Dosimetric comparison of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy for local advanced non-small cell lung cancer

Objective:To compare dosimetric difference of treatment planning of three-dimensional conformal radiotherapy(3D-CRT)and intensity-modulated radiotherapy(IMRT)for local advanced non-small cell lung cancer(LANSCLC).Methods:Ten LANSCLC patients to be treated by radiotherapy were investigated.3D-CRT and IMRT plannings were designed for each patient.The prescribed dose was 60Gy(2Gy/f×30f),95% of the planning target volume was covered by this dose for each patient.The dose was computed with treatment planning system of Eclipse 10.0 using convolution / superposition algorithm.Two plans were compared according to the homogeneity index(HI)and conformity index(CI)of dosimetry in the planning target volume and the parameters of dose-volume histogram(DVH)in normal tissue.Results:In the terms of CI and HI,IMRT radiotherapy planning was significantly superior to 3D-CRT plan(P0.05),the index of V20 and V30 in normal lung tissue of IMRT planning was significantly superior to the 3D-CRT planning(P0.05).There were no significant differences between the MLD and V15 in two kinds of planning,but V5 was significantly increased(P=0.05)in the IMRT planning.The dose of esophagus,heart and spinal cord in the IMRT planning was lower than that of3D-CRT planning.Conclusion:For LANSCLC,IMRT has some dosimetric advantages over 3D-CRT.