MR findings of cartilage invasion by laryngeal cancer: value in predicting outcome of radiation therapy.

Thirty-nine patients who underwent radiation therapy with curative intent for laryngeal cancer were examined before treatment with magnetic resonance (MR) imaging, between November 1985 and January 1987. MR findings of cartilage invasion were correlated with the effectiveness of radiation treatment. Adequate interpretation of the MR examinations was not possible in four cases (10%). Cartilage invasion was found in 16 of the 35 remaining patients and was found even in small glottic lesions, clinically staged as T1b and T2. Laryngeal cancer recurred in 10 of the 16 patients with cartilage invasion shown by MR imaging. The presence of even small foci of invasion of the thyroid cartilage by laryngeal cancer appeared to increase the subsequent risk of tumor recurrence. Cartilage invasion seen at MR imaging might therefore shift the preference to partial laryngectomy as the initial treatment for small glottic tumors. Alternatively, radiation therapy alone would appear to require stringent follow-up to detect possible recurrence.