局所進行がン治療における陽子線治療の適応選択に関する研究

质子束放射治疗局部晚期及深部肿瘤的潜在适用性探讨。在质子束放射治疗中，改善了辐射的剂量分布，以便对肿瘤给予较高的剂量，而对正常组织给予较低的剂量，这种特性比光子提供了明确的治疗优势。本研究评估了其他治疗方式的价值，包括快中子治疗、近距离治疗、术中放疗、构象放疗、各种分次放疗、放疗联合热疗或化疗。通过考虑这些评估的结果，最终研究了可以成功地用质子治疗的临床实例。剂量-体积直方图分析显示了质子束比常规辐射的优越性。加速短期放疗、场对场、不均匀分割放疗在质子治疗中具有重要的应用价值。筑波大学的临床质子疗法治疗了各种深层器官的肿瘤，在头颈部、肺部、食道、肝脏、子宫颈、膀胱和前列腺肿瘤的治疗中取得了令人印象深刻的临床成功。与其他放疗方式相比，质子束放疗被认为在以下方面有价值：(1)IIIb期宫颈癌、局部进展期肺癌、食道癌以及术后复发或不能手术的胆道癌的根治性治疗；(2)直肠癌的术前放疗；(3)质子与化疗联合治疗。本研究取得的上述成果促使我们设计专用质子治疗设备。

Investigation on potential applicability of proton beam radiotherapy for treatment of locally advanced and deep-seated tumors.In proton beam radiotherapy improved dose distribution of radiation is accomplished so that a higher dose can be administered to the tumor while a lesser dose is given to the normal tissue, and such characteristic provides definite treatment advantage over photons. In this study the value of other treatment modalities were evaluated including fast neutron therapy, brachytherapy, intraoperative radiotherapy, conformation irradiation, variously fractionated radiation, and radiotherapy combined with hyperthermia or chemotherapy. By taking into account for the results of such evaluations, clinical examples which could be successfully treated with protons were finally investigated.The dose-volume histogram analysis has demonstrated the superiority of proton beams over conventional radiations. It was also demonstrated that accelerated short-term radiation, 'field in field' method, and unevenly fractionated radiation were of great value in proton therapy. In a clinical proton therapy at University of Tsukuba, tumors of various deep-seated organs have been treated, and impressive clinical success has been achieved in treatment of tumors of the head and neck, lung, esophagus, liver, uterine cervix, bladder and prostate. In contrast to other radiotherapeutic modalities, proton beam radiotherapy is considered to be valuable in : (1) radical treatment of stage IIIb uterine cervix ca, locally advanced lung ca, esophagus ca, and post-operative recurrent or inoperable ca of the biliary tract, (2) pre-operative radiotherapy of rectal ca, and (3) combined treatment of protons and chemotherapy.The above accomplishment obtained in this study has stimulated us to design a dedicated proton therapy facility.