Dosimetric evaluation of three commercial radiotherapy planning systems for lung cancer and nasopharyngeal carcinoma cases

Abstract Purpose: To identify planning systems and techniques suitable for different sites tumors by analyzing dosimetric differences using three commercial radiotherapy planning systems: Tomotherapy, Monaco and Eclipse.Methods: We retrospectively analyzed 20 lung cancer and 8 nasopharyngeal carcinoma (NPC), and each patient plans were designed using the three systems. The dose distribution of the target and organs at risk (OARs) were compared, and monitor unit (MU) and treatment time were also evaluated.Results: For lung cancer, mean dose of PGTV, PTV1 and PTV2 in Monaco and Tomo plans were lower than Eclipse plan. PTV2 CI in Monaco and Eclipse plans were better than Tomo plans (p=0.002, p=0.022). Monaco and Tomo plans were better than Eclipse plan regarding to mean dose and V15Gy of lungs; the lowest lungs V20Gy and V30Gy were provided by Tomo plan. The esophagus, heart and SpinalCord_03 dose were lowest in Monaco plan, and the maximum dose and V45Gy of SpinalCord_03 were 592.1cGy and 1.37% lower than Eclipse plan, respectively. For NPC, mean dose of PGTV, PTV1 and PTV2 in Eclipse plan were superior to Tomo plan (p=0.008, p=0.000, p=0.003); PTV2 V95% in Tomo plan was increased by 1.64% than Eclipse plan. There was no significant difference between Monaco and Eclipse plans. Tomo plan showed better spinal cord and brainstem protection, with spinal cord max dose 249.38cGy lower than Eclipse plan and 555cGy lower than Monaco plan, respectively.Conclusion: Although the three plans reflected their respective advantages in different aspects, in general, the Monaco plan (VMAT) was the best choice for lung cancer, and for the more advanced nasopharyngeal carcinoma, the Tomo plan (HT) was superior to the other two plans.