Ablative Carbon Ion Radiotherapy With Pencil Beam Scanning for Locally Advanced Unresectable Pancreatic Cancer

Patients with locally advanced unresectable pancreatic cancer without invasion of gastrointestinal tract will received ablative carbon ion radiotherapy. The prescription dose for primary pancreatic lesion, positive lymph node, and retroperitoneal high-risk recurrence area is 67.5 Gy (RBE weighted dose) in 15 fractions for 3 weeks; Pancreatic primary lesion and positive lymph node SIB to 75 Gy (RBE weighted dose) in 15 fractions for 3 weeks.