Department of Surgical Oncology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Division of Nuclear Medicine, Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Dis Colon Rectum. 2018 Mar;61(3):320-327. doi: 10.1097/DCR.0000000000000959.
Neoadjuvant chemoradiotherapy followed by an optimal surgery is the standard treatment for patients with locally advanced rectal cancer. FDG-PET/CT is commonly used as the modality for assessing the effect of chemoradiotherapy.
The purpose of this study was to investigate whether PET/CT-based volumetry could contribute to the prediction of pathological complete response or prognosis after neoadjuvant chemoradiotherapy.
This was a retrospective cohort study.
This study was conducted at a single research center.
Ninety-one consecutive patients with locally advanced rectal cancer were enrolled between January 2005 and December 2015.
Patients underwent PET/CT before and after neoadjuvant chemoradiotherapy.
Maximum standardized uptake value and total lesion glycolysis on PET/CT before and after neoadjuvant chemoradiotherapy were calculated using isocontour methods. Correlations between these variables and clinicopathological factors and prognosis were assessed.
PET/CT-associated variables before chemoradiotherapy were not correlated with either clinicopathological factors or prognosis. Maximum standardized uptake value was associated with pathological complete response, but total lesion glycolysis was not. Maximum standardized uptake value correlated with ypT, whereas total lesion glycolysis correlated with both ypT and ypN. High total lesion glycolysis was associated with a considerably poorer prognosis; the 5-year recurrence rate was 65% and the 5-year mortality rate 42%, whereas in lesions with low total lesion glycolysis, these were 6% and 2%. On multivariate analysis, high total lesion glycolysis was an independent risk factor for recurrence (HR = 4.718; p = 0.04).
The gain in fluoro-2-deoxy-D-glucose uptake may differ between scanners, thus the general applicability of this threshold should be validated.
In patients with locally advanced rectal cancer, high total lesion glycolysis after neoadjuvant chemoradiotherapy is strongly associated with a worse prognosis. Total lesion glycolysis after chemoradiotherapy may be a promising preoperative predictor of recurrence and death. See Video Abstract at http://links.lww.com/DCR/A464.
新辅助放化疗后行最佳手术是局部进展期直肠癌患者的标准治疗方法。氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（FDG-PET/CT）常用于评估放化疗效果。
本研究旨在探讨基于 PET/CT 的容积测量是否有助于预测新辅助放化疗后的病理完全缓解或预后。
这是一项回顾性队列研究。
本研究在一家研究中心进行。
2005 年 1 月至 2015 年 12 月期间共纳入 91 例局部进展期直肠癌患者。
患者在新辅助放化疗前后进行 PET/CT 检查。
采用等轮廓法计算新辅助放化疗前后 PET/CT 的最大标准化摄取值和肿瘤总糖酵解值。评估这些变量与临床病理因素和预后的相关性。
放化疗前的 PET/CT 相关变量与临床病理因素或预后均无相关性。最大标准化摄取值与病理完全缓解相关，但肿瘤总糖酵解值与之无关。最大标准化摄取值与 ypT 相关，而肿瘤总糖酵解值与 ypT 和 ypN 均相关。高肿瘤总糖酵解值与预后显著较差相关；5 年复发率为 65%，死亡率为 42%，而肿瘤总糖酵解值较低的患者分别为 6%和 2%。多变量分析显示，高肿瘤总糖酵解值是复发的独立危险因素（HR=4.718，p=0.04）。
氟代脱氧葡萄糖摄取的增加可能因扫描仪而异，因此该阈值的普遍适用性尚需验证。
在局部进展期直肠癌患者中，新辅助放化疗后肿瘤总糖酵解值较高与预后较差密切相关。放化疗后肿瘤总糖酵解值可能是预测复发和死亡的有前途的术前指标。详见视频摘要，网址：http://links.lww.com/DCR/A464。
