Laryngeal or hypopharyngeal squamous cell carcinoma: Can follow-up CT after definitive radiation therapy be used to detect local failure earlier thanclinical examination alone?

PURPOSE: To determine if follow-up computed tomography (CT) after definitiv e radiation therapy for laryngeal or hypopharyngeal (laryngopharyngeal) car cinoma allows the detection of local failure earlier than clinical examinat ion alone. MATERIALS AND METHODS: Pre- and post-radiation therapy follow-up CT scans i n 66 patients were reviewed retrospectively. All patients underwent definit ive hyperfractionated radiation therapy and were followed up clinically for at least 2 years after its completion. Post-radiation therapy CT scans (N = 153)were evaluated for posttreatment changes with a three-point score: A score of 1 represented expected posttreatment changes; 2, focal mass with a maximal diameter of less than 1 cm and/or asymmetric obliteration of laryn geal tissue planes; or 3, focal mass with a maximal diameter equal to or gr eater than 1 cm or estimated tumor volume reduction of less than 50%. All p atients underwent the first posttreatment CT study 1-6 months after therapy . New or progressive laryngeal cartilage changes were noted. The clinical i mpression of the larynx at the time of each follow-up CT scan was also reco rded. RESULTS: In 12 of 29 (41%) patients with treatment failure at the primary s ite, follow-up CT scans were definite for local failure (score, 3) a mean o f 5.5 months (median, 3.5 months; range, 1-17 months) before clinical exami nation results. CONCLUSION: In many patients, follow-up CT shows local failure earlier than does clinical examination alone.