ORIGINAL ARTICLE Prognostic value of 18 F-FDG uptake by regional lymph nodes on pretreatment PET/CT in patients with resectable colorectal cancer Byung Hyun Byun & Sun Mi Moon & Ui Sup Shin & Ilhan Lim & Byung Il Kim & Chang Woon Choi & Sang Moo Lim Received: 13 April 2014 /Accepted: 16 June 2014 /Published online: 3 July 2014 # Springer-Verlag Berlin Heidelberg 2014 Abstract Purpose We evaluated the ability of pretreatment 18 F-FDG uptake by regional lymph nodes to predict the survival of patients with resectable colorectal cancer. Methods The records of 78 patients with AJCC stage III colorectal cancer (pathologically confirmed node-positive dis- ease without evidence of distant metastasis) treated with sur- gery and adjuvant chemotherapy were retrospectively reviewed. The maximum standardized uptake values of the primary tumor (SUVp) and regional lymph nodes (SUVn) were measured by pretreatment 18 F-FDG PET/CT. The ROC curve analyses and the Cox proportional hazard model were used to analyze whether SUVp, SUVn, and clinicopath- ologic parameters could predict disease-free survival. Results Although there were no significant differences be- tween the median SUVp in the event group and that in the non-event group, the median SUVn was significantly higher in the event group (1.7) than in the non-event group (0.8, p = 0.023). Based on the ROC curve analysis, SUVn predicted the event for disease-free survival (AUC=0.668, p =0.02) with the optimal criterion, sensitivity, specificity, and accuracy of> 1.2, 71 %, 63 %, and 65 %, respectively. However, SUVp did not predict disease-free survival (AUC=0.570, p =0.349). Univariate analysis revealed that SUVn (p =0.011) and venous invasion (p =0.016) were associated with disease-free surviv- al, but pathologic N stage was not (p =0.09). By multivariate analysis, only SUVn>1.2 independently shortened the disease-free survival (relative risk, 2.97; 95 % CI, 1.14–7.74, p =0.026). Conclusion SUVn before surgery may be a useful prognostic marker in patients with AJCC stage III colorectal cancer. Keywords FDG PET/CT . Lymph node . SUV . Colorectal cancer . Survival Introduction Colorectal cancer is the third most common type of cancer in the United States, accounting for about 9 % of new cancer cases and 9 % of all cancer deaths [1]. The American Joint Committee on Cancer (AJCC) tumor node metastasis (TNM) system is currently regarded as the strongest predictor of survival in colorectal cancer [2], and the indication for adju- vant chemotherapy is mainly guided by the presence of re- gional lymph node (LN) metastasis, which is associated with a poor prognosis [3]. Hence, accurate LN staging is needed for risk-adapted therapy in colorectal cancer. Although the abso- lute number of metastatic LNs determines the AJCC N stage and has repeatedly been validated as an important predictor of survival in colorectal cancer [2, 4], the differentiation of metastatic LN from tumor deposits in mesorectal/pericolic fat is difficult [5]. Moreover, the recommended minimum number of retrieved LNs (at least 12 LNs) to prevent false- negative reporting of LN metastasis is often not achieved [6]. 18 F-fluorodeoxyglucose positron emission tomography/ computed tomography (FDG PET/CT) has been widely used for staging [7, 8], restaging [9], and therapy response Electronic supplementary material The online version of this article (doi:10.1007/s00259-014-2840-5) contains supplementary material, which is available to authorized users. B. H. Byun : I. Lim : B. I. Kim : C. W. Choi : S. M. Lim (*) Department of Nuclear Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowongil, Nowon Gu, Seoul 139-706, South Korea e-mail: smlim328@kcch.re.kr S. M. Moon : U. S. Shin Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul, Republic of Korea Eur J Nucl Med Mol Imaging (2014) 41:2203–2211 DOI 10.1007/s00259-014-2840-5