The Journal of the Korea Contents Association (한국콘텐츠학회논문지)

The Korea Contents Association (한국콘텐츠학회)
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Efficiency on the Field Edge Block which was used at Junction Field of Head & Neck Cancer in the Radiotherapy

두경부 종양의 방사선치료 시 접합 조사야에 사용된 조사면 끝단 차폐물의 유용성

  • 이재승 (한동대학교 선린병원 방사선종양학과) ;
  • 김정남 (경희의료원 방사선종양학과)
  • Published : 2008.11.28
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Abstract

If the target volume cannot be included with one field at head and neck cancer, we commonly used two or more field. It is very important to irradiate uniform dose at junction area of the fields. However, according to body shape of patient or general condition of patient, skin junction area can be matched incorrect, So overdose area or underdose area can be appeared in the junction area. This study researched therapy technique which can give uniform dose at skin junction owing to applying the edge block of lateral field at head and neck cancer. We measured the changed distance and rotational angle between central line of anterior supraclavicle lymph node and low margin of right lateral field on simulation process using the shielding block of variable rotation. As a result, the changed distance between central line of anterior supraclavicle lymph node and low margin of right lateral field was below 2mm to ${\pm}$10cm distance at central line of Y axis, changed angle was average 1.28 degree. But by using it the shielding block of variable rotation, the incorrect match at junction can be minimized. We think that this technique is very efficient one to apply this technique at head and neck cancered by the movement of organs can be not included, Therefore we have to pay attention on the process to imput MLC layer

두경부 종양에서 표적용적(target volume)을 하나의 조사야로 포함하지 못하는 경우는 조사야를 둘, 또는 그 이상으로 접합시켜 방사선치료를 시행한다. 방사선치료 시 두 조사야 경계면에서 균등한 선량을 부여하는 것이 매우 중요하다. 하지만 환자의 외형적인 인자나 전신 상태에 따라 피부 접합면( skin Junction area)의 불일치가 발생할 수 있으며 이로 인한 접합면에서의 과선량 또는 저선량 영역이 존재할 수 있다. 본 연구는 두경부 종양의 측면 조사면 끝단 차폐물(edge block)을 회전 가변형으로 제작하여 피부 접합면에 균등한 선량을 부여할 수 있는 치료 기술에 대하여 연구하였다. 모의치료에서 전방 상쇄골 하림프절(supraclavicle lymph node)의 중심선을 우측방 조사야 하단과 접합면으로 하여 회전 가변형 차 폐물을 이용하여 변형되는 거리와 회전각을 측정하였다. 연구 결과에서 원발병소와 상부 경부 림프절 우측방 조사야의 하단에서 회전 가변형 차폐물의 변형 거리는 Y축 중심선에 수직인 ${\pm}$10cm 거리에서 2mm 이내 였으며, 회전각은 평균적으로 약 1.28도의 회전 변형이 발생하였다. 하지만 조사면 끝단 차폐물을 회전 가변형으로 제작함으로서 기존에 발생하던 피부 접합면에서의 불일치를 최소화 할 수 있었다. 두경부 종양의 경우는 원발병소와 상, 하부 경부 임파절에 적절한 선량을 부여하기 위한 조사면 끝단 차폐물을 이용한 방법이 임상에서 적용할 수 있는 효율적인 방안이라 사료된다.

Keywords

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