Open AccessSBRT for early-stage glottic larynx cancer—Initial clinical outcomes from a phase I clinical trial
Author(s) -
David L. Schwartz,
Alan Sosa,
Stephen G. Chun,
Ding Chiuxiong,
Xian Jin Xie,
Lucien A. Nedzi,
Robert Timmerman,
Baran D. Sumer
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0172055
Subject(s) - medicine , larynx , cohort , toxicity , dysphagia , cyberknife , surgery , stage (stratigraphy) , clinical trial , glottis , cancer , radiation therapy , radiosurgery , biology , paleontology
Purpose To confirm safety and feasibility of hypofractionated SBRT for early-stage glottic laryngeal cancer. Methods Twenty consecutive patients with cTis-T2N0M0 carcinoma of glottic larynx were enrolled. Patients entered dose-fractionation cohorts of incrementally shorter bio-equivalent schedules starting with 50 Gy in 15 fractions (fx), followed by 45 Gy/10 fx and, finally, 42.5 Gy/5 fx. Maximum combined CTV-PTV expansion was limited to 5 mm. Patients were treated on a Model G5 Cyberknife (Accuray, Sunnyvale, CA). Results Median follow-up is 13.4 months (range: 5.6–24.6 months), with 12 patients followed for at least one year. Maximum acute toxicity consisted of grade 2 hoarseness and dysphagia. Maximum chronic toxicity was seen in one patient treated with 45 Gy/10 fx who continued to smoke >1 pack/day and ultimately required protective tracheostomy. At 1-year follow-up, estimated local disease free survival for the full cohort was 82%. Overall survival is 100% at last follow-up. Conclusions We were able to reduce equipotent total fractions of SBRT from 15 to 5 without exceeding protocol-defined acute/subacute toxicity limits. With limited follow-up, disease control appears comparable to standard treatment. We continue to enroll to the 42.5 Gy/5 fx cohort and follow patients for late toxicity. Trial registration ClinicalTrials.gov NCT01984502