Future radiation therapy: photons, protons and particles.

Radiation therapy plays a critical role in the current management of cancer patients. The most common linear accelerator-based treatment device delivers photons of radiation. In an ever more precise fashion, state-of-the-art technology has recently allowed for both modulation of the radiation beam and imaging for this treatment delivery. This has resulted in better patient outcome with far fewer side effects than were achieved even a decade ago. Recently, a push has begun for proton therapy, which may have clinical advantage in select indications, although significant limitations for these devices have become apparent. In addition, currently, heavy particle therapy has been touted as a potential means to improve cancer patient outcomes. This article will highlight current benefits and drawbacks to modern radiation therapy and speculate on future tools that will likely dramatically improve radiation oncology.