Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Korea.
Cancer Res Treat. 2019 Jan;51(1):12-23. doi: 10.4143/crt.2017.273. Epub 2018 Feb 5.
The purpose of this study was to investigate the effect of hospital case volume on clinical outcomes in patients with nasopharyngeal carcinoma (NPC).
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).
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).
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.
本研究旨在探讨鼻咽癌（NPC）患者的医院病例量对临床结局的影响。
从一个多机构回顾性数据库（KROG 11-06）中收集了 1073 例 cT1-4N0-3M0 NPC 患者的数据。所有患者均接受了根治性放疗（RT），其中 576 例接受了三维适形放疗（3D-CRT），497 例接受了调强放疗（IMRT）。将患者分为两组：在高病例量机构（HVI）治疗的患者（n=750）和在低病例量机构（LVI）治疗的患者（n=323），定义为每年接受治疗的患者人数≥10 例（中位数为 13 例；范围为 10 至 18 例）和＜10 例（中位数为 3 例；范围为 2 至 6 例）。终点为总生存（OS）和局部区域无进展生存（LRPFS）。
在中位随访 56.7 个月时，HVI 组的治疗结果明显优于 LVI 组。在经过倾向评分匹配的 614 例患者的队列中，HVI 组的 5 年 OS 和 LRPFS 均显著高于 LVI 组（OS：78.4% vs. 62.7%，p<0.001；LRPFS：86.2% vs. 65.8%，p<0.001）。根据 RT 方式，接受 3D-CRT 治疗的患者 5 年 OS 差异显著（HVI 组为 78.7%，LVI 组为 58.9%，p<0.001），而接受 IMRT 治疗的患者则无显著差异（HVI 组为 77.3%，LVI 组为 75.5%，p=0.170）。
HVI 和 LVI 与 NPC 患者的临床结局显著相关。然而，在调强放疗时代，由于通过教育实现了实践的标准化，结果的差异变得不显著。
