Pancreatic cancer is the fourth leading cause of cancer-related death, with nearly 60,000 cases each year and less than a 10% 5-year overall survival rate. Radiation therapy (RT) is highly beneficial as a local-regional anticancer treatment. As anatomical variation is of great concern, motion management techniques, such as DIBH, are commonly used to minimize OARs toxicities; however, the variability between DIBHs has not been well studied. Here, we present an unprecedented systematic analysis of patients’ anatomical reproducibility over multiple DIBH motion-management technique uses for pancreatic cancer RT. We used data from 20 patients; four DIBH scans were available for each patient to design 80 SBRT plans. Our results demonstrated that (i) there is considerable variation in OAR geometry and dose between same-subject DIBH scans; (ii) the RT plan designed for one scan may not be directly applicable to another scan; (iii) the RT treatment designed using a DIBH simulation CT results in different dosimetry in the DIBH treatment delivery; and (iv) this confirms the importance of adaptive radiation therapy (ART), such as MR-Linacs, for pancreatic RT delivery. The ART treatment delivery technique can account for anatomical variation between referenced and scheduled plans, and thus avoid toxicities of OARs because of anatomical variations between DIBH patient setups.
胰腺癌是癌症相关死亡的第四大原因，每年新增近6万例病例，其5年总生存率不足10%。放射治疗（RT）作为一种局部区域抗癌治疗手段具有显著优势。鉴于解剖结构变异备受关注，临床上常采用深呼吸屏气（DIBH）等运动管理技术以最大限度减少危及器官（OARs）的毒性反应，然而不同DIBH操作间的变异性尚未得到充分研究。本文首次系统分析了胰腺癌放疗中多次应用DIBH运动管理技术时患者解剖结构的可重复性。我们采用20例患者的数据，每例患者均获得四次DIBH扫描影像，据此设计了80个立体定向放射治疗（SBRT）计划。研究结果表明：（1）同一受试者的不同DIBH扫描间，OARs的几何形态和受照剂量存在显著差异；（2）基于某次扫描设计的放疗计划可能无法直接适用于其他扫描；（3）采用DIBH模拟CT设计的放疗方案在实际DIBH治疗实施中会产生不同的剂量学结果；（4）这证实了自适应放射治疗（ART，如磁共振直线加速器）在胰腺癌放疗实施中的重要性。ART治疗实施技术能够兼顾参考计划与预定计划间的解剖结构变异，从而避免因DIBH患者摆位间的解剖差异导致的OARs毒性反应。
肿瘤(癌症)患者之家