Singh Pratibha, Singh Manoj Kumar, Mishra Atul
Department of Physics, Institute of Applied Sciences and Humanities, GLA University, Mathura, Uttar Pradesh, India.
Department of Radiation Oncology, Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan, India.
J Med Phys. 2025 Jan-Mar;50(1):67-74. doi: 10.4103/jmp.jmp_201_24. Epub 2025 Mar 24.
This study aims to compare the dosimetric efficacy of RapidArc (RA) and intensity-modulated radiation therapy (IMRT) in the treatment of head-and-neck cancer, focusing on treatment efficiency and organ at risk (OAR) dose.
A cohort of 10 patients with head-and-neck cancer was recreated for RA, which was earlier treated with IMRT techniques. Dosimetric parameters evaluated or planning target volume (PTV) included monitor units (MUs), beam on time (BoT), gamma passing rate (GP), and various normal tissue dose indices such as V, V, V, V, and gradient indices (gradient index [GI], low GI [LGI], high GI). In addition, doses of OARs, including the spinal cord, brainstem, cochleae, esophagus, lips, larynx, and parotid glands, were compared.
RA demonstrated significant improvements in treatment efficiency, requiring fewer MU and shorter BoT, while maintaining comparable GP to IMRT. RA achieved a lower LGI, indicating better sparing of normal tissues from intermediate doses. Most other dosimetric parameters, including those for the spinal cord, parotid glands, and PRV spinal cord, demonstrated significant differences, with the RA technique showing superior performance.
This study highlights the dosimetric superiority of RA over IMRT, with significantly fewer MU, reduced BoT, and comparable GPs. RA achieved slightly higher mean PTV doses with similar homogeneity and conformity while delivering lower doses to critical OARs, such as the spinal cord, PRV spinal cord, and parotid glands, making it clinically advantageous.
本研究旨在比较容积旋转调强放疗（RA）与调强放射治疗（IMRT）在头颈部癌治疗中的剂量学疗效，重点关注治疗效率和危及器官（OAR）剂量。
选取10名头颈部癌患者，重建其容积旋转调强放疗的病例，这些患者之前接受过调强放射治疗技术。评估计划靶区（PTV）的剂量学参数包括监测单位（MUs）、射束开启时间（BoT）、伽马通过率（GP）以及各种正常组织剂量指数，如V、V、V、V和梯度指数（梯度指数[GI]、低梯度指数[LGI]、高梯度指数）。此外，还比较了包括脊髓、脑干、耳蜗、食管、嘴唇、喉和腮腺在内的危及器官的剂量。
容积旋转调强放疗在治疗效率方面有显著提高，所需监测单位更少，射束开启时间更短，同时与调强放射治疗的伽马通过率相当。容积旋转调强放疗的低梯度指数更低，表明正常组织在中等剂量下受保护更好。大多数其他剂量学参数，包括脊髓、腮腺和脊髓计划靶区的参数，均显示出显著差异，容积旋转调强放疗技术表现更优。
本研究突出了容积旋转调强放疗相对于调强放射治疗在剂量学方面的优势，监测单位显著减少，射束开启时间缩短，伽马通过率相当。容积旋转调强放疗在保持相似的均匀性和适形性的同时，平均计划靶区剂量略高，而对关键危及器官，如脊髓、脊髓计划靶区和腮腺的剂量更低，具有临床优势。
