Figure 3.

Lateral profiles (in the x-direction in the MC geometry) of E_dep, for each code at different depths. (a) Three profiles taken in the patient with a lung tumor. (b) Four profiles taken in the patient with head and neck cancer. The profiles were taken in the isocenter slice, which is shown in Figure 2. The location of each profile on the depth dose curve is shown in Figure 4, and their locations correspond to the beam entrance, proximal SOBP, distal SOBP, and, in the head and neck case, the distal fall-off region. Abbreviations: E_dep, energy deposited; MC, Monte Carlo; SOBP, spread-out Bragg peak.