Stereotactic body radiation therapy (SBRT) and hypofractionation using pencil-beam scanning (PBS) proton therapy (PBSPT) is an attractive option for thoracic malignancies. Combining the advantages of target coverage conformity and critical organ sparing from both PBSPT and SBRT, this new delivery technique has great potential to improve the therapeutic ratio, particularly for tumors near critical organs. Safe and effective implementation of PBSPT SBRT/hypofractionation to treat thoracic malignancies is more challenging than the conventionally-fractionated PBSPT due to concerns of amplified uncertainties at the larger dose per fraction. NRG Oncology and Particle Therapy Cooperative Group (PTCOG) Thoracic Subcommittee surveyed US proton centers to identify practice patterns of thoracic PBSPT SBRT/hypofractionation. From these patterns, we present recommendations for future technical development of proton SBRT/hypofractionation for thoracic treatment. Amongst other points, the recommendations highlight the need for volumetric image guidance and multiple CT-based robust optimization and robustness tools to minimize further the impact of uncertainties associated with respiratory motion. Advances in direct motion analysis techniques are urgently needed to supplement current motion management techniques.

中文翻译：

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质子笔束扫描立体定向全身放射治疗和胸部恶性肿瘤的大分割放射治疗：NRG 肿瘤学和 PTCOG 的实践调查模式和未来发展建议

立体定向全身放射治疗 (SBRT) 和使用笔形束扫描 (PBS) 质子治疗 (PBSPT) 的大分割是治疗胸部恶性肿瘤的一种有吸引力的选择。这种新的递送技术结合了 PBSPT 和 SBRT 的靶点覆盖一致性和关键器官保留的优点，具有提高治疗率的巨大潜力，特别是对于关键器官附近的肿瘤。安全有效地实施 PBSPT SBRT/大分割治疗胸部恶性肿瘤比传统分割 PBSPT 更具挑战性，因为担心每次分割剂量较大时不确定性会增加。NRG 肿瘤学和粒子治疗合作组 (PTCOG) 胸部小组委员会对美国质子中心进行了调查，以确定胸部 PBSPT SBRT/大分割的实践模式。根据这些模式，我们为胸部治疗质子 SBRT/大分割的未来技术发展提出建议。除其他外，这些建议强调需要体积图像引导和多个基于 CT 的鲁棒优化和鲁棒性工具，以进一步最大限度地减少与呼吸运动相关的不确定性的影响。迫切需要直接运动分析技术的进步来补充当前的运动管理技术。