Image-guided radiotherapy: has it influenced patient outcomes?

Cancer control and toxicity outcomes are the mainstay of evidence-based medicine in radiation oncology. However, radiotherapy is an intricate therapy involving numerous processes that need to be executed appropriately in order for the therapy to be delivered successfully. The use of image-guided radiation therapy (IGRT), referring to imaging occurring in the radiation therapy room with per-patient adjustments, can increase the agreement between the planned and the actual dose delivered. However, the absence of direct evidence regarding the clinical benefit of IGRT has been a criticism. Here, we dissect the role of IGRT in the radiotherapy (RT) process and emphasize its role in improving the quality of the intervention. The literature is reviewed to collect evidence that supports that higher-quality dose delivery enabled by IGRT results in higher clinical control rates, reduced toxicity, and new treatment options for patients that previously were without viable options.