Dosimetric Comparison of Inverse Three-Dimensional Conformal Radiotherapy and Forward Three-Dimensional Conformal Radiotherapy for Non-Small Cell Lung Cancer

Objective:To compare inverse three-dimensional conformal radiotherapy (Inv 3D-CRT) and forward three-dimensional conformal radiotherapy (3D-CRT) for non-small cell lung cancer. Methods: For a cohort of 10patients, Inv 3D-CRT and 3D-CRT planning was designed. The prescribed dose was 60Gy/2Gy/30f,95% of the planning target volume received this dose. Doses were computed with a commercially available TPS using convolution/superposition (CS) algorithm. Plans were compared according to dose-volume histogram (DVH) analysis in terms of PTV homogeneity and conformity indices (HI and CI) as well as OARs dose and volume parameters. Results: In terms of HI and CI, no significant difference was observed. Compared with 3D-CRT, no statistically significant differences between Inv 3D-CRT and 3D-CRT in terms of esophagus,heart and normal lung tissue while the maximum dose of cord of Inv 3D-CRT decreased by 7.43%. Conclusions: For NSCLC, Inv 3D-CRT planning reduced the maximum irradiated dose of cord obviously and is worth spreading in clinical work.