Towards a noninvasive intracranial tumor irradiation using 3d optical imaging and multimodal data registration.
Towards a noninvasive intracranial tumor irradiation using 3d optical imaging and multimodal data registration.
复制标题
使用3D光学成像和多模式数据登记迈向非侵入性颅内肿瘤辐照。
DOI：
10.1155/2007/62030
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发表时间：
2007
影响因子：
7.6
通讯作者：
Aletti, P
中科院分区：
文献类型：
--
作者：
Posada, R;Daul, Ch;Wolf, D;Aletti, P
适形放射治疗（CRT）导致高精度的肿瘤体积照射。在分次放射治疗（FRT）中，病变在几个疗程中照射，以便比在一个疗程中进行治疗时更好地保护健康的邻近组织。在颅内肿瘤的情况下，患者在照射机坐标系中定位的经典方法是侵入性的，并且仅允许在一次照射会话中进行CRT。这一贡献提出了一种非侵入性的定位方法，代表了CRT和FRT相结合的第一步。用于定位的3D数据是散布在患者头部的点云（通常在治疗期间获取的CT数据）和分布在患者面部的点，这些点是用固定在治疗室中的结构光传感器获取的。通过配准由两个3D点集表示的表面来获得链接诊断设备（CT模态）和治疗室的3D传感器（可见光模态）的坐标系的几何变换。3D传感器和照射机的坐标系之间的几何关系由治疗室中的传感器位置的校准给出。用前两个变换计算的全局变换足以预测照射机坐标系中的肿瘤位置，仅具有CT坐标系中的对应位置。获得的一个幻影的结果表明，平均定位误差的肿瘤治疗机等中心为0.4毫米。与人体数据进行的测试证明，注册算法是准确的（0.1毫米的平均同源点之间的距离）和强大的，即使面部表情的变化。
Conformal radiotherapy (CRT) results in high-precision tumor volume irradiation. In fractioned radiotherapy (FRT), lesions are irradiated in several sessions so that healthy neighbouring tissues are better preserved than when treatment is carried out in one fraction. In the case of intracranial tumors, classical methods of patient positioning in the irradiation machine coordinate system are invasive and only allow for CRT in one irradiation session. This contribution presents a noninvasive positioning method representing a first step towards the combination of CRT and FRT. The 3D data used for the positioning is point clouds spread over the patient's head (CT-data usually acquired during treatment) and points distributed over the patient's face which are acquired with a structured light sensor fixed in the therapy room. The geometrical transformation linking the coordinate systems of the diagnosis device (CT-modality) and the 3D sensor of the therapy room (visible light modality) is obtained by registering the surfaces represented by the two 3D point sets. The geometrical relationship between the coordinate systems of the 3D sensor and the irradiation machine is given by a calibration of the sensor position in the therapy room. The global transformation, computed with the two previous transformations, is sufficient to predict the tumor position in the irradiation machine coordinate system with only the corresponding position in the CT-coordinate system. Results obtained for a phantom show that the mean positioning error of tumors on the treatment machine isocentre is 0.4 mm. Tests performed with human data proved that the registration algorithm is accurate (0.1 mm mean distance between homologous points) and robust even for facial expression changes.