Figure 2

Isodose distribution by different irradiation techniques. An example of isodose distribution using different irradiation techniques delivering 2 Gy to the tumor bed for one cholangiocarcinoma patient. A) The conventional radiation therapy (2DRT). B) Three-dimensional conformal radiotherapy (3DCRT). C) Intensive modulated radiotherapy (IMRT). D) Tomotherapy. Orange line, liver; green line, stomach; bright orange line, planning target volume; purple line, clinical target volume for 2DRT and 3DCRT; light green line, IMRT and tomotherapy. The areas for 2 Gy and 0.5 Gy were contoured with red and blue color lines for 2DRT, 3DCRT and IMRT, respectively. The areas for 2 Gy and 0.5 Gy are red and blue, respectively, for tomotherapy.