Chen Xiaoming, Hayes Shelly, Cohen Randi, Ma Charlie
Radiation Oncology, Fox Chase Cancer Center, Philadelphia, USA.
Cureus. 2025 Jun 20;17(6):e86436. doi: 10.7759/cureus.86436. eCollection 2025 Jun.
Large respiratory motion presents a challenging issue for stereotactic body radiotherapy (SBRT) treatment of thoracic or abdominal lesions. In clinical practice, it is common to use the internal target volume (ITV) method to account for respiratory motion. This leads to a larger target volume than the real tumor volume. When the tumor motion is large, the ITV-to-tumor volumetric ratio increases significantly, causing a proportionally large amount of normal tissue to receive a high prescription dose. While there exist different approaches to reduce the ITV, adaptive motion management (AMM), e.g., the respiratory synchrony target tracking method used by CyberKnife (CK), presents an interesting one. In this report, we present a lung SBRT case in which the tumor exhibits huge respiratory motion. The elongated shape of the lesion and the motion made the treatment more challenging if a conventional ITV method was used. After being evaluated initially for the conventional ITV method, the patient was selected to be treated under adaptive motion management with CyberKnife. A dosimetric comparison was performed between plans with/without AMM. The results demonstrated the benefits of the application of AMM and may provide useful clinical data for the future practice of treating lesions with large respiratory motion.
对于胸部或腹部病变的立体定向体部放射治疗（SBRT）而言，较大的呼吸运动是一个具有挑战性的问题。在临床实践中，使用内部靶区体积（ITV）方法来考虑呼吸运动是很常见的。这导致靶区体积比实际肿瘤体积更大。当肿瘤运动较大时，ITV与肿瘤的体积比会显著增加，从而使相当数量的正常组织接受高处方剂量。虽然存在不同的方法来减小ITV，但自适应运动管理（AMM），例如射波刀（CK）所使用的呼吸同步靶区追踪方法，是一种值得关注的方法。在本报告中，我们展示了一例肺部SBRT病例，其中肿瘤表现出巨大的呼吸运动。如果使用传统的ITV方法，病变的细长形状和运动使得治疗更具挑战性。在最初对传统ITV方法进行评估后，该患者被选择采用射波刀进行自适应运动管理治疗。对有/无AMM的计划进行了剂量学比较。结果证明了应用AMM的益处，并可能为未来治疗具有较大呼吸运动病变的实践提供有用的临床数据。
