Background: The recommended treatment strategies for early glottic
carcinoma with intent of larynx preservation are primarily
radiotherapy. However, the outcomes of
radiotherapy for bulky T1 or T2 glottic
carcinoma are unsatisfactory. We designed a protocol consisting of
concurrent chemoradiotherapy using S-1 as the radiosensitizer. We have performed this protocol in patients with favorable T2 lesions and demonstrated its efficacy and safety. In contrast, we have treated non-bulky T1 glottic
carcinomas with 2.25 Gy per fraction, for a total of 25-28 fractions, starting in 2011 to improve efficacy and shorten the treatment period. Since this treatment strategy was implemented for T1 disease, no local failure has occurred to date, and it appears to be almost as safe as
radiotherapy using 2.0 Gy per fraction. With the aim of improving the local control rate and shortening the treatment period primarily for favorable T2 disease, we changed the dose of radiation in our protocol from 2.0 Gy to 2.25 Gy per fraction, for a total of 25 fractions (from 30 fractions). The present study aims to evaluate the efficacy and safety of this new protocol. Methods: This study will be conducted as a clinical, prospective, single-armed, non-randomized trial. Patients are to receive S-1 (55.3 mg /m2 /day, once daily) and
radiotherapy (2.25 Gy per fraction, for a total of 25 fractions). S-1 and
radiotherapy are started on the same day that
radiotherapy is performed, 3-6 hours after
oral administration of S-1. The primary study aim is the 3-year local control rate. The secondary study aims are overall survival, voice-preservation survival, disease-free survival, complete response rate, completion rate, and toxicity. Result and conclusion: This is the first single-center, non-randomized, prospective study of
concurrent chemoradiotherapy with S-1 and hypofractionated
radiotherapy to be conducted. The trial will evaluate the efficacy and safety of our protocol.