Value of Diffusion Weighted MRI in Assessment of Thyroid Cartilage Invasion in Cases of Laryngeal Carcinoma Compared to CT Scan

Abstract

aryngeal cancer represents 4.5% of all malignancies and 28% of cancers of the upper aerodigestive tract. 90% of the malignant tumors of the larynx are composed of squamous cell carcinoma, so the larynx is the most common site of squamous cell carcinoma of the head and neck. In cases of laryngeal carcinoma, thyroid cartilage invasion is associated with a lower response rate to radiation therapy and a higher risk of tumor recurrence. Hence, accurate assessment of any thyroid cartilage invasion by the tumor is vital for staging and treatment. According to the current American Joint Committee on Cancer (AJCC) staging guidelines, minor thyroid cartilage invasion is classified as T3, whereas invasion throughout the cartilage is considered as T4. These definitions are inherently problematic owing to the subjective nature of cartilage invasion. Survival is related to the stage of disease at diagnosis. Five-year survival rates are highest for patients presenting at stage I (94% to 100%) and lowest for those diagnosed with stage IV disease (40% to 65%). Accurate assessment of tumor extension is criti