Response to Surgery Assessments for Sparing Radioiodine Remnant Ablation in Intermediate-risk Papillary Thyroid Cancer


 
 
 Using response to surgery upon tailoring radioiodine (RAI) therapy for papillary thyroid cancer (PTC) is valued while lacking prospective validation.
 
 
 
 To spare RAI thyroid-remnant ablation among intermediate-risk PTCs by three-tiered assessments with response to surgery highlighted besides the risk of the recurrence stratification and TNM staging.
 
 
 
 Patients with no evidence of disease (NED) identified as excellent response (ER) or indeterminate response (IDR) to surgery were spared from RAI thyroid-remnant ablation after informed consent and prospectively enrolled under active surveillance. Those involved in other trials or without sufficient follow-up data were excluded. Dynamic responses were followed and compared longitudinally.
 
 
 
 NED presenting as durable ER or IDR for over 12 months.
 
 
 
 Of the enrolled 215 patients, 47.4% (102/215) ER and 52.6% (113/215) IDR were identified upon RAI decision-making. After a median of 23.6 (IQR 13.8-31.6) months, the share of ER increased to 82.8%(178/215) and IDR decreased to 16.3% (35/215), with 85 patients shifting from IDR to ER over time, only 0.5% (1/215) structural and 0.5% (1/215) biochemical incomplete response observed. Successful remnant ablation was observed in 27.7%(26/94) of the patients completing two diagnostic whole-body scannings after a median interval of 13.0 months, indicating a theranostic effect. In the 173 patients followed for over 12 months, the NED rate didn’t differ between ER and IDR subgroups (100% vs. 97.9%, P = 0.20).
 
 
 
 Through the three-tiered assessments with response to surgery highlighted, postoperative ER and IDR spared from RAI remnant ablation may indicate similar favorable responses in intermediate-risk PTC patients during 23.6 months follow-up.
