Impact of radioguided occult lesion localization in the management of cervical recurrences from differentiated thyroid cancer.

Background: Surgery is the elective treatment for cervical relapse from differentiated thyroid cancer (DTC) but it is technically challenging, with risk of failure and morbidity. We explored the feasibility and the efficacy of radioguided occult lesion localization (ROLL) with intratumoral 99mTc radiolabeled human albumin macroaggregates ([99mTc]MAA) injection in this setting.

Methods: Fifteen patients who underwent ROLL by ultrasonography (US)-guided intratumoral injection of [99mTc]MAA between December 2013 and October 2016 for DTC recurrence were considered for this study. A hand-held gamma-probe was employed for intrasurgical lesion detection. Mini-invasive ROLL-guided excision for soft tissue recurrence and ROLL-assisted modified radical neck dissection for lymph-node metastases were performed respectively.

Results: DTC recurrence was located in loco-regional lymph-nodes (N.=8 patients) and in thyroid bed (N.=7 patients). A total of 27 lesions was identified and injected before surgery. On a total of 124 lesions resected, histology showed 38 DTC metastases. In particular, 26 out of 27 lesions injected with [99mTc]MAA were correctly detected intra-operatively and resected without surgical complications. Ten patients received subsequent radioactive iodine (RAI) treatment to verify the complete recurrence resection. At a median follow-up of 16 months patients were classified in complete response (N.=4), biochemical incomplete response (N.=3), indeterminate response (N.=1) with no evidence of structural disease. The remaining 7 patients were classified as structural incomplete response for cervical persistent disease (N.=2), for cervical recurrence (N.=2) and for both cervical and lung metastases progression (N.=3).

Conclusions: ROLL is a simple and safe procedure in the surgical management of DTC loco-regional relapse.