Department of Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
Department of Medical Imaging and Radiation Sciences, Monash University, Clayton, Victoria, Australia.
J Med Radiat Sci. 2024 Jun;71(2):177-185. doi: 10.1002/jmrs.781. Epub 2024 Mar 25.
Surface-guided radiation therapy (SGRT) has emerged as a powerful tool to improve patient setup accuracy in radiation therapy (RT). Combined with the goal of increasing RT accuracy is an ongoing effort to decrease RT side effects. The application of a prophylactic skin dressing to the treatment site is a well-documented method of reducing skin-related side effects from RT. This paper aims to investigate whether the application of Mepitel, a prophylactic skin dressing, has an impact on the accuracy of surface-guided patient setups in chest wall RT.
A retrospective analysis of daily image-guided Online Corrections (OLCs) from patients undergoing chest wall irradiation with SGRT was performed. Translational (superior-inferior, lateral, and anterior-posterior) OLC magnitude and direction were compared between patients treated with Mepitel applied and those treated without. Systematic and random errors were calculated and compared between groups.
OLCs from 275 fractions were analysed. Mean OLCs were larger for patients with Mepitel applied in the superior_inferior axis (0.34 vs. 0.22 cm, P = 0.049) and for the combined translational vector (0.54 vs. 0.43 cm, P = 0.043). Combined translational systematic error was slightly larger for patients with Mepitel applied (0.15 vs. 0.09 cm).
Mepitel can impact the accuracy of SGRT patient-positioning in chest wall RT. The variation however is small and unlikely to have any clinical impact if SGRT is coupled with image guidance and appropriate PTV margins. Further investigation is required to assess the effect of Mepitel on SGRT accuracy in other treatment sites, as well as any potential dosimetric impacts.
表面引导放射治疗（SGRT）已成为提高放射治疗（RT）中患者摆位准确性的有力工具。结合提高 RT 准确性的目标，人们一直在努力降低 RT 的副作用。在治疗部位应用预防性皮肤敷料是减少 RT 相关皮肤副作用的一种已有充分记录的方法。本文旨在研究预防性皮肤敷料 Mepitel 的应用是否会影响胸部壁 RT 中表面引导患者摆位的准确性。
对接受 SGRT 胸部壁照射的患者进行每日图像引导在线校正（OLC）的回顾性分析。比较了 Mepitel 应用组和未应用组患者的横向（上下、左右和前后）OLC 幅度和方向。计算并比较了两组的系统和随机误差。
分析了 275 个分次的 OLC。应用 Mepitel 的患者在上下轴的 OLC 平均值较大（0.34 比 0.22cm，P=0.049），且总平移矢量较大（0.54 比 0.43cm，P=0.043）。应用 Mepitel 的患者总平移系统误差略大（0.15 比 0.09cm）。
Mepitel 可能会影响胸部壁 RT 中 SGRT 患者定位的准确性。然而，如果 SGRT 与图像引导和适当的 PTV 边界结合使用，这种变化很小，不太可能产生任何临床影响。需要进一步研究以评估 Mepitel 对其他治疗部位 SGRT 准确性的影响，以及任何潜在的剂量学影响。
