Cheng-Chiao Huang, MD, MSc Risk Factors of Central Lymph Node Metastases in Papillary Thyroid Cancer Cheng-Chiao Huang, MD, MSc Division of Breast & Endocrine Surgery, TMUH The Ph.D. Program for Cancer Biology and Drug Discovery, TMU

Thyroid Image Reporting And Data System TIRADS 1 Normal thyroid gland TIRADS 2 Benign conditions 0% malignancy TIRADS 3 Probably benign nodules 5% malignancy TIRADS 4 Suspicious nodules 5–80% malignancy TIRADS 5 Probably malignant nodules >80% malignancy TIRADS 6 Biopsy proven malignant nodules A subdivision into 4a (malignancy between 5 and 10%) and 4b (malignancy between 10 and 80%) was optional 沒有TIRADS 0

TIRADS 3 TIRADS 4 TIRADS 5 RFA Core biopsy

Current status of core needle biopsy of the thyroid CNB has been suggested as an alternative to FNA in patients with previous nondiagnostic results or atypia of undetermined significance It is also useful for the differentiation rapidly growing thyroid tumors (lymphoma vs. anaplastic thyroid carcinoma) follicular lesions (follicular neoplasm vs. nodular hyperplasia) medullary thyroid carcinoma calcified thyroid nodules degenerating thyroid nodules CNB要小心！

40-year-old man Right thyroid nodule TIRADS 5 FNA solid or almost completely solid: 2 hypoechoic: 2 wider than tall: 0 lobulated/irregular: 2 macrocalcifications: 1 TIRADS 5 FNA atypical cellular change CNB papillary carcinoma

Total thyroidectomy? Known distant metastases Tumor > 4cm in diameter Cervical lymph node metastases Poorly differentiated Consider for prior radiation exposure (category 2B) Consider bilateral nodularity NCCN guidelines

40-year-old man Right hemithyroidectomy Prophylactic CLND Level VI lymph nodes Negative (0/6) pT1bN0M0 Stage I

Papillary thyroid cancer February 2015 to August 2017 136 patients Central neck lymph node dissection (CLND) 21.3% 78.7%

13/29 (44.8%) 42/107 (39.3%) 2015-2017

Discussion In thyroid cancer, women encounter a potentially higher incidence of the disease. However, several studies suggested that LNM rate in men was higher than that in women, and could be used as an independent predictor of LNM The CLNM rate in <20 years group was as high as 90.9%. Thus, we proposed that the treatment of such patients with routine prophylactic CLND be rather beneficial Liu et al. Medicine (2017) 96:43

Prophylactic CLND Disease recurrence significantly lower (2.52% vs. 4.59%) Transient RLN injury significantly higher (3.53% vs. 1.99%) Transient hypocalcemia significantly higher (25.75% vs. 14.83%) Permanent hypocalcemia significantly higher (4.11% vs. 1.95%) No significant difference in permanent RLN injury No significant difference in disease-free survival Chen L, et al. World J Surg. 2018

Take home messages Thyroid core biopsy can prevent repeated FNA or unnecessary thyroidectomy Tumor size > 2cm and extrathyroidal distension should consider prophylactic CLND CLND helps us decide to perform total thyroidectomy or not, but must be careful