Goldwein J W, Zimmerman R, Corn B W
Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia 19104, USA.
Radiat Oncol Investig. 1997;5(1):38-42. doi: 10.1002/(SICI)1520-6823(1997)5:1<38::AID-ROI6>3.0.CO;2-L.
A technique is described for simulating intracranial radiation fields. The method involves the projection of images from magnetic resonance (MR) scans to orthogonal simulation radiographs. This approach often can supplement and occasionally obviate the need for computerized tomographic (CT) assisted treatment simulation for co-planar beam arrangements in brain irradiation. Because magnetic resonance imaging can be performed in virtually any plane and is routinely carried out in sagittal and coronal planes, transferring tumor volumes to orthogonal simulation films using this technique can be done simply and accurately. The method employs an inexpensive photographic enlarger to superimpose sagittal MR scans on the lateral skull simulation films. Tumor volumes along with other structures of interest are treated onto the film and appropriate fields and blocks are contoured. The technique is performed easily in conjunction with routine simulation sessions, provided that the appropriate MR images are available. It is most suitable for planning treatment of tumors located at midline (e.g., medulloblastomas, craniopharyngiomas, brainstem gliomas, germinomas, etc.). The technique has also been used to verify the accuracy of CT-assisted treatment planning. With relatively minor modifications, eccentric tumors also can be accurately planned, and although we have restricted our description to brain tumours, the technique may be extrapolated to tumors in other sites.
描述了一种模拟颅内辐射野的技术。该方法包括将磁共振（MR）扫描的图像投影到正交模拟放射片上。对于脑部放疗中共面射束排列，这种方法常常可以补充并偶尔消除计算机断层扫描（CT）辅助治疗模拟的需求。由于磁共振成像几乎可以在任何平面进行，并且常规在矢状面和冠状面进行，使用该技术将肿瘤体积转移到正交模拟片上可以简单且准确地完成。该方法使用一台廉价的照片放大机将矢状面MR扫描叠加在侧位颅骨模拟片上。将肿瘤体积以及其他感兴趣的结构处理到片子上，并勾勒出合适的射野和挡块。只要有合适的MR图像，该技术很容易与常规模拟流程结合进行。它最适合用于规划位于中线的肿瘤（如髓母细胞瘤、颅咽管瘤、脑干胶质瘤、生殖细胞瘤等）的治疗。该技术也已用于验证CT辅助治疗计划的准确性。经过相对较小的修改，偏心肿瘤也能准确规划，并且尽管我们的描述限于脑肿瘤，但该技术可能可外推至其他部位的肿瘤。
