Clinically determined type of ¹⁸F-fluoro-2-deoxyglucose uptake as an alternative prognostic marker in resectable pancreatic cancer

Purpose: To investigate the association between clinical PET (positron emission tomography) type and oncologic outcome in resectable pancreatic cancer. Methods: Between January 2008 and October 2012, patients who underwent potentially curative resection for resectable pancreatic ductal adenocarcinoma without neoadjuvant treatment were retrospectively investigated. Clinical PET type was defined as follows: pancreatic cancer with similar ¹⁸FDG uptake to renal calyx was determined as kidney-type (K-type), and relatively lower ¹⁸FDG uptake than that of renal calyx was regarded as Non-K type. Results: A total of 53 patients were enrolled. After agreement-based reclassification, agreement based K-type (aK-type) was noted in 34 patients (64.2%), and agreement based Non-K type (aNon K-type) was found in 19 patients (35.8%). There was a significant difference between aK-type and aNon K-type pancreatic cancer (tumor size (P = 0.030), adjusted CA 19-9 (P = 0.007), maximum standard uptake value (SUV_max,P<0.001), metabolic tumor volume (MTV_2.5, P<0.001), total lesion glycolysis (TLG, P<0.001)). K-type pancreatic cancer (n = 31) showed a significantly shorter disease-free time compared with Non-K type (n = 16) (10.8 vs. 24.1 months, P = 0.013). It was also noted that aK-type showed inferior diseasefree survival to that of aNon-K type pancreatic cancer (11.9 vs. 28.6 months, P = 0.012). Conclusions; Clinical PET type is a reliable clinical marker to estimate aggressive tumor biology and can be utilized in predicting tumor recurrence and necessity for postoperative chemotherapy.