Richter E
Strahlenther Onkol. 1987 Jun;163(6):403-9.
In radiotherapy planning, the shape of a target volume can at present be exactly delimited by means of computed tomography. A method often applied is to project the largest target volume scan on the plane of the central ray and to calculate the dose in this plane. This method does not allow to take into account any change of the target volume scan which will be mainly due to the body contours of the patient. The results of dose calculations made in several planes for pharyngeal and laryngeal tumors are presented. With this procedure, 33 out of 60 irradiation techniques for nine tumor sites meet the requirements with regard to the central ray plane. If several planes are regarded, this is only true for ten irradiation plans. It is therefore absolutely necessary to calculate the doses of several planes if the target volume has an irregular shape or if the body contours vary considerably. This is the only way to prevent a false treatment caused by possibly severe dose excesses or dose insufficiencies in radiotherapy.
在放射治疗计划中，目前可以通过计算机断层扫描精确界定靶区的形状。一种常用的方法是将最大靶区扫描投影到中心射线平面上，并计算该平面内的剂量。这种方法无法考虑靶区扫描的任何变化，而这种变化主要是由患者的身体轮廓引起的。本文给出了针对咽喉部肿瘤在多个平面进行剂量计算的结果。通过此程序，九个肿瘤部位的60种照射技术中有33种满足中心射线平面的要求。如果考虑多个平面，只有十个照射计划符合要求。因此，如果靶区形状不规则或身体轮廓变化很大，绝对有必要计算多个平面的剂量。这是防止放射治疗中因可能出现的严重剂量过量或剂量不足而导致错误治疗的唯一方法。
