Fattori Giovanni, Via Riccardo, Lomax Antony J, Safai Sairos
Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland.
Department of Physics, ETH Zürich, Switzerland.
Phys Imaging Radiat Oncol. 2025 Jun 24;35:100799. doi: 10.1016/j.phro.2025.100799. eCollection 2025 Jul.
In-room computer tomography (CT) on-rails scanners are available in proton therapy centers but often limited to control imaging, due to geometric distortion and lack of integration. We present a calibration method combining CT-on-rails with a robotic table to achieve sub-millimeter patient positioning accuracy. Geometric distortions in 3DCT and topogram images were corrected using affine models and validated with laser tracker data. Phantom experiments simulating clinical conditions showed errors below 0.15 mm for 3D/3D and 0.3-0.55 mm for 2D/3D registration, the latter using a novel algorithm for digitally reconstructed topograms. The workflow enables accurate positioning without isocenter verification, supporting high-precision radiotherapy.
质子治疗中心配备了室内计算机断层扫描（CT）轨道式扫描仪，但由于几何畸变和缺乏集成，这些扫描仪通常仅限于控制成像。我们提出了一种将轨道式CT与机器人治疗床相结合的校准方法，以实现亚毫米级的患者定位精度。使用仿射模型校正了三维CT和体表图图像中的几何畸变，并通过激光跟踪仪数据进行了验证。模拟临床情况的体模实验表明，三维/三维配准的误差低于0.15毫米，二维/三维配准的误差为0.3-0.55毫米，后者使用了一种用于数字重建体表图的新算法。该工作流程无需等中心验证即可实现精确的定位，支持高精度放疗。
