Dynamic conical conformal radiotherapy using a C-arm mounted accelerator and its treatment planning software

本研究的目的是改善剂量分布与旋转适形放射治疗（RCRT）使用C形臂安装加速器。直线加速器头被设计为以最大60度的角度（从垂直位置朝向机架）沿C形臂沿着移动。机架的同时旋转产生动态锥形照射技术。动态锥形适形放射治疗（Dyconic CRT）是将该技术与多叶准直器（MLC）的连续运动相结合而发展起来的。用胶片密度法测量了体模中的剂量分布，并与常规RCRT进行了比较。在实际的放射治疗患者的剂量分布。Dyconic CRT实现了精确的非共面射束进入，无需工作台旋转。此外，在市售RTP计算机上完成了Dyconic CRT的专门治疗计划软件。测量结果表明，与传统的RCRT相比，Dyconic CRT实现了三维比例剂量梯度。Dyconic CRT矢状方向的剂量均匀性通过使用30度楔形来补偿。本技术克服了RCRT在剂量分布上的缺点。

The aim of the study was to improve dose distribution with rotational conformal radiotherapy (RCRT) using a C-arm mounted accelerator. The linac head was designed to move along the C-arm with a maximum angle of 60 degrees (from a vertical position toward the gantry). Simultaneous rotation of the gantry creates a dynamic conical irradiation technique. Dynamic conical conformal radiation therapy (Dyconic CRT) was developed by combining the technique with continuous motion of multi-leaf collimator (MLC). Dose distributions were measured in phantoms using film densitometry and compared with conventional RCRT. Dose distributions in actual radiation therapy patients are also presented. Dyconic CRT actualized precise non-coplanar beam entry without table rotation. In addition, a specialized treatment planning software for Dyconic CRT was completed on a commercially available RTP computer. The measurements showed that three-dimensionally proportional dose gradient was achieved with Dyconic CRT, when compared to that with conventional RCRT. Dose in homogeneity in the sagittal direction with Dyconic CRT was compensated by use of 30-degree wedge. Drawback of RCRT in dose distribution was overcome with the present technique.