调强放射治疗(intensity modulated radiationtherapy,IMRT)是现代放射治疗最主要的技术之一,可较大程度地控制剂量分布,使肿瘤控制率得以增高。随着计算机技术和医学影像工程的不断发展,虽然CT、MRI、SPECT、PET等,为肿瘤病灶诊断提供了多种模态的图像,然而在靶区勾画中,单一模态的图像往往不能完全满足我们所需的足够信息。故运用两个或者更多的成像技术,为治疗靶区 Intensity modulated radiation therapy (IMRT) is one of the most important techniques in modern radiotherapy. It can control the dose distribution to a great extent and increase the tumor control rate. With the continuous development of computer technology and medical imaging projects, although CT, MRI, SPECT, PET and so on, provide a variety of modal images for the diagnosis of tumor lesions, single-modal images are often not completely Sufficient information to meet our needs. Therefore, the use of two or more imaging techniques for the treatment of target