The comparison of helical-imrt, direct-imrt and 3d radiotherapy modalities in breast radiotherapy planning

Abstract

OBJECTIVE This study aims to compare dosimetric 3D-CRT, Tomo-helical IMRT and Direct IMRT methods in intact breast irradiation. METHODS Radiotherapy was planned with three different techniques simulated images of 30 breast cancer patients with negative lymph nodes who underwent breast-conserving surgery. RESULTS The maximum and minimum doses, homogeneity and conformity index and cold-zone volumes were found to be different in all three techniques (p<0.001). The PTV boost maximum doses and homogeneity index were found to be different (p<0.001). The maximum non-PTV dose (110% volume) and the hot zone volumes grasped by these doses, the V5 volume of the body and V5 volumes, outer of PTV were found to be statistically significant for all three techniques (p<0.001). A statistically significant difference was found between the three techniques concerning the ipsilateral lung V5 and V20 volumes, the contralateral lung V5 and V10 volumes and the counter breast maximum and mean doses (p<0.001). The mean and V10 volume of the heart was statistically significant (p<0.001), while the left breast irradiation and mean values were not statistically significant between the three techniques (p=0.529). However, there was a statistically significant difference in the V10 volume of the left breast irradiation between the three techniques (p=0.033). CONCLUSION According to 3D-CRT, it is possible to achieve better dose distribution and dose homogeneity with Tomo-helical and direct IMRT. Low dose volumes are high with tomo-helical IMRT. Tomo-helical IMRT planning provides better ipsilateral lung and heart doses but causes an increase in heart dose/contralateral breast and for right breast irradiation causes an increase in heart dose.