• Title/Summary/Keyword: Hyperthermia

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Therapeutic Effect of Combined Radiotherapy and Hyperthermia in Primary Hepatocellular Carcinoma (원발성 간암의 방사선치료및 온열요법의 병용치료 효과)

  • Kang Ki Mun;Choi Ihl Bohng;Kay Chul Seung;Choi Byung Ok;Chung Su Mi;Kim In Ah;Han Sung Tae;Sun Hee Sik;Chung Kyu Won;Shinn Keyong Sub
    • Radiation Oncology Journal
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    • v.12 no.2
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    • pp.191-199
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    • 1994
  • Purpose : This study was undertaken to show the clinical results of combined radiotherapy and hyperthermia in primary hepatoma Materials and Methods : Between December 1989 and March 1993, 50 patients with hepatomas were treated by combined radiotherapy and hyperthermia. Among them, we analyzed retrospectively 33 patients who received the complete course of treatment. The ages of the patients ranged from 36 to 75(mean age: 55.5 years). Twenty-six patients ($78.8\%$) were men, and 7 ($21.2\%$ were women. According to Child's classification, nine patients ($27.3{\%}$) were A group, 9 ($27.3\%$) were B group, 15 ($45.4\%$) were C group. Radiation therapy was done by a 6 MV and 15 MV linear accelerator. Patients were treated with daily fractions of 150-180 cCy to doses of 2550 cGy -4950 cGy (median : 3000 cGy). Local hyperthermia was done by 8 MHZ RF capacitive heating device (Cancermia. Green Cross Co., Korea), 50-60 min/session, 1-2 sessions/wk, and 8.5 sessions (median number)/patient. We analyzed the prognostic factors including age, sex, tumor type, Child's classification, $\alpha$-fetoprotein, liver cirrhosis, ascites, portal vein invasion, esophageal varix, number of hyperthermia, chemotherapy, total bilirubin level, Karnofsky perfomance status. Results : The overall 1-year survival was $24.2\%$, with a mean survival of 10months. Of 33 patients, tumor regression (PR+MR) was seen in $30.4\%$, no response was seen in $52.2\%,\;17.4\%$ patient was progressed. In patients who had tumor regression, the overall 1-year survival was $42.1\%$ with a mean survival of 14 months. Factors influencing the survival were sex (p=0.05), tumor type (p=0.0248), Child's classification (p=0.0001), liver cirrhosis (p=0.0108), ascites (p=0.0009), and Karnofsky perfomance status (p=0.0028). Complications developed in 28 patients, including 18 hot pain,5 fat necrosis, 3 transient fever, 2 nausea and vomiting. Conclusion : In this study, the results suggests that combined radiotherauy and hyperthermia may improve the survival rate of hepatoma.

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Waveguide Applicator System for Head and Neck Hyperthermia Treatment

  • Fiser, Ondrej;Merunka, Ilja;Vrba, Jan
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1744-1753
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    • 2016
  • The main purpose of this article is a complex hyperthermia applicator system design for treatment of head and neck region. The applicator system is composed of four waveguides with a stripline horn aperture and circular water bolus. The specific absorption rate (SAR) and temperature distribution from this applicator in various numerical phantom models was investigated. For used targets, the treatment planning based on the optimization process made through the SEMCAD X software is added to show the steering possibilities of SAR and thereby temperature distribution. Using treatment planning software, we proved that the SAR and temperature distribution can be effectively controlled (by amplitude and phase changing) improving the SAR and temperature target coverage approximately by 20 %. For the proposed applicator system analysis and quantitative evaluation of two parameters 25 % iso-SAR and $41^{\circ}C$ iso-temperature contours in the treatment area with the respect to sensitive structures in treatment area were defined. To verify our simulation results, the real measurement of reflectivity coefficient as well as the temperature distribution in a homogenous phantom were performed.

Intracavitary Ultrasound Hyperthermia Applicators for Gynecological Cancer

  • Lee, Rena J. .;Suh, Hyun-Suk
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.53-53
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    • 2003
  • For evaluating the feasibility of treating recurrent lesions in the vaginal cuff and cervix by hyperthermia, ultrasound applicators were designed, constructed, and characterized. For the treatment A half-cylindrical transducer Cd=1cm, length=lcm) and cylindrical transducer (d=2.5cm, length= 1.5cm) were used to construct ovoid type and cylindrical applicators. For the ovoid type applicator, each element was operated at 1.5MHz and characterized by measuring transducer efficiency and acoustic power distribution. Thermocouple probes were used to measure the temperature rise in phantom. The element sizes used in this study were selected to be comparable for high dose rate brachytherapy colpostat applicator. Each element was powered separately to achieve a desired temperature pattern in a target. The acoustic output power as a function of applied electric power of the element 1 and 2 was linear over this 1 to 40 W range and efficiencies were 32.2${\pm}$3.4% and 46.2${\pm}$0.8%, respectively. The temperature measurements in phantom showed that 6$^{\circ}C$ temperature rise was achieved at 2 cm from the applicator surface. As a conclusion, the ability of the ultrasound colpostat applicator to be used for hyperthermia was demonstrated by measuring acoustic output power, ultrasound field distribution, and temperature rise in phantom. Based on the characteristics of this applicator, it has the potential to be useful for inducing hyperthermnia to the vaginal cuff in clinic.

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Non-Invasive in vivo Loss Tangent Imaging: Thermal Sensitivity Estimation at the Larmor Frequency

  • Choi, Narae;Kim, Min-Oh;Shin, Jaewook;Lee, Joonsung;Kim, Dong-Hyun
    • Investigative Magnetic Resonance Imaging
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    • v.20 no.1
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    • pp.36-43
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    • 2016
  • Visualization of the tissue loss tangent property can provide distinct contrast and offer new information related to tissue electrical properties. A method for non-invasive imaging of the electrical loss tangent of tissue using magnetic resonance imaging (MRI) was demonstrated, and the effect of loss tangent was observed through simulations assuming a hyperthermia procedure. For measurement of tissue loss tangent, radiofrequency field maps ($B_1{^+}$ complex map) were acquired using a double-angle actual flip angle imaging MRI sequence. The conductivity and permittivity were estimated from the complex valued $B_1{^+}$ map using Helmholtz equations. Phantom and ex-vivo experiments were then performed. Electromagnetic simulations of hyperthermia were carried out for observation of temperature elevation with respect to loss tangent. Non-invasive imaging of tissue loss tangent via complex valued $B_1{^+}$ mapping using MRI was successfully conducted. Simulation results indicated that loss tangent is a dominant factor in temperature elevation in the high frequency range during hyperthermia. Knowledge of the tissue loss tangent value can be a useful marker for thermotherapy applications.

Clinical Result of Combined Radiotherapy and Hyperthermia Induced by 915 MHz Microwave and Ultrasound in Locally Advanced Malignant Tumors of Head and Neck (915 MHz 극초단파 및 초음파를 이용한 온열치료와 방사선치료 병합치료에 의한 두경부암의 치료성적)

  • Koh Kyoung-Hwan;Park Young-Hwan;Cho Chul-Koo;Yoo Seong-Yul
    • Korean Journal of Head & Neck Oncology
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    • v.6 no.1
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    • pp.40-45
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    • 1990
  • Thirty five lesions of 35 patients with locally advanced malignant tumors of head and neck were received thermoradiotherapy with ultrasound and/or 915 MHz microwave. Most of all patients were failed with previous conventional therapeutic trial. Hyperthermia had been done immediately after radiotherapy, twice a week, $43^{\circ}C$ for one hour and radiotherapy had been done 5 fractions per week with a fraction size of 2 Gy up to total 30 to 60 Gy. Conclusions are as follows; 1) Total response rate (CR+PR) of thermoradiotherapy with microwave and ultrasound was 80%. 2) Tumor depth, minimum temperature of tumor center, number of heat fraction and irradiation dose were statistically significant factors affecting response. 3) Hyperthermia with microwave and ultrasound can be used efficiently to control locally advanced malignant tumors in head and neck whether previously received near tolerance dose of radiotherapy or not.

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SAR Analysis on the Coaxial-Slot Antenna for Hyperthermia (Hyperthermia용 Coaxial-Slot 안테나의 SAR 분석)

  • Shin, Kook-Sun;Shin, Ho-Sub;Kim, Nam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.7
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    • pp.732-739
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    • 2002
  • Performance of the applicator for hyperthermia is determined by both the degree of impedance matching and specific absorption rate(SAR) distribution in the surrounding tissue. In this paper, the coaxial-slot antenna using staircasing approximation in the FDTD is analyzed and the coaxial-slot antenna for the hyperthermia improving heating characteristics is designed. The SAR of the coaxial-slot antenna approximated to staircasing and square model is analyzed, and the SAR of staircasing model is compared with Saito's SAR measurement and square model. As a result, the SAR of proposed model exhibited agreement with the Saito's measurement of square model. Ig averaged SAR on the liver caused by proposed antenna in this paper is 195 W/kg, and is about 27.9 % higher than the Saito's antenna 152.5 W/kg, respectively.

Effects of Thermotherapy on Th1/Th2 Cells in Esophageal Cancer Patients Treated with Radiotherapy

  • Hong, Mei;Jiang, Zao;Zhou, Ying-Feng
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2359-2362
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    • 2014
  • Background: To investigate the effects of double radiofrequency hyperthermia on Th1/Th2 cells in esophageal cancer patients treated with radiotherapy. Materials and Methods: 22 patients with esophageal cancer were divided into a radiotherapy group (10 cases) and a combined group (double radiofrequency hyperthermia combined with radiotherapy group, 12 cases). Both groups received conventional radiotherapy using a cobalt-60 therapy apparatus (TD60-66Gy/30-33F). Patients in the combined group also underwent double radiofrequency hyperthermia (2F/W, 8-10F). Before and after treatment, Th1, Th2, Tc1 and Tc2 cells in peripheral blood were determined with flow cytometry. Results: In the radiotherapy group, Th1 cell contents before and after radiotherapy were $17.5{\pm}5.26%$ and $9.69{\pm}4.86%$, respectively, with a significant difference (p<0.01). The Th1/Th2 ratio was significantly decreased from $28.2{\pm}14.3$ to $16.5{\pm}10.4 $(p<0.01). In the combined group, Th1 cell content before radiotherapy was $15.9{\pm}8.18%$, and it increased to $18.6{\pm}8.84$ after radiotherapy (p>0.05), the Th1/Th2 ratio decreasing from $38.4{\pm}36.3$ to $28.1{\pm}24.0$ (p>0.05). Changes in Th2, Tc1 and Tc2 cell levels were not significant in the two groups before and after therapy (p>0.05). Conclusions: Double radiofrequency hyperthermia can promote the conversion from Th2 to Th1 cells, and regulate the balance of Th1/Th2 cells.

A Case Report of Recurred Hepatocellular Carcinoma Patient Treated with Radio-Frequency Hyperthermia in Conjunction with Sorafenib (고주파 온열치료와 소라페닙을 병용하여 호전된 재발성 간암환자 1례)

  • Kim, Jee-Hye;Lee, Jong-Hoon;Joo, Jong-Cheon;Lee, Jeong-Bok;Cho, Chong-Kwan;Yoo, Hwa-Seung
    • Journal of Korean Traditional Oncology
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    • v.21 no.2
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    • pp.63-74
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    • 2016
  • Objective : The purpose of this study is to report the effects of radio-frequency hyperthermia cancer treatment in conjunction with Sorafenib on hepatocellular carcinoma patient. Method : The patient was diagnosed with hepatocellular carcinoma at S6/7 and treated with right posterior sectionectomy. After 4 months, tumor recurrence was found at S4, 5 and 8. After transarterial chemoembolization, the patient was prescribed Sorafenib (proprietary name $Nexavar^{(R)}$ ) as well as proceeding with radio-frequency hyperthermia. The clinical outcomes were measured by computed tomography, laboratory findings including tumor markers (AFP, PIVKA-II), natural killer (NK) cell activity, and numeric rating scales (NRS). Results : After the treatment, tumor size was decreased accompanying by reducing the level of tumor markers (AFP, PIVKA-II). Major clinical symptoms were improved with increasing NK cell activity. There were no adverse events based on National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Conclusion : This case suggests that radio-frequency hyperthermia has synergistic effect for the treatment of hepatocellular carcinoma patient in conjunction with Sorafenib.

Thermographic Findings in Craniomandibular Disorders ; Clinical Evaluation (두개하악장애환자의 임상적 평가를 위한 컴퓨터적외선체열검사)

  • Ick-Joo Cho;Jung-Pyo Hong;Sang-Rae Lee
    • Journal of Oral Medicine and Pain
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    • v.20 no.2
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    • pp.477-487
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    • 1995
  • The purpose of this study was to assess the thermographic differences of craniomandibular area between normal individual and patients with craniomandibular disorders and to compare the differences between clinical and thermographical assessment. The author had used 50 subjects as materials for this study, which was divided into 2 groups (first group included 15 healthy subjects and second group included 35 patients) with craiomandibular disorders; 17 subjects had normal disc-condyle relationship, 13 subjects had disc displacement with reduction and 5 subjects had disc displacement without reduction. Agema 870 thermovision(D.I.T.I.) was used to take thermographs with $0.1^{\circ}C$ difference of gradual temperature shift. The results were as follows : 1. Of 34 patients with craniofacial pain, 15(44%) subjects showed hyperthermia on the pain site in the thermography, 8(23.5%)exhibited hyperthermia on the site opposed to the pain site, and 11(32.4%) did not show any significant thermal change. One patient without craniofacial pain showed hyperthermia on the site opposed to the site of disc displacement without reductin. 2. Of 35 patients with craniofacial pain or disc displacement, 24(68.6%) subjects showed a significant thermal difference between symptomatic and asymptomatic sides of the face, but 11(31.4%) did not show any difference. 3. Of 17 patients with pain but with normal disc-condyle relationship, 8(47.1 subjects showed hyperthermia on the pain site, 4(23.5%) showed on the site opposed to the pain site, and 5(29.4%) did not show any significant thermal change. 4. Or 13 patients with pain and disc displacement with reduction, 6(46.2%) subjects showed hyperthermia on the pain site, 3(23.1%) showed on the site opposed to the pain site, and 4(30.8%) did not show any significant thermal change. 5. 15 healthy subjects did not show any thermal differences between the both sides of the face.

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Combined Effects of Gamma-irradiation and Hyperthermia on the Human Cell Lines for Various Temperatures and Time Sequences (감마선과 온열치료 병용시 세포 치사 능력 증강에 관한 실험적 연구)

  • Koh Kyung Hwan;Cho Chul Koo;Park Woo Yoon;Yoo Seong Yul;Yun Hyong Geun;Shim Jae Won;Lee Mi Jung
    • Radiation Oncology Journal
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    • v.11 no.1
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    • pp.51-58
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    • 1993
  • We tried to establish the theoretical basis of clinical use of combined modality of hyperthermia and radiation therapy. For this purpose, we made an in vitro experiment in order to get the synergistic and/or additive effects on the cell killing of hyperthermia combined with radiation therapy by using the microwave-hyperthermia machine already installed at our department. In our experiment, we use two human cell lines: MKN-45 (adenocarcinoma of stomach) and K-562 (leukemia cell lines). In cases of combined treatments of hyperthermia and gamma-irradiation, the therapeutic effect was the highest in the simultaneous trial. Hyperthermia after gamma irradiation showed slightly higher therapeutic effect than that before irradiation without significant difference, but its effect was the same in the interval of 6 hours between hyperthermia and irradiation. The higher temperature and the longer treatment time were applied, the higher therapeutic effects were observed. We could observe the thermoresistance by time elapse at $43^{\circ}C$. When hyperthermia was done for 30 minutes at the same temperature, thermal enhancement ratio (TER) at DO. 01 (dose required surviving fraction of 0.01) were $2.5{\pm}0.08,\;3.75{\pm}0.18$, and $5.0{\pm}0.15\;at\;436{\circ}C,\;44^{\circ}C,\;and\;45^{\circ}C$ respectively in K-562 leukemia cell lines. Our experimental data showed that more cell killing effect can be obtained in the leukemia cell lines, although they usually are known to be radiosensitive, when treated with combined hyperthermia and radiation therapy. Furthermore, our data show that leukemia cell lines may have various intrinsic radiosensitivity, especially in vitro experiments. The magnitude of cell killing effect, however, will be less than that of MKN-45.

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