This is a report of a joint randomized clinical trial in Hokkaido for Small-Cell Lung Cancer (SCLC) started in November 1985 and closed in November 1988. Theobjective of this first trial was to compare the effects of a three drug regimen (CDDP+VP-16+IFOS) with that of two drugs (CDDP+VP-16), both followed by regional radiotherapy. This study included a total of 92 patients with SCLC. The analysis focused especially on 46 LD patients, to show a prognostic factor and pattern of relapse relative to the field of irradiation. Results were as follows: 1) no significant benefit of survival was obtained by a three drug regimen; 2) the degree of tumor response to initial treatment was the major prognostic factor for both 2-year disease free survival, and local control; 3) chest recurrence, especially “in-field” recurrence was the major cause of failure despite thoracic irradiation of 40-50Gy.

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Radiation brain injury, including functional disturbances or morphological changes (brain atrophy, periventricular lucencies or ventricular dilatation), were studied by CT in patients with primary intracranial neoplasms who were followed-up for at least 5 months after receiving radiotherapy. Each of 33 patients with medulloblastoma, pinealregion tumor or malignant lymphoma received a total dose of 40-61Gy by conventional fractionation using a whole brain irradiation field boosted by a localized field. Of these patients, 19 (58%) developed radiation brain injury. It was concluded that the volume-dose was one of the most. important factors influencing the development of radiation brain injury. Age at the time of radiotherapy and time of follow-upafter the treatment were also considered to be important factors.

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We previously reported the hollow out technique with no absorber, using conformation radiotherapy with over-centerable collimators. In the present report, we discuss determination of the calculated dose distribution. So the software of the radiation treatment planning system (MODULEX) was modified and expanded to calculate dose distribution in the conformation hollow out technique. The calculated dose distrbution was compared with measurements by film dosimetry. The distributions coincide well, with an error of about 5%. The conformation hollow out technique was applied to patients with lung cancer and esophageal cancer.

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Effects of the hypoxic cell radiosensitizer (RP-170) in fractionated radiotherapy on therapeutic benefit were studied using Lewis lung carcinoma. A single dose of irradiation with RP-170 prolonged the tumor growth time depending on the dose of RP-170 and irradiation. Although, there was no significant difference, high doses of RP-170 also seemed to slightly enhance the skin reaction to irradiation in ICR and BDF1 mice. Fractionated irradiation combined with RP-170 significantly prolonged the tumor growth time depending on total dosage and each fractionated dose of RP-170. Sixteen administrations of low doses of RP170 (80mg/kg) with 3Gy of radiation achieved a therapeutic gain of 1.1. Survival time of mice was prolonged and was related to the growth prolongation. The radiosensitizer, RP-170, may be valuable in fractionated radiation therapy.

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The right legs of C₃Hf/Bu mice were exposed to 25Gy in a single dose in a 3 cm diameter field, using two opposing ¹³⁷Cs sources. The irradiated legs were observed for early skin reaction (ESR), epilation, skin shrinkage measured 40days and 250days after irradiation, and leg contraction measured 250days after irradiation (LC).Although the materials and methods used were the same for all experiments, the degree of normal tissue injury at the end points differed widely for each animal. The histograms and the dose response curves for each injury showed that the standard deviation of variation of tissue injury was about equal to 5Gy variation. Relations between early and late tissue injuries, such as ESR and LC, after irradiation show wide variation in the late tissue injuries in animals that have the same degree of early tissue injury. This implies that it is very difficult to predict the outcome of late tissue injury in an individual animal from the degree of early tissue injury.

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This report analyzes 18 cases of primary malignant lymphoma of the brain treated by whole cranial and local boost irradiation (total dose, mean 54Gy) in Niigata University Hospital between January 1980 and December 1987. The cumulative 5-year survival rate was 12%. During the treatment, tumors responded well and disappeared in all cases. However, relapse in 7 patients was detected by follow-up CT study or autopsy. The site of relapse was the CNS in 5 cases (one at the original site and 4 at other sites), anth e extra-CNS in two cases. Multiplicity of lesion was considered to be at high risk for relapse. In cases without relapse, deterioration of mental and physical activity was observed frequently. The CT study revealed brain damage such as diffuse brain atrophy and low density of white matter in these patients. Our results indicated that reduction of brain damage was necessary, and considering the mode and risk of relapse, radiotherapy might be optimized. The possibility of reduction of cranial radiation dose and significance of prophylactic spinal irradiation are discussed.

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This is an analysis of 69 patients with primarily unresectable or recurrent colorectal cancer who were treated by radiation therapy between 1981 and 1989. Primary tumor response of 63 tumors including 8 recurrent tumors in previously irradiated area could be evaluated mainly by CT scan. Of the 63 tumors, 6 (10%) responded completely (CR), 23 (37%) responded partially (PR), and 34 (54%) did not respond. The response rates (CR+PR) according to the treatment methods were: 33%(8/24) for external irradiation alone, 50%(16/32) for radiation plus regional hyperthermia, 50%(2/4) for radiation plus chemotherapy, 100%(3/3) for radiation, hyperthermia, and chemotherapy. Thus, the response rate of the combined modality group was higher than that of the external irradiation only group, although the difference was not significant. Good palliative effects were observed in 44 of 48 patients. The 1-year and 5-year survival rates for the 69 patients were 58% and 9%, respectively, with a median survival of 15 months. Favorable prognosis was obtained in patients without distant metastasis (p<0.001) and in those treated with surgical resection of the tumors with or without intraoperative radiation therapy (p<0.005). The multimodal treatment approach, including external irradiation, hyperthermia, chemotherapy, intraoperative radiation therapy, and surgical resection, should be considered in the treatment of advanced colorectal cancer, especially for patients without distant metastasis.

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