Fonseca Gabriel P, Johansen Jacob G, Smith Ryan L, Beaulieu Luc, Beddar Sam, Kertzscher Gustavo, Verhaegen Frank, Tanderup Kari
Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre+, Maastricht, Doctor Tanslaan 12, 6229 ET Maastricht, the Netherlands.
Department of Oncology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus, Denmark.
Phys Imaging Radiat Oncol. 2020 Sep 28;16:1-11. doi: 10.1016/j.phro.2020.09.002. eCollection 2020 Oct.
Brachytherapy can deliver high doses to the target while sparing healthy tissues due to its steep dose gradient leading to excellent clinical outcome. Treatment accuracy depends on several manual steps making brachytherapy susceptible to operational mistakes. Currently, treatment delivery verification is not routinely available and has led, in some cases, to systematic errors going unnoticed for years. The brachytherapy community promoted developments in dosimetry (IVD) through research groups and small companies. Although very few of the systems have been used clinically, it was demonstrated that the likelihood of detecting deviations from the treatment plan increases significantly with time-resolved methods. Time-resolved methods could interrupt a treatment avoiding gross errors which is not possible with time-integrated dosimetry. In addition, lower experimental uncertainties can be achieved by using source-tracking instead of direct dose measurements. However, the detector position in relation to the patient anatomy remains a main source of uncertainty. The next steps towards clinical implementation will require clinical trials and systematic reporting of errors and near-misses. It is of utmost importance for each IVD system that its sensitivity to different types of errors is well understood, so that end-users can select the most suitable method for their needs. This report aims to formulate requirements for the stakeholders (clinics, vendors, and researchers) to facilitate increased clinical use of IVD in brachytherapy. The report focuses on high dose-rate IVD in brachytherapy providing an overview and outlining the need for further development and research.
近距离放射治疗能够在保护健康组织的同时，将高剂量的射线精准地作用于靶区，这得益于其陡峭的剂量梯度，从而带来卓越的临床治疗效果。然而，由于治疗过程涉及多个手动操作步骤，近距离放射治疗容易出现操作失误。目前，治疗剂量验证并未作为常规流程执行，这在某些情况下导致系统性误差多年未被察觉。近距离放射治疗领域通过研究团队和小型公司推动了剂量测定（IVD）技术的发展。尽管只有极少数系统应用于临床，但研究表明，采用时间分辨方法能够显著提高检测治疗计划偏差的可能性。时间分辨方法可以中断治疗，避免严重错误，而这是时间积分剂量测定法无法做到的。此外，通过源跟踪而非直接剂量测量，可以降低实验不确定性。然而，探测器相对于患者解剖结构的位置仍然是不确定性的主要来源。迈向临床应用的下一步需要开展临床试验，并对错误和险些发生的错误进行系统报告。对于每个IVD系统而言，充分了解其对不同类型错误的敏感性至关重要，这样终端用户才能根据自身需求选择最合适的方法。本报告旨在为利益相关者（诊所、供应商和研究人员）制定要求，以促进IVD在近距离放射治疗中的临床应用。本报告聚焦于近距离放射治疗中的高剂量率IVD，提供概述并阐述进一步发展和研究的必要性。
