Figure 3. 3D-conformal treatment planning in a patient with unresectable cancer of the pancreatic head. Horizontal slize in upper field boundary (a.), central ray level (b.) and in lower field boundary (c.). Gross tumor volume (enclosed by the 100%-isodose) and tumor with locoregional lymph nodes (enclosed by the 90%-isodose) were marked as treatment volumes. Radiotherapy is administered with 4-field arrangement.