Study Protocol: Prospective Study of Concurrent Chemoradiotherapy with S-1 and Hypofractionated Radiotherapy for Outpatients with Early Glottic Squamous Cell Carcinomas

Abstract

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