西氏内科学精要：放射性肺炎

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Radiation pneumonitis usually develops within the first 3 months following irradiation, whereas radiation fibrosis typically presents much later (greater than 6 months). Symptoms are nonspecific and included dyspnea and a dry cough. Constitutional symptoms (fevers, malaise) may also be present. The physical exam typically reveals inspiratory crackles. Chest radiographs typically show hazy opacities in acute pneumonitis or reticulonodular opacities when fibrosis is present. HRCT imaging is generally done and provides more detailed information, demonstrating ground-glass opacities and areas of consolidation in radiation pneumonitis and reticular opacities, traction changes, and architectural distortion in the setting of radiation fibrosis. Although not always present, a “straight line effect”—the presence of radiographic or CT opacity that terminates abruptly, with a demarcation border that does not respect normal anatomic boundaries (Fig. 17.7)—is virtually pathognomonic for RILI.

放射性肺炎（RP）通常出现在放疗后前3个月，而放射性肺纤维化典型的出现时间则更晚（6个月以后）。

症状为非特异性，包括呼吸困难与干咳。也可出现全身性症状，包括发热与疲乏。

体征主要是吸气相湿罗音。

胸片急性肺炎表现为模糊影，纤维化时则为网结状影。

胸部CT可提供更多的细节，RP时表现为GGO与局部实变，纤维化时表现为网状影，牵拉性改变，结构扭曲等。

直线效应（straight line effect）并非总是出现，表现为不符合正常解剖结构的，突然出现的边界：

CT示纵隔放疗后肺纤维化。正常肺组织与纤维化区域有边缘锐利的边界（箭头），跨越叶间裂，表现为“直线效应”

There are reports of RILI occurring outside of the radiation field, but the mechanisms for more widespread lung injury after radiation are unknown. Bronchoscopy with BAL and/or lung biopsy can be helpful for ruling out infection or other processes (e.g., progression of cancer), but otherwise these modalities have little role in the diagnosis of RILI since the BAL fluid characteristics and histologic features are nonspecific.

有报道RILI（放射相关性肺损伤）可发生在放射野之外，但其机制不明。

气管镜BAL或肺活检有助于排除感染 or 其它疾病，如肺癌等，但这些检查对诊断意义不大，因BALF与组织病理表现为非特异性的。

Treatment of symptomatic, moderate-to-severe radiation pneumonitis typically consists of an extended course (4-6 weeks) of high-dose glucocorticoids, followed by gradual tapering. There can often be significant improvement in symptoms, lung function, and radiographic abnormalities in the subacute setting. However, those patients who develop radiation lung fibrosis generally do not improve, and corticosteroids (or other treatments) are generally ineffective.

对症治疗，中重度RP常用长疗程、高剂量的激素（4-6周），随后逐步减量。症状、肺功能与影像学异常可明显改善。但进展为肺纤维化的患者常无改善，激素（或其它治疗）通常无效。

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