There are four types of external-beam radiation therapy: Three-dimensional conformal radiation therapy (3D-CRT), Intensity modulated radiation therapy (IMRT), Proton beam therapy, and Stereotactic radiation therapy. 3D-CRT has special computers creating detailed 3D pictures of the cancer allowing the treatment team to target the beam more accurately. With this method, they are able to use higher doses of radiation while having reduced risk of healthy tissue damage. IMRT uses a Varian Clinac iX-S linear accelerator and focuses the radiation dose specifically at the tumor by varying the intensity of the beam. This manner of therapy is better at treating tumors and protects healthy tissue than when compared to the 3D-CRT. Proton beam therapy as
