Reliability of radioguided occult lesion localization in reoperation of loco-regional persistent/recurrent differentiated thyroid cancer: Retrospective cohort study

Objectives: We aimed to determine the radioguided occult lesion localization (ROLL) reliability in the reoperation of patients with differentiated thyroid cancer (DTC) and persistent or recurrent non-palpable loco-regional disease who underwent surgery at the Instituto Nacional de Cancerología between 2012 and 2021.

Design: Observational retrospective cohort study.

Participants: We included data from patients with DTC that underwent resection with ROLL.

Main outcome measures: Reliability analysed as percentage of patients with complete resection of tumour lesion using ROLL, disease-free survival, second loco-regional relapse, adequate resectability and complications.

Results: Two hundred and four cases were obtained. Pathological examination revealed papillary thyroid carcinoma in 202 patients, and follicular thyroid carcinoma in 2. Reliability was 96.57% in patients who underwent ROLL. When wide resection was performed-at surgeon's discretion-the reliability increased to 97.5%.

Conclusions: The high reliability obtained suggests that ROLL was effective to localize non-palpable relapsing lesions. To our knowledge, this is the largest sample size published on this topic to date.