Abstract：
Traditionally, external beam radiotherapy (EBRT) for localized prostate cancer (PCa) involved lengthy courses with low daily doses. However, advancements in radiation delivery and a better understanding of prostate radiobiology have enabled the development of shorter courses of EBRT. Ultrahypofractionated radiotherapy, administering doses greater than 5 Gy per fraction, is now considered a standard of care regimen for localized PCa, particularly for intermediate-risk disease. Stereotactic body radiotherapy (SBRT), a specific type of ultrahypofractionated radiotherapy employing advanced planning, imaging, and treatment technology to deliver in five or fewer fractions, is gaining prominence as a cost-effective, convenient, and safe alternative to longer radiotherapy courses. It is crucial to address practical considerations related to patient selection, fractionation scheme, target delineation, and planning objectives. This is especially important in challenging clinical situations where clear evidence for guidance may be lacking. The Radiosurgery Society endorses this case-based guide with the aim of providing a practical framework for delivering SBRT to the intact prostate, exemplified by two case studies. The article will explore common SBRT dose/fractionation schemes and dose constraints for organs-at-risk. Additionally, it will review existing evidence and expert opinions on topics such as SBRT dose escalation, the use of rectal spacers, the role of androgen deprivation therapy in the context of SBRT, SBRT in special patient populations (e.g., high-risk disease, large prostate, high baseline urinary symptom burdens, and inflammatory bowel disease), as well as new imaging-guidance techniques like Magnetic Resonance Imaging for SBRT delivery.
摘要：
外照射放射治疗是一种安全有效的治疗方法，适用于男性局限性前列腺癌（PCa）。虽然传统上需要长期治疗，每日剂量低，对前列腺放射生物学的认识和放射给药的进步使EBRT的疗程更短。超分割放疗，这涉及>5Gy/分数的交付，现在被认为是局部PCa的标准护理方案，尤其是中危疾病.立体定向身体放射治疗（SBRT），一种特殊形式的超小分割放射治疗，利用先进的计划，成像,和处理技术，以提供≤5个馏分，特别是作为一种具有成本效益的，方便,和长期放射治疗的安全替代方案。鉴于SBRT最近被采用为PCa治疗的标准护理设备，并且在这种情况下越来越多地使用它，重要的是要强调与患者选择有关的实际考虑，分馏方案，目标划定和规划目标，特别是当从业者面对困难的临床情况时，没有明确的证据提供指导。放射外科学会认可的基于案例的指南的目的是为完整的前列腺提供一个实用的框架，特别是在有争议的领域，以两个具有挑战性的案例为例。在这篇文章中,我们将讨论常见的SBRT剂量/分级方案和高危器官的剂量限制.我们还将审查现有证据和专家意见，例如SBRT剂量增加，直肠间隔器的效用，雄激素剥夺治疗在SBRT设置中的作用，SBRT在特殊患者人群中，如高危疾病患者，大前列腺,高基线泌尿症状负担和炎症性肠病，以及用于SBRT递送的新的成像引导技术(例如磁共振成像)。
