Abstract: Objective:To investigate the clinical value of Fluorine¹⁸F-luorodeoxyglucose ( ¹⁸F-FDG) PET/CT examination to predict the prognosis of patients with pancreatic cancer.
Methods:The retrospective crosssectional study was conducted. The clinicopathologic data of 104 patients with pancreatic cancer who were admitted to the First Affiliated Hospital of Nanjing Medical University between February 2009 and November 2015 were collected. All the patients underwent preoperative ¹⁸F-FDG PET/CT examination. The maximum standardized uptake value (SUVmax), metabolism of volume (MTV) and total lesion of glycolysis (TLG) in primary lesion were calculated. According to the patient′s condition, chemotherapy, operation and comprehensive therapy were performed. Observation indicators included: (1) results of imaging examination before treatment; (2) treatment and followup; (3) analysis of prognosis factors of patients with pancreatic cancer. Followup using outpatient examination and telephone interview was performed to detect survival of patients up to June 2016. Measurement data with skewed distribution were represented as median (range). The survival curve was drawn by the KaplanMeier method and the Logrank test was used for survival analysis. The univariate analysis and multivariate analysis were respectively done by the Logrank test and COX proportional hazards model.
Results:(1) Results of imaging examination before treatment: the ¹⁸F-FDG PET/CT imaging of 104 patients with pancreatic cancer showed the slightly hypodense shadow with inordinately uptake of ¹⁸F-FDG, with an unclear boundary. The contrastenhanced CT showed slight enhancement and hypodense, and partial lesions surrounding adjacent vessels can merge with peripheral enlarged lymph nodes. There were high ¹⁸F-FDG uptakes of lymph node metastases, hepatic metastases, adrenal metastases and bone metastases. Of 75 lesions of pulmonary metastases, 23 showed high ¹⁸F-FDG uptakes and 52 showed no high ¹⁸F-FDG uptakes. The SUVmax, MTV and TLG in primary lesion of 104 patients were 7.41 (range, 2.00-31.65), 14.86 cm3 (range, 2.17-79.65 cm3) and 66.34 (range, 5.31-598.22), respectively. (2) Treatment and followup: of 104 patients, 12 underwent single operation, 13 underwent operation+chemotherapy, 53 underwent single chemotherapy and 26 underwent chemoradiotherapy. All the 104 patients were followed up for 7.0-88.0 months, with a median time of 26.0 months. The median survival time, 6months and 1year survival rates of 104 patients with pancreatic cancer were respectively 7.1 months (range, 1.0-42.7 months), 52% and 26%. Results of further analysis showed that the median survival time, 6months and 1 year survival rates were respectively 6.5 months (range, 1.4-39.6 months), 49%, 27% in 51 patients with carcinoma of head of pancreas and 7.2 months (range, 1.0-42.7 months), 54%, 30% in 53 patients with carcinoma of pancreatic body and tail. (3) Prognosis factors of patients with pancreatic cancer: results of univariate analysis showed that sex, CA199, maximum diameter of tumor, lymph node metastases, hepatic metastases, distant metastases, clinical staging, surgery, chemotherapy, comprehensive treatment, SUVmax, MTV and TLG were related factors affecting prognosis of patients with pancreatic cancer ［HR=1.603, 1.657, 2.017, 1.873, 2.668, 1.822, 2.157, 2.054, 2.154, 3.208, 1.596, 2.096, 3.411,95% confidence interval (CI): 1.029-2.499, 1.045-2.626, 1.305-3.115, 1.181-2.971, 1.735-4.101, 1.453-2.285, 1.257-3.703, 1.245-3.387, 1.399-3.317, 2.047-5.028, 1.052-2.421, 1.372-3.201, 2.181-5.335, P<0.05］. Results of multivariate analysis showed that distant metastases, chemotherapy, comprehensive treatment and TLG≥66.34 were independent risk factors affecting poor prognosis of patients with pancreatic cancer (HR=1.906, 2.966, 2.946, 2.053, 95%CI: 1.201-3.022, 1.775-4.956, 1.753-4.951, 1.104-3.820, P<0.05). (4) Prognostic factors of patients with carcinoma of head of pancreas: results of univariate analysis showed that maximum diameter of tumor, tumor invading major vessels, hepatic metastases, distant metastases, clinical staging, surgery, chemotherapy, comprehensive treatment, SUVmax, MTV and TLG were related factors affecting prognosis of patients with carcinoma of head of pancreas (HR=2.282, 2.320, 4.125, 5.753, 6.155, 2.841, 4.144, 3.131, 2.229, 2.064, 5.380, 95% CI: 1.231-4.230, 1.098-4.903, 1.993-8.539, 2.682-12.341, 1.850-20.483, 1.362-5.926, 2.106-8.154, 1.545-6.345, 1.202-4.132, 1.121-3.803, 2.630-11.004, P<0.05). Results of multivariate analysis showed that chemotherapy and TLG≥66.66 were independent risk factors affecting poor prognosis of patients with carcinoma of head of pancreas (HR=7.953, 2.824, 95%CI: 3.110-20.338, 1.005-7.932, P<0.05). (5) Prognostic factors of patients with carcinoma of pancreatic body and tail: results of univariate analysis showed that hepatic metastases, distant metastases, surgery, comprehensive treatment, MTV and TLG were related factors affecting prognosis of patients with carcinoma of pancreatic body and tail (HR=2.083, 2.501, 3.464, 2.295, 2.231, 3.572, 95%CI: 1.157-3.784, 1.363-4.590, 1.441-8.329, 1.158-4.546, 1.166-4.268, 1.901-6.711, P<0.05）. Results of multivariate analysis showed that distant metastases, MTV≥15.70 cm3 and TLG≥62.75 were independent risk factors affecting poor prognosis of patients with carcinoma of pancreatic body and tail (HR=1.700, 2.096, 4.047, 95%CI: 1.080-2.675, 1.065-4.126, 2.072-7.906, P<0.05).
Conclusion:TLG≥66.34, ≥66.66, ≥62.75 in ¹⁸F-FDG PET/CT examination are independent risk factors affecting poor prognosis of patients with pancreatic cancer or pancreatic head cancer or pancreatic body and tail cancer respectively, and MTV≥15.70 cm3 is also an independent risk factor affecting poor prognosis of patient with pancreatic body and tail cancer. ¹⁸F-FDG PET/CT examination has certainly reference value for prognosis of patients with pancreatic cancer.