Abstract: Background and purpose: Respiratory motion may adversely affect radiotherapy for lung cancer, and improving plan delivery efficiency can alleviate this effect to some extent. The aim of this study was to investigate the feasibility of using beam angle and multicriteria optimization (BAMCO) to conduct the treatment planning of lung cancer radiotherapy and the delivery efficiency. Methods: We extracted the planning data of 10 lung cancer patients from Pinnacle treatment planning system, and then created new plan in RayStation system. The corresponding clinical beam set was used as initial reference to conduct beam angle optimization. The obtained beams were used as final beam set to complete multicriteria optimization (MCO). We selected the best clinical compromise and generated deliverable plan. Finally, the clinical and BAMCO plans were compared. Results: BAMCO plan design could determine the best plan after one-time optimization and avoid trial-and-error process. The plan qualities of clinical and BAMCO plans were similar. The machine units of BAMCO were much lower than those of clinical ones (31.1%±16.9%). Conclusion: BAMCO technique can improve delivery efficiency significantly and guarantee good plan quality.

Key words: Beam angle optimization, Multicriteria optimization, Intensity-modulated radiation therapy, Delivery efficiency