The advantage of proton therapy is reduction of treatment volumes relative to those feasible with conventinal photon therapy. The consequence is that the radiation dose to the target can be raised, with a resultant increse in tumor control probability. Proton beams, however, yield no biological gains because their biological properties are similar to conventional low LET radiations. As more sophisticated technologies are needed, there have been many advances which are applicable to photon therapy; 3-D treatment planning, DVH analysis, and systems for positioning, etc.
As of January 1994, a total of about 13, 000 cases were reported as having had treatmemts with proton beams in 16 centers world wide. The. tumor sites for those include uveal melanoma (30-40%), intra-cranial small targets (40%), and others. Uveal melanomas had been most extensively treated with 70Gy/5fx or 60Gy/4fx which resulted in local control and survival rates of>96%and 80%, respectively. For chordoma and chondrosarcoma of the skull base and cervical spine, the 5 year local control rates were 65% and 91%, respectively. Promising results are also being obtained for headand neck and pelvic tumors. Deeper-seated tumors have been treated only at Tsukuba University with successful results in some anatomic sites. Among these, inoperable primary hepatocellular carcinomas were effectively treated with a total dose of 75-85Gy (3.0-4.5Gy/fx). The 3 year survival rates for all patients, Child A+B patients, and Child A patients were 38%, 47%, and 60%, respectively, which compare favorably to other modalities.
These successful results of world wide proton therapy have led us to the conclusion that a hospital-based proton facility will provide opportunities for additional patients to be treated with protons. Thus, new plans are proposed from more than 10 institutions to build a new treatment center or upgrade the energy of currently available proton beams.

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Rotational multi-leaf conformation is a standard high precision radiation technique in Japan. It is a combined gantry rotation and movement of multi-leaf collimaters to create a similar dose distribution to the target volume. Although treatment planning for this technique is rather simple when compared to further complex techniques such as the non-coplanar technique, i t is time and man-power consuming. The authors developed a new type of planning machine for the conformation therapy. Fully automatic field setting based on the beam's-eye-view principle reduces planning time quite drastically. The authors hope that the present planning system will enhance the availability of conformation radiation therapy.

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The status of radiotherapy in Japan at the end of 1990 was investigated. The census was carried out by mailing a questionnaire to radiotherapy facilities. Four hundred and thirty one (431) questionnaires were returned out of the 778 mailed. Available data on radiotherapy equipment and staff of 378 facilities in which some cancer patients received radiotherapy during 1990 were analyzed.
Although most university hospitals or cancer centers had sufficient radiotherapy equipment and staff, less than 25% of hospitals were recognized as general radiotherapy facilities which have an external radiotherapy unit, brachytherapy unit (both intracavitary and interstitial irradiation units) and supportive equipments such as X-ray simulators. The average numbers of full-time radiotherapists and radiotherapy technicians per facility were 1.6. In small facilities which treat less than 50 patients per year, radiotherapy was performed with collaboration of part-time radiotherapists and technicians.

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The purpose of this multi-institutional study was to investigate the actual condition of five-year survivors in non-small cell lung cancer patients treated by radiation therapy without resection. The final registration time was October 31, 1993.
A total of 436 patients from 78 institutions in Japan were registered.
An analysis of the characteristics of patients and tumors, treatment planning, tumor response. late radiation injuries, double primary cancer, and other factors was performed.

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Between 1986 and 1992, 10 patients (12 lesions) of advanced breast cancer were treated with multidisciplinary treatment including brachytherapy. The lesions treated included 5 primary breast tumors, 3 metastatic lesions in the contra lateral breast, 2 recurrences after external beam irradiation, 1 metastasis to the axillary lymph node and 1 metastasis to the upper arm skin. The interstitial irradiation techniques used were 192Ir low dose-rate iradiation for 5 lesions and high dose-rate for 7 lesions (including 3 with mould irradiation ). External hyperthermia as perfomed for 6 lesions and interstitial hyperthermia were perfomed for 4 lesions. The local response was CR for 3 lesions, PRa for 8 lesions, PRb for 1 lesions with the local response rate being 100%. Excellent local control could be achieved by combination external and interstitial irradiation, indicating that radiotherapy is definitely useful for the treatment of advanced breast cancer.

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The purpose of this study, which involved 240 acute leukemia patients (ALL: 115, ANL: 125) who received an allo-geneic bone marrow transplantation (BMT) with preconditioning by total body irradiation (TBI) and chemotherapy, was to examine retrospectively the TBI factors that may have influenced a leukemic relapse. The patients were divided into two groups: 124 patients who had received their BMT within a diagnosis-transplantation period of 9 months or less (DTP9 group), and 116 patients who had received their BMT within a diagnosistransplantation period of 10 months or more (DTP 10 group). It was concluded that:(1) The higher the TBI dose, the fewer the relapse rates in DTP9 group.(2) The longer the TBI period, the greater the increase in the relapse rate in DTP 10 group. It was thus speculated that an effective TBI regimen for acute leukemia patients may vary depending on the length of time that has elapsed from the diagnosis of leukemia to the BMT.

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We have previously described the increased proliferation, and appearance of abnormally large nuclei in renal proximal tubule cells relatively soon after irradiation. A model has been proposed that the large nuclear cells might be dying cells and that the increased proliferation might lead to mitotic death of these cells and possibly cause functional damage. We have also reported that the transient increase in cell proliferation by unilateral nephrectomy after radiation accelerated late radiation damage of the kidney, which supported the model for late radiation damage. The administration of folic acid induced another transient increase in cell proliferation of the kidney although these mechanisms are different to each other. The acceleration of late radiation damage of the kidney by folic acid also supported the model for late radiation damage.

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Two cases of primary malignant lymphoma of the uterine cervix are reported. Both of them presented with vaginal bleeding. One patient had malignant lymphoma of the diffuse small cleaved cell type, and the other lymphoblastic type lymphoma. The stage in both was IIB (FIGO). The former patient, who was treated by radiation therapy, is free of disease and alive and well 4 years after completion of treatment. The patient with lymphoblastic lymphoma received chemotherapy, radical surgery and postoperative radiotherapy, but died of distant metastasis 3 years after initial chemotherapy. Radiation therapy alone is a curative treatment for this rare malignant lymphoma when confined to the pelvis; but for aggressive or extensive malignant lymphomas, combination chemotherapy should be used.

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