Feasibility of pancreatectomy following high-dose proton therapy for unresectable pancreatic cancer

Figure 2 Conventional radiotherapy. With conventional radiotherapy (A) using X-rays (photons), the highest dose is deposited where the beam enters the patient. The dose at the tumor target is significantly less than the entry dose. Also, an exit dose is delivered beyond the tumor target. With protons (B), the entry dose is low. The highest dose is deposited at the depth of the tumor target, and there is no exit dose beyond the target.