X-ray Drug Delivery System (DDS) is the most advanced radiation therapy coming after IMRT (Intensity Modulated Radiation Therapy) and IGRT (Image Guided). DDS uses advanced nano-scaled polymers which contain and deliver drug or contrast agent to cancers without side effects. Several X-ray DDS poses high-Z atoms like Pt and Au to absorb X-rays effectively and used as contrast agent for inspection. Moreover, they have radiation enhancement effect by emission of Auger electron and successive characteristic X-rays. The enhancement factor of Pt and Au is more than five. This can be used for therapy. This new modality must be very important for inspection and therapy of deep cancers. We are making use of our Compton scattering monochromatic keV X-ray source and MeV linac aspinpoint keV/MeV X-ray sources for the purpose. Physical analysis and evaluation of the contrast efficiency and radiation enhancement of the X-ray DDS are under way. Furthermore, a new compact X-band linac with a multi-beam klystron for a pinpoint X-ray source is proposed and designed. Updated research status and result are presented.