Dosimetric Comparison between Helical Tomotherapy and Biologically Based IMRT Treatment Planning System for Selected Cases

摘要

In this work, we have dosimetrically compared two treatment planning systems used in our clinic to create intensity-modulated radiation therapy (IMRT) plans. A new commercial inverse treatment planning system (Monaco™, CMS, Inc, St. Louis, Missouri) allowing Monte-Carlo calculations, aperture based optimization, and biological cost functions was compared to the TomoTherapy Hi-ART™ (To-moTherapy, Madison, WI) planning system. Six clinical test cases (head and neck, prostate, and breast) were planned and compared using DVHs and dosimetric parameters (maximum dose, mean dose, conformity and heterogeneity indexes). Both treatment planning systems provided adequate deliverable plans. Overall, tomotherapy plans provided a better confor-mality and heterogeneity in most of the clinical cases with improved sparing of major organs at risk. The dosimetric analysis shows that although the treatment planning systems have differences, they are each capable of producing substantially equivalent treatment plans in term of target coverage and normal tissue sparing.