Is it possible to predict the need for completion thyroidectomy in patients whoundergone lobectomy for nodular goiter?

Objective: To determine pre-operative independent predictive factors influencing the need for completion thyroidectomy in patients undergone lobectomy-istmectomy and to create a nomogram which calculates the risk of completion thyroidectomy using these factors and to adopt it in our clinical practice. Materials and Methods: 232 patients over the age of 18 underwent lobectomy-isthmectomy due to benign or differentiated thyroid cancer at General Surgery Clinic, Tokat Gaziosmanpaşa University (TOGU) between January 2010 and June 2023. A nomogram was created using the formula E(Y)=pr(Y=1)=1/[1+exp(β0 +Sk j βjXj with the risk factors that were significant in univariate analysis and the independent predictive factors affecting completion thyroidectomy detected in the logistic regression analysis. Area under the curve (AUC) value was calculated by performing ROC (Receiver-operating characteristic) analysis depending on whether completion thyroidectomy was performed or not. A value of p<0.05 was considered statistically significant. Results: In this study, presence of hypoechoic echogenicity (p=0.01), presence of heterogeneous echogenicity (p=0.01), presence of cystic structure (p=0.01), irregular border structure (p=0.01), presence of intranodular blood flow (p=0.01), follicular neoplasm or its suspicion (p=0.01), non-diagnostic or benign histopathology (p=0.01) were determined as independent predictive factors. The nomogram which made by using these factors was found to be effective in detecting the need for completion thyroidectomy with a cut-off of 0.386 (AUC: 0.81, specificity: 0.79 and sensitivity: 0.77). Conclusion: The nomogram is effective in predicting the potentiality of completion thyroidectomy. It can be suggested that the nomogram should be used pre-operatively when deciding on lobectomy. It is recommended to be experienced in large patient groups. Key words: Completion thyroidectomy, thyroid nomogram, lobectomy-istmectomy, thyroid cancer.