Computed tomography in therapy planning: Abdominal region

The radiotherapy community is continuing to appreciate the significant contribution CBT can make to planning abdominal radiotherapy and is also beginning to appreciate the pitfalls and limitations of the technique. Specific attention should continue to focus on patient registration with the scanner and simulator radiographs, patient position during scanning and treatment, and effects of involuntary patient motion, especially breathing, on organ and tumor localization. Effects of patient positional changes and of involuntary motion during treatment on treatment planning and execution should be quantitated, as should effects of inhomogeneities, especially gut air, on abdominal dose distribution. Radiotherapy planned with CBT data can impact significantly on morbidity and mortality associated with abdominal malignancies. Faster scanners (with a scanning time of 9 sec or less) should be employed where possible to obtain maximum diagnostic information. Multiplanar reconstruction and true three-dimensional treatment planning can enhance significantly the value of CBT in treatment planning. Radiotherapists, radiodiagnosticians, radiation physicists, and oncologists must be continue to meet the challenge of realizing the true potential of CBT for the benefit of the cancer patients entrusted to their care