The prerequisite, which can be acquired by CT, NMR or PET technology, is to localize the tumor and determine its region.

• 实施放射治疗的先决条件是确定肿瘤的位置和判断肿瘤的生长范围。 这可以由计算机断层扫描(CT)、核磁共振(NMR)或正电子发射断层扫描(PET)等技术手段来提供病人的三维解剖信息。