Liao Zhongxing, Simone Charles B
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, MD, USA.
Transl Lung Cancer Res. 2018 Apr;7(2):141-152. doi: 10.21037/tlcr.2018.04.11.
The finite range of proton beams in tissues offers unique dosimetric advantages that theoretically allow the dose to the target to be escalated while minimizing exposure of surrounding tissues and thereby minimizing radiation-induced toxicity. These theoretical advantages have led to widespread adoption of proton therapy around the world for a wide variety of tumors at different anatomic sites. Many treatment-planning comparisons have shown that proton therapy has substantial dosimetric advantages over conventional photon (X-ray) radiation therapy. However, given the typically significant difference in cost between proton therapy versus conventional photon therapy, strong evidence of proton therapy's clinical benefits in terms of toxicity and survival is warranted. Some findings from retrospective studies, single-arm prospective studies, and a very few randomized clinical trials comparing these modalities are beginning to emerge. In this review, we examine the available data on proton therapy for (non-small cell lung cancer NSCLC). We begin by discussing the unique challenges involved in treating moving targets with significant tissue heterogeneity and the technologic efforts underway to overcome these challenges. We then discuss the rationale for minimizing normal tissue toxicity, particularly pulmonary, cardiac, and hematologic toxicity, within the context of previously unsuccessful attempts at dose escalation for lung cancer. Finally, we explore strategies for accelerating the development of trials aimed at measuring meaningful clinical endpoints and for maximizing the value of proton therapy by personalizing its use for individual patients.
质子束在组织中的射程有限，具有独特的剂量学优势，理论上可在增加靶区剂量的同时，使周围组织的受照剂量最小化，从而降低辐射诱发的毒性。这些理论优势促使质子治疗在全球范围内广泛应用于不同解剖部位的多种肿瘤。许多治疗计划比较表明，质子治疗在剂量学方面比传统光子（X射线）放射治疗具有显著优势。然而，鉴于质子治疗与传统光子治疗的成本通常存在显著差异，需要有强有力的证据证明质子治疗在毒性和生存方面的临床益处。一些回顾性研究、单臂前瞻性研究以及极少数比较这些治疗方式的随机临床试验的结果已开始显现。在本综述中，我们研究了有关质子治疗非小细胞肺癌（NSCLC）的现有数据。我们首先讨论治疗具有显著组织异质性的移动靶区所涉及的独特挑战以及为克服这些挑战正在进行的技术努力。然后，我们在之前肺癌剂量递增尝试未成功的背景下，讨论将正常组织毒性（尤其是肺部、心脏和血液学毒性）降至最低的基本原理。最后，我们探讨加速开展旨在测量有意义临床终点的试验的策略，以及通过针对个体患者个性化使用质子治疗来最大化其价值的策略。
