Volume 33, Issue 6, June 2006
Index of content:
- Therapy Continuing Education Course: Room 24C
- CE: Daily Localization ‐ I: Kilovolt Imaging
33(2006); http://dx.doi.org/10.1118/1.2241392View Description Hide Description
Daily target localization is a critical step to secure accurate delivery for 3‐D conformal radiation therapy and intensity‐modulated radiation therapy. One emerging technology using in‐room kilovoltage (kV) imaging has shown to be very promising for targeting treatment volumes. The major advantages of using kV imaging are 1) its comparable contrast between soft tissue and bone structure to that in simulation images, 2) real‐time high resolution fluoroscopic imaging, 3) lower radiationdose to patient compared to conventional MV imaging, and 4) availability of reconstructing tomographic images (for example, cone‐beam CT) using 2‐ D kV projection images. At present, different types of in‐room kV imagingsystems are being developed for different applications such as in‐room CT on rail, ceiling‐mounted dual‐source/detector configuration, and gantrymounted single source/detector system. In terms of clinical applications, some generate 2‐D radiographic images for target verification based on bony marks or implanted surrogator while others generate 3‐D tomographic images for target verification based on both soft tissues and bony structures. Some could be used for viewing organ motion to verify applied margin while others could be used for monitoring target motion to verify dynamic delivering or gated treatment. Issues related to the risk and benefit between imaging information and radiationdose using 2‐D or 3‐D imaging, the geometric accuracy of imagingsystems, trade‐off between treatment accuracy vs. time required to carry on imaging and manipulation process, early image‐guided protocols for basic clinical applications, etc. will be discussed. Some new developments related to effective and efficient use of in‐room kV and MV imaging, tomographic image reconstruction using limited number and angle projections have shown very promising for future clinical applications.
This lecture will describe the commercially avaialbe kV imagingsystems, as we as their applicable clinical protocols, acceptance testing and commissioning processes, basic QA requirements, system limitations, and potential future developments.
1. Understand the latest commercial available technologies for in‐room kV and CBCTsystems.
2. Understand the basic functionalities of in‐room kV imagingsystem.
3. Understand the basic imaging applications.
4. Understand the basic system limitations and QA.