Effects of high-frequency speech therapy on speech-related quality of life and objective speech intelligibility of oral cancer patients.

To analyze objective and subjective progression of speech intelligibility in oral cancer patients undergoing high-frequency speech therapy during early rehabilitation. Oral cancer patients in the Department of Maxillofacial Surgery, University Hospital of Schleswig-Holstein, Kiel, Germany, participated in the study from March 2016 to November 2017. Speech intelligibility was analyzed preoperatively (t1), post radiation (t2), and post speech therapy (t3). Objective measures were the Munich Intelligibility Profile (Online) and the Frenchay Dysarthria Assessment-2 (FDA-2). Subjective measures were the Speech Handicap Index (SHI), the speech subscale of the EORTC QLQ-C30&HN35, and the WHO-5 Index II. For nine patients with complete data, progression analyses showed a non-existent-to-low intelligibility impairment at t1 (means/SDs: e.g. FDA-2: 8.96/0.11, SHI: 17.5/15.15), increasing towards t2 (means/SDs/p-values for difference from t1: e.g. FDA-2: 7.40/0.80/0.000, SHI: 21.7/14.24/0.213), and then decreasing towards t3, without ever reaching the initial level (means/SDs/p-values for difference from t1: e.g. FDA-2: 8.22/0.60/0.005, SHI: 23.5/15.85/0.481). The objective changes in intelligibility were significant; the subjective changes were not. Overall, the ability to speak intelligibly after oral cancer treatment follows a typical pattern. Therefore, high-frequency speech therapy in the early rehabilitation phase might be recommendable. It might help patients to adapt to their situation after surgery, and facilitates compensating for possible functional deficits.