Progress in Medical Physics (한국의학물리학회지:의학물리)

Korean Society of Medical Physics (한국의학물리학회)
권호 표지

Measurement of Dose Distribution in Small Fields of NEC LINAC 6 MVX Using Films and Tissue Equivalent Phantoms

필름 및 tissue equivalent 팬톰을 이용한 NEC LINAC 6 MVX 소조사면에 대한 선량분포 측정

  • Suh, Tae-Suk (Department of Radiology, Catholic University Medical College) ;
  • Park, Dong-Rak (Department of Radiology, Catholic University Medical College) ;
  • Choe, Bo-Young (Department of Radiology, Catholic University Medical College) ;
  • Yoon, Sei-Chul (Department of Radiology, Catholic University Medical College) ;
  • Jang, Hong-Seok (Department of Radiology, Catholic University Medical College) ;
  • Park, Il-Bong (Department of Radiology, Catholic University Medical College) ;
  • Kim, Moon-Chan (Department of Neurosurgery, Catholic University Medical College) ;
  • Bahk, Yong-Whee (Department of Radiology, Catholic University Medical College) ;
  • Shin, Kyung-Sub (Department of Radiology, Catholic University Medical College)
  • Published : 1993.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

The purpose of this paper is to develop a simple system to measure dose distribution in small fields of NEC LINAC 6 MVX using film and solid water instead of ion chamber and water phantom. Specific quantities measured include percent depth dose (PDD), off-axis ratio (OAR). We produced square fields of 1 to 3cm in perimeter in 1cm steps measured at SAD of 80cm. The PDD and OAR measured by film was compared with measurement made with ion chamber. We calculated the TMR from the basic PDD data using the conversion formula. The trends of our measured beam data and philips LINAC are similar each other. The measurement for the small field using film and solid water was simple. Hand-made film phantom was especially useful to measure OARs for the stereotactic radiosurgery.

본 논문의 목적의 NEC LINAC 6 MVX 선의 소조사면에 대한 선량분포를 복잡한 물팬톰 및 ion chamber대신 film 및 고체 물팬톰을 이용하여 간단히 측정하고 분석하는 시스템을 개발하는 데 있다. 단일 선속측정을 위하여 필름과 고체 물팬톰이 이용되었으며, 측정된 데이타는 percent depth dose (PDD), off-axis ratio (OAR) 등을 포함하며, 한변이 1, 2, 3cm의 정사각형 소조사면에 대하여 측정이 이루어 졌다. 또한 Output factor측정은 ion chamber로 측정되었으며, 필름에 의하여 측정된 PDD, OAR 등은 ion chamber측정기로 측정된 값과 비교 검토되었다. 필름으로 부터 측정된 PDD값으로 부터 환산식을 이용하여 tissue maximum ratio (TMR) 값을 얻었으며, 본 실험에서 얻어진 TMR, OAR 값들은 같은 에너지를 나타내는 Philips LINAC의 선량 데이타와 유사한 결과를 보여주었다. 고체 물팬톰 및 필름을 이용한 소조사면 측정은 간편하고도 유용한 방법이었으며, 특히, 자체 개발된 필름팬톰은 뇌정위적 방사선 수술을 위한 OAR 선량을 측정하는 데 유용하였다.

Keywords