Intra-operative 3D guidance and edema detection in prostate brachytherapy using a non-isocentric C-arm.
Intra-operative 3D guidance and edema detection in prostate brachytherapy using a non-isocentric C-arm.
复制标题
使用非以上为中心的C型臂在前列腺放射治疗中术中3D指导和水肿检测。
DOI：
10.1016/j.media.2010.07.011
复制
发表时间：
2012-04
影响因子：
10.9
通讯作者：
Fichtinger G
中科院分区：
文献类型：
--
作者：
Jain A;Deguet A;Iordachita I;Chintalapani G;Vikal S;Blevins J;Le Y;Armour E;Burdette C;Song D;Fichtinger G
近距离放射治疗（放射性粒子植入）已成为前列腺癌患者最有效的治疗选择之一，并具有方便的门诊手术的额外好处。当代近距离放射治疗的主要限制是错误的粒子放置，主要是由于术中水肿（组织扩张）的存在。虽然目前还不可用，但术中监测种子分布的能力可以显著改善癌症控制。我们在这里介绍这样一个系统。前列腺近距离放射治疗中水肿的术中测量需要相对于前列腺定位插入的放射性粒子。使用典型的非等中心C形臂重建种子，并导出到商业近距离放射治疗计划系统。在非等中心C形臂上进行3D重建的技术障碍包括姿势相关C形臂校准;失真校正; C形臂图像的姿势估计;种子重建;以及C形臂与TRUS配准。在含有40-100粒种子的精密加工硬体模和含有45-87粒种子的软组织体模中，我们分别以0.35 mm和0.24 mm的平均3D精度正确地重建了种子种植体形状。在一项DoD I期临床试验中，6名患者计划植入48-82粒粒子，我们实现了术中粒子分布和剂量测定监测，通过在6名入组患者中平均插入超过4粒粒子（最少1粒;最多9粒）来校正剂量不均匀性。此外，在每例患者中，系统自动检测到由于水肿引起的术中粒子移位（平均值3.84 mm，STD 2.13 mm，Max 16.19 mm）。所提出的系统是第一种可以在任何典型的非等中心C形臂上进行水肿术中检测（以及随后的重新优化）的系统，对现有的临床装置的额外成本可以忽略不计。它实现了更均匀的种子分布，并有可能影响临床实践的范式转变。目前正在进行大规模的研究和商业化。
Brachytherapy (radioactive seed insertion) has emerged as one of the most effective treatment options for patients with prostate cancer, with the added benefit of a convenient outpatient procedure. The main limitation in contemporary brachytherapy is faulty seed placement, predominantly due to the presence of intra-operative edema (tissue expansion). Though currently not available, the capability to intra-operatively monitor the seed distribution, can make a significant improvement in cancer control. We present such a system here. Intra-operative measurement of edema in prostate brachytherapy requires localization of inserted radioactive seeds relative to the prostate. Seeds were reconstructed using a typical non-isocentric C-arm, and exported to a commercial brachytherapy treatment planning system. Technical obstacles for 3D reconstruction on a non-isocentric C-arm include pose-dependent C-arm calibration; distortion correction; pose estimation of C-arm images; seed reconstruction; and C-arm to TRUS registration. In precision-machined hard phantoms with 40–100 seeds and soft tissue phantoms with 45–87 seeds, we correctly reconstructed the seed implant shape with an average 3D precision of 0.35 mm and 0.24 mm, respectively. In a DoD Phase-1 clinical trial on six patients with 48–82 planned seeds, we achieved intra-operative monitoring of seed distribution and dosimetry, correcting for dose inhomogeneities by inserting an average of over four additional seeds in the six enrolled patients (minimum 1; maximum 9). Additionally, in each patient, the system automatically detected intra-operative seed migration induced due to edema (mean 3.84 mm, STD 2.13 mm, Max 16.19 mm). The proposed system is the first of a kind that makes intra-operative detection of edema (and subsequent re-optimization) possible on any typical non-isocentric C-arm, at negligible additional cost to the existing clinical installation. It achieves a significantly more homogeneous seed distribution, and has the potential to affect a paradigm shift in clinical practice. Large scale studies and commercialization are currently underway.