Introduction FDG-PET/CT is a diagnostic method based on the FDG uptake reflecting the active glucose metabolism and plays an important role in cancer diagnosis. There are several metabolic parameters utilised in quantifying glucose metabolism. Of these, SUV max, metabolic tumour volume (MTV) and total legion glycolysis (TLG) are the most well known parameters. The aim of this study is to evaluate the association between tumour staging and metabolic parameters in FDG-PET/CT, such as SUV max, MTV, TLG.

Method Between August 2012 and March 2014, 143 patients were retrospectively included. Our inclusion criteria was as below 1)patients who underwent FDG-PET/CT, followed by resection of colorectal cancer, 2)FDG uptake was detectable in primary tumour. Three metabolic parameters in FDG-PET/CT were measured. The individual metabolic parameters were obtained with SUV threshold of 2.5. The association between these parameters and TNM stage were compared by analysing with Mann-Whitney U test or Spearman’s rank correlation coefficient test.

Results The average of SUV max, MTV, TLG was 12.8 ± 6.54 SUV, 31.4 ± 31.6ml, and 186.8 ± 220.2SUV・ml respectively. Spearman’s correlation test showed that all three parameters were positively associated with the increased number of T stage (SUV max: rs = 0.256 p = 0.002, MTV: rs = 0.498 p＜0.005, TLG: rs = 0.480 p＜0.005). And Spearman’s correlation test showed that N stage had significant positive associations with MTV and TLG (MTV: rs = 0.211 p = 0.012, TLG: rs = 0.211 p = 0.012). At M stage, there were no significant differences in any parameters with Mann-Whitney U test (SUV max: p = 0.534, MTV: p = 0.063, TLG: p = 0.070).

Conclusion Not only SUV max, MTV and TLG also have a strongly positive association with TNM stage. Using these parameters, more accurate preoperative diagnosis of colorectal cancer can be realised.

Disclosure of interest None Declared.