Do Hoon Koo

Surgical completeness of bilateral axillo-breast approach robotic thyroidectomy: Comparison with conventional open thyroidectomy after propensity score matching

BACKGROUND Bilateral axillo-breast approach (BABA) robotic thyroidectomy (RoT) has good postoperative and excellent cosmetic outcomes. To assess the surgical completeness of BABA RoT, it was compared to open thyroidectomy (OT) after propensity score matching of the cohorts. METHODS Between 2008 and 2010, 760 patients who underwent total thyroidectomy with central node dissection (CND) caused by papillary thyroid carcinoma (PTC) in Seoul National University Hospital were enrolled; 327 BABA robotic and 423 open method operations were performed. We selected 174 robotic and 237 open thyroidectomy patients who received radioactive iodine (RAI) ablation. Propensity score matching using 3 demographic and 5 pathologic factors was used to generate 2 matched cohorts, each composed of 108 patients. RESULTS The matched BABA RoT and OT cohorts were not different with regard to the RAI uptake ratio, stimulated thyroglobulin (Tg) levels, or proportion of patients with stimulated Tg levels <1.0 ng/mL on the first ablation. The number of RAI ablation sessions and RAI doses needed to achieve a complete ablation also did not differ significantly. CONCLUSION The surgical completeness of BABA RoT did not differ from OT. BABA RoT may be suitable for patients with PTC who prefer scarless neck surgery.

BRAF mutation in follicular variant of papillary thyroid carcinoma is associated with unfavourable clinicopathological characteristics and malignant features on ultrasonography

Follicular variant of papillary thyroid carcinoma (FVPTC) is a common variant of papillary thyroid carcinoma (PTC), but the association between BRAF mutation and the clinicopathological and ultrasonographical characteristics of FVPTC has not been well studied. The aim of this study was to determine the significance of BRAF mutation in FVPTC.

Clinicopathological characteristics and treatment outcomes of 38 cases of primary thyroid lymphoma: a multicenter study

Purpose Primary thyroid lymphoma (PTL) is a rare disease and it has been investigated in a limited number of studies. The present multicenter study evaluated the clinical features and treatment outcomes of PTL. Methods The medical records of patients diagnosed with PTL between 2000 and 2013 in three centers were retrospectively reviewed. Results The study included 11 men and 27 women with a median age of 63.3 years (range, 42-83 years). The median follow-up was 56.0 months (range, 3-156 months). Of the 38 patients included, 16 had mucosa-associated lymphoid tissue (MALT) lymphoma, six had mixed MALT and diffuse large B-cell lymphoma (DLBCL), and 16 had DLBCL. Thirty-five patients (92.1%) had early stage (stage I/II) disease. Of the 16 MALT lymphoma patients, 14 were treated by surgery, and radiotherapy (RT) or chemotherapy was combined in five patients. Two patients received RT or chemotherapy alone. Of the six mixed MALT and DLBCL patients, three underwent surgery with chemotherapy and three underwent chemotherapy alone, RT alone, or surgery with RT. All of the 16 DLBCL patients received chemotherapy, and surgery and RT was combined in 4 and 1 patients, respectively. The 5-year survival was 100% for MALT lymphoma (7 of 7) and mixed MALT and DLBCL patients (5 of 5) and 87.5% for DLBCL patients (7 of 8). Conclusion Early stage PTL has an excellent prognosis when managed by single or combined treatment modalities. Clinicians should consider PTL in patients with underlying Hashimotos thyroiditis presenting with an enlarging thyroid mass.

Clinical Outcome of Remnant Thyroid Ablation with Low Dose Radioiodine in Korean Patients with Low to Intermediate-risk Thyroid Cancer

Radioiodine activity required for remnant thyroid ablation is of great concern, to avoid unnecessary exposure to radiation and minimize adverse effects. We investigated clinical outcomes of remnant thyroid ablation with a low radioiodine activity in Korean patients with low to intermediate-risk thyroid cancer. For remnant thyroid ablation, 176 patients received radioiodine of 1.1 GBq, under a standard thyroid hormone withdrawal and a low iodine diet protocol. Serum levels of thyroid stimulating hormone stimulated thyroglobulin (off-Tg) and thyroglobulin-antibody (Tg-Ab), and a post-therapy whole body scan (RxWBS) were evaluated. Completion of remnant ablation was considered when there was no visible uptake on RxWBS and undetectable off-Tg (<1.0 ng/mL). Various factors including age, off-Tg, and histopathology were analyzed to predict ablation success rates. Of 176 patients, 68.8% (n = 121) who achieved successful remnant ablation were classified into Group A, and the remaining 55 were classified into Group B. Group A presented with significantly lower off-Tg at the first radioiodine administration (pre-ablative Tg) than those of Group B (1.2 ± 2.3 ng/mL vs. 6.2 ± 15.2 ng/mL, P = 0.027). Pre-ablative Tg was the only significant factor related with ablation success rates. Diagnostic performances of pre-ablative Tg < 10.0 ng/mL were sensitivity of 99.1%, specificity of 14.0%, positive predictive value of 71.1%, and negative predictive value of 87.5%, respectively. Single administration of low radioiodine activity could be sufficient for remnant thyroid ablation in patients with low to intermediate-risk thyroid cancer. Pre-ablative Tg with cutoff value of 10.0 ng/mL is a promising factor to predict successful remnant ablation. Graphical Abstract

In-Depth Survey of Scarring and Distress in Patients Undergoing Bilateral Axillo-Breast Approach Robotic Thyroidectomy or Conventional Open Thyroidectomy.

Purpose: Oncologic and surgical outcomes of bilateral axillo-breast approach (BABA) robotic thyroidectomy (RoT) are comparable with those of open thyroidectomy (OT). We compared degree of scarring and psychological/physical distress between OT and BABA RoT. Materials and Methods: Study included 129 cases of thyroidectomy (78 OT, 51 BABA RoT). Patients were evaluated by psychology consultant using 5-point scale questionnaire. Results: BABA RoT was associated with lower degree of scarring than OT (7.8 vs. 11.7, P<0.001). Psychological distress immediately after operation and during surveillance period was higher in OT than in BABA RoT (3.1 vs. 2.6, P=0.009 and 2.4 vs. 1.9, P<0.001). Physical distress (pain and exercise limitation) did not differ between groups (2.5 vs. 2.6, P=0.321 and 2.0 vs. 1.9, P=0.0175). Conclusions: BABA RoT was associated with less scarring and psychological distress than OT. BABA RoT might be alternative for patients who are concerned about neck scar.

Endoscopic completion thyroidectomy by the bilateral axillo-breast approach.

Purpose Bilateral axillo-breast approach (BABA) endoscopic thyroidectomy has been successfully used for various thyroid diseases, with an excellent cosmetic outcome. Patients with a confirmed thyroid malignancy on a permanent thyroid section after endoscopic thyroid lobectomy require completion thyroidectomy. Here, we sought to demonstrate the feasibility of endoscopic completion thyroidectomy by BABA. Patients and Methods Between June, 2006 and February, 2009, 13 patients underwent endoscopic completion thyroidectomy by BABA for minimally invasive follicular thyroid and papillary thyroid carcinomas diagnosed after BABA endoscopic thyroid lobectomy. The median interval between thyroid lobectomy and completion thyroidectomy was 5.6 months (range, 4.2-28.2 mo). We used the same port sites (bilateral breast and axillary region) as were created at the initial operation. Flap adhesion was minimal. After identifying the remnant thyroid lobe, completion thyroidectomy was performed under full visualization of the thyroidal vessels, parathyroid glands, and recurrent laryngeal nerve. Results We performed 5 right and 8 left endoscopic completion thyroidectomies by BABA. The mean operation time was 109.3±23.3 minutes. There were no cases of open conversion. The resulting 6 (46.2%) cases of transient hypocalcemia resolved within 2 postoperative weeks and there were no cases of vocal cord palsy or wound infection. One patient had immediate postoperative breast flap bleeding that required cauterization. No patient had evidence of recurrence, as indicated by follow-up neck ultrasonography and serum thyroglobulin levels. The cosmetic outcomes were excellent and all patients were satisfied. Conclusions BABA endoscopic thyroidectomy appears feasible and safe procedure for completion thyroidectomy, making it a viable technique for reapplication in cases of thyroid carcinoma diagnosed after endoscopic thyroid lobectomy.

Does Tumor Size Influence the Diagnostic Accuracy of Ultrasound-Guided Fine-Needle Aspiration Cytology for Thyroid Nodules?

Background. Fine-needle aspiration cytology (FNAC) is diagnostic standard for thyroid nodules. However, the influence of size on FNAC accuracy remains unclear especially in too small or too large thyroid nodules. The objective of this retrospective cohort study was to investigate the effect of nodule size on FNAC accuracy. Methods. All consecutive patients who underwent thyroidectomy for nodules in 2010 were enrolled. FNAC results (according to the Bethesda system) were compared to pathological diagnosis. The nodules were categorized into groups A–E on the basis of maximal diameter on ultrasound (≤0.5, >0.5–1, >1-2, >2–4, and >4 cm, resp.). Results. There were 502 cases with 690 nodules. Overall FNAC sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.4%, 98.2%, 99.4%, 86.4%, and 96.0%, respectively. False-negative rates (FNRs) of groups A–E were 3.2%, 5.1%, 1.3%, 13.3%, and 50%, respectively. Accuracy rates of groups A–E were 96.8%, 94.8%, 99%, 94.7%, and 87.5%, respectively. Conclusion. Although accuracy rates of FNAC in thyroid nodules smaller than 0.5 cm are comparable to the other group, thyroid nodules larger than 4 cm with benign cytology carry a higher risk of malignancy, which suggest that those should be considered for intensive follow-up or repeated biopsy.

Clinical significance of microscopic anaplastic focus in papillary thyroid carcinoma

BACKGROUND On occasion, a microscopic anaplastic focus (MAF) is discovered in papillary thyroid carcinoma (PTC). The relevance of MAF has not been well studied with regard to its clinical implications. MAF is defined as the microscopic presence of focally dedifferentiated follicular cells within the PTC. METHODS A total of 3,606 patients who underwent primary thyroid surgery between 1995 and 2007 were selected from the database of Seoul National University Hospital. Patients were divided into 3 groups based on histology: PTC without MAF (3,574 patients), PTC with MAF (13 patients), and anaplastic thyroid carcinoma (19 patients). RESULTS Mean ± standard deviation age was 48 ± 12 years (range, 17-83) in the PTC without MAF group, 57 ± 14 years (range, 29-76) in the PTC with MAF group, and 64 ± 14 years (range, 24-86) in the ATC group (P < .001). Mean tumor sizes were 1.2 ± 0.9 cm (range, 0.5-13), 2.1 ± 1.2 cm (range, 0.7-5), and 3.7 ± 1.4 cm (range, 0.4-6), respectively (P < .001). The median follow-up was 32 months. The cause-specific survival at 5 years was 98% in the PTC without MAF group, 64% in the PTC with MAF group, and 11% in the ATC group (P < .001). Multivariate analysis showed that MAF was a prognostic factor for the outcome of PTC patients (hazard ratio, 12.9; 95% confidence interval, 3.1-54.1; P < .001). CONCLUSION MAF negatively influenced the prognosis of patients with PTC. Further research and the design of more aggressive treatment strategies for MAF might be helpful for patients with PTC.

Differences in the characteristics of papillary thyroid microcarcinoma ≤5 mm and >5 mm in diameter

The behavior and optimal management of papillary thyroid microcarcinomas (PTMCs) after thyroidectomy remain unclear. The purpose of this study was to compare the clinicopathologic features and tumor recurrence rates of patients with PTMCs ≤5 mm and >5 mm in diameter after total thyroidectomy.

Prospective, randomized controlled trial on use of ropivacaine after robotic thyroid surgery: Effects on postoperative pain.

We evaluated the effects of ropivacaine for pain relief after robotic thyroid surgery.