QUANTIFYING INTERFRACTION AND INTRAFRACTION TUMOR MOTION IN LUNG STEREOTACTIC BODY RADIOTHERAPY USING RESPIRATION-CORRELATED CONE BEAM COMPUTED TOMOGRAPHY
QUANTIFYING INTERFRACTION AND INTRAFRACTION TUMOR MOTION IN LUNG STEREOTACTIC BODY RADIOTHERAPY USING RESPIRATION-CORRELATED CONE BEAM COMPUTED TOMOGRAPHY
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DOI：
10.1016/j.ijrobp.2008.11.066
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发表时间：
2009-11-01
影响因子：
7
通讯作者：
Bezjak, Andrea
中科院分区：
文献类型：
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作者：
Bissonnette, Jean-Pierre;Franks, Kevin N.;Bezjak, Andrea
目的：立体定向放射治疗（SBRT）是医学上不能手术的I期非小细胞肺癌的有效治疗方法。然而，SBRT过程中患者呼吸模式的变化可能会导致地理遗漏或健康组织过度暴露于辐射。然而，这些呼吸模式变化的确切程度并不清楚。我们评估了间和intrafraction变化的肿瘤运动幅度（Δ M）在SBRTcourse.Methods和材料：18例患者接受了图像引导的SBRT提供了三个分数，这种治疗是在4例患者腹部压缩。对于每个部分，进行锥形束计算机断层扫描（CBCT）以进行肿瘤定位（+/- 3 mm公差），然后重复以确认几何准确性。在每个SBRT部分的中点和结束时采集额外的CBCT图像。呼吸相关CBCT（rcCBCT）重建允许通过比较所有四维CT和rcCBCT扫描中的肿瘤位移来回顾性评估分次间和分次内Delta M。结果：共分析了201例rcCBCT图像。从肿瘤定位到CBCT终末部分的平均时间为35 +/- 7 min。与四维CT记录的运动相比，平均Delta M分别为0.4、1.0和0.4 mm，在内外侧、上下和前后方向。在治疗中，观察到的Δ M平均为，
Purpose: Stereotactic body radiation therapy (SBRT) is an effective treatment for medically inoperable Stage I non-small-cell lung cancer. However, changes in the patient's breathing patterns during the course of SBRT may result in a geographic miss or an overexposure of healthy tissues to radiation. However, the precise extent of these changes in breathing pattern is not well known. We evaluated the inter- and intrafractional changes in tumor motion amplitude (Delta M) over an SBRT course.Methods and Materials: Eighteen patients received image-guided SBRT delivered in three fractions; this therapy was done with abdominal compression in four patients. For each fraction, cone beam computed tomography (CBCT) was performed for tumor localization (+/- 3-mm tolerance) and then repeated to confirm geometric accuracy. Additional CBCT images were acquired at the midpoint and end of each SBRT fraction. Respiration-correlated CBCT (rcCBCT) reconstructions allowed retrospective assessment of inter- and intrafractional Delta M by a comparison of tumor displacements in all four-dimensional CT and rcCBCT scans. The Delta M was measured in mediolateral, superior-inferior, and anterior-posterior directions.Results: A total of 201 rcCBCT images were analyzed. The mean time from localization of the tumor to the end-fraction CBCT was 35 +/- 7 min. Compared with the motion recorded on four-dimensional CT, the mean Delta M was 0.4, 1.0, and 0.4 mm, respectively, in the mediolateral, superior-inferior, and anterior-posterior directions. On treatment, the observed Delta M was, on average,