• 제목/요약/키워드: Radiation Patterns

검색결과 763건 처리시간 0.025초

Failure patterns of cervical lymph nodes in metastases of unknown origin according to target volume

  • Kim, Dong-Yun;Heo, Dae Seog;Keam, Bhumsuk;Ock, Chan Young;Ahn, Soon Hyun;Kim, Ji-hoon;Jung, Kyeong Cheon;Kim, Jin Ho;Wu, Hong-Gyun
    • Radiation Oncology Journal
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    • 제38권1호
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    • pp.18-25
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    • 2020
  • Purpose: This study was aim to evaluate the patterns of failure according to radiotherapy (RT) target volume for cervical lymph nodes in metastases of unknown primary origin in head and neck region (HNMUO). Materials and Methods: Sixty-two patients with HNMUO between 1998 and 2016 were retrospectively reviewed. We analyzed the clinical outcomes and primary site failure depending on the radiation target volume. The target volume was classified according to whether the potential head and neck mucosal sites were included and whether the neck node was treated involved side only or bilaterally. Results: Potential mucosal site RT (mucosal RT) was done to 23 patients and 39 patients did not receive mucosal RT. Mucosal RT showed no significant effect on overall survival (OS) and locoregional recurrence (LRR). The location of primary site failure encountered during follow-up period was found to be unpredictable and 75% of patients with recurrence received successful salvage therapies. No significant differences in OS and LRR were found between patients treated to unilateral (n = 35) and bilateral neck irradiation (n = 21). Treatment of both necks resulted in significantly higher mucositis. Conclusions: We found no advantages in OS and LRR of patients with HNMUO when mucosal sites and bilateral neck node were included in the radiation target volume.

PCS 대역 안테나 내장형 단말기와 외장형 단말기의 방사패턴과 무선감도 (Radiation Pattern and Radio Sensitivity of PCS Band Mobile Phones with Internal Antenna and External Antenna)

  • 공성신;오종대;양운근
    • 한국전자파학회논문지
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    • 제15권4호
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    • pp.397-405
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    • 2004
  • 본 논문에서는PCS대역 안테나내장형 단말기의 성능에 관하여 살펴보았다. 안테나와 안테나 내장형 단말기의 방사패턴을 3차원 전산모의실험 프로그램인 HFSS(High Frequency Structure Simulator)와 SEMCAD(Simulator Platform for Electromagnetic Compatibility Antenna Design and Dosimetry)를 이용하여 전산모의실험하였다. 단말기에 장착된 LED(Light Emitting Bi여e) 회로와 접지판의 형태에 따른 방사패턴의 변화를 살펴보았으며, 외장형안테나 단말기와 내장형 안테나 단말기의 안테나 방사패턴을 원거리장 측정 시스템을 사용하여 전자파 무반사실에서 측정하였다. 측정결과 내장형 안테나는 전산모의실험 결과와 유사한 패턴을 보였다. 그리고 전자파 무반사실에서 Agilent E5515C를 사용하여 안테나 외장형 단말기와 안테나 내장형 단말기의 무선감도를 측정하여 비교하였다. 측정된 안테나내장형 단말기의 무선감도는 안테나 외장형 단말기의 무선감도와 비교해 유사한 성능을 보였으며 수평면상의 동일편파 무선감도 평균치의 경우 차이가 0.12 ㏈로 나타났다.

슬랏을 갖는 부분 단락 MSA의 특성 (Characteristics of Partially Shorted MSA with a Slot)

  • 조창혁;박성교;박종백
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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    • pp.401-404
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    • 2000
  • We designed and fabricated partially shorted MSA with a slot for 850 MHz on Copper-clad Laminate substrate, where the width of the radiation patch is identical with that of the ground plane and one side of the radiation patch is partially shorted to the ground plane. The radiation patterns of ZX, XY and ZY planes were measured. As a result, a better co and cross polarization lot ZX plane was obtained, compared to the partially shorted MSA without a slot.

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유한한 마이크로스트립 안테나구조에서 CG-FFT 방법을 이용한 복사 해석 (Radiation Analysis of a Finite Microstrip Antenna Structure Using the CG-FFT Method : Volume Formulation)

  • 손창우;이철훈김종규조영기
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.343-346
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    • 1998
  • In this paper a radiation problem for a finite microstrip antenna structure is analyzed. For the analysis of finite structures we utilize the equivalent volume current. Intergral equation for the unknown equivalent volume current induced on a finite microstrip structure is derived and solved by the use of conjugate gradient-fast fourier. transform (CG-FFT) method. Some numerical examples are radiation patterns derived by the equivalent volume current solved by the conjugate gradient-fast fourier transform.

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마이크로스트립 배열 안테나의 급전 방식에 관한 연구 (A Study on the Feed Network for Microstrip Array Antenna)

  • 안계선;안우영
    • 한국통신학회논문지
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    • 제19권9호
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    • pp.1739-1747
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    • 1994
  • 본 연구에서는 비균일 배열 안테나의 방사패턴 합성을 위하여 폭이 다른 마이크로스트립 패치 안테나를 급전소자 하는 급전 방식에 대하여 연구하였다. 마이크로스트립 패치 안테나는 전송선로 모델 해석 방법을 적용하여 해석하였으며, 급전소자 간의 급전 선로 길이가 h_g의 정수 배가되면 안테나 각 급전소자의 상대적 전류 비와 입력 어드미턴스의 비가 같음을 유도하였다. 급전소자의 수가 각각 6개와 9개로 제작된 비균일 구형 마이크로스트립 패치 배열 안테나를 실험한 결과 방사패턴에 대한 이론치와 실험치가 잘 일치함을 확인할 수 있다. 따라서 본 연구 결과는 비균일 배열 안테나를 구현하기 위한 급전 방식으로 사용될 수 있을 것으로 사료된다.

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전진 속도를 가지는 부유체 운동 문제에 대한 방사기법 비교 연구 (Comparative Study on the Radiation Techniques for the Problem of Floating Body Motion with Forward Speed)

  • 오승훈
    • 대한조선학회논문집
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    • 제56권5호
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    • pp.396-409
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    • 2019
  • In this paper, a comparative study on the radiation techniques for the motion analysis of the three dimensional floating structure with the forward speed was carried out. The Sommerfeld radiation condition, the damping technique, and the point shift technique were used for the comparative study. Radiated wave patterns and hydrodynamic coefficients of the heave motion of floating structure with the forward speed were compared and analyzed. The characteristics and limitations of each radiation technique were analyzed through the calculation results. To overcome the limitations of conventional radiation techniques, the hybrid radiation technique combining the Sommerfeld radiation condition with the damping technique was proposed. It is confirmed that the proposed method, the Hybrid radiation technique, improves the limitation of the speed range and the dissipation of the wave of the conventional radiation technique. The motion analysis code of the three dimensional floating structure with the forward speed based on the Rankine source method with hybrid radiation technique was developed. In order to validate the developed code, hydrodynamic analyses were carried and compared with published experiments.

Survival in Head and Neck Cancers - Results of A Multi-Institution Study

  • Nandakumar, Ambakumar
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.1745-1754
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    • 2016
  • Background: The prime output of Hospital Based Cancer Registries is stage and treatment based survival to evaluate patient care, but because of challenges of obtaining follow-up details a separate study on Patterns of Care and Survival for selected sites was initiated under the National Cancer Registry Programme of India. The results of stage and treatment based survival for head and neck cancers by individual organ sites are presented. Materials and Methods: A standardized Patient Information Form recorded the details and entered on-line at www.hbccrindia.org to a central repository - National Centre for Disease Informatics and Research. Cases from 12 institutions diagnosed between 1 January 2006 and 31 December 2008 comprised the study subjects. The patterns of treatment were examined for 14053 and survival for 4773 patients from five institutions who reported at least 70% follow-up as of 31 December 2012. Results: Surgical treatment with radiation for cancer tongue and mouth showed five year cumulative survival (FCS) of 67.5% and 60.4% respectively for locally advanced stage. Chemo-radiation compared to radiation alone showed better survival benefit of around 15% in both oro and hypo-pharyngeal cancers and their FCS was 40.0%; Hazard Ratio (HR):1.5;CI=1.2-1.9) and 38.7%; (HR):1.7; CI=1.3-2.2). Conclusions: The awareness about the requirement of concurrent chemo-radiation in specifically cancers of the oro and hypopharynx has to be promoted in developing countries. The annual (2014) estimate number of new Head and Neck cancers with locally advanced disease in India is around 140,000 and 91,000 (65%) patients do not receive the benefit of optimal treatment with ensuing poorer survival.

Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma

  • Seol, Ki Ho;Lee, Jeong Eun
    • Radiation Oncology Journal
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    • 제34권1호
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    • pp.10-17
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    • 2016
  • Purpose: To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Materials and Methods: Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4-72 Gy (39.6-45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. Results: The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. Conclusion: No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC.

이중 모드 Inductor Loaded 패치 안테나의 방사 특성 (Radiation Characteristics of a Dual Mode Inductor Loaded Patch Antenna)

  • 곽은혁;윤영민;김부균
    • 대한전자공학회논문지TC
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    • 제48권7호
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    • pp.28-34
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    • 2011
  • 영차 공진과 반파장 공진을 이용한 이중 모드 Inductor loaded 패치 안테나의 방사 특성을 연구하였다. 반파장 공진 모드에서 수평방향으로의 방사 이득을 최소화시키는 동시에 전방 방사 이득을 향상시켜 영차 공진 모드 방사 패턴과의 격리도를 향상시켰다. 이중 모드 inductor loaded 패치 안테나 기판의 유전상수가 작을수록, 안테나의 동작 주파수 대역이 높을수록 두 모드 간의 공진 주파수 간격이 증가함을 확인하였다.

T2N0M0 비소세포성 폐암의 근치적 방사선치료 (Curative Radiation Therapy for T2N0M0 Non-small Cell Lung Cancer)

  • 박인규;김재철
    • Radiation Oncology Journal
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    • 제13권1호
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    • pp.19-26
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    • 1995
  • Purpose : Surgery is the treatment of choice for resectable non-small cell lung cancer. For patients who are medically unable to tolerate a surgical resection or who refuse surgery, radiation therapy is an acceptable alternative. A retrospective analysis of Patients with stage I non-samll cell lung cancer treated with curative radiation therapy was performed to determine the results of curative radiation therapy and patterns of failure, and to identify factors that may influence survival. Materials and Methods : From 1986 through 1993, 39 Patients with T2N0M0 non-small cell lung cancer were treated with curative radiation therapy at department of radiation oncology, Kyungpook national university hospital. All Patients were not candidates for surgical resection because of either Patient refusal (16 patients), poor pulmonary function (12 patients), old age (7 patients), Poor Performance (2 patients) or coexisting medical disease (2 patients). Median age of patients was 67 years. Histologic cell type was squamous cell carcinoma in 36, adenocarcinoma in 1, large cell carcinoma in 1 and mucoepidermoid carcinoma in 1. All patients were treated with megavoltage irradiation and radiation dose ranged from 5000cgy to 6150cGy with a median dose of 6000cGy. The median follow-up was 17 months with a range of 4 to 82 months, Survival was measured from the date therapy initiated. Results : The overall survival rate for entire Patients was $40.6\%$ at 2 years and $27.7\%$ at 3 years, with a median survival time of 21 months. The disease-free survival at 2 and 3 years was $51.7\%$ and $25.8\%$, respectively. Of evaluable 20 patients with complete response, 15 patients were considered to have failed. Of these, 13 patients showed local failure and 2 patients failed distantly. Response to treatment (p=0.0001), tumor size (p=0.0019) and age (p=0.0247) were favorably associated with overall survival. Only age was predictive for disease-free survival (p = 0.0452). Conclusion : Radiation therapy is an effective treatment for small (less than 3cm) tumors, and should be offered as an alternative to surgery in elderly or infirm patients. Since local failure is the prominent Patterns of relapse, potential methods to improve local control with radiation therapy are discussed.

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