Purpose: Radiation therapy planning for locally-advanced non-small cell lung cancer (NSCLC) is challenging due to the balancing of target coverage and organs-at-risk (OAR) sparing. Using the Varian Ethos Treatment Planning System (TPS), we developed a methodology to automatically generate efficient, high-quality treatment plans for locally-advanced lung cancer patients. Methods and Materials: Fifty patients previously treated with Eclipse-generated plans for inoperable Stage IIIA-IIIC NSCLC were included in this Institutional Review Board (IRB)-approved retrospective study. Fifteen patients were used to iteratively optimize an Ethos TPS planning template, and the remaining thirty-five patients had plans automatically generated without manual intervention using the created template. Ethos and Eclipse plan quality was then assessed using 1) standard dose volume histogram (DVH) metrics, 2) adherence to clinical trial objectives, and 3) radiation oncologist qualitative review. Results: Ethos-generated plans showed improved primary and nodal planning target volume (PTVp and PTVn, respectively) V100% and V95% coverage (p<0.001) and reduced PTVp Dmax values (p=0.023). Furthermore, the Ethos template-generated plans had lower spinal cord Dmax, lungs V5Gy, and heart V25Gy, V30Gy, and V45Gy values (p≤0.021). However, Ethos esophagus metrics (mean, V35Gy, V50Gy, Dmax) and brachial plexus metrics (Dmax) were greater than Eclipse (p≤0.008), but were still clinically acceptable. A large majority (80%) of automatically generated plans had entirely per protocol or variation acceptable metrics. Three radiation oncologists qualitatively scored the Ethos plans; 78% of plans were scored as clinically acceptable during physician evaluation, with zero plans receiving scores requiring major changes. Conclusions: A standard Ethos template generated lung cancer radiotherapy plans with greater target coverage, increased spinal cord, heart, and lung V5Gy sparing, but increased esophagus and brachial plexus dose, compared to manually generated Eclipse plans. This template elucidates an efficient approach for generating automated, high quality lung radiation therapy treatment plans.

Richard Popples institution, University of Alabama at Birmingham, has product evaluation agreements and research grants with Varian Medical Systems. He has a patent licensed by UAB Research Foundation to Varian Medical Systems. He has received honoraria for presentations on behalf of Varian Medical Systems. He has received a stipend to speak at Sun Nuclear meetings. Varian Medical Systems provides equipment to UAB as a part of a product evaluation agreement. Andrew McDonald and his institution, University of Alabama at Birmingham, have received payment from Varian Medical Systems. Dennis N. Stanley and his institution, University of Alabama at Birmingham, have received payment from Varian Medical Systems

This study did not receive any funding

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IRB-1207033005 of University of Alabama at Birmingham gave ethical approval for this work

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All data produced in the present study are available upon reasonable request to the authors