Lee Danny, Sohn Jason, Kirichenko Alexander
Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA.
Radiologic Sciences, Drexel University College of Medicine, Philadelphia, PA 19104, USA.
Cancers (Basel). 2022 Oct 27;14(21):5269. doi: 10.3390/cancers14215269.
The use of super-paramagnetic iron oxide nanoparticles (SPIONs) as an MRI contrast agent (SPION-CA) can safely label hepatic macrophages and be localized within hepatic parenchyma for T2*- and R2*-MRI of the liver. To date, no study has utilized the R2*-MRI with SPIONs for quantifying liver heterogeneity to characterize functional liver parenchyma (FLP) and hepatic tumors. This study investigates whether SPIONs enhance liver heterogeneity for an auto-contouring tool to identify the voxel-wise functional liver parenchyma volume (FLPV). This was the first study to directly evaluate the impact of SPIONs on the FLPV in R2*-MRI for 12 liver cancer patients. By using SPIONs, liver heterogeneity was improved across pre- and post-SPION MRI sessions. On average, 60% of the liver [range 40-78%] was identified as the FLPV in our auto-contouring tool with a pre-determined threshold of the mean R2* of the tumor and liver. This method performed well in 10 out of 12 liver cancer patients; the remaining 2 needed a longer echo time. These results demonstrate that our contouring tool with SPIONs can facilitate the heterogeneous R2* of the liver to automatically characterize FLP. This is a desirable technique for achieving more accurate FLPV contouring during liver radiation treatment planning.
使用超顺磁性氧化铁纳米颗粒（SPIONs）作为磁共振成像（MRI）造影剂（SPION-CA）可安全地标记肝巨噬细胞，并定位在肝实质内，用于肝脏的T2和R2 MRI检查。迄今为止，尚无研究利用基于SPIONs的R2* MRI来量化肝脏异质性，以表征功能性肝实质（FLP）和肝肿瘤。本研究调查SPIONs是否能增强肝脏异质性，从而为自动勾勒工具提供帮助，以识别体素级功能性肝实质体积（FLPV）。这是第一项直接评估SPIONs对12例肝癌患者R2* MRI中FLPV影响的研究。通过使用SPIONs，在注射SPION前后的MRI检查中，肝脏异质性均得到改善。在我们的自动勾勒工具中，以肿瘤和肝脏的平均R2的预定阈值为标准，平均60%的肝脏[范围为40 - 78%]被识别为FLPV。该方法在12例肝癌患者中的10例中表现良好；其余2例需要更长的回波时间。这些结果表明，我们基于SPIONs的勾勒工具能够促进肝脏异质性R2的分析，从而自动表征FLP。这是一种在肝脏放射治疗计划中实现更准确的FLPV勾勒的理想技术。
