Failure patterns and individualized treatment plans of reirradiation for inoperable locally recurrent nasopharyngeal carcinoma

• Published in: Scientific reports Vol. 14; no. 1; pp. 17887 - 10
• Main Authors: Lin, Cheng, Lu, Qiongjiao, Chen, Yuebing, Chen, Xiaoqiang, Huang, Yiping, Zhong, Hangyan, Peng, Xiane, Hu, Cairong, Chen, Bijuan, Lin, Shaojun, Zong, Jingfeng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.08.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/67; 692/4028; Adult; Aged; Clinical target volume; Failure; Female; Humanities and Social Sciences; Humans; Intensity modulated radiation therapy; Irradiation; Male; Medical prognosis; Middle Aged; multidisciplinary; Multivariate analysis; Nasopharyngeal carcinoma; Nasopharyngeal Carcinoma - mortality; Nasopharyngeal Carcinoma - pathology; Nasopharyngeal Carcinoma - radiotherapy; Nasopharyngeal Neoplasms - mortality; Nasopharyngeal Neoplasms - pathology; Nasopharyngeal Neoplasms - radiotherapy; Neoplasm Recurrence, Local - radiotherapy; Patients; Precision Medicine - methods; Prognosis; Radiation; Radiation therapy; Radiotherapy Planning, Computer-Assisted - methods; Radiotherapy, Intensity-Modulated - adverse effects; Radiotherapy, Intensity-Modulated - methods; Re-Irradiation - methods; Recurrent nasopharyngeal carcinoma; Reirradiation; Retrospective Studies; Risk groups; Science; Science (multidisciplinary); Survival; Throat cancer; Toxicities; Toxicity; Treatment Failure; Young Adult; Reirradiation; Recurrent nasopharyngeal carcinoma; Toxicities; Intensity modulated radiation therapy; Clinical target volume
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-68676-1

Re-irradiation with intensity-modulated radiotherapy (IMRT) remains the primary treatment modality for inoperable locally recurrent nasopharyngeal carcinoma (NPC). However, the rate of radiation-related late adverse effects is often substantially high. Therefore, we aimed to explore failure patterns and individualized treatment plans of re-irradiation for inoperable locally recurrent NPC. Ninety-seven patients who underwent IMRT were retrospectively analyzed. Sixty-two patients had clinical target volume of recurrence (rCTV) delineated, and thirty-five patients had only gross tumor volume of recurrence (rGTV) delineated. Twenty-nine patients developed second local failures after re-irradiation with IMRT (28 cases available). Among those patients, 64.3% (18/28) of patients and 35.7% (10/28) developed in-field or out-field, respectively. No statistical correlation was observed between target volume (rGTV or rCTV) and the local recurrence rate, local failure patterns, grade ≥ 3 toxicity, and survival. Multivariate analysis showed that recurrent T (rT) stage (HR 2.62, P  = 0.019) and rGTV volume (HR 1.73, P  = 0.037) were independent prognostic factors for overall survival (OS). Risk stratification based on rT stage and rGTV volume revealed that low risk group had a longer 3-year OS rate (66.7% vs. 23.4%), lower total grade ≥ 3 toxicity ( P  = 0.004), and lower re-radiation associated mortality rates (HR 0.45, P  = 0.03) than high risk group. This study demonstrates that the delineation of rCTV may not be beneficial for re-irradiation using IMRT in locally recurrent NPC. Patients with low risk were most suitable for re-irradiation, with maximizing local salvage and minimizing radiation-related toxicities. More precise and individualized plans of re-irradiation are warranted.