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

这项研究的目的是使用安装在C臂上的加速器改善旋转适形放射治疗(RCRT)的剂量分布。直线加速器机头设计为沿C形臂移动，最大角度为60度(从垂直位置朝向机架)。机架的同时旋转创造了一种动态锥形照射技术。将动态锥形适形放射治疗(Dyconic CRT)技术与多叶准直器(MLC)的连续运动相结合，发展了动态锥形适形放射治疗(Dyconic CRT)。使用胶片密度测量法测量了体模中的剂量分布，并与传统的RCRT进行了比较。还给出了实际放射治疗患者的剂量分布。Dyconic CRT实现了无需工作台旋转的精确非共面射束。此外，在商用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，与常规CRT相比，Dyconic CRT获得了三维正比的剂量梯度。用30度楔形补偿非圆锥形CRT矢状面的均匀剂量。该技术克服了RCRT在剂量分布方面的缺陷。

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.