The objective of radiation treatment of cancer is eradication of the tumor. The disadvantage of radiation therapy is that it may injure or destroy adjacent normal tissues. Therefore, if we could focalize the radiant energy exactly on the tumor cells, then the adjacent normal tissues would be protected. X-ray holography permits us the realization of this idea. In this paper three methods are proposed in order to record and reconstruct required holograms by x-ray and the advantages and disadvantages of each method are discussed.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.