fig2

Figure 2. A comparison of the relative dose-distributions for each beam arrangement: 3-field, 3D conformal, IMRT, and SBRT. Compared to IMRT, SBRT utilizes a slightly different beam profile (flattening filter free) and allows for the dose calculation algorithm freedom to not restrict the central hot spot (given motion management) compared to more uniform dose planning in IMRT, ultimately achieving higher tumor dose relative to normal liver dose. IMRT: Intensity-modulated radiotherapy; SBRT: stereotactic body radiation therapy.