Comparative analysis of FDG PET SUVmax cutoff values in detection of mediastinal lymph node metastasis and hilar/intralobar lymph node metastasis in patients with non-small cell lung cancer / 中华核医学与分子影像杂志

ABSTRACT

Objective To study the FDG SUVmax cutoff values in detection of metastases in mediastinal lymph nodes (MLN) and hilar/intralobar lymph nodes (HILN) in pre-operative patients with N0-2 stage NSCLC.Methods A total of 69 patients with stage N0-2 NSCLC (40 males,29 females,age 36-87 years) were included in this retrospective study.18F-FDG PET/CT was performed and followed by lung cancer resection with lymph node dissection in 1 month.The excised lymph nodes were compared one by one between their SUVmax and histopathology.The SUVmax cutoff value in detection of lymph node metastases was determined by the ROC curve.Mann-Whitney u test,x2 test,and Fisher exact test were used for data analysis.Results Metastatic MLN and (or) HILN were found in 21 of 69 NSCLC patients.The histopathologic results demonstrated metastases in 61 of 339 lymph nodes.The SUVmax of metastatic lymph nodes (4.95(3.46,7.19)) was significantly higher than that of benign lymph nodes (2.10(1.59,3.22);z=-7.576,P＜0.05).The SUVmax of metastatic HILN (6.32 (4.28,8.27)) was significantly higher than that of metastatic MLN (3.90(2.12,6.41);z=-2.921,P＜0.05).With cutoff of SUVmax ≥2.5,the sensitivity,specificity and accuracy in detection of all metastatic lymph nodes were 83.6％ (51/61),61.9％ (172/278)and 65.8％ (223/339) respectively,and the parameters were 74.2％ (23/31),79.6％ (160/201) and 78.9％ (183/232) for metastatic MLN,and 93.3％ (28/30),15.6％ (12/77) and 37.4％ (40/107) for metastatic HILN.The diagnostic sensitivities for metastatic MLN and for metastatic HILN were not significantly different (Fisher exact test,P＞0.05),while the specificities and accuracies between the two groups were significantly different (x2 values96.7 and 56.1,both P＜0.05).According to ROC curves,cutoff values of SUVmax in detecting metastatic MLN and metastatic HILN were 2.78 and 4.93.With the specific cutoff value,the sensitivity,specificity and accuracy in detection of metastatic MLN were 71.0％ (22/31),87.1％ (175/201)and 84.9％(197/232),respectively.The corresponding data in detection of metastatic HILN were 73.3％ (22/30),77.9％(60/77) and 76.6％(82/107).Conclusion Different cutoff values of SUVmax in detecting metastatic MLN and metastatic HILN should be considered for more accurate lymph nodes staging in patients with NSCLC.