When joining beams of a high energy photon, one of the most important problems is the dose non-homogeneity in the matching region. To solve this problem, a technique to create a wide pseudo-penumbra has been developed. The wedge to create the wide penumbra is a match-line wedge, and its shape is defined by photon energy, spreading, flatness and the geometry of the beam. In this study, the shape of the match-line wedge for a 10 MV photon was determined. Comparison of several matching methods, those are skin gap method and shifting gap method, are made.
