PURPOSE To determine whether rectal displacement devices (RDDs) have a prostate-stabilizing effect during prostate external beam radiotherapy (EBRT). METHODS A systematic literature search using the PubMed database from January 1, 2000 to December 30th, 2019 was conducted. The effect of RDDs on inter- and intra-fractional prostate displacements was extracted. RESULTS From 356 articles identified via the PubMed database and hand search, 21 articles were included in the systematic review. There was no randomized study. Twelve studies evaluated the role of the endorectal balloon (ERB) in managing prostate motion. Four studies reported the effect of hydrogel spacer on prostate motion. Four studies examined the effect of the rectal retractor (RR) on intra-fractional prostate motion, and only one study assessed the impact of ProSpare (Nottinghamshire, UK) in reducing prostate motion. CONCLUSION Using an ERB significantly reduces intra-fractional prostate motion. This prostate-stabilizing effect of the ERB can translate into reduced planning target volume (PTV) margins and additional rectal dose sparing. Even with an ERB in place, inter-fractional prostate displacements are seen. As a consequence, ERB application does not obviate daily verification; however, this is not a crucial topic because pretreatment imaging is always done nowadays. As compared with ERB, the hydrogel spacer significantly reduces rectal dose and toxicity without influencing prostate immobilization. The RR can increase prostate and rectal inter- and intra-fractional stability without a clear influence on the reduction of rectal toxicity. Finally, it is unclear whether ProSpare is a suitable device reducing prostate motion. Further study will be required to clarify whether the prostate-stabilizing effects of the ERB and RR can result in a safe reduction of PTV margins and further sparing of organs at risks, especially the rectum.

中文翻译：

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直肠移位装置在管理前列腺运动中的有效性：系统评价。

目的确定在前列腺外束放射疗法（EBRT）期间直肠移位装置（RDD）是否具有前列腺稳定作用。方法使用2000年1月1日至2019年12月30日使用PubMed数据库进行系统的文献检索。提取了RDDs对小部分间和小部分内前列腺移位的影响。结果通过PubMed数据库和人工搜索鉴定的356篇文章中，有21篇文章被纳入系统评价。没有随机研究。十二项研究评估了直肠内球囊（ERB）在控制前列腺运动中的作用。四项研究报道了水凝胶垫片对前列腺运动的影响。有四项研究检查了直肠牵开器（RR）对部分前列腺运动的影响，只有一项研究评估了ProSpare的影响（诺丁汉郡，英国）减少前列腺运动。结论使用ERB可显着降低小部分前列腺运动。ERB的这种前列腺稳定作用可以转化为减少计划目标体积（PTV）余量和额外的直肠剂量节约。即使在ERB到位的情况下，也可以看到部分间前列腺移位。因此，ERB申请不会消除日常验证；但是，这并不是一个至关重要的话题，因为如今预处理成像始终在进行。与ERB相比，水凝胶垫片可显着降低直肠剂量和毒性，而不会影响前列腺固定。RR可以增加前列腺和直肠的分数间和分数内稳定性，而对降低直肠毒性没有明显的影响。最后，尚不清楚ProSpare是否适合降低前列腺运动。