Hadrontherapy is a high-precision technique in cancer radiation therapy, which allows obtaining a superior conformal treatment with respect to photons used in conventional radiation therapy. To reach this ambitious goal without reducing the patient throughput needed in a hospital-based environment, the physical and radiobiological properties of charged hadrons, protons and carbon ions in particular, have to be exploited at best, making use of the most modern technologies issued from research in nuclear and particle physics. In the present days, we are assisting to a continuous technological challenge, leading to the conception and to the development of innovative methods and instruments. In this paper, the most relevant challenges in dose delivery systems, gantries, imaging, quality assurance and particle accelerators are reviewed.