P33: PROPOSAL OF A NEW SCORING TOOL FOR PREDICTION OF HYPOCALCEMIA IN PATIENTS UNDERGOING SURGERY FOR PAPILLARY THYROID CANCER

Post-operative hypocalcemia occurs more frequently in certain high-risk patients. The aim of our study is to propose a preliminary scoring system to identify patients who are more likely to develop hypocalcemia following surgery for papillary thyroid cancer. Method The study was performed with a retrospective developmental cohort(n=131) and a prospective validation cohort(n=71). Patients underwent either Total Thyroidectomy(TT), TT+Central Neck Dissection(CND) or TT+CND+Modified Radical Neck Dissection(MRND). Significant pre-operative variables and operative findings were converted into categorical variables for analysis. Univariate, multivariate analysis and a logistic regression were used to select significant predictors. The score was constructed by converting into integer, the regression coefficients of independently predictive factors in the logistic regression model. This score was validated prospectively in the validation cohort. Result 24(18%) out of 131 patients in the developmental cohort and 16(22.5%) out of 71 patients in the validation cohort had symptomatic hypocalcemia. Thyroiditis, positive lymph node metastasis, central and lateral compartment dissection, Neutrophil-to-lymphocyte ratio(NLR)>3.35 and platelet-to-lymphocyte ratio(PLR)>135 were selected as significant predictors. A score with a range of 0-11 was created. The cut-off value for the score was 6 points(sensitivity of 92.0% and specificity of 89.0%). Areas under the ROC curve for the scores were 0.926 and 0.901 in the developmental and validation cohorts, respectively. Conclusion This score could be a tool in the prediction of hypocalcemia and could help in identifying patients at a higher risk of post-operative hypocalcemia and guide calcium/Vitamin D treatment, as well as facilitate a safe earlier hospital discharge for low risk patients. Take-home message The proposed scoring system could help in identification of patients at a higher risk of post-operative hypocalcemia.