Figure 1.

Frontal (a), sagital (b), and axial (c)–(e) views of the PRESAGE™ dosimeter showing the segmented structures used for treatment planning; the external contour (BODY), OAR, and PTV, respectively. The locations of the three axial views (c–e) are indicated as the dotted lines 1–3 in (a). In the axial view, the multicomponent PTV appears to gradually change from an upset schematic face (c), to neutral (d), and to a happy schematic face (e). There is a 4 mm margin between the PTV and the surrounding OAR. Delivery of a homogenous uniform dose to the multicomponent PTV, while minimizing the dose to the surrounding OAR, represents an extremely challenging treatment planning problem for the ECLIPSE® IMRT algorithm.