Radiation therapy is usually applied on orthovoltage machines (with 100 - 120 kV X-rays) or linear accelerators (with 4 - 6 MeV electrons). On both radiation machines the intention is to provide sufficient dose to the palmar side of the hand and avoid dose to the dorsal side of the hand.
With this in mind a recent publication from Ruby Meridith et al. regarding dose optimization is important. They show that the application of sufficient bolus material (5 - 10mm) is important to place on the treatment area to adapt the dose depth profile. The enclosed figure demonstrate the dose distribution within the hand in a cross section view:
Figure 1: Dupuytren_RT_3D-Planning
The different depth dose profiles of electrons (6 MeV and 18 MeV) and photons (6 MV) are demonstrated in the other figure.
Figure 2: Radiation-Dose-Depth-Profile of Electrons-and-Photons