The internal organ at risk volume (IRV) concept might improve toxicity profiles in stereotactic body radiation therapy (SBRT) for non-small cell lung cancer (NSCLC). We studied (1) clinical aspects in central vs. peripheral tumors, (2) the IRV concept in central tumors, (3) organ motion, and (4) associated normal tissue complication probabilities (NTCPs). We analyzed patients who received SBRT for NSCLC (clinical aspects,n= 78; motion management,n= 35). We found lower biologically effective doses, larger planning target volume sizes, higher lung doses, and worse locoregional control for central vs. peripheral tumors. Organ motion was greater in males and tall patients (bronchial tree), whereas volume changes were lower in patients with a high body mass index (BMI) (esophagus). Applying the IRV concept (retrospectively, without new optimization), we found an absolute increase of >10% in NTCPs for the bronchial tree in three patients. This study emphasizes the need to optimize methods to balance dose escalation with toxicities in central tumors. There is evidence that organ motion/volume changes could be more pronounced in males and tall patients, and less pronounced in patients with higher BMI. Since recent studies have made efforts to further subclassify central tumors to refine treatment, the IRV concept should be considered for optimal risk assessment.
危及器官体积（IRV）概念可能改善非小细胞肺癌（NSCLC）立体定向放射治疗（SBRT）的毒性特征。本研究探讨了（1）中央型与周围型肿瘤的临床特征差异，（2）中央型肿瘤的IRV概念应用，（3）器官运动特性，以及（4）相关正常组织并发症概率（NTCP）。我们分析了接受SBRT治疗的NSCLC患者（临床特征分析n=78；运动管理分析n=35）。研究发现，与周围型肿瘤相比，中央型肿瘤的生物有效剂量较低、计划靶区体积较大、肺受照剂量较高，且局部区域控制率较差。器官运动在男性和身高较高患者中更为显著（支气管树），而高体重指数（BMI）患者的器官体积变化较小（食管）。应用IRV概念（回顾性分析，未重新优化计划）发现三名患者的支气管树NTCP绝对值增加超过10%。本研究强调需要优化方法以平衡中央型肿瘤的剂量提升与毒性风险。有证据表明器官运动/体积变化在男性和身高较高患者中可能更显著，而在高BMI患者中则较不明显。鉴于近期研究致力于进一步细分中央型肿瘤以优化治疗，IRV概念应被纳入最佳风险评估体系。
肿瘤(癌症)患者之家