Department of Radiation Oncology, Chaim Sheba Medical Center, Tel Hashomer, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Department of Radiation Oncology, Chaim Sheba Medical Center, Tel Hashomer, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Center for Translational Research in Radiation Oncology, Tel Hashomer, Israel.
Int J Radiat Oncol Biol Phys. 2021 Aug 1;110(5):1466-1472. doi: 10.1016/j.ijrobp.2021.03.044. Epub 2021 May 5.
This study aimed to study the impact of continuous positive airway pressure (CPAP) on chest anatomy and tumor motion in patients receiving radiation therapy.
Patients with primary or secondary lung tumors, left-sided breast cancer, or liver metastases referred for radiation therapy were trained to breathe with a CPAP device using a face mask to a maximal pressure of 15 cm HO. Three- and 4-dimensional computed tomography simulation was performed twice for each patient: once with free breathing (FB) and again using CPAP. Volumetric and dosimetric parameters of treatment plans were compared.
Forty-nine patients were enrolled, of whom 6 withdrew consent before simulation and 3 withdrew because of discomfort. Thus, a total of 40 patients were analyzed. Twenty-seven patients (67.5%) were treated with CPAP based on confirmation of the volumetric or dosimetric benefit of CPAP. Mean lung volume increased by 37% (P < .001). The mean augmentation was 1283 ± 1128 cm (CPAP vs FB; P = .0006) in patients with normal lung function tests and 719 ± 341 cm (P = .003) in patients with a restrictive pattern. Increased lung volume was independent of age, body mass index, sex, chronic obstructive pulmonary disease, smoking status, and heart disease. Tumor motion in the lung was decreased as reflected in a mean reduction of planning target volume by 19% (P < .001). The greatest reduction of tumor trajectory and planning target volume occurred in tumors in the lower lung, particularly in the range of up to 6 cm above the dome of the diaphragm. The mean lung dose was reduced by 15%, lung V20 by 20%, lung V5 by 11%, and heart V5 by 16% (P < .01).
In this prospective trial, the use of CPAP was associated with significant volumetric and dosimetric benefits compared with FB. CPAP was safe, simple to implement, and well tolerated by most patients, and it should be studied further as a method to reduce the risk of lung and heart toxicity.
本研究旨在探讨持续气道正压通气（CPAP）对接受放射治疗的患者胸部解剖结构和肿瘤运动的影响。
将原发性或继发性肺肿瘤、左侧乳腺癌或肝转移患者纳入研究，使用面罩以 15 cm H2O 的最大压力接受 CPAP 设备呼吸训练。对每位患者进行 3 次和 4 次的计算机断层扫描模拟：一次是自由呼吸（FB），另一次是使用 CPAP。比较治疗计划的容积和剂量学参数。
共纳入 49 例患者，其中 6 例在模拟前撤回同意，3 例因不适而撤回。因此，共分析了 40 例患者。27 例（67.5%）患者接受 CPAP 治疗，因为确认了 CPAP 的容积或剂量学获益。肺容积平均增加 37%（P<.001）。在肺功能正常的患者中，平均增加量为 1283±1128cm（CPAP 与 FB 相比；P=.0006），在有受限模式的患者中增加 719±341cm（P=.003）。肺容积的增加与年龄、体重指数、性别、慢性阻塞性肺疾病、吸烟状况和心脏病无关。肺部肿瘤运动减少，表现为计划靶体积平均减少 19%（P<.001）。肿瘤轨迹和计划靶体积的最大减少发生在肺部下部的肿瘤中，尤其是在膈顶上方 6cm 范围内。平均肺剂量降低 15%，肺 V20 降低 20%，肺 V5 降低 11%，心脏 V5 降低 16%（P<.01）。
在这项前瞻性试验中，与 FB 相比，CPAP 的使用与显著的容积和剂量学获益相关。CPAP 安全、简单易行，大多数患者均能耐受，应进一步研究作为降低肺和心脏毒性风险的方法。
