Abstract

Objective To compare the dosimetric differences of target and organs at risk (OAR) induced by the tangential and non-coplanar multi-fields used in the dynamic intensity modulated radiotherapy (IMRT) plans for breast cancer patients after breast-conserving surgery.Methods Forty patients with early-stage left breast cancer after breast-conserving surgery were included.Based on the CT anatomy of the same patient,dynamic IMRT treatment plans using two tangential fields,3,4 and 5 non-coplanar fields were designed respectively utilizing the same optimization objects.The plans were compared by means of target dose distribution,the doses and irradiated volumes of heat,left lung,right breast,and total monitor units (MUs).Results The conformal index (CI) and homogeneity index (HI) of planning target volume (PTV) in the plans using 4 and 5 fields were better than that using 2 fields (P ＜ 0.05).Maximum doses (Dmax) in PTV were significantly lower in the plans of 4 and 5 fields than of 2 fields (P ＜0.05).Yet the plans of 4 and 5 fields generated significant higher minimum doses (Dmin) in PTV than that of 2 fields (P ＜ 0.05).No significant difference was observed between plans of 2 or 3 fields.Across the four plans,the differences of right breast V5 (relative volume acquired at least 5 Gy of dose),heart V30,heart mean dose (D),left lung V20,V5 and D were not significant.Yet the disparities of total MUs were statistically significant (F =25.63,P ＜ 0.05).The least MUs were used by the 2 fields and the most MUs were observed in the 5-field plans.Conclusions Comparing with IMRT plans of 2 fields,using 4 or 5 non-coplanar fields can improve the target dose distribution without increasing OAR doses.As a tradeoff,more MUs are needed for multi-fields plans. Key words: Breast cancer; Breast-conserving therapy; Intensity modulated radiation therapy; Dosimetric study

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.