PP194 - LONGITUDINAL CT-DERIVED BODY COMPOSITION CHANGES AND CLINICAL OUTCOMES IN PATIENTS WITH ADVANCED THYROID CARCINOMA TREATED WITH TYROSINE KINASE INHIBITORS

PP194

LONGITUDINAL CT-DERIVED BODY COMPOSITION CHANGES AND CLINICAL OUTCOMES IN PATIENTS WITH ADVANCED THYROID CARCINOMA TREATED WITH TYROSINE KINASE INHIBITORS

M. Del Vecchio¹, G. Imbimbo^1,*, C. Gallicchio¹, F. Tambaro¹, V. Rizzo², G. Grani¹, C. Durante¹, M. Muscaritoli¹, A. Molfino^1,3

¹Department of Translational and Precision Medicine, ²Department of Radiological, Oncological and Pathological , ³Department of Interdisciplinary Studies on WellBeing, Health and Environmental Sustainability (BeSSA), Sapienza University of Rome, Rome, Italy

Rationale: Body composition changes may influence treatment tolerance and clinical outcomes in patients with advanced radioiodine-refractory thyroid carcinoma receiving tyrosine kinase inhibitors (TKIs). We investigated changes overtime in computed tomography (CT)-derived body composition parameters and their association with treatment-related toxicity, dose reduction, and treatment discontinuation.

Methods: Patients with advanced thyroid carcinoma treated with TKIs were considered. Longitudinal analysis was performed in patients with CT scans available before treatment initiation (T0) and during follow-up (T1). Malnutrition was assessed using GLIM criteria. Body composition was analyzed on CT images at the third lumbar vertebra to quantify total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), skeletal muscle area (SMA), and skeletal muscle index (SMI).

Results: We enrolled 30 patients with a median BMI of 24.7 kg/m²; 43% of patients were malnourished according to GLIM. Changes were observed between T0 and T1 for TAT (p=0.02), SAT (p=0.02), SMA (p=0.03), and SMI (46.6±14.2 vs 43.8±11.6 cm²/m², p=0.04). No significant association emerged between body composition changes and grade 3-4 toxicity. Patients requiring TKI dose reduction showed significant reductions in TAT (p=0.04), VAT (p=0.04), SMA (p=0.02), and SMI (p=0.02). Among patients who did not discontinue therapy, reductions in adipose tissue compartments (TAT p=0.01, VAT p=0.03, SAT p=0.03) were observed, while skeletal muscle indices remained unchanged.

Conclusion: Clinically relevant changes in body composition parameters were observed during TKI therapy, with different patterns between muscle and adipose tissue compartments. These findings indicate the importance of assessing CT-derived body composition to identify patients at higher risk for adverse outcomes.

Disclosure of Interest: None declared