% (49/49), and negative predictive value of 98.6% (72/73). Eleven lesions were referred for CNB after prior inconclusive FNA results in thyroidectomy bed lesions, for all of which CNB yielded correct conclusive pathologic diagnoses. According to the pathological analysis of CNB, there were various benign lesions (58.9%, 73/124) besides recurrence, including benign postoperative lesions other than suture granuloma (32.3%, 40/124), suture granuloma (15.3%, 19/124), remnant thyroid tissue (5.6%, 7/124), parathyroid lesions (4%, 5/124), and abscesses (1.6%, 2/124). No major or minor complications were associated with the CNB procedure. CONCLUSION: US-guided CNB is accurate and safe for characterizing thyroidectomy bed lesions.

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.

Thyroid-dedicated internally-cooled wet electrode for benign thyroid nodules: experimental and clinical study.

BACKGROUND: To assess the effects of radiofrequency ablation (RFA) using an internally-cooled wet (ICW) electrode in ex vivo bovine liver and evaluate the feasibility of the ICW electrode for benign thyroid nodules. METHODS: We developed an 18-gauge ICW electrode with a microhole at the distal tip for tissue infusion of chilled (0 - 4 °C) isotonic saline (rate = 1.5 ml/min). RFA using ICW and IC electrodes were performed in bovine livers (40 pairs, 1-cm active tip, 50 W, 1-min). We compared the morphological characteristics of ablation zones and presence of carbonization. Twenty patients with benign thyroid nodules larger than 5 ml were prospectively enrolled in a clinical study and underwent ultrasound-guided RFA with ICW electrodes. Ultrasound examinations, laboratory data, and symptom and cosmetic scores were evaluated preprocedure and 1 and 6 months after the procedure. RESULTS: In the ex vivo study, the ICW achieved significantly larger ablation zones than the IC (p<.001). In the clinical study, ICW electrodes were tolerable in all patients. At last follow-up, nodule volume had decreased from 15.6 ± 12.1 ml to 4.1 ± 4.3 ml (p<.001), and the mean volume reduction ratio (VRR) was 73.3 ± 13.7% at 6.0 months follow-up. Cosmetic and symptom scores were reduced from 3.52 ± 1.03 to 2.65 ± 0.88 and 3.10 ± 2.17 to 0.85 ± 0.99 (both p<.001), respectively. After RFA, thyroid function was well preserved in all patients, and mean thyroglobulin level decreased from 36.6 ± 52.1 ng/ml to 26.9 ± 62.2 ng/ml. One patient experienced a temporary voice change that recovered within a week. CONCLUSIONS: We developed a thyroid-dedicated ICW electrode that we showed to be feasible and effective in patients with benign thyroid nodules.

Is Maintaining Thyroid-Stimulating Hormone Effective in Patients Undergoing Thyroid Lobectomy for Low-Risk Differentiated Thyroid Cancer? A Systematic Review and Meta-Analysis.

There is no clear evidence that post-operative maintenance of thyroid-stimulating hormone (TSH) in the mid to lower reference range (0.5-2 mU/L) improves prognosis in patients undergoing thyroid lobectomy for low-risk differentiated thyroid cancer (DTC). The purpose of this systematic review and meta-analysis was to compare and analyze the recurrence rate according to whether the serum TSH level was maintained below 2 mU/L in patients who underwent thyroid lobectomy for low-risk DTC. Clinical data and outcomes were collected from MEDLINE, Embase, and the Cochrane Database of Systematic Reviews. The inclusion criteria were related studies on TSH maintenance or serum TSH concentration after surgery for DTC. Seven observational studies with a total of 3974 patients were included in this study. In the patients who received TSH maintenance less than 2 mU/L, the recurrence rate during the follow-up period was 2.3%. A subgroup analysis of five studies showed that the odds ratio for recurrence in patients who received TSH maintenance was 1.45 (p-value = 0.45) compared to patients who did not receive TSH maintenance. In conclusion, the evidence for the effectiveness of post-operative TSH maintenance less than 2 mU/L in patients undergoing thyroid lobectomy for low-risk DTC is insufficient.

Parathyroidectomy versus cinacalcet in the treatment of tertiary hyperparathyroidism after kidney transplantation: a retrospective study.

BACKGROUND: Hyperparathyroidism is common in patients with chronic kidney disease with reduced renal function and has been observed after kidney transplantation. The optimal treatment for cases in which hyperparathyroidism persists after kidney transplantation has not been determined. METHODS: This retrospective study included 83 patients with tertiary hyperparathyroidism who underwent kidney transplantation between 2000 and 2018 at a single tertiary center in Korea. Sixty-four patients underwent parathyroidectomy and 19 patients were treated with cinacalcet following renal transplantation. Biochemical parameters and clinical outcomes were compared between the two groups. RESULTS: Serum calcium and parathyroid hormone (PTH) levels improved in both the parathyroidectomy and cinacalcet groups. One year after treatment, parathyroidectomy resulted in a lower mean serum calcium level than cinacalcet (9.7 ± 0.7 mg/dL vs. 10.5 ± 0.7 mg/dL, p = 0.001). Regarding serum PTH, the parathyroidectomy group showed a significantly lower PTH level than the cinacalcet group at 6 months (129.1 ± 80.3 pg/mL vs. 219.2 ± 92.5 pg/mL, p = 0.002) and 1 year (118.8 ± 75.5 pg/mL vs. 250.6 ± 94.5 pg/ mL, p < 0.001). There was no statistically significant difference in the incidence of kidney transplant rejection, graft failure, cardiovascular events, fracture risk, or bone mineral density changes between the two groups. CONCLUSION: Parathyroidectomy appears to reduce PTH and calcium levels effectively in tertiary hyperparathyroidism. However, creatinine level and allograft rejection should be monitored closely.

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.