Diagnostic value, sensitivity and specificity of CT, MRI, and PET in evaluation of cartilage invasion in laryngeal and hypopharyngeal cancer

In advanced laryngeal (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC), concurrent chemoradiation is the standard approach for organ preservation. However, in T4a disease, upfront surgery followed by adjuvant radio(chemo)therapy is recommended due to suboptimal outcomes with non-surgical treatment. Since cartilage invasion is the principal determinant of T4 staging, its accurate detection is essential for optimal treatment selection. The comparative diagnostic performance of CT, MRI, and FDG-PET in this setting remains uncertain. This retrospective study included 204 patients with LSCC or HPSCC treated between 2010 and 2019 at a tertiary cancer center. All patients underwent pre-therapeutic hybrid FDG-PET combined with CT and/or MRI. Demographic, clinical, and imaging data were collected. Diagnostic accuracy for cartilage invasion was assessed against histopathological findings, and the prevalence of imaging artifacts was analyzed. The study included 204 patients. CT demonstrated higher specificity than MRI for detecting cartilage invasion (86.7% vs. 70.0%), whereas MRI showed greater sensitivity than CT (80.0% vs. 77.1%) but was limited by motion artifacts in 20% of cases. FDG-PET-based metabolic assessment revealed that elevated tumoral SUVmax correlated with cartilage invasion in upfront surgery cases (p = 0.043) but not in salvage surgery cases (p = 0.90). CT is more reliable than MRI for detecting cartilage invasion in LSCC and HPSCC, particularly in patients prone to motion artifacts. FDG-PET adds diagnostic value in upfront surgery candidates, supporting the combined use of CT and PET as the preferred preoperative imaging strategy.