放射性治疗前的极化 (3)氦肺功能磁共振成像。
Hyperpolarized (3)He pulmonary functional magnetic resonance imaging prior to radiation therapy.
机构信息
Department of Medical Biophysics, The University of Western Ontario, London, Ontario N6A 5K8, Canada.
出版信息
Med Phys. 2012 Jul;39(7):4284-90. doi: 10.1118/1.4729713.
PURPOSE
Radiation-induced lung injury (RILI) is the primary dose-limiting toxicity for radiation therapy of the lung, and although the effects of radiation dose on RILI development have been well characterized, the influence of chronic obstructive pulmonary disease (COPD) on the development of RILI and other outcomes is not well understood. The purpose of this small pilot study was to evaluate the relationship between hyperpolarized (3)He magnetic resonance imaging (MRI) measurements of COPD with RILI and 12-month survival in lung cancer patients undergoing radical radiotherapy and to evaluate the feasibility of pulmonary functional MRI as an image guidance∕planning tool for radiation therapy.
METHODS
Fifteen non-small cell and small cell lung cancer patients underwent pulmonary function tests, x-ray computed tomography (CT), and hyperpolarized (3)He MRI prior to radical radiation therapy (≥60 Gy). Conventional thoracic (1)H and hyperpolarized (3)He MRI were acquired to generate ventilation defect percent and the apparent diffusion coefficient for the ipsilateral and contralateral lungs independently. CT was acquired postradiation therapy and qualitatively evaluated for radiological evidence of RILI and 12-month survival was reported.
RESULTS
Hyperpolarized (3)He MRI measurements of COPD classified 10∕15 subjects with contralateral lung COPD (CLC), and five subjects without COPD [contralateral lung normal (CLN)]. Of the 10 subjects with CLC, only four had a previous clinical diagnosis of COPD. CT images were acquired postradiation therapy for 13 subjects, and for eight (62%) of these there was qualitative evidence of RILI, including 5∕9 CLC and 3∕4 CLN subjects. The one-year survival was 2∕10 for CLC and 3∕5 for CLN subjects.
CONCLUSIONS
In this small pilot study, we report the use of (3)He MRI to stratify lung cancer patients based on MRI evidence of COPD and showed that comorbid COPD was present in the majority of lung cancer subjects stratified for radiation therapy. Lung cancer patients with imaging evidence of COPD did not have an increased incidence of RILI compared to patients without COPD. However, preliminary data presented here indicated that one-year survival in COPD subjects was lower than expected based on previously published survival rates, which may have implications for radiation therapy in lung cancer patients with comorbid COPD.
目的
放射性肺损伤（RILI）是肺部放射治疗的主要剂量限制毒性，尽管放射剂量对 RILI 发展的影响已得到很好的描述，但慢性阻塞性肺疾病（COPD）对 RILI 发展和其他结果的影响尚不清楚。本小型试点研究的目的是评估肺癌患者根治性放疗中 COPD 的超极化（3）氦磁共振成像（MRI）测量与 RILI 以及 12 个月生存率之间的关系，并评估肺部功能 MRI 作为放射治疗图像引导/规划工具的可行性。
方法
15 例非小细胞和小细胞肺癌患者在根治性放疗（≥60Gy）前接受了肺功能测试、X 射线计算机断层扫描（CT）和超极化（3）氦 MRI。采集常规胸部（1）H 和超极化（3）He MRI，分别生成同侧和对侧肺的通气缺陷百分比和表观扩散系数。放疗后采集 CT 并进行定性评估，以评估 RILI 的放射学证据，并报告 12 个月生存率。
结果
超极化（3）He MRI 对 COPD 的测量将 15 例患者中的 10 例（CLC）同侧肺 COPD 与 5 例无 COPD（CLN）分类。在 10 例 CLC 患者中，只有 4 例有 COPD 的临床诊断。对 13 例患者进行了放疗后的 CT 图像采集，其中 8 例（62%）有 RILI 的定性证据，包括 5/9 例 CLC 和 3/4 例 CLN 患者。CLC 患者的一年生存率为 2/10，CLN 患者为 3/5。
结论
在这项小型试点研究中，我们报告了使用（3）He MRI 根据 MRI 证据对肺癌患者进行分层，并表明在接受放射治疗的患者中，大多数患者都有合并的 COPD。与无 COPD 的患者相比，有影像学证据的 COPD 肺癌患者 RILI 的发生率没有增加。然而，这里提出的初步数据表明，根据以前发表的生存率，COPD 患者的一年生存率低于预期，这可能对患有合并 COPD 的肺癌患者的放射治疗产生影响。
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