Tenhunen M, Usenius T, Lahtinen T
Department of Radiotherapy and Oncology, Kuopio University Hospital, Finland.
Acta Oncol. 1994;33(6):661-5. doi: 10.3109/02841869409121779.
When the whole neuraxis is irradiated, as in medulloblastoma, the large target volume makes field arrangement complicated and 3-4 adjacent fields have to be used. A calculation method, based on geometrical matching of field edges, is presented for determining optimal separation between the opposed cranial fields and the posterior spinal field as orthogonal movements of the treatment couch top. The dosimetric verification of the method with a 4 MV photon beam indicates a dose inhomogeneity below +/- 7%.
当全神经轴受到照射时，如髓母细胞瘤的情况，大的靶区体积使得射野布置变得复杂，必须使用3 - 4个相邻射野。本文提出一种基于射野边缘几何匹配的计算方法，用于确定相对的颅脑射野与后脊髓射野之间的最佳间距，作为治疗床顶部的正交移动。用4兆伏光子束对该方法进行剂量验证，结果显示剂量不均匀性低于±7%。
