A-292 SINGLE INSTITUTION EXPERIENCE IN THE MANAGEMENT OF LOCALLY ADVANCED (pT4) DIFFERENTIATED THYROID CARCINOMAS

Abstract

Abstract Background Locally infiltrating (T4) differentiated thyroid carcinomas (DTC) represent a challenge. Surgical strategy and adjuvant therapy should be planned balancing morbidity and oncologic outcome. A series of T4 DTC who underwent multidisciplinary evaluation and treatment is reported. Methods All DTC cases operated between 2009 and 2021 were reviewed and T4 DTC cases were identified. En bloc resection of inferior laryngeal nerve (ILN), tracheal (TR) and/or internal jugular vein (IJV) was performed in cases of massive infiltration. In case of pharyngoesophageal junction (PEJ) invasion shaving technique was always chosen. Results Among 4775 DTC cases, 60 (1.25%) were T4. ILN infiltration was documented in 45 cases (75% - en bloc resection in 9), TR infiltration in 14 (23.3% - tracheal resection in 2), PEJ invasion in 11 (18.3% - in 7 cases R0 resection, in 4 cases <1cm residual tissue), and IJV resection in 6 (10%). Eleven post-operative ILN palsies, 23 cases with transient hypoparathyroidism and two hematomas requiring reoperation were registered. Final histology showed 7pN0, 22pN1a, 31pN1b tumors. Aggressive variants were observed in 78%. All patients underwent radioiodine treatment and 12 adjuvant external beam radiation therapy (EBRT). At a median follow-up of 47 months, no tumour-related death was registered. Seven patients required re-operation (DFS mean 123.7 months, CI:111.2-136.2). Conclusion Multidisciplinary approach is essential for the management of T4 DTC. Individualised and balanced surgical strategy and adjuvant treatments, in particular EBRT, ensure control of locally advanced disease with acceptable morbidity.