The Effect of Hospital Case Volume on Clinical Outcomes in Patients with Nasopharyngeal Carcinoma: A Multi-institutional Retrospective Analysis (KROG-1106) / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to investigate the effect of hospital case volume on clinical outcomes in patients with nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: Data on 1,073 patients with cT1-4N0-3M0 NPC were collected from a multi-institutional retrospective database (KROG 11-06). All patients received definitive radiotherapy (RT) either with three-dimensional-conformal RT (3D-CRT) (n=576) or intensity-modulated RT (IMRT) (n=497). The patients were divided into two groups treated at high volume institution (HVI) (n=750) and low volume institution (LVI) (n=323), defined as patient volume ≥ 10 (median, 13; range, 10 to 18) and < 10 patients per year (median, 3; range, 2 to 6), respectively. Endpoints were overall survival (OS) and loco-regional progression-free survival (LRPFS). RESULTS: At a median follow-up of 56.7 months, the outcomes were significantly better in those treated at HVI than at LVI. For the 614 patients of propensity score-matched cohort, 5-year OS and LRPFS were consistently higher in the HVI group than in the LVI group (OS: 78.4% vs. 62.7%, p < 0.001; LRPFS: 86.2% vs. 65.8%, p < 0.001, respectively). According to RT modality, significant difference in 5-year OS was observed in patients receiving 3D-CRT (78.7% for HVI vs. 58.9% for LVI, p < 0.001) and not in those receiving IMRT (77.3% for HVI vs. 75.5% for LVI, p=0.170). CONCLUSION: A significant relationship was observed between HVI and LVI for the clinical outcomes of patients with NPC. However, the difference in outcome becomes insignificant in the IMRT era, probably due to the standardization of practice by education.

Prognostic value of nodal SUVmax of 18F-FDG PET/CT in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

PURPOSE: To investigate the predictive role of maximum standardized uptake value (SUVmax) of 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in nasopharyngeal cancer patients treated with intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Between October 2006 and April 2016, 53 patients were treated with IMRT in two institutions and their PET/CT at the time of diagnosis was reviewed. The SUVmax of their nasopharyngeal lesions and metastatic lymph nodes (LN) was recorded. IMRT was delivered using helical tomotherapy. All patients except for one were treated with concurrent chemoradiation therapy (CCRT). Correlations between SUVmax and patients’ survival and recurrence were analyzed. RESULTS: At a median follow-up time of 31.5 months (range, 3.4 to 98.7 months), the 3-year overall survival (OS) and disease-free survival (DFS) rates were 83.2% and 77.5%, respectively. In univariate analysis, patients with a higher nodal pre-treatment SUVmax (≥ 13.4) demonstrated significantly lower 3-year OS (93.1% vs. 55.5%; p = 0.003), DFS (92.7% vs. 38.5%; p < 0.001), locoregional recurrence-free survival (100% vs. 50.5%; p < 0.001), and distant metastasis-free survival (100% vs. 69.2%; p = 0.004), respectively. In multivariate analysis, high pre-treatment nodal SUVmax (≥ 13.4) was a negative prognostic factor for OS (hazard ratio [HR], 7.799; 95% confidence interval [CI], 1.506–40.397; p = 0.014) and DFS (HR, 9.392; 95% CI, 1.989–44.339; p = 0.005). CONCLUSIONS: High pre-treatment nodal SUVmax was an independent prognosticator of survival and disease progression in nasopharyngeal carcinoma patients treated with IMRT in our cohort. Therefore, nodal SUVmax may provide important information for identifying patients who require more aggressive treatment.