Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, People's Republic of China.
Department of Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, People's Republic of China.
Eur J Cancer. 2023 Nov;194:113336. doi: 10.1016/j.ejca.2023.113336. Epub 2023 Sep 9.
Radiotherapy-related toxicities of nasopharyngeal carcinoma (NPC) caused by a standard dose of 70 Gy remain a critical issue. Therefore, we assessed whether a radiotherapy dose of 60 Gy was non-inferior to the standard dose in patients with low-risk stage III NPC with a favourable response to induction chemotherapy (IC).
We did a single-arm, single-centre, phase II clinical trial in China. Patients with low-risk (Epstein-Barr virus [EBV] DNA level <4000 copies/ml) stage III NPC were treated with two cycles IC. Patients with complete/partial response and undetectable EBV DNA level were assigned 60 Gy intensity-modulated radiotherapy concurrently with three cycles of cisplatin. The primary end-point was 2-year progression-free survival (PFS). This trial is registered with ClinicalTrials.gov, number NCT03668730.
One patient quit because of withdrawal of informed consent after IC. In total, 215 patients completed two cycles of IC, after which 116 (54.0%) and 99 (46.0%) patients were assigned 60 and 70 Gy radiotherapy, respectively. For 215 patients, the 2-year PFS was 90.7% (95% CI, 86.8%-94.6%) with a median follow-up of 43.9 months (interquartile range [IQR], 39.8-46.2). For patients treated with 60 Gy radiotherapy, the 2-year PFS rate was 94.8% (95%CI 90.7%-98.9%) with a median follow-up of 43.9 months (IQR 40.2-46.2). The most common late toxicity was grade 1-2 dry mouth (incidence rate: 54.3%). No grade 3+ long-term adverse event was observed, and most quality-of-life items, domains, and symptom scores returned to baseline by 6 months.
Reduced-dose radiation (60 Gy) is associated with favourable survival outcomes and limited treatment-related toxicities in patients with low-risk stage III NPC sensitive to IC.
标准剂量 70Gy 的鼻咽癌（NPC）放射治疗相关毒性仍然是一个关键问题。因此，我们评估了对于诱导化疗（IC）反应良好的低危 III 期 NPC 患者，60Gy 的放疗剂量是否不劣于标准剂量。
我们在中国进行了一项单臂、单中心、二期临床试验。低危（EBV DNA 水平 <4000 拷贝/ml）III 期 NPC 患者接受两个周期的 IC 治疗。完全/部分缓解且 EBV DNA 水平不可检测的患者接受 60Gy 强度调节放疗，并同时接受三个周期顺铂化疗。主要终点是 2 年无进展生存率（PFS）。该试验在 ClinicalTrials.gov 注册，编号为 NCT03668730。
一名患者在 IC 后因知情同意书撤回而退出。共有 215 名患者完成了两个周期的 IC，其中 116 名（54.0%）和 99 名（46.0%）患者分别接受了 60Gy 和 70Gy 放疗。对于 215 名患者，2 年 PFS 率为 90.7%（95%CI，86.8%-94.6%），中位随访时间为 43.9 个月（四分位距 [IQR]，39.8-46.2）。接受 60Gy 放疗的患者 2 年 PFS 率为 94.8%（95%CI，90.7%-98.9%），中位随访时间为 43.9 个月（IQR，40.2-46.2）。最常见的晚期毒性是 1-2 级口干（发生率：54.3%）。未观察到 3 级及以上的长期不良事件，大多数生活质量项目、领域和症状评分在 6 个月时恢复到基线。
对于对 IC 敏感的低危 III 期 NPC 患者，降低剂量的放疗（60Gy）与良好的生存结果和有限的治疗相关毒性相关。
