Sato Kentaro, Morohashi Hajime, Tsushima Fumiyasu, Sakamoto Yoshiyuki, Miura Takuya, Fujita Hiromasa, Umemura Kotaro, Suzuki Takahiro, Tsuruta Satoru, Kura Ryoto, Ono Shuichi, Aoki Masahiko, Hakamada Kenichi
Department of Gastroenterological Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
Department of Radiation and Oncology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
Mol Clin Oncol. 2019 Jun;10(6):625-630. doi: 10.3892/mco.2019.1834. Epub 2019 Mar 28.
The aim of the present retrospective study was to investigate the predictability of dual-energy computed tomography (DECT) for pararectal lymph node (PRLN) metastasis and lateral pelvic lymph node (LPLN) metastasis in rectal cancer (RC). The present study involved 44 patients with RC who were examined by DECT and then underwent surgery between May 2015 and September 2017. LPLN dissection was performed in 24 patients. The normalized iodine concentration (nIC), the ratio of iodine concentration in the lymph node (LN) to that in the common iliac artery on DECT, of the largest PRLN and LPLN was calculated, and the association between LN metastasis and nIC was analyzed. The median nIC value for PRLNs was significantly lower in PRLN metastasis-positive cases compared with PRLN metastasis-negative cases in the arterial phase [0.18 vs. 0.25; P=0.01; cut-off, 0.24; area under the curve (AUC), 0.733] and portal phase (0.47 vs. 0.61; P=0.03; cut-off, 0.59; AUC, 0.701). A significant difference was not identified between the median maximum short axis diameter of PRLNs in PRLN metastasis-positive and metastasis-negative cases (7.6 vs. 6.4 mm; P=0.33). The nIC for LPLNs was not significantly different between LPLN metastasis-positive and metastasis-negative cases in the arterial phase (0.15 vs. 0.21; P=0.19); but was significantly lower in LPLN metastasis-positive cases compared with LPLN metastasis-negative cases in the portal phase (0.29 vs. 0.56; P=0.04; cut-off, 0.29; AUC, 0.877). The maximum short axis diameter of LPLNs was significantly larger in metastasis-positive cases compared with LPLN metastasis-negative cases (9.1 vs. 4.8 mm; P=0.03; cut-off, 7.0 mm; AUC, 0.912). In conclusion, the nIC was identified to be significantly lower in metastasis-positive cases, which may be useful for the prediction of PRLN and LPLN metastases. A combination of size-based diagnosis and DECT may increase the accuracy of preoperative diagnosis.
本回顾性研究的目的是探讨双能计算机断层扫描（DECT）对直肠癌（RC）中直肠旁淋巴结（PRLN）转移和盆腔外侧淋巴结（LPLN）转移的预测能力。本研究纳入了44例RC患者，这些患者于2015年5月至2017年9月期间接受了DECT检查，随后接受了手术。24例患者进行了LPLN清扫。计算最大PRLN和LPLN在DECT上的归一化碘浓度（nIC），即淋巴结（LN）中的碘浓度与髂总动脉中碘浓度的比值，并分析LN转移与nIC之间的关联。在动脉期，PRLN转移阳性病例中PRLN的nIC中位数显著低于PRLN转移阴性病例[0.18对0.25；P = 0.01；截断值，0.24；曲线下面积（AUC），0.733]，在门静脉期也是如此（0.47对0.61；P = 0.03；截断值，0.59；AUC，0.701）。PRLN转移阳性和转移阴性病例中PRLN的最大短轴直径中位数之间未发现显著差异（7.6对6.4 mm；P = 0.33）。在动脉期，LPLN转移阳性和转移阴性病例中LPLN的nIC无显著差异（0.15对0.21；P = 0.19）；但在门静脉期，LPLN转移阳性病例中LPLN的nIC显著低于LPLN转移阴性病例（0.29对0.56；P = 0.04；截断值，0.29；AUC，0.877）。LPLN转移阳性病例中LPLN的最大短轴直径显著大于LPLN转移阴性病例（9.1对4.8 mm；P = 0.03；截断值，7.0 mm；AUC，0.912）。总之，转移阳性病例中的nIC显著较低，这可能有助于预测PRLN和LPLN转移。基于大小的诊断与DECT相结合可能会提高术前诊断的准确性。
