Determinants of successful ablation and complete remission after total thyroidectomy and ¹³¹I therapy of paediatric differentiated thyroid cancer.

purposeIn adult differentiated thyroid cancer (DTC) patients, successful ablation and the number of (131)I therapies needed carry a prognostic significance. The goal was to assess the prognosis of DTC in children and adolescents treated in our centre in relation to the number of treatments needed and to establish the determinants of both complete remission (CR) and successful ablation.

methodsSeventy-six DTC patients <21 years of age at diagnosis were included. Recurrence and death rates, rates of CR (=negative stimulated thyroglobulin, negative neck ultrasound and negative (131)I whole-body scintigraphy) and successful ablation (=CR after initial (131)I therapy) were studied.

resultsNo patients died of DTC. Seven patients were treated by surgery alone and did not show signs of recurrence during follow-up. Of the 69 patients also treated with (131)I therapy, 47 patients achieved CR, 25 of whom had successful ablation. In multivariate analysis, female gender and the absence of distant metastases were independent determinants of a higher CR rate. Female gender, lower T stage and higher (131)I activity (successful ablation, median activity 3.1 GBq, unsuccessful ablation 2.6 GBq) were determinants of a higher rate of successful ablation. After (131)I therapy no patient showed recurrence after reaching CR or disease progression if CR was not reached.

conclusionIn our paediatric DTC population prognosis is extremely good with no deaths or recurrences occurring regardless of the number of (131)I therapies needed or whether CR was reached. The determinants of CR and successful ablation can be used to optimize the chance of therapy success.