Maebayashi Katsuya, Nasu Sachiko, Seki Kaori, Kiyoduka Makoto, Hashimoto Yaichirou, Mitsuhashi Norio
Dept. of Radiology and Radiation Oncology, School of Medicine, Tokyo Women's Medical University.
Gan To Kagaku Ryoho. 2006 Apr;33(4):436-43.
Radiotherapy plays an important role in the management of cancer patients, and half of the patients with malignant tumors are treated with radiotherapy in the United States. In Japan, the necessity of radiation therapy has come to be widely acknowledged in cancer treatment, and more and more cancer patients are being treated with radiation. External beam radiation is the most-used radiotherapy at the present time. The advantage is that this treatment modality can be used in a short time, although the problem is that not only the cancer lesion but also the surrounding normal tissue is irradiated,causing an adverse effect on normal tissue. In order to solve this problem,treatments such as 3D-Conformal Radiation Therapy (3D-CRT), Intensity Modulated Radiation Therapy (IMRT), Stereotactic Radiation Surgery (SRS) and Stereotactic Radiation Therapy (SRT) are clinically used as an extremely precise radiotherapy, thanks to the advances in computer technology in recent years. Therefore, the purpose of these extremely precise radiation therapies is to administer a high dose to the tumor intensively, and to suppress quantities of magnetism to normal tissues. IMRT treatment results for prostate cancer patients and head and neck cancer patients are reportedly better than with other irradiation methods. In this chapter,we explain the external irradiation method with the focus on IMRT and the extremely precise radiotherapy preformed in the Tokyo Women's Medical University Hospital.
放射治疗在癌症患者的治疗中发挥着重要作用，在美国，一半的恶性肿瘤患者接受放射治疗。在日本，放射治疗在癌症治疗中的必要性已得到广泛认可，越来越多的癌症患者正在接受放射治疗。目前，外照射是最常用的放射治疗方式。其优点是这种治疗方式可以在短时间内使用，不过问题是不仅癌灶，周围正常组织也会受到照射，对正常组织产生不良影响。为了解决这个问题，近年来随着计算机技术的进步，诸如三维适形放射治疗（3D-CRT）、调强放射治疗（IMRT）、立体定向放射外科（SRS）和立体定向放射治疗（SRT）等治疗方法作为极其精确的放射治疗在临床上得到应用。因此，这些极其精确的放射治疗的目的是向肿瘤集中给予高剂量照射，并减少对正常组织的照射量。据报道，前列腺癌患者和头颈癌患者的调强放射治疗效果优于其他照射方法。在本章中，我们将重点介绍调强放射治疗以及东京女子医科大学医院进行的极其精确的放射治疗的外照射方法。
