Image-guided activation of drugs with electromagnetic radiation.

Image-guided pharmacotherapy, in which drug activity is strictly confined to disease areas revealed by medical imaging modalities, holds great promise for the development of personalized medicine. A key step in realizing this potential is the development of safe and precise methods for drug activation. Electromagnetic radiation, spanning the energy ranges from γ-rays to ultraviolet-visible and infrared light, has emerged as a method of choice for this purpose. Because many imaging modalities rely on electromagnetic radiation to generate signals (for example, optical and optoacoustic imaging, computed tomography and positron emission tomography), this phenomenon can be used to both activate a drug and monitor tissue response, creating a theranostic synergy. This Perspective outlines the molecular basis for drug activation with electromagnetic radiation, offers a clinical perspective in discussing the most suitable applications and advantages available and discusses the challenges, such as the delivery of light at the site of interest, and steps needed for successful translation into daily clinical practice.