Stanford University Medical Center, 300 Pasteur Drive, R354, Stanford, CA, 94305, USA.
Department of Radiation Oncology, Stanford University Medical Center, 875 Blake Wilbur Drive, Stanford, CA, 94305-5152, USA.
Abdom Radiol (NY). 2017 Apr;42(4):1132-1140. doi: 10.1007/s00261-016-0983-5.
To evaluate the capacity of perfusion CT imaging to distinguish between complete and incomplete responders after neoadjuvant chemoradiation therapy for rectal carcinoma, with particular attention to segmentation technique.
17 patients were evaluated in this prospective IRB-approved study. For each patient, a perfusion CT acquisition was obtained prior to the initiation of chemoradiation, at 1-2 weeks after the start of chemoradiation, and at 12 weeks after the start of chemoradiation therapy. From each dataset, three perfusion parameters were measured, each in two different ways: a region of interest incorporating only "hot spots" of greatest enhancement and whole-tumor measurements.
In univariate analysis, blood volume and permeability differed significantly between responders and non-responders. In logistic regression analysis evaluating predictors of the "complete response" outcome, only two predictors were retained as statistically significant: peak hot spot blood volume 1-2 weeks into therapy (OR 10.25, p = 0.0026) and hot spot permeability decline at 12 weeks after the initiation of therapy (OR 5.62, p = 0.03). The overall likelihood ratio test for this model supported the conclusion that hot spot blood volume and hot spot permeability decline were significant predictors of the complete pathologic response outcome (p < 0.0001).
In this pilot study, peak tumor blood volume and decline in tumor permeability, when measured in "hot spots" of greatest enhancement, were strong predictors of complete therapeutic response in rectal cancer after neoadjuvant therapy.
评估灌注 CT 成像在新辅助放化疗治疗直肠癌后区分完全和不完全缓解者的能力，特别关注分割技术。
本前瞻性 IRB 批准的研究共评估了 17 例患者。对于每位患者，在开始放化疗前、放化疗开始后 1-2 周和放化疗开始后 12 周进行灌注 CT 采集。从每个数据集测量三个灌注参数，每个参数用两种不同的方法测量：仅包含最大强化“热点”的感兴趣区和全肿瘤测量。
在单变量分析中， responders 和 non-responders 之间的血容量和通透性有显著差异。在逻辑回归分析中，评价“完全缓解”结果的预测因子，只有两个预测因子具有统计学意义：治疗 1-2 周时的峰值热点血容量（OR 10.25，p = 0.0026）和治疗开始后 12 周时的热点通透性下降（OR 5.62，p = 0.03）。该模型的整体似然比检验支持热点血容量和热点通透性下降是新辅助治疗后直肠癌完全病理缓解的重要预测因子的结论（p < 0.0001）。
在这项初步研究中，当在最大强化的“热点”中测量时，肿瘤血容量峰值和肿瘤通透性下降是新辅助治疗后直肠癌完全治疗反应的强有力预测因子。
