文章：

在磁共振引导自适应放疗时代下对局限性前列腺癌的立体定向体部放疗：HERMES试验中两分次与五分次治疗的剂量对比

Stereotactic Body Radiotherapy (SBRT) to Localised Prostate Cancer in the Era of MRI-Guided Adaptive Radiotherapy: Doses Delivered in the HERMES Trial Comparing Two- and Five-Fraction Treatments

原文发布日期：30 May 2024

DOI: 10.3390/cancers16112073

类型: Article

开放获取: 是

英文摘要：

HERMES is a phase II trial of MRI-guided daily-adaptive radiotherapy (MRIgART) randomising men with localised prostate cancer to either 2-fractions of SBRT with a boost to the tumour or 5-fraction SBRT. In the context of this highly innovative regime the dose delivered must be carefully considered. The first ten patients recruited to HERMES were analysed in order to establish the dose received by the targets and organs at risk (OARS) in the context of intrafraction motion. A regression analysis was performed to measure how the volume of air within the rectum might further impact rectal dose secondary to the electron return effect (ERE). One hundred percent of CTV target objectives were achieved on the MRI taken prior to beam-on-time. The post-delivery MRI showed that high-dose CTV coverage was achieved in 90% of sub-fractions (each fraction is delivered in two sub-fractions) in the 2-fraction cohort and in 88% of fractions the 5-fraction cohort. Rectal D1 cm3was the most exceeded constraint; three patients exceeded the D1 cm3< 20.8 Gy in the 2-fraction cohort and one patient exceeded the D1 cm3< 36 Gy in the 5-fraction cohort. The volume of rectal gas within 1 cm of the prostate was directly proportional to the increase in rectal D1 cm3, with a strong (R = 0.69) and very strong (R = 0.90) correlation in the 2-fraction and 5-fraction cohort respectively. Dose delivery specified in HERMES is feasible, although for some patients delivered doses to both target and OARs may vary from those planned.

摘要翻译： 

HERMES是一项关于磁共振引导每日自适应放疗（MRIgART）的II期临床试验，该研究将局部前列腺癌患者随机分配至两组：一组接受2次立体定向放射治疗（SBRT）并对肿瘤进行增量照射，另一组接受5次SBRT。在这一高度创新的治疗方案背景下，必须仔细考量所施予的剂量。本研究对HERMES试验中招募的前十名患者进行了分析，旨在确定在分次内运动情况下靶区及危及器官（OARs）所接受的剂量。通过回归分析评估了直肠内气体体积如何通过电子回旋效应（ERE）进一步影响直肠剂量。在照射前获取的磁共振图像上，100%的临床靶体积（CTV）目标剂量得以实现。照射后磁共振显示，在2次治疗组中，90%的子分次（每次治疗分为两个子分次）实现了CTV的高剂量覆盖；在5次治疗组中，88%的分次实现了该目标。直肠D1 cm³是最常超标的限制参数：2次治疗组中有三名患者的直肠D1 cm³超过了20.8 Gy的限制，5次治疗组中有一名患者超过了36 Gy的限制。距离前列腺1厘米范围内的直肠气体体积与直肠D1 cm³的增加呈正相关，在2次治疗组和5次治疗组中分别表现出强相关（R = 0.69）和极强相关（R = 0.90）。尽管部分患者的靶区和危及器官实际受照剂量可能与计划剂量存在差异，但HERMES方案中规定的剂量施予是可行的。

原文链接：

Stereotactic Body Radiotherapy (SBRT) to Localised Prostate Cancer in the Era of MRI-Guided Adaptive Radiotherapy: Doses Delivered in the HERMES Trial Comparing Two- and Five-Fraction Treatments