CAJ | 학술논문

目的探讨用机载千伏级锥形束CT (CBCT)对鼻咽癌患者治疗前扫描图像直接进行剂量计算的可行性.方法选取治疗前行扇形束CT (FBCT)和CBCT扫描的11例鼻咽癌患者,将体位校正后重新扫描的CBCT图像传输至治疗计划系统中.在治疗计划系统中将FBCT和CBCT图像融合,将FBCT的计划移植至CBCT上.选择CBCT图像自己的HU-ED校正曲线重新进行剂量计算,与FBCT计划的靶区和正常器官的剂量体积直方图以及等中心层面剂量分布的γ通过率分析(阈值3%/3 mm)结果进行比较.结果 11例鼻咽癌患者中CBCT和FBCT计划的剂量体积直方图相似,等中心层面剂量分布中平均γ通过率为98.0%±1.33%.FBCT计划和CBCT计划的靶区受量差异都<1%,正常组织器官受量差异<2%.结论治疗过程中得到的CBCT图像能用来进行剂量计算.
목적 탐토용궤재천복급추형속CT (CBCT)대비인암환자치료전소묘도상직접진행제량계산적가행성.방법 선취치료전행선형속CT (FBCT)화CBCT소묘적11례비인암환자,장체위교정후중신소묘적CBCT도상전수지치료계화계통중.재치료계화계통중장FBCT화CBCT도상융합,장FBCT적계화이식지CBCT상.선택CBCT도상자기적HU-ED교정곡선중신진행제량계산,여FBCT계화적파구화정상기관적제량체적직방도이급등중심층면제량분포적γ통과솔분석(역치3%/3 mm)결과진행비교.결과 11례비인암환자중CBCT화FBCT계화적제량체적직방도상사,등중심층면제량분포중평균γ통과솔위98.0%±1.33%.FBCT계화화CBCT계화적파구수량차이도<1%,정상조직기관수량차이<2%.결론 치료과정중득도적CBCT도상능용래진행제량계산.
Objective To study the feasibility of dose calculation using kilovoltage X-ray cone-beam CT (KVCBCT) imaging for head-and-neck radiation therapy.Methods 11 patients with nasopharyngeal carcinoma were scanned with KVCBCT to adjust position before treatment, and rescanning images with KVCBCT after correction were input a treatment-planning system.The dose was recalculated by applying the patients′ treatment plans based on planning CT to the KVCBCT images.The dose distributions and dose volume histograms (DVH) of the tumor and critical structures were compared with the original treatment plan.Results The DVH and dose distribution of the plan based on the KVCBCT are compared with that of the planning CT, and they shows a good consistency for the 11 cases.The doses calculated from the planning CT and KVCBCT were compared on the isocenter planes.Using γ analysis with a criterion of 3%/3 mm, 98.0%±1.33% of the points on the isocenter planes in the planning CT and KVCBCT.The difference of the dose to target volume was<1% and to normal structure was<2%.Conclusions This study indicated that CBCT images can be used to make a treatment plan with its individual hounsfield unit-electron density calibration curve.