RF Capacitive Heating Research Articles

피하에 효과적인 열 자극을 위한 고주파 자극 프로토콜 개발

뜸은 질병에 대한 면역력을 높이고 질병을 치유하는데 효과적인 반면 뜸의 열 자극 세기를 조절하기 힘들어 피부에 고통을 유발시키며 화상을 입히는 부작용이 발생된다. 이런 한계점을 극복하기 위해 자극 조절이 가능한 고주파 열 자극 시스템을 개발하였으며, 동물에게 뜸질을 할 경우 얻어지는 온도분포와 유사한 자극 프로토콜을 개발하였다. 자극을 위한 시스템은 2MHz, 200W의 고주파유전가열장치, 절연프로브, 절연플레이트, 음압 발생부 및 온도측정부로 구성되어있다. 자극 프로토콜 설계를 위해서 일차적으로 토끼의 대퇴부에 뜸질시 표피, 피하 5mm와 피하10mm에서 온도분포를 획득하였다. 획득된 뜸질의 온도분포와 유사한 온도분포로 자극하기 위해서 자극펄스의 duty ratio와 반복회수 및 출력을 제어하였다. 뜸질과 고주파 자극시 피하의 온도분포를 비교해본 결과 피하 5mm와 10mm 부위에서의 상관관계는 각각 95%와 91%로 일치함을 보여주었다. 또한, 고주파 자극시 표피에서의 온도분포는 뜸에 비해 현저하게 낮게 나옴을 확인하였다. 이를 통해 고주파 열 자극 시스템은 뜸질의 문제점인 화농, 물집과 같은 부작용을 유발시키지 않으면서 피하에 뜸질과 유사한 열 자극이 가능함을 보여주었다.

Definitive radiotherapy plus regional hyperthermia with or without chemotherapy for superior sulcus tumors: A 20-year, single center experience

PurposeTo assess the efficacy and toxicity of definitive radiotherapy (RT) plus regional hyperthermia (HT) in treating superior sulcus tumors (SSTs), and to identify predictors of positive outcomes. Methods and materialsTwenty-four patients with SSTs treated with definitive RT plus regional HT were retrospectively analyzed. The median total dose of RT was 70Gy. All patients were treated with an 8-MHz RF-capacitive heating device. Twelve of 24 (50%) patients also underwent chemotherapy. Those with either subcutaneous fat measuring 2.5cm or greater, or any other serious complications did not undergo this therapy. ResultsOverall survival, local control, and distant metastasis-free survival rates at 3 years were 47%, 55%, and 71%, respectively. Chemotherapy and younger age (<65 years) were significant predictors of the overall survival rate. Clinical stage (IIB) was a statistically significant prognostic indicator for local control survival rate. Toxicities were mild, with Grade 3 dermatitis seen in one patient. ConclusionsDefinitive RT plus regional HT with chemotherapy may be a promising treatment for SSTs. The results justify further evaluation with detailed treatment protocols in a large number of patients.

A Case of Lung Cancer with Chest Wall Invasion Showed a Pathologically Complete Response to Preoperative Thermo-chemo-radiotherapy

A case of lung cancer with chest wall invasion treated by preoperative thermo-chemo-radiotherapy revealed a histologically complete response after complete resection is reported. A 55-year-old male was diagnosed as primary lung cancer originating from the right upper lobe, cT3N0M0, stage IIB. The tumor invaded the right chest wall accompanied with obstructive pneumonia at its dorsal side and was rapidly growing. Thus, preoperative thermo-chemo-radiotherapy was performed. He was treated with conventional irradiation with a 10 MV X-ray, a total dose of 40 Gy, and concurrent chemotherapy with cisplatin (CDDP) and vinorelbine (VNR). Hyperthermia was applied within 30 min after each radiotherapy with a RF-capacitive heating apparatus (Thermotron RF-8, Ymamamoto Vinyter, Osaka, Japan), 40 min/time, once a week, for a total of 4 times. The tumor revealed necrotic change on CT images after thermo-chemo-radiotherapy and was completely resected. No viable cancer cells were observed in the histological examination (Ef 3). Even 17 months later, there was no recurrence.

Radiotherapy With 8-MHz Radiofrequency-Capacitive Regional Hyperthermia for Stage III Non–Small-Cell Lung Cancer: The Radiofrequency-Output Power Correlates With the Intraesophageal Temperature and Clinical Outcomes

To assess the efficacy of radiotherapy (RT) combined with regional hyperthermia (HT) guided by radiofrequency (RF)-output power and intraesophageal temperature and evaluate the potential contribution of HT to clinical outcomes in patients with Stage III non-small-cell lung cancer (NSCLC). Thirty-five patients with Stage III NSCLC treated with RT plus regional HT were retrospectively analyzed. Twenty-two of the 35 patients underwent intraesophageal temperature measurements. Patients with subcutaneous fat of 2.5 cm or greater, older age, or other serious complications did not undergo this therapy. The 8-MHz RF-capacitive heating device was applied, and in all patients, both the upper and lower electrodes were 30 cm in diameter, placed on opposite sides of the whole thoracic region, and treatment posture was the prone position. The HT was applied within 15 minutes after RT once or twice a week. All thermal parameters, minimum, maximum, and mean of the four intraesophageal temperature measurements at the end of each session and the proportion of the time during which at least one of the four intraesophageal measurements was 41 degrees C or higher in the total period of each session of HT, of the intraesophageal temperature significantly correlated with median RF-output power. Median RF-output power (>/=1,200 W) was a statistically significant prognostic factor for overall, local recurrence-free, and distant metastasis-free survival. The RT combined with regional HT using a higher RF-output power could contribute to better clinical outcomes in patients with Stage III NSCLC. The RF-output power thus may be used as a promising parameter to assess the treatment of deep regional HT if deep heating using this device is performed with the same size electrodes and in the same body posture.

RF誘電加温における微粒子状加温媒体の特性

RF誘電加温における微粒子状加温媒体の特性

RF容量結合型加温併用による挿入電極の加温領域の拡大に関する基礎研究

RF容量結合型加温併用による挿入電極の加温領域の拡大に関する基礎研究

Development of RF and microwave heating equipment and clinical applications to cancer treatment in Japan

Development of RF and microwave (MW) heating equipment for hyperthermia and their clinical applications to various cancers undertaken in Japan have been reviewed in this paper. Originally developed heating devices include an RF capacitive and RF inductive heating device, an MW heating device with a lens applicator, an RF intraluminal heating device, an RF current interstitial heating device, and a ferromagnetic implant heating device. The concept and characteristics of those devices are described herein. Nonrandomized and randomized trials undertaken for superficial and deep-seated tumors demonstrated improved local response with the combined use of hyperthermia. Furthermore, the complications associated with treatment were not generally serious, except for chronic bowel damages suggested in a trial for colorectal cancers. These clinical results indicate the benefit of combined treatment of hyperthermia and radiotherapy. With the advancement of heating and thermometry technologies, hyperthermia will be more widely and safely used in the treatment of cancers.

胸腔内腫瘍に対する8MHz誘電加温装置による温熱療法の副作用

胸腔内腫瘍に対する8MHz誘電加温装置による温熱療法の副作用

8MHz誘電加温装置による温熱療法における外部冷却装置の有用性

8MHz誘電加温装置による温熱療法における外部冷却装置の有用性

8MHz誘電加温装置を使用した高出力温熱併用放射線療法による非小細胞性肺癌の局所効果

8MHz誘電加温装置を使用した高出力温熱併用放射線療法による非小細胞性肺癌の局所効果

8MHz誘電加温装置による温熱療法におけるオーバーレイボーラス循環液の改良

8MHz誘電加温装置による温熱療法におけるオーバーレイボーラス循環液の改良

8MHz誘電加温装置による胸腔内深在性腫瘍の温熱療法における治療体位の重要性

8MHz誘電加温装置による胸腔内深在性腫瘍の温熱療法における治療体位の重要性

8MHz誘電加温装置による温熱療法におけるボディ・アースの有効性

8MHz誘電加温装置による温熱療法におけるボディ・アースの有効性

Clinical Usefulness of Determining the Rate of Thermal Clearance within Heated Tumors

Between June 1987 and June 1988, 28 patients (28 tumors) with liver, retroperitoneal, intrapelvic, or superficial tumors were treated with hyperthermia combined with radiotherapy and/or chemotherapy. Hyperthermia was administered once or twice a week for 30-60 min per session, up to a total of 2-11 sessions, with an 8-MHz RF capacitive heating device. Blood flow in the tumors was evaluated from the rate of thermal clearance (TCR) using the bio-heat transfer equation. The TCR was measured in the middle of the first heating session and at the end of the last heating session by turning off the output power of the heating device. For 9 patients, contrast-enhanced CT scans were taken and CT numbers at the centers of tumors were measured before and after the entire course of hyperthermia. Changes in TCR were closely related to average tumor center temperature, changes in CT number, and tumor response. When smaller and more superficial tumors were treated by hyperthermia combined with radiotherapy and/or chemotherapy that consisted of many heating sessions and during which a high average tumor center temperature was achieved, a better tumor response was obtained. The better the tumor response, the higher the local control rate became. The cause-specific survival rate of patients who achieved good tumor responses was higher than that of patients who showed poor tumor responses. Changes in TCR and CT number in heated tumors were useful and important indicators of tumor response to hyperthermia.

温熱療法の現状に関するアンケート調査 ＲＦ誘電加温研究会参加２０施設の現状

温熱療法の現状に関するアンケート調査 ＲＦ誘電加温研究会参加２０施設の現状

122. マイクロ波加温装置 HTS-100 及び RF 波加温装置 HEH-1000C の使用経験(治療-6 温熱療法)

122. マイクロ波加温装置 HTS-100 及び RF 波加温装置 HEH-1000C の使用経験(治療-6 温熱療法)

Regional hyperthermia combined with radiotherapy in the treatment of lung cancers

Twenty locally advanced lung cancers were treated by hyperthermia in combination with radiotherapy between November 1980 and January 1990. All tumors selected had invaded or were in contact with the chest wall, so that transcutaneous insertion of thermal probes into the tumor was possible. Using an 8 or 13.56 MHZ RF capacitive heating device, hyperthermia was given once or twice a week after irradiation for 30–60 min per session (1–12 sessions in total). Radiotherapy was delivered at dose of 13.6–70 Gy. The thermal parameters analyzed were a) maximum, average, and minimum intratumor temperatures (Tmax, Tav, and Tmin), which were recorded at the termination of each treatment, and b) the percentages of the intratumor points that exceeded 41 C (%T ≥ 41 C). The mean SD for Tmax, Tav, Tmin, and %T ≥ 41 C was 42.9 ± 1.7 C, 41.6 ± 1.2 C, 39.7 ± 1.1 C, and 56.2 ± 25.8, respectively. Larger tumors showed higher thermal parameters than the smaller tumors. Of the 12 tumors treated by definitive therapy, 2 (17%) achieved CR, 7 (58%) PR, and 3 (25%) NR. Four of 10 tumors that did not achieve CR showed large intratumor low density areas on post-treatment Or, reflecting massive coagulation necrosis. Higher thermal parameters were closely related to the appearance of low-density areas but not to changes in tumor size. Four tumors treated preoperatively were successfully resected 2 weeks after thermoradiotherapy, whereas four palliatively-treated tumors showed no regression. The side effects associated with hyperthermia were pain in 12 patients (60%) and dyspnea in 3 (15%), all of which resolved after termination of treatment. A skin abscess and a pneumothorax attributed to thermal probe insertion were observed in one patient each. These results indicate that regional RF capacitive hyperthermia is clinically feasible for local treatment of selected lung cancers.

ＲＦ容量結合型加温方式の加温特性解析

ＲＦ容量結合型加温方式の加温特性解析

122. マイクロ波加温装置 HTS-100 及び RF 波加温装置 HEH-1000C の使用経験(第 20 回秋季学術大会一般研究発表予稿)

122. マイクロ波加温装置 HTS-100 及び RF 波加温装置 HEH-1000C の使用経験(第 20 回秋季学術大会一般研究発表予稿)

ＲＦ誘電加温における副作用

ＲＦ誘電加温における副作用