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Objective: This study inventively combines epidermal growth factor receptor (EGFR) expression of the primary lesion and standardized uptake value (SUV) of positron emission tomography and computed tomography (PET/CT) to predict the prognosis of nasopharyngeal carcinoma (NPC). This study aimed to evaluate the predictive efficacy of maximum standard uptake value (SUVmax) and EGFR for treatment failure in patients with NPC. Methods: This retrospective study reviewed the results of EGFR expression and pretreatment 18F-FDG PET/CT of 313 patients with NPC. Time-dependent receiver operator characteristics was used for analyzing results and selecting the optimal cutoff values. Cox regression was used to screen out multiple risk factors. Cumulative survival rate was calculated by Kaplan–Meier. Results: The selected cutoff value of SUVmax-T was 8.5. The patients were categorized into four groups according to EGFR expression and SUVmax-T. There were significant differences in the 3-year local recurrence-free survival (LRFS) (p = 0.0083), locoregional relapse-free survival (LRRFS) (p = 0.0077), distant metastasis-free survival (DMFS) (p = 0.013), and progression-free survival (PFS) (p = 0.0018) among the four groups. Patients in the EGFR-positive and SUVmax-T > 8.5 group had the worst survival, while patients in the EGFR-negative and SUVmax-T ≤ 8.5 group had the best prognosis. Subsequently, patients with only positive EGFR expression or high SUVmax-T were classified as the middle-risk group. There were also a significant difference in 3-year overall survival among the three risk groups (p = 0.034). SUVmax-T was associated with regional recurrence-free survival and LRRFS in multivariate analysis, whereas EGFR was an independent prognostic factor for LRRFS, DMFS, and PFS. Conclusion: The combination of SUVmax-T and EGFR expression can refine prognosis and indicate clinical therapy. [ABSTRACT FROM AUTHOR]

Purpose: To assess whether the high metabolic region of fluorine-18-fluorode-oxyglucose (18F-FDG) in the primary lesion is the crux for recurrence in patients with nasopharyngeal carcinoma (NPC), to assess the feasibility and rationale for use of biological target volume (BTV) based on 18F-FDG positron emission tomography/computed tomography (18F-FDG-PET/CT). Methods: The retrospective study included 33 patients with NPC who underwent 18F-FDG-PET/CT at the time of initial diagnosis as well as the time of diagnosis of local recurrence. Paired 18F-FDG-PET/CT images for primary and recurrent lesion were matched by deformation coregistration method to determine the cross-failure rate between two lesions. Results: The median volume of the Vpri (primary tumor volume using the SUV thresholds of 2.5), the Vhigh (the volume of high FDG uptake using the SUV50%max isocontour), and the Vrecur (the recurrent tumor volume using the SUV thresholds of 2.5) were 22.85, 5.57, and 9.98 cm3, respectively. The cross-failure rate of Vrecur∩high showed that 82.82% (27/33) of local recurrent lesions had < 50% overlap volume with the region of high FDG uptake. The cross-failure rate of Vrecur∩pri showed that 96.97% (32/33) of local recurrent lesions had > 20% overlap volume with the primary tumor lesions and the median cross rate was up to 71.74%. Conclusion: 18F-FDG-PET/CT may be a powerful tool for automatic target volume delineation, but it may not be the optimal imaging modality for dose escalation radiotherapy based on applicable isocontour. The combination of other functional imaging could delineate the BTV more accurately. [ABSTRACT FROM AUTHOR]

Objective: To identify the main risk factors for metachronous metastatic nasopharyngeal carcinoma (NPC) in different periods after radiotherapy and estimate the weight of various factors in the early or late metachronous metastasis (EMM/LMM) groups. Methods: This retrospective registry consists of 4434 patients with newly diagnosed NPC. Cox regression analysis was used to assess the independent significance of various risk factors. The Interactive Risk Attributable Program (IRAP) was used to calculate the attributable risks (ARs) for metastatic patients during different periods. Results: Among 514 metastatic patients, 346 (67.32%) patients diagnosed with metastasis within 2 years after treatment were classified into the EMM group, while other 168 patients were classified into the LMM group. The ARs of T-stage, N-stage, pre-Epstein-Barr virus (EBV) DNA, post-EBV DNA, age, sex, pre-neutrophil-to-lymphocyte ratio, pre-platelet-to-lymphocyte ratio, pre-hemoglobin (HB), and post-HB were 20.19, 67.25, 2.81, 14.28, 18.50, - 11.17%, 14.54, 9.60, 3.74% and - 9.79%, respectively, in the EMM group. In the LMM group, the corresponding ARs were 3.68, 49.11, - 18.04%, 2.19, 6.11, 0.36, 4.62, 19.77, 9.57 and 7.76%, respectively. After multivariable adjustment, the total AR for tumor-related factors was 78.19%, and that for patient-related factors was 26.07% in the EMM group. In the LMM group, the total AR of tumor-related factors was 43.85%, while the weights of patient-related factors was 39.97%. In addition, except for these identified tumor- and patient-related factors, other unevaluated factors played a more important role in patients with late metastasis, with the weight increasing by 15.77%, from 17.76% in the EMM group to 33.53% in the LMM group. Conclusion: Most metachronous metastatic NPC cases occurred in the first 2 years after treatment. Early metastasis was mainly affected by tumor-related factors, which accounted for a declining percentage in the LMM group. [ABSTRACT FROM AUTHOR]

Background: To rethink the clinical significance of standardized uptake values (SUVs) of nasopharyngeal carcinoma (NPC) on 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET). Methods: We retrospectively reviewed 369 NPC patients who underwent pretreatment 18F-FDG PET. The predictive value of the SUVmax of the primary tumor (SUVmax-t) and regional lymph nodes (SUVmax-n) was evaluated using probability density functions. Receiver operating characteristic curves were used to determine optimal cutoffs for the SUVmax-n/SUVmax-t ratio (NTR). Kaplan–Meier and Cox regression analyses were used to assess survival. Results: The optimal SUVmax-t and SUVmax-n cutoffs were 7.5 and 6.9, respectively. High SUVmax-t and SUVmax-n were related to local and regional recurrence, respectively. Patients with low SUVmax had better 3-year overall survival (OS). To avoid cross-sensitization of cutoff points, we stratified patients with high SUVmax into the low and high NTR groups. The 3-year distant metastasis-free survival (DMFS; 92.3 vs. 80.6%, P = 0.009), progression-free survival (PFS; 84.0 vs. 67.7%, P = 0.011), and OS (95.9 vs. 89.2%, P = 0.002) significantly differed between the high vs. low NTR groups for patients with high SUVmax. Multivariable analysis showed that NTR was an independent prognostic factor for DMFS (hazard ratio [HR]: 2.037, 95% CI: 1.039–3.992, P = 0.038), PFS (HR: 1.636, 95% CI: 1.021–2.621, P = 0.041), and OS (HR: 2.543, 95% CI: 1.214–5.325, P = 0.013). Conclusion: High SUVmax was associated with NPC recurrence. NTR is a potential prognosticator for DMFS, suggesting that heterogeneity in the pretreatment 18F-FDG uptake between the primary tumor and lymph nodes is associated with high invasion and metastatic potential. [ABSTRACT FROM AUTHOR]

Introduction: To identify the subset of patients with de novo nasopharyngeal carcinoma (NPC) for whom [18F] fluorodeoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT) should be recommended, and to determine whether PET/CT is a cost-effective decision for precise M staging in endemic areas.Materials and Methods: Retrospective analysis of data of 4469 patients diagnosed with de novo NPC between January 2014 and December 2019. The detection rate of distant metastasis was compared between different groups. Univariate and multiple logistic regression analysis was applied to identify the risk factors for distant metastasis. The cost-effectiveness of the diagnostic strategies was assessed.Results: The detection rate of distant metastasis in the whole cohort was 5.46%. In multivariate analysis, male sex, T3-4 stage, N2-3 stage, and high plasma Epstein-Barr virus (EBV) DNA (≥ 14,650 copies/mL) were risk factors for distant metastases. NPC patients with T3-4 stage combined with N2-3 stage, high EBV DNA combined with male sex, or N2-3 stage combined with high EBV DNA were defined as recommended group with relatively higher tendency for metastasis. Distant metastasis incidence in recommended group and unrecommended group were 10.25% and 1.75%, respectively (P < 0.001). In the recommended group, PET/CT significantly improved the detection rate of distant metastasis (13.25% vs 9.02%, P = 0.005). Cost-effectiveness analysis revealed that additional cost for every one percent increase in distant metastasis detection rate was $22,785.58 in the recommended group (< Willingness-to-pay (WTP) threshold of $32,700.00) and $310,912.90 in the unrecommended group.Conclusions: In patients with de novo NPC, the tendency for metastasis can be predicted based on clinical parameters. 18F-FDG PET/CT should be selectively recommended for the subset of patients with a relatively higher tendency for metastasis. [ABSTRACT FROM AUTHOR]