CAJ | 학술논문

目的比较γ刀3种聚焦方式形成的单靶点辐射野,探讨提高放射治疗剂量准确性的方法.方法使用EBT3型免冲洗胶片测量γ刀多源静态聚焦、多源单轴线旋转聚焦和单源双轴线旋转聚焦方式形成的单靶点辐射野,对辐射野剂量分布的均匀性和辐射野半影关系进行比较分析.结果 3种聚焦方式形成的单靶点二维等剂量曲线分布不同.轴线(x、y和z轴)上,多源静态聚焦、多源单轴线旋转聚焦与单源双轴线旋转聚焦形成的半影轴长比范围,依次为0.13 ～0.48、0.17 ～0.33和0.28 ～0.54;翅膀平面的对角线(NSD、PSD)上,依次为0.31～0.39、0.38～0.43和0.54 ～0.72,单源双轴线旋转聚焦方式形成的半影轴长比明显大于多源静态聚焦和多源单轴线旋转聚焦方式.非翅膀平面上,多源静态聚焦、多源单轴线旋转聚焦与单源双轴线旋转聚焦形成的辐射野80％剂量曲线与50％剂量曲线包绕面积比(A80％/A50％)依次为0.40、0.47和0.19;翅膀平面上,依次为0.61、0.53和0.35.多源静态聚焦和多源单轴线旋转聚焦方式形成的辐射野剂量分布均匀性优于单源双轴线旋转聚焦方式.结论从单靶点辐射野吸收剂量分布角度考虑,当靶区周围有重要的组织器官时,宜选择使用多源静态聚焦和多源单轴线旋转聚焦方式的γ刀;多源静态聚焦和多源单轴线旋转聚焦方式相对于单源双轴线旋转聚焦方式,能够使更多的肿瘤组织被高剂量曲线所包绕.
목적 비교γ도3충취초방식형성적단파점복사야,탐토제고방사치료제량준학성적방법.방법 사용EBT3형면충세효편측량γ도다원정태취초、다원단축선선전취초화단원쌍축선선전취초방식형성적단파점복사야,대복사야제량분포적균균성화복사야반영관계진행비교분석.결과 3충취초방식형성적단파점이유등제량곡선분포불동.축선(x、y화z축)상,다원정태취초、다원단축선선전취초여단원쌍축선선전취초형성적반영축장비범위,의차위0.13 ～0.48、0.17 ～0.33화0.28 ～0.54;시방평면적대각선(NSD、PSD)상,의차위0.31～0.39、0.38～0.43화0.54 ～0.72,단원쌍축선선전취초방식형성적반영축장비명현대우다원정태취초화다원단축선선전취초방식.비시방평면상,다원정태취초、다원단축선선전취초여단원쌍축선선전취초형성적복사야80％제량곡선여50％제량곡선포요면적비(A80％/A50％)의차위0.40、0.47화0.19;시방평면상,의차위0.61、0.53화0.35.다원정태취초화다원단축선선전취초방식형성적복사야제량분포균균성우우단원쌍축선선전취초방식.결론 종단파점복사야흡수제량분포각도고필,당파구주위유중요적조직기관시,의선택사용다원정태취초화다원단축선선전취초방식적γ도;다원정태취초화다원단축선선전취초방식상대우단원쌍축선선전취초방식,능구사경다적종류조직피고제량곡선소포요.
Objective To compare the single-shot fields irradiated by three focusing modes of γ-knife and explore the approaches for improving the quality of stereotactic radiosurgery.Methods GAFCHROMIC(R) EBT3 mode flushing-free film was used to measure the single-shot fields irradiated by multi-source static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode of γ-knife.Also the uniformity and penumbra of the single-shot fields were compared.Results The 2D dose distribution of the single-shot fields irradiated by three focusing modes of γ-knife was different.In the axis (x,y,z),the rang of penumbra axial length ratios of multisource static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode were 0.13-0.48,0.17-0.33 and 0.28-0.54,in the diagonal direction of the wings plane (NSD,PSD),were 0.31-0.39,0.38-0.43 and 0.54-0.72,respectively;the penumbra axial length ratio of single-source double-axis rotating focusing mode was bigger than in multi-source static focusing modes and multi-source single-axis rotating focusing mode.On the no-wings plane,the area ratios of 80％ dose curve enveloped and 50％ dose curve enveloped(A80％/A50％)were 0.40,0.47 and 0.19,on the wings plane,were 0.61,0.53 and 0.35,respectively.The field uniformity of multi-source static focusing modes and multi-source single-axis rotating focusing mode were superior to single-source doubleaxis rotating focusing mode.Conclusions Considering dose distribution of the single-shot fields,the multi-source static focusing modes devices and the multi-source single-axis rotating focusing mode devices should be preferred,when important tissues and organs are adjacent to the target areas.Compared with single-source double-axis rotating focusing mode,both multi-source static focusing modes and multi-source single-axis rotating focusing mode could make more target areas to be surrounded by high dose region.