IMRT is the primary development of 3D-CRT, because it represents a dose distribution to the tumor cell in superior way also sending of highly conformal radiation to irregularly and concave shaped target volume. The purpose of the present study is to compare the dosimetric analysis of two plans of radiotherapy (IMRT) and 3D-CRT, which include target volume and organ at risk for both plans. The present study selected eight patients, seven cases with different types of brain cancer and one case with chordoma cancer, all the cases previously irradiated in Zhianawa Cancer Center. All selected cases were re-planned by both techniques. IMRT planning provides reducing the dose of both right and left optic nerve mean dose for right optic nerve 23.52 Gy and left 22.51 Gy compared with the 3D-CRT plan (right optic nerve 28.06 Gy and left 25.71 Gy). IMRT plan reduces dose of both right and left eye compared to 3D-CRT plan, the mean dose for right eye 17.53 Gy and left 13.71 Gy compared with the 3D-CRT plan (right eye 18.4 Gy and left 16.97 Gy). IMRT plan provided better target cover (PTV95%) (97.33± 1.16) for (prescribed dose of 40Gy) than 3D-CRT (96.96±1.83).

Keywords: 3D-CRT, IMRT, PTV, Radiotherapy, Reduce dose

DOI: http://doi.org/10.24086/biohs2022/paper.654