PDF(Pubmed)
Abstract：
High dose-rate brachytherapy is a treatment technique for gynecologic cancers where intracavitary applicators are placed within the patient\'s pelvic cavity. To ensure accurate radiation delivery, localization of the applicator at the time of insertion is vital. This study proposes a novel method for acquiring, registering, and fusing three-dimensional (3D) trans-abdominal and 3D trans-rectal ultrasound (US) images for visualization of the pelvic anatomy and applicators during gynecologic brachytherapy. The workflow was validated using custom multi-modal pelvic phantoms and demonstrated during two patient procedures. Experiments were performed for three types of intracavitary applicators: ring-and-tandem, ring-and-tandem with interstitial needles, and tandem-and-ovoids. Fused 3D US images were registered to magnetic resonance (MR) and computed tomography (CT) images for validation. The target registration error (TRE) and fiducial localization error (FLE) were calculated to quantify the accuracy of our fusion technique. For both phantom and patient images, TRE and FLE across all modality registrations (3D US versus MR or CT) resulted in mean ± standard deviation of 4.01 ± 1.01 mm and 0.43 ± 0.24 mm, respectively. This work indicates proof of concept for conducting further clinical studies leveraging 3D US imaging as an accurate, accessible alternative to advanced modalities for localizing brachytherapy applicators.
摘要：
高剂量率近距离放射治疗是一种用于妇科癌症的治疗技术，其中腔内涂抹器放置在患者的盆腔内。为了确保准确的辐射输送，在插入时涂药器的定位是至关重要的。这项研究提出了一种新的获取方法，注册,并融合三维（3D）经腹和3D经直肠超声（US）图像，以在妇科近距离放射治疗期间可视化盆腔解剖结构和应用器。使用定制的多模态骨盆体对工作流程进行了验证，并在两个患者程序中进行了演示。对三种类型的腔内涂抹器进行了实验：环形和串联，与间质针环状串联，和串联和卵形。融合的3DUS图像与磁共振（MR）和计算机断层扫描（CT）图像进行配准以进行验证。计算目标配准误差（TRE）和基准定位误差（FLE）以量化我们的融合技术的准确性。对于幻影和患者图像，所有模态配准的TRE和FLE（3DUS与MR或CT）导致平均值±标准偏差为4.01±1.01mm和0.43±0.24mm，分别。这项工作表明了利用3DUS成像进行进一步临床研究的概念证明，可替代的先进的方式定位近距离放射治疗施药器。
