Resumen
In proton therapy, there is a sharp peak in the delivered dose followed by a rapid falloff, known as the Bragg peak, which is not present in photons. This allows for treatment plans that deliver lower doses to normal tissue than can be performed with photons. This requires a high degree of accuracy and precision of delivery due to the short distance between an area of high and low doses. Image guidance allows for better visualization of the target and more accurate delivery of proton (and photon) radiation. The equipment used to deliver proton therapy differs in several ways from that of photon radiation, which impacts the methods used for image guidance in proton therapy. This paper aims to summarize the various methods of image guidance in current proton therapy and their relative advantages and disadvantages, as well as areas for future improvements.