It was not too long ago when CT based treatment planning was reserved for the few patients that was critical to have volumetric imaging, and treatment verification was limited to planar films of mediocre quality from a megavoltage imaging source. Today, we use multi‐modality based planning (CT, MRI, PET etc) and we employ sophisticated imaging tools and techniques to verify the correct delivery of the treatment. Such imaging capabilities include electronic portal imaging devices coupled with megavoltage (MV) or kilovoltage (kV) x‐ray sources, MV and kV cone beam CT, ultrasound guidance, optical systems, MV computed tomography, CT on rails and others. The goal of any in‐room imaging device is to verify that the patient setup is accurate and in accordance to the treatment plan. While some modalities allow for pre‐treatment verification, others can also provide on‐treatment verification feedback. The choice of the modality to use depends largely on user preference but also on the investment the clinic is willing to make to purchase the necessary equipment. Nonetheless, image based treatment verification has become a necessary and valuable aspect of our clinical practice and is enabling us to become a lot more aggressive with the planning and delivery of radiation treatments. Image Guided Radiation Therapy (IGRT) is undoubtedly the future of radiation therapy. In this presentation we will discuss some of the most popular methods of imaging for treatment verification techniques. Clinical examples will also be presented to demonstrate the implementation, use, and clinical experience with these modalities. Educational Objectives: 1. Review of existing image based treatment verification modalities. 2. Discuss pros and cons of each modality and appropriateness of use.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging