The value of the first postoperative diagnostic I-131 scan in patients with papillary thyroid carcinoma

Abstract

ObjectiveTo explore the feasibility of the postoperative diagnostic 131I whole-body planar scans (Dx-WBS) in papillary thyroid cancer (PTC) patients, and to clarify its value for accurate staging, risk stratification, and postoperative radioactive iodine (RAI) treatment management.DesignRetrospective study from 2015 to 2021.SettingA total of 1294 PTC patients in the tertiary referral hospital.ParticipantsPatients with differentiated thyroid cancer who underwent total/subtotal thyroidectomy were included. Patients with non-PTC pathological type, non-first RAI treatment, and incomplete data such as Dx-WBS and postablation WBS (Rx-WBS) were excluded.MethodsThe diagnostic efficacy of Dx-WBS was calculated with Rx-WBS as the reference. All patients were initially staged by the 8th edition of TNM staging, and risk stratification was performed based on clinical and pathological information. After Dx-WBS, the risk stratification was re-evaluated, and management was reconfirmed.ResultsThe detection rates of Dx-WBS for residual thyroid, cervical lymph nodes, upper mediastinal lymph nodes, lung, and bone distant metastasis were 97.6%, 78.3%, 82.1%, 66.7%, and 61.2%, respectively. The risk stratification of 113 patients (8.7%) changed after Dx-WBS, of which 107 patients changed from low to intermediate risk, 2 from low to high risk, and 4 from medium to high risk. A total of 241 patients (18.6%) adjusted the RAI regimen after Dx-WBS.ConclusionThis study confirms the diagnostic efficacy of the postoperative Dx-WBS in PTC patients and the value of Dx-WBS in accurately assessing risk stratification, as well as assisting in determining RAI treatment.