SBRT for early-stage glottic larynx cancer-Initial clinical outcomes from a phase I clinical trial

David L Schwartz; Alan Sosa; Stephen G Chun; Chiuxiong Ding; Xian-Jin Xie; Lucien A Nedzi; Robert D Timmerman; Baran D Sumer

doi:10.1371/journal.pone.0172055

SBRT for early-stage glottic larynx cancer-Initial clinical outcomes from a phase I clinical trial

PLoS One. 2017 Mar 2;12(3):e0172055. doi: 10.1371/journal.pone.0172055. eCollection 2017.

Authors

David L Schwartz¹, Alan Sosa¹, Stephen G Chun¹, Chiuxiong Ding¹, Xian-Jin Xie¹, Lucien A Nedzi¹, Robert D Timmerman¹, Baran D Sumer²

Affiliations

¹ Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
² Department of Otolaryngology, Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.

Abstract

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.

Publication types

Clinical Trial, Phase I

MeSH terms

Dose Fractionation, Radiation
Female
Glottis / radiation effects*
Humans
Laryngeal Neoplasms / pathology*
Laryngeal Neoplasms / radiotherapy*
Male
Middle Aged
Molybdoferredoxin
Neoplasm Staging
Radiosurgery*
Treatment Outcome

Substances

Molybdoferredoxin

Associated data

ClinicalTrials.gov/NCT01984502

Grants and funding

This work was supported by Cancer Prevention and Research Institute of Texas (CPRIT, http://www.cprit.state.tx.us/), Individual Investigator Research Awards RP150386 and RP150485. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.