2929 - The 5-Year Follow-Up Results of the Efficacy and Safety of Pulse Low-Dose-Rate Radiotherapy (PLDR) Re-Irradiation in Recurrent Nasopharyngeal Carcinoma Patients, A Prospective, Open-Label,Multicenter, Phase II Clinical Trial
Presenter(s)
R. Huang1, Z. Li2, F. Yang3, Y. Zhang4, and P. Zhang5; 1Sichuan Clinical ResearchCenter for Cancer, Sichuan Cancer Hospital & Institute, SichuanCancerCenter, University ofElectronic Science and Technology of China, Chengdu, China, 2department of Radiation Oncology, chengdu general hospital of western theater, Chengdu Sichuan, chengdu, China, 3Xinqiao Hospital,Army Medical University,Chongqin, chongqin, China, 4Departmant of Oncology, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China, 5Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, Affiliated Cancer Hospital of University of Electronic Science and Technology of China, Chengdu, China
Purpose/Objective(s):
Recurrence is the major failure pattern among patients with nasopharyngeal carcinoma who have undergone radical treatment. When reirradiation of the recurrent lesion is required, exploring a new approach is key to improving survival benefits while enhancing efficacy and reducing severe adverse reactions.Materials/Methods:
From March 2018 to December 2023, a prospective multicenter clinical trial (ChiCTR-OIC-17013579) initiated by Zhang Peng's team evaluated the efficacy and adverse effects of pulse low-dose-rate intensity-modulated radiotherapy (PLDR-IMRT) based on IMRT for local reirradiation in patients with recurrent nasopharyngeal carcinoma.Results:
The study enrolled 52 patients across five tumor centers, all of whom received PLDR-IMRT in combination with systemic therapy. The median dose administered was 60Gy(50.4-70 Gy/28-35 f). A retrospective analysis was conducted on follow-up data spanning from March 2018 to December 2025, encompassing 14 patients who received treatment subsequent to January 2020 (during the 2019 - nCoV epidemic control period), revealing an overall objective response rate (ORR) of 91.6%. The entire cohort demonstrated a median overall survival (OS) of 28 months and a median progression - free survival (PFS) of 27 months. The locoregional relapse - free survival (LRFS) was 28 months, while the distant metastasis - free survival (DMFS) was 27 months.In the non-COVID - 19 control cohort, the median OS was 38 months, with corresponding medians of 37 months for PFS, 37 months for LRFS, and 38 months for DMFS. Conversely, patients treated during the COVID - 19 control period exhibited median OS of 17.5 months, median PFS of 14.5 months, median LRFS of17.5 months, and median DMFS of 14.5 months.Statistical analysis of survival outcomes demonstrated significant differences in median PFS (p = 0.013) and median DMFS (p = 0.009) when comparing the periods before and after January 2020 (pre- and post-COVID - 19 control implementation). The incidence of PLDR acute serious adverse events (SAE) (grade 3+) was 11.5%, while the incidence of chronic SAEs was approximately 15.6%.Conclusion:
The combination of PLDR-IMRT and systemic therapy is a safe and effective re-irradiation regimen for treating locally recurrent nasopharyngeal carcinoma