A Dosimetric Study of Conformal Radiotherapy Plan With Wedge and Field-in-Field-Forward-Planned Radiotherapy in Left Sided Breast Cancer.

Abstract

Key words:- Dosimetric, ,Breast cancer, conformal RT, field in field planPurpose: To perform a dosimetric comparison of field in field forward planned radiotherapy (FiF-FP) and (3D-CRT) with wedge which are used in whole breast irradiation. Method: In thirty patients, two techniques per patient were done (3D-CRT )with wedge and (FiF-FP).A comparison of treatment plans was done, using dose volume histograms for (PTV) and organs at risk. Volumes: V95, V105, D mean, D max, D min V20, V30 and V5 were chosen for the comparison. Results: The 2 plans, revealed a comparable good dose coverage, V95 >95% of PTV. V105% of doses were observed in less than 10% of the (PTV). D max. > 110% of prescribed doses in FiF-FP and > 110% for 3D-CRT. D mean of PTVs were 101.1% for 3D-CRT versus 100.1% for FiF-FP ,all values were less than the tolerance doses of OARs , the two plans were equivalent in sparing (OARs) , V20 Gy and V30 Gy for heart and ipsilateral lung in the 3D-CRT had an edge over FiF-FP. D max of the heart and ipsilateral lung were higher in 3D-CRT than FiF-FP , D max was lower in 3D-CRT than FiF-FP for contralateral breast. (MUs ) needed to deliver 3D-CRT with wedge plan were more than the values needed to deliver FiF-FP. Conclusion: FiF-FP had better dose homogeneity in (PTV) than (3D-CRT) with wedge and with less dose to OARs. (MUs) were less in (FiF-FP) with less time on the machine and less machine consumption. This technique lead to good expected breast irradiation outcome and encourages breast conservative surgery in developing countries Copy Right, IJAR, 2017,. All rights reserved.