Background: Nasopharyngeal carcinoma (NPC) is a special subtype of head and neck cancer (HNC). At present, there are no highly specific prognostic markers to aid in tumor grading and guide patient treatment modalities for NPC. The prognostic value of pretreatment 18 F-fluorodeoxyglucose positron emission tomography-computed tomography ( 18 F-PET-CT) in NPC patients is controversial and no consensus exists as to its predictive capability.Methods: To analyze the predictive efficacy of 18 F-PET-CT imaging in NPC patients, data from MEDLINE, EMBASE, the Cochrane library, CBM, CNKI, and VIP (inception to July 2016) were accessed. Results from prospective and retrospective observational studies that used 18 F-FDG PET to predict disease prognosis in NPC patients were used for analysis. Two authors independently assessed study quality and extracted data. Event-free survival (EFS) was considered the primary endpoint and overall survival rate (OS) was considered the secondary endpoint.Results: Data from 14 studies and 1134 patients were included in our analysis. The hazard ratios (HRs) of maximum standardized uptake value of primary tumor (SUVmax-T), metabolic tumor volume of primary tumor (MTV-T), and total lesional glycolysis of primary tumor (TLG-T) for EFS were 1.31 (95% confidence interval [CI], 1.11-1.55, P = .001), 2.38 (95% CI 1.53-3.70, P < .001), and 1.65 (95% CI 0.76-3.59, P = .21), respectively. Among studies including TLG-T, those with a fixed SUV of 2.5 had an HR of 3.55 (95% CI, 1.42-8.84, P = .007). The HRs of SUVmax-T and MTV-T for OS were 2.19 (95% CI, 1.47-3.27, P < .001) and 2.69 (95% CI, 1.01-7.17, P = .05), respectively. Among studies including MTV-T, those with a fixed SUV of 2.5 had an HR of 4.07 (95% CI, 2.22-7.46, P < .001). Tests used for assessing predictive value of pretreatment SUVmax, MTV, and TLG of lymph nodes for EFS and OS showed that these parameters did not have significant predictive value (P>.05).
Conclusion:Our results suggested that SUVmax, MTV, and TLG (with a fixed SUV of 2.5) of primary tumors before treatment initiation may be independent prognostic factors for NPC patients; however, SUVmax, MTV, and TLG of metastatic lymph nodes are not.
Abbreviations:18 F-FDG PET = 18 F-fluorodeoxyglucose positron emission tomography, CI = confidence interval, CT = computed tomography, DFS = disease-free survival, DMFS = distant metastasis-free survival, EFS = event-free survival, HNC = head and neck cancer, HNSCC = head and neck squamous cell carcinoma, HR = hazard ratio, LN = lymph node, MTV = metabolic tumor volume, MTV-LN = metabolic-tumor-volume of lymph node, MTV-T = metabolic tumor volume of primary tumor, NPC = nasopharyngeal carcinoma, OS = overall survival, ROC = receiver operating characteristic curve, SUVmax = maximum standardized uptake value, SUVmax-LN = maximum standardized uptake value of LN, SUVmax-T = maximum standardized uptake value of primary tumor, TLG = total lesional glycolysis, TLG-LN = total lesional glycolysis of lymph node, TLG-T = total lesional glycolysis...