Dipartimento di Diagnostica per immagini, Radioterapia Oncologica ed Ematologia, UOC Radioterapia Oncologica, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Roma, Italia.
Dipartimento di Diagnostica per immagini, Radioterapia Oncologica ed Ematologia, UOC Fisica Sanitaria, Fondazione Policlinico Policlinico Universitario "A. Gemelli" IRCCS, Roma, Italia.
Radiat Oncol. 2019 Apr 29;14(1):71. doi: 10.1186/s13014-019-1275-3.
Different studies have proved in recent years that hypofractionated radiotherapy (RT) improves overall survival of patients affected by locally advanced, unresectable, pancreatic cancer. The clinical management of these patients generally leads to poor results and is considered very challenging, due to different factors, heavily influencing treatment delivery and its outcomes. Firstly, the dose prescribed to the target is limited by the toxicity that the highly radio-sensitive organs at risk (OARs) surrounding the disease can develop. Treatment delivery is also complicated by the significant inter-fractional and intra-fractional variability of therapy volumes, mainly related to the presence of hollow organs and to the breathing cycle. The recent introduction of magnetic resonance guided radiotherapy (MRgRT) systems leads to the opportunity to control most of the aforementioned sources of uncertainty influencing RT treatment workflow in pancreatic cancer. MRgRT offers the possibility to accurately identify radiotherapy volumes, thanks to the high soft-tissue contrast provided by the Magnetic Resonance imaging (MRI), and to monitor the tumour and OARs positions during the treatment fraction using a high-temporal cine MRI. However, the main advantage offered by the MRgRT is the possibility to online adapt the RT treatment plan, changing the dose distribution while the patient is still on couch and successfully addressing most of the sources of variability.
Aim of this study is to present and discuss the state of the art, the main pitfalls and the innovative opportunities offered by online adaptive MRgRT in pancreatic cancer treatment.
近年来，不同的研究已经证明，缩短分割放疗（RT）可以提高局部晚期、不可切除的胰腺癌患者的总生存率。由于多种因素严重影响治疗的实施及其结果，这些患者的临床管理通常导致较差的结果，被认为极具挑战性。首先，由于疾病周围的高放射性敏感器官（OARs）可能会产生毒性，因此规定给靶区的剂量是有限的。治疗的实施也因治疗体积的显著分次间和分次内变异性而变得复杂，主要与空心器官的存在和呼吸周期有关。最近引入的磁共振引导放疗（MRgRT）系统为控制影响胰腺癌 RT 治疗流程的大多数上述不确定性来源提供了机会。MRgRT 提供了准确识别放疗体积的可能性，这要归功于磁共振成像（MRI）提供的高软组织对比度，并可以使用高时间分辨率电影 MRI 在治疗过程中监测肿瘤和 OARs 的位置。然而，MRgRT 的主要优势是能够在线自适应调整 RT 治疗计划，改变剂量分布，同时患者仍在治疗台上，从而成功解决大多数变异性来源。
本研究旨在介绍和讨论在线自适应 MRgRT 在胰腺癌治疗中的最新技术、主要缺陷和创新机会。
