Geise R A, McCullough E C
Radiology. 1977 Jul;124(1):133-41. doi: 10.1148/124.1.133.
Several problems related to the true value of quantitative information from CT scanners in improving estimates of photon-beam isodose distribution remain unanswered. The authors conclude that two widely used correction factors provide satisfactory isodose corrections behind heterogeneities of simple geometry. Lateral perturbations were found to be small for megavoltage photon beams, indicating that complex computational schemes are uncalled for. It appears doubtful that the use of CT information in megavoltage photon-beam isodose curve generation requires (a) larger computers than those currently available either in existing therapy planning systems or on the scanner itself or (b) direct access to the CT numbers.
与CT扫描仪定量信息在改善光子束等剂量分布估计中的真实价值相关的几个问题仍未得到解答。作者得出结论，两个广泛使用的校正因子在简单几何形状的不均匀性之后能提供令人满意的等剂量校正。发现兆伏级光子束的横向扰动很小，这表明不需要复杂的计算方案。在兆伏级光子束等剂量曲线生成中使用CT信息是否需要（a）比现有治疗计划系统或扫描仪本身当前可用的计算机更大的计算机，或者（b）直接访问CT数值，这似乎值得怀疑。
