一种新型直立式CT用于质子治疗的可靠性评估
Characterizing the Reliability of a Novel Upright CT for Proton Therapy
AI总结：
本研究评估了新型直立式CT在质子治疗剂量计算中的可靠性及简化模体配置用于快速QA的可行性，证实其具备优异稳定性和临床等效性，支持自适应质子治疗。
摘要：
目的：评估直立式CT用于质子剂量计算的可靠性，以及用于加速日常QA的简化模体配置的可行性。方法：在直立式CT上按照共识指南扫描校准模体，共进行14次扫描/7个月。通过标准差（SD）评估CT值重复性。推导阻止本领比（SPR）查找表。评估模体尺寸依赖性。对简化模体配置进行15次扫描/8个月。评估重复性。将CT值和SPR与共识配置进行比较。两种配置均在仰卧式CT上进行扫描以验证结果。在直立式和仰卧式CT上扫描人形模体。绘制靶区以模拟脊柱和前列腺肿瘤。使用笔形束扫描技术和鲁棒优化制定质子计划。通过对照比较评估剂量计算的等效性。结果：简化配置在1次扫描中测得所有CT值，而共识指南需5次。直立式CT表现出优异的纵向稳定性（会话间和会话内SD分别<4.9 HU和1.6 HU）。发现尺寸依赖性，CT值存在显著（p<.05）差异，传播至ΔSPR<5.3%。比较2种配置测得的直立式CT值发现显著（p<.05）差异（ΔSPR<2.6%）。仰卧式CT显示较小的ΔSPR（<0.7%）。两项剂量学比较显示局部差异（<处方剂量的8%），而在不同CT机器和模体配置的所有对照比较中，发现临床等效性，靶区覆盖差异<0.2%，且在3 mm/3%标准下伽马通过率=100%。结论：直立式CT证明了支持自适应质子治疗的可靠性。简化配置展示了快速QA的可行性。
英文摘要：
Purpose: To evaluate reliability of upright CT for proton dose calculation and feasibility of a simplified phantom configuration for accelerated routine QA. Methods: A calibration phantom was scanned on an upright CT following consensus guidelines for 14 sessions/7 months. CT number repeatability was assessed by standard deviation (SD). Stopping power ratio (SPR) look-up table was derived. Phantom size dependency was assessed. The simplified phantom configuration was scanned for 15 sessions/8 months. Repeatability was assessed. CT numbers and SPR were compared with consensus configuration. Both configurations were scanned on a recumbent CT to validate the findings. An anthropomorphic phantom was scanned on upright and recumbent CT. Targets were drawn mimicking spine and prostate tumor. Proton plans were developed using pencil beam scanning techniques and robust optimization. Equivalence of dose calculation were assessed via controlled comparisons. Results: Simplified configuration measured all CT numbers in 1 scan vs 5 for consensus guidelines. Upright CT demonstrated excellent longitudinal stability (inter- and intrasession SD <4.9 HU and 1.6 HU, respectively). Size dependency was identified with significant (p<.05) differences in CT numbers, propagated to $Δ$SPR <5.3%. Significant (p<.05) differences were found comparing upright CT numbers measured by 2 configurations ($Δ$SPR<2.6%). Recumbent CT showed smaller $Δ$SPR (<0.7%). Both dosimetric comparison showed local differences (<8% of prescription dose) while clinical equivalence was found with target coverage differences <0.2% and gamma pass rates=100% at 3 mm/3% for all controlled comparison of different CT machines and phantom configurations. Conclusions: The upright CT demonstrated reliability to support adaptive proton therapy. The simplified configuration shows feasibility for rapid QA.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
