Dosimetric Comparison of Inverse Three-Dimensional Conformal Radiotherapy and Intensity Modulated Radiotherapy for Non-Ssmall Cell Lung Cancer

Objective:To compare inverse three-dimensional conformal radiotherapy(Inv 3D-CRT) and intensity modulated radiotherapy(IMRT) for non-small cell lung cancer. Methods:For a cohort of 10 patients,Inv 3D-CRT and three groups of IMRT plannings were designed for per patient. The prescribed dose was 60 Gy/2 Gy/30f,95% of the planning target volume received this dose. Dose was computed with a commercially available TPS using convolution/superposition(CS) algorithm. Plans were compared according to the PTV95/V20 ratio(PTV95/V20) and Dmax-Dmin. Results:Compared with Inv 3D-CRT,the PTV95/V20 ratio of three groups of IMRT increased by 1.08(P = 0.014) ,0.72(P = 0.089) and 0.42(P = 0.318) ,respectively. Conclusions:For NSCLC,IMRT can reduce the dose to the lungs compared with inverse 3D-CRT by improving the conformity of the plan and is worth spreading in clinical work.