Background: The use of radioiodine treatment (RAI) in cases categorized as low to intermediate risk papillary thyroid cancer (PTC) is still uncertain. Current guidelines recommend a selective use of RAI based upon the clinicopathologic features of each case. In this context, postoperative serum thyroglobulin (pTg) could be useful but the predictive role for recurrence and the optimal cut off value to be applied is not clearly established. Objectives: To determine the predictive value of postoperative Tg and the optimal cutoff to avoid radioactive iodine therapy in patients with low to intermediate-risk PTC Methods: We selected patients with low to intermediate risk PTC diagnosed between 2009-2015 with available data on histology, follow-up and laboratory tests. All patients had TSH ≤3.5 mU/l and negative AbTg. Tg was measured by a second-generation assay (Abbot Architect). Results: We selected 200 patients followed in our institution. RAI was performed in 100 of 200 patients (50%), 15 individuals (13,3%) displayed biochemical or structural disease after a median duration follow-up of 17.5 months. At univariate analysis, factors associated with recurrent disease were male sex, RAI, pTg tumor size, mETE, lymph node MTS. The factor independently associated with recurrence, identified through multivariate COX proportional hazard analysis, was pTg (HR: 1.2, 95%CI: 1.07-1.34, p: 0.01). The optimal basal pTg to identify recurrence was 0.5 (AUC: 0.74, 95%CI: 0.61-0.89). When evaluating the combination of tumor size and pTg, Tg <0.5 ng/ml and size <1.5 cm had a NPV of 95.5%. When considering RAI, propensity score-based matching was performed, and no significant differences were found between treated and non-treated patients. Conclusions: The study suggests that the combination of postoperative Tg and tumor diameter is a critical factor in low to intermediate PTC that should be routinely integrated into RAI decision-making and could be easily applied in clinical practice to manage PTC patients.
Postoperative basal serum thyroglobulin and need for radioiodine in patients with low to intermediate-risk papillary thyroid cancer
Piticchio, Tommaso;Le, Moli Rosario;
2024-01-01
Abstract
Background: The use of radioiodine treatment (RAI) in cases categorized as low to intermediate risk papillary thyroid cancer (PTC) is still uncertain. Current guidelines recommend a selective use of RAI based upon the clinicopathologic features of each case. In this context, postoperative serum thyroglobulin (pTg) could be useful but the predictive role for recurrence and the optimal cut off value to be applied is not clearly established. Objectives: To determine the predictive value of postoperative Tg and the optimal cutoff to avoid radioactive iodine therapy in patients with low to intermediate-risk PTC Methods: We selected patients with low to intermediate risk PTC diagnosed between 2009-2015 with available data on histology, follow-up and laboratory tests. All patients had TSH ≤3.5 mU/l and negative AbTg. Tg was measured by a second-generation assay (Abbot Architect). Results: We selected 200 patients followed in our institution. RAI was performed in 100 of 200 patients (50%), 15 individuals (13,3%) displayed biochemical or structural disease after a median duration follow-up of 17.5 months. At univariate analysis, factors associated with recurrent disease were male sex, RAI, pTg tumor size, mETE, lymph node MTS. The factor independently associated with recurrence, identified through multivariate COX proportional hazard analysis, was pTg (HR: 1.2, 95%CI: 1.07-1.34, p: 0.01). The optimal basal pTg to identify recurrence was 0.5 (AUC: 0.74, 95%CI: 0.61-0.89). When evaluating the combination of tumor size and pTg, Tg <0.5 ng/ml and size <1.5 cm had a NPV of 95.5%. When considering RAI, propensity score-based matching was performed, and no significant differences were found between treated and non-treated patients. Conclusions: The study suggests that the combination of postoperative Tg and tumor diameter is a critical factor in low to intermediate PTC that should be routinely integrated into RAI decision-making and could be easily applied in clinical practice to manage PTC patients.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
