At the National Cancer Center Hospital, Tokyo, BSD-1000 (APAS) was introduced into clinical practice in February 1982, followed by Thermotron RF-8 in January 1983.
Comparisons were made between both devices about various treatment parameters including the percentage of effective hyperthermia which a temperature elevation to more than 42°C, and a concomitant increase in body temperature.
Tumors of the lower extremity, effective hyperthermia rate was 93% (37/40) with APAS as against 60% (6/10) with Thermotron RF-8.
Upper abdominal tumors, effective hyperthermia rate was 37% (19/51) with APAS and 81% (25/31) with Thermotron RF-8. Tumor of the pelvic cavity, the effective hyperthermia rate was 95% (61/65) with APAS as against 40% (12/30) with Thermotron RF-8.
The increase in pulse rate and body temperature was greater with APAS. It appears that with APAS, systemic stress caused by the increase in pulse rate and body temperature might possibly be a limiting factor, while with Thermotron local intense pains that tend to be felt by patients with a thick subcutaneous fat tissue may possibly be a limiting factor that interfere with successful performance of hyperthermia.

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The histopathological study was performed on 16 human malignant tumors which were treated with thermoradiotherapy. The microscopic examination revealed marked necrosis throughout entire sections in 4 tumors to which irradiation to more than 60 Gy in combination with heating at over 42°C was delivered. In other 7 tumors, a massive coagulation necrosis occupied three fourths of tumor tissues, mainly in the part of the core. The remaining 5 tumors showed only slight histological changes, that is, the area of intratumor necrosis was less than three fourths of an entir tumor section.
A marked destruction of blood vessels appeared in the tumor parenchyma in 13 of the 16 tumors, while in the stroma in only 2 tumors. A condensation of destroyed nuclei was revealed in 11 tumors.
Viable tumor cells surviving after thermoradiotherapy were observed in the central area in 3 tumors, around blood vessels in 2 tumors and in the peripheral zone in 12 tumors. These results indicated that thermoradiotherapy affected the center area of tumors more prominently than the peripheral zone, and provided a rationale for the combined use of a high dose of radiation and hyperthermia in the definitive treatment of bulky tumors.

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Response rate of malignant tumors for the treatment of combined radiotherapy and hyperthermia in 1986, from April to December were compared to the earlier results which were already reported.
Sixty percent of 25 superficial tumors showed good response (complete response and partial response more than 50% in size), for 26 deep seated tumors, response rate was 23%. These results are not different from the response rate of the treatment for earlier group of patients, even so many technical improvements were done during this period. Kajira already reported that the response rate of deep seated tumors will go up higher, when it is adjusted by histological findings of X - ray computed tomography of tumors after the treatment.

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From October 1986 to June 1989, 79 patients of malignant tumors were treated by radiation therapy combined with hyperthermia at National Medical Center Hospital. Seventy two patients (male : 48, female : 23) were evaluable. Average age was 62. 4 years old (ranged 20-81 years old). Irradiation was delivered twice to fifth weekly in tumor doses of 50 to 60 Gy (TDF 82-122). We used 3 types of hyperthermic equipment, Thermotron RF8, BSD 1000 System and Endoradiotherm 100A.
Hyperthermia was initiated within 30 minutes following irradiation, most of the patients being treated with adequet equipment, 41-44°C, for 60-70 minutes every 72 hours. Fifteen of 71 patients (20.8%) showed a complete response and 36 patients (50%) showed a partial response, so effective rate was 70.8% of all. In superficial tumors, 4 of 21 patients (21.5%) showed a complete response and 8 of 21 patients showed a partial response, effective rate was 63.2% of all.
In deep seated tumor, 10 of 46 patients (21.7%) showed a complete response and 25 of all patients showed a partial response, so effective rate was 76.1 % of all.
Five patients were heated following only intra-tumor injection of OK-432 and its effective rate was 75%. We think that this modality of therapy will be effective in cases which heating area had been irradiated over tolerable doses.
CR rate of superficial tumors according to intra-tumor center temperature tends to higher in the cases of higher tumor temperature. In deep seated tumor, 11 patients (23.9%) had reached over 43°C, 29 patients (63.0%) heated 41-43°C, 6 patients (13.0%) heated under 41°C and CR rate of each group ware 36.4%, 17.2%, 16.7%, respectively.
We think that thermotherapy with irradiation is an effective therapy in the treatment of malignancies but the improvement of heating equipment will be expected.

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Various type of 25 refractory tumors (16 : shallow-seated tumors, 9 : deep-seated tumors) were treated with radiotherapy and RF capacitive heating using HEH-500. Heating state, acute toxity and clinical result were analysed as follows.
Mean maximum intratumor temperature over 42°C and 41-42°C could be obtained in 9 (36%) and 8 (32%) respectively. Bulky shallow-seated tumors in the flat portion were capable of getting good heating state. But the temperatures of deep-seated tumors in the pelvis and lung could not be reached 42°C. In the rugged portions such as neck, supraclavicular region and chest wall after radical mastectomy, heatings tend to be unstable due to complaining of hot spot. The frequency of painful hot spot which was the cause of power limiting factor decreased from 81% to 41% by using large water bolus. Acute toxicity occured in 15 cases (12 : burns, 3 : subcutaneous indurations). There were no serious complications. Tumor response was evaluated by tumor shrinkage and complete responses were observed in 28% (7/ 25), partial responses in 40% (10/25) and no responses in 32% (8/25). Therefore the heating device (HEH -500) is thus suitable for heating of shallow-seated bulky tumors. It is considered that further improvement of applicators and boluses and increasing power of machine are necessary in order to heat deepseated tumors and other various site of tumors properly.

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肥料の種類並びに施肥時期とリンゴ腐らん病の発生を検討したところ, 4月施肥で有機質肥料区は無機質肥料区より発生が多かった。また, 9月施肥区は4月施肥より発生が多かった。発病率と葉中窒素含量の間に負の相関があり, 本病に対する樹体抵抗性が発現される葉中窒素含量の下限値は7月下旬で2.6%前後であった。

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Microwave radiation is one of the most useful techniques for creating thermal fields in tissue, but its use is limited because of the rapid attenuation of propagation through the body. Therefore, a superficial localized tumor is only the object of microwave hyperthermia.
This study was designed to perform fundamental experiments with localized hyperthermia induced by 2450 MHz microwave radiation. In order to improve the temperature distribution and heating efficiency produced by Microtizer (Minato Medical Science Co., Ltd), we used a cylindrical cardboad cone covered with alminum foil and a collimator with a hole in the alminum plate that were specially designed. The characteristics of temperature distribution patterns using these applicators were tested using a tissueequivalent agar phantom and an unhomogeneous phantom which contained a ham or animal muscle with fat.
The conclusions were drawn from our experimental results as follows;
1) By the use of specially desinged cone and collimator, focusing microwave radiation was improved, that is, both the homogeneity of temperature distribution patterns and the high elevation of temperature were achieved.
2) The relation between the distance from an antenna-tip to phantom surface and the heating efficiency depended on conditions of microwave radiation. With a single refrector, the heating effect decreased in inverse proportion to the distance. With the use of a cone and a collimator, however, the optimum distance of 13 cm exsisted, depending on a given frequency.
3) The hole diameter of collimators for obtaining effective temperature distribution patterns depended on a frequency employed. The heating efficiency was not achieved when the hole diameter was less than λ/4.
4) There was no relationship between VSWR (voltage standing wave ratio) and heating effect.

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36 patients with inoperable malignant pelvic tumors were treated by local hyperthermia combined with radiotherapy. The purpose of this study is to evaluate the thermometry results and the antitumor effects of this treatment.
The 36 patients consisted of 14 colorectal cancers, 6 uterine cancers, 7 metastatic bone tumors, 5 urinary bladder cancers and 4 ovarian cancers. Hyperthermia was performed by 8 MHz RF capacitive heating equipment, once or twice a week after irradiation, four to 10 sessions in total. All cases underwent radiotherapy (total dose, 2050Gy), and 14 patients received combination chemotherapy in an addition to radiothermotherapy.
20 (55.6%) of the 36 patients could undergo intratumor thermometry by direct puncture. In 8 cases (40.0%) of these 20 patients, the maximum tumor core temperature (Tmax) could be elevated to more than 42°C, and the mean Tmax was 41.7± 0.3°C (40.044.7°C). There was a significant correlation between Tmax and electric output during heating. Any tumors could not be heated to more than 42°C using electric output under 600 watt. And electric output was limited by a painful sensation due to overheating of subcutaneous fat tissue.
The local response rate based on tumor regression of all cases was 38.9% (CR 1, PR 13, NC 22). The tumor response was dependent on Tmax and the tumor size. The response rate was fairly higher in the higher Tmax (≥ 42°C) group than the lower Tmax (< 42°C) group (75% vs 25%). And greater response was observed in small tumors. On the contrary, large tumors over 10cm in diameter tended only to become necrotic, but not to become smaller.
There was no clinically severe complication associated with hyperthermia in this trial. So this combination therapy is a very promising therapeutic modality for unresectable malignant pelvic tumors.

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胃癌の手術根治性を高める目的で, 34例の胃癌患者に対して術中照射療法を行った.
方法:腸管等周囲臓器を照射野外に待避せしめたのち, 30～35Gy (18MeV)の電子線を腫瘍床に照射した.術中照射群の5年累積生存率はstage I: 100%, stage II: 72.7%, stage III: 68.8%, stage IV: 20%であり,一方手術単独群のそれはstage I: 95.2%, stage II: 68.4%, stage III: 48.8%, stage IV: 8.0%であり, stage IIIで術中照射群はかなり高い5生率を示した.また,術中照射後372日後に死亡した症例の剖検で被照射リンパ節はfibrotic changeとcancer regressionがみられ,術中照射の効果が確認された.術中照射を行った症例ではリンパ球数やT-cell, Tγ-cellなどに照射による有意の変化はみられず, 2例の吻合部縫合不全以外重大な合併症はみられなかった.
以上の結果,術中照射療法は限局した進行胃癌の治療成績向上に有効である可能性が示唆された.

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The thermometry results of radiofrequency (RF) capacitive hyperthermia for 60 deep-seated tumors in 59 patient are reported. Hyperthermia was administered regionally employing two RF capacitive heating equipments which we have developed in cooperation with Yamamoto Vinyter Co. Ltd.
Thermometry results obtained were summarized as follows. (1) A maximum tumor center temperature over 43°C and 42-43°C was obtained in 23 (38%) and 14 (23%) of the 60 tumors respectively. (2) Temperature variations within a tumor exceeded over 2°C in 81 % of tumors heated over 43°C. The lowest tumor temperature over 42°C was accomplished in 6 of the 53 tumors (11%). Out of 42 tumors in which temperatures of the subcutaneous fat, surrounding normal tissues and the tumor center were compared, 24 (57%) showed the highest temperature in the tumor center and 10 (24%) in the subcutaneous fat. (3) When the heating efficacy was assessed in terms of a maximum tumor center, it greatly depended on the treatment site, tumor size, thickness of subcutaneous fat and tumor type. Tumors in the head and neck, thorax, and pelvis could be heated better than tumors in abdomen. Greater heating efficacy was shown in patients with large, hypovascular tumors and with the subcutaneous fat measuring less than 15mm in thickness. (4) The predominant limiting factor for power elevation was pain associated with heating. Systemic signs including increases in pulse rate and body temperature were not serious and seldom became limiting factors for power elevation.
Our thermometry results indicate that the advantages of deep RF capacitive heating are its applicability to various anatominal sites and negligible systemic effects. The disadvantages are, on the other hand, that its primary usefulness is limited to patients with thin subcutaneous fat and with large or hypovascular tumors.

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Surface overheating is a most frequent limiting factor in clinical application of RF capacitive heatig of deep seated tumors. The surface hot spots often occured around the margin of electrodes and were not prevented merely by perfusing cold water into the conventional pads attached to the electrodes. We have designed a new type coolig pad, 33 × 37 cm in size and 2 cm thick, which is put beneath the conventional pad and widely covers the skin surface. In the phantom experiments and clinical trials of deep hyperthermia using Thermotron RF8, the excessive surface heating around the margin of the electrodes completely disappeared by this new cooling pad.

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