Technological advances in MRI-guided radiation therapy (MRIgRT) have improved real-time visualization of the prostate and its surrounding structures over CT-guided radiation therapy. Seminal studies have demonstrated safe dose escalation achieved through ultrahypofractionation with MRIgRT due to planning target volume (PTV) margin reduction and treatment gating. On-table adaptation with MRI-based technologies can also incorporate real-time changes in target shape and volume and can reduce high doses of radiation to sensitive surrounding structures that may move into the treatment field. Ongoing clinical trials seek to refine ultrahypofractionated radiotherapy treatments for prostate cancer using MRIgRT. Though these studies have the potential to demonstrate improved biochemical control and reduced side effects, limitations concerning patient treatment times and operational workflows may preclude wide adoption of this technology outside of centers of excellence. In this review, we discuss the advantages and limitations of MRIgRT for prostate cancer, as well as clinical trials testing the efficacy and toxicity of ultrafractionation in patients with localized or post-prostatectomy recurrent prostate cancer.
与CT引导的放射治疗相比，MRI引导放射治疗（MRIgRT）的技术进步提高了前列腺及其周围结构的实时可视化能力。开创性研究表明，通过MRIgRT实现超分割治疗，借助计划靶区（PTV）边界缩减和治疗门控技术，能够安全地提升放射剂量。基于MRI的实时自适应技术还能纳入靶区形状和体积的即时变化，并减少对可能移入治疗区域的敏感周围结构的高剂量辐射。目前正在进行的临床试验旨在利用MRIgRT优化前列腺癌的超分割放射治疗方案。尽管这些研究有望展示改善生化控制和减少副作用的效果，但患者治疗时间和操作流程方面的限制可能阻碍该技术在卓越中心之外的广泛采用。本综述探讨了MRIgRT在前列腺癌治疗中的优势与局限，以及测试超分割治疗对局限性或前列腺切除术后复发性前列腺癌患者疗效和毒性的临床试验。
MRI-Guided Radiation Therapy for Prostate Cancer: The Next Frontier in Ultrahypofractionation
肿瘤(癌症)患者之家