Movement of a small tumour in contact with the diaphragm: characterisation with four-dimensional CT
Movement of a small tumour in contact with the diaphragm: characterisation with four-dimensional CT
复制标题
与膈肌接触的小肿瘤的运动：四维 CT 表征
DOI：
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发表时间：
2016
影响因子：
2.1
通讯作者：
S. Mori
中科院分区：
文献类型：
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作者：
M. Kumagai;S. Mori
胸部和腹部放射治疗可能需要调整计划靶体积（PTV）以补偿呼吸运动。我们评估了可能发生在靠近隔膜的小目标上的剂量变化。我们用呼气峰值作为基线，比较了一个膈周围病变患者在门控和非门控四维计算机断层扫描（CT）上的肿瘤和膈移位。膈肌下向运动12.7 mm。肿瘤向右移动1.0 mm，向前移动1.1 mm，向上移动1.4 mm。肿瘤在纵轴上与横膈膜方向相反。这种矛盾的运动没有影响剂量分布，因为在非门控治疗方案中，光束没有照射肝脏，并保持在PTV内。我们在4D CT上观察到一个小肿瘤的微小运动，尽管它与横膈膜接触并向相反方向移动。本例患者在照射过程中不需要进行呼吸门控，从而有可能缩短治疗时间。
Radiotherapy to the thoracic and abdominal regions can require tailoring of the planning target volume (PTV) to compensate for respiratory motion. We evaluated dose variations that might occur to a small target close to the diaphragm. We compared tumour and diaphragm displacement in gated and non-gated four-dimensional computed tomography (CT) of a patient with a peridiaphragmatic lesion, using peak exhalation as a baseline. Diaphragmatic motion was 12.7 mm in the inferior direction. The tumour was noted to move 1.0 mm to the right, 1.1 mm anteriorly, and 1.4 mm superiorly. The tumour moved in the opposite direction from the diaphragm in the vertical axis. This paradoxical motion did not affect the dose distribution because the beam did not irradiate the liver on non-gated treatment plans, and remained within the PTV. We observed minimal movement of a small tumour on 4D CT, in spite of it being in contact with, and moving opposite to, the diaphragm. In this patient, respiratory gating during irradiation was not needed, making it possible to reduce the treatment time.