Practice patterns among thyroid cancer surgeons: implications of performing a prophylactic central neck dissection

BACKGROUND Indications for performing a prophylactic central neck dissection (pCND) in papillary thyroid cancer (PTC) remain controversial. It is unclear how identification of lymph node (LN) metastases should impact the decision to treat with radioactive iodine (RAI). The goals of this study were to identify indications for performing pCND and identify factors that predict the use of adjuvant RAI. METHODS This was a population based cross-sectional analysis. A prospectively collected database identified 594 patients who underwent total thyroidectomy +/- CND. A multivariate model was constructed to identify indications for pCND and predictors of the use of RAI. RESULTS 425 CNDs were performed of which 224 were prophylactic. Conventional risk factors (age, tumor size, extra-thyroidal extension) were not associated with performing a pCND. The presence of clinically suspicious lymphadenopathy was the only factor associated with performing CND, thus rendering the CND therapeutic. Positive LNs were retrieved in 39 % of pCND's, upstaging 87 patients. Among all peri-operative predictors of receiving RAI, presence of LN metastases was the strongest predictor [OR = 5.9 (3.7-9.5)], while tumor size was a modest predictor [OR = 1.8 (1.5-2.1)]. Other conventional risk factors did not predict use of adjuvant RAI. CONCLUSIONS Conventional risk factors were not indications for performing a pCND, implying that the decision was based on individual surgeon preference. Performing pCND upstaged 39 % of patients from cN0 to pN1a, increasing the likelihood of receiving RAI 6-fold. Conventional risk factors were not predictors of receiving adjuvant RAI. This highlights the need for a unified approach to performing a pCND and administering RAI.