The modification of the radiosensitivity of murine tumor was studied in vivo using chemicals (mainly radiosensitizers and BRMs) with radiotherapy. Both LD50/5-days (GI death) and LD50/30-days (BM death) for normal tissue response were not enhanced with combined radiotherapy using hypoxic cell radiosensitizers. In addition, radiosensitizing effects to murine tumor with combined radiotherapy showed enhancement of the tumor target cell population. Moreover, no significant differences were found in radiosensitivity between aerobic cells treated by radiation alone and those treated by radiation in combination with raiosensitizers. On the other hand, the dose modifying factor of BRM's in combined radiotherapy of murine tumor was observed, however, the ratio of modification was smaller than the radiosensitizer's effect.
It is well known that radiosensitizers can have physiological side effects.
The author believes that it is best to employ radiosensitizers that increase the sensitivity only of tumor target cells, not normal cells, thereby allowing greater effects of radiotherapy without increasing overall radiotherapy doses.

View full abstract

Large bowel cancer is one of the remarkably increasing cancers in Japan after World War II. However, contrary to colon cancer which continues to incease more and more, rectal cancer shows an increasing trend recently to have stopped in females or lessened in males. More than 97% of rectal cancers are adenocarcinoma and the principal modality of treatment is surgery. However, surgical intervention of rectal cancer which is deep in the pelvic cavity accompanies more or less undesirable disturbances of anal, sexual and or urinary functions. Furthermore, because of the dilemma between the radical and systematic dissection of lymphatic tissues, and the preservation of genitourinary functions, today's task of the surgeon is to find the best point of balance between these two issues. To arrive at the balanced point, firstly a high quality assessment of the anatomical extent of the tumor, i. e. the information about local extent, lymph node involvement and remote organ metastasis, is mandatory. The surgeon's choice of surgical procedures must be accurate in respect of preservation of function and the curability of the cancer. Finally the surgeon must be skillful enough to conduct the surgical procedures adeptly. The contribution of radiation therapy and chemotherapy in this field, especially to extend the possibility of preservation of function is strongly expected. For squamous cell carcinoma of the anal canal and perianal skin, chemo-radiotherapy has succeeded in achieving ideal radical treatment with minor surgical intervention and complete preservation of anal, urinary and sexual functions.

View full abstract

To evaluate the role of combined hyperthermia (HT) and radiotherapy (RT) in the management of loco-regional recurrent breast cancer, a multi-institutional retrospective analysis was undertaken by the JASTRO Hyperthermia Study Group. Clinical records of recurrent breast cancer treated with thermoradiotherapy in six Japanese institutions were reviewed. In total, 128 fields in 118 patients were enrolled in this study. Thirty-four fields (27%) were recurrence in previously irradiated areas. Hyperthermia was given within 30 min after RT for most tumors, once-a-week (70 fields) or twice-a-week (58 fields). Average total RT dose was 51.2±11.6 Gy. In total, 764 HT sessions were administered for the 128 fields, and invasive measurements of tumor temperature were performed in 531 HT sessions (70%). Effective HT sessions (tumor temperatures of>42°C for>20 min) were achieved in 311 HT sessions (59%). Response rates 1 month after the combined treatment were: complete response (CR) 46%, partial response (PR) 38%, and no change (NC) 15%. At 6 months following the treatment, 60% of the tumors were locally controlled. Mean tumor depth and tumor volume of CR responders were significantly smaller than those of PR responders. In terms of thermal parameters, the number of effective HT sessions of CR responders were significantly higher than those of NC responders, and the mean percentage of intratumor points of>41°C in CR responders was significantly higher than that in PR responders. Thus, some correlation between thermal parameters and tumor response was obtained. Complications associated with thermoradiotherapy were not serious. The present analysis will aid in the design of subsequent phase III trials of thermoradiotherapy for the localregional recurrent breast cancer.

View full abstract

Purpose The role of local field radiation therapy (RT) to bulky lesions of non-Hodgkin's lymphoma in multimodal treatment using MACOP-B therapy (CT) was analysed. Materials and Methods Between December 1986 and December 1991, 53 cases (male: 29, female: 24) with non-Hodgkin's lymphoma were treated at Nihon University Itabashi Hospital. The mean age was 52 years (19-71). The cases were classified as follows, CS I: 4, CS II: 14, CS III: 14 and CS IV: 21 and 28 showed B symptom. Histopathological classification (WF) showed DL of 30, DSC of 12, IBL of 6, DM of 4, FL of 1. RT was performed on 23 with bulky lesions (more than 5cm in the longest diameter) and to 4 with non-bulky lesions. Irradiation fields were limited to bulky or residual tumor lesions or regions including these types of lesions. The dose ranged from 40 to 52.2 Gy excluding 2 cases which received 15.5 and 38 Gy, respectively.
Results Cumulative 5-year survival rate of was 66% for all cases;(CSI: 75%(3-year), CS II: 85%, CS III: 77%, CS IV: 43%). The prognostic factors were clinical stage, bulky lesion, serum LDH level and total protein content.
In the 34 cases evaluated with bulky lesions, 23 were treated with CT+RT and 11 were treated with CT alone. CR rates of the CT+RT and the CT alone groups were 83% and 64%, respectively and cumulative 5-year survival rates of those were 67% and 62%, respectively. Relapses from bulky lesions and those outside of bulky lesions were 2/19 and 4/19, respectively in the RT+CT group and those were 3/7 and 1/7 in the CT alone group.
Conclusion Boost radiation therapy to bulky lesions or residual tumors after CT is effective for local control and it is a possible modality in the combination treatment of non-Hodgkin's lymphoma, although the contribution to final survival is small.

View full abstract

Bone atrophy is frequently seen following radiotherapy, occasionally resulting ininsufficiency fracture or necrosis as late sequelae, however, there have been no reportsconcerning early changes in bone mineral metabolism due to radiotherapy. In this study, temporal change of bone mineral density (BMD) in thoracic vertebrae during radiotherapy wasmeasured by Dual Energy X-ray Absorptiometry (DXA). To assess the accuracy of themeasurement of BMD in thoracic vertebrae, we studied experimentally with a phantom patient.From the results of the coefficient of variation (CV%) ranging from 0.13 to 0.59, this techniquewas considered to accurately quantify BMD. In a clinical study, the BMD of thoracic vertebraein 74 patients (lung cancer: 55, esophageal cancer: 12, malignant lymphoma: 7) who receivedradiotherapy for treatment of malignancies were measured by DXA. The patients' ages rangedfrom 52 to 79 (average=60.8±11.5), with 57 male cases, and 17 female cases. The doses ranged from 50 to 60Gy. The BMD of thoracic vertebrae located in the region ventral to the sternumwas measured. Also, the serum levels of parathyroid hormone (PTH) before and after radiotherapy were measured in 31 patients. The BMD of Th12 in the nonirradiated field did notchange appreciably. The BMD of thoracic vertebrae in the irradiated field decreased graduallyduring radiotherapy and reached 89.6±7.8% of the preradiation value after 50Gy, and 87.1±4.5% of the preradiation value after 60Gy. The value of PTH after radiotherapy increased slightly in comparison with that before radiotherapy (P<0.05).

View full abstract

This study reviews the experience of palliative radiotherapy to patients with multiple myeloma to define the optimal dose for pain relief. The records of 31 patients (66 sites) withmultiple myeloma irradiated for palliation at Kumamoto University hospital between 1985 and 1994 were reviewed. Total dose ranged from 8 to 50Gy, with a mean of 32.2Gy. Symptomsincluded pain (78.1%), neurological abnormalities (28.1%), and palpable masses (34.3%). Symptomatic remission was obtained in 45 of 46 evaluable sites (97.8%). Complete remission of symptoms were obtained in 28.3%, and partial remission in 69.6%. According to fraction size, there was no significant difference between 3-5Gy and 1.8-2Gy. The incidence of complete remission increased when a total dose of more than 20 Gy was given. When the quality of life isconsidered, hypofractionation was recommended for the palliative radiation therapy of multiple myeloma.

View full abstract

The Japanese Society for Therapeutic Radiology and Oncology conducted a survey ofthe present state of thermoradiotherapy for colorectal carcinomas in Japan. In this survey, 105cases at the 9 institutions were registered which had been treated from January 1981 to December 1992. From this data, we analyzed the trend of hyperthermia for the colorectal carcinoma and the treatment parameters which might have an influence on the treatment results.
1) Ninety-four of 105 cases were recurrent or metastatic lesions.
2) Mainly, the RF capacitive heating equipment were applied for the colorectal carcinoma.
3) The number of cases in which hyperthermia were given once or twice a week were almostequal, and there, was no significant difference in the treatment response rate.
4) The mean duration of hyperthermia at therapeutic temperature was 42 min. Measurements oftemperature in lesions were performed in 86% of sessions, and the mean tumor temperaturewas 43.1°C
5) Higher maximum tumor temperature and longer treatment time have brought significantly better response.
6) Responder groups have shown better survival than non-responder groups.
7) Acute reactions associated with hyperthermia were as follows: pain in 35 cases, burn and/orskin erosion in 12 cases, abscess formation in 3 cases and others in 3 cases. Late effects oftreatment were ileus in 9 cases, ulcer of intestinal tract in 5 cases, subcutaneous' fibrosis in 3and others in 6.
In conclusion, the application of thermoradiotherapy for reflactory colorectal carcinoma maycontribute to the improvement of prognosis and quality of life of patients.

View full abstract

The contribution of a denture-type spacer, fabricated by a denture duplicationtechnique, in reducing the incidence of radiation bone complication (osteonecrosis) was examined retrospectively. Fifty-five edentulous patients with previously untreated T1 and T2 carcinoma of the oral tongue were treated mainly by interstitial brachytherapy between April, 1978 and November, 1992. A spacer was used in 12 patients who were treated after 1991.Osteonecrosis was found in 3 patients treated without a spacer but in no patient treated with thespacer. However, there was no significant relationship between the incidence of osteonecrosis and the use of the spacer. The failure was attributed to specific procedural alterations, i.e., reduction of the frequency of use of external irradiation and thereby of total dose, during theperiod in which spacers were applied. Despite the failure to observe any significant contribution of the denture-type spacer to reducion of the incidence of osteonecrosis in this study, a reductionof the dose to the mandible can be expected when a spacer is used. We have therefore adoptedthis type of spacer as a part of our interstitial brachytherapy procedure.

View full abstract