Current ATA guidelines endorse either thyroid lobectomy and total thyroidectomy for the treatment of papillary thyroid cancer (PTC) up to 4cm. At present, radioactive iodine (RAI) is one of the major indication to total thyroidectomy whereas lobectomy in still underused especially for PTC between 2-4cm.

We retrospectively reviewed patients with pre-operative unifocal cN0 2-4cm PTC treated between January 2019 and December 2020. Patients who underwent total thyroidectomy and RAI were included in GroupA, whereas those who underwent total thyroidectomy alone or thyroid lobectomy were included in GroupB. The primary objective of the study was to compare the response to therapy of the two groups in a tertiary referral Institution.

GroupA included 64 patients (57.7%), whereas GroupB included 47 patients (42.3%). No deaths occurred in both groups and no statistically significant difference was documented in terms of recurrence (p=0.841). Moreover, no statistically significant difference was documented in terms of response to therapy between GroupA and GroupB (excellent response: 59.4% vs 53.2%, respectively; indeterminate response: 32.8% vs 38.3%, respectively; biochemical incomplete response: 6.3% vs 8.5%, respectively; structural incomplete response: 1.6% vs 0%, respectively; p=0.599). At logistic regression analysis, no statistically significant association was found between aggressive variant (p=0.389), thyroid capsule invasion (p=0.957), vascular invasion (p=0.187) and presence of > 4 foci of vascular invasion (p=0.601) and no excellent response to therapy.

Application of current ATA guidelines in patients with cN0 2-4cm PTC is associated to good prognosis regardless of RAI. If RAI is not indicated, lobectomy may be a safe treatment strategy.