放射性诱发的癌症（RIC）是治疗过鼻咽癌（NPC）患者晚期并发症。目前暂无对不同放疗方式（调强放射治疗[IMRT]、三维适形放疗[3D-CRT]和传统二维放疗）后NPC患者RIC的解剖学位置指数、组织学类型指数和生存率进行比较的研究。 回顾了1986年1月至2017年12月在中山大学附属肿瘤医院接受治愈性放疗的38,565名NPC患者，其中满足研究标准的141名RIC患者被纳入研究。采用卡方检验或费舍尔检验比较分类变量。使用Kaplan-Meier曲线评估总体生存率。使用Cox比例风险模型研究RIC治疗的独立意义。 在IMRT、3D-CRT和传统的2D放疗中，下颌骨RIC的发生率在接受3D-CRT的患者中较高（0.07%），而在接受IMRT的患者中为0％。接受3D-CRT的患者下颌骨RIC比例较高（16.667%），而接受IMRT（0%）和传统2D放疗（3.529％）的患者较低。关于组织学类型，接受传统2D放疗的患者鳞状细胞癌（SCC）的发生率较高（0.266%），而接受3D-CRT的患者为0.175％。接受IMRT的患者中SCC的比例高于接受3D-CRT /传统2D放疗的患者（86.4% vs. 41.7% vs. 74.2%）；接受3D-CRT的患者肉瘤的发生率较高（0.175%），而接受IMRT的患者为0.025％。接受3D-CRT的患者中肉瘤的比例高于接受IMRT（6.818% vs. 41.667%）和传统2D放疗（17.647%）的患者。接受手术治疗RIC的患者的生存率较未接受手术治疗的患者高（64.49比12.42个月）。在单变量和多变量分析中，手术是总生存期的独立预后因素。 我们的研究结果对RIC的长期随访、多学科管理和治疗临床医生后NPC治疗RIC患者的患者咨询具有重要意义。

Radiation-induced cancer (RIC) is a late complication in patients who have been treated for nasopharyngeal carcinoma (NPC). The comparison of index anatomic location, index histological type, and survival of RIC in patients with NPC after different radiotherapy modalities (intensity-modulated radiotherapy [IMRT], 3-dimensional conformal radiotherapy [3D-CRT], and conventional 2D radiotherapy) is currently unavailable.A total of 38,565 patients with NPC who received curative-intent radiotherapy at Sun Yat-sen University Cancer Center between January 1986 and December 2017 were reviewed. A total of 141 patients who developed RIC and fulfilled the study criteria were included. Categorical variables were compared by the chi-square test or Fisher's exact test. Kaplan-Meier curves were used to evaluate overall survival. Cox proportional hazards models were used to examine the independent significance of RIC treatment.Among IMRT, 3D-CRT, and conventional 2D radiotherapy, the incidence of mandible RIC was higher in patients who received 3D-CRT (0.07%) than in those who received IMRT (0%). The proportion of mandible RICs was higher in patients who received 3D-CRT (16.667%) than in those who received IMRT (0%) and conventional 2D radiotherapy (3.529%). Regarding the histological type, the incidence of squamous cell carcinoma (SCC) was higher in patients who received conventional 2D radiotherapy (0.266%) than in those who received 3D-CRT (0.175%); patients who received IMRT had a higher proportion of SCC than those who received 3D-CRT/conventional 2D radiotherapy (86.4% vs. 41.7% vs. 74.2%); the incidence of sarcoma was higher in patients who received 3D-CRT (0.175%) than in those who received IMRT (0.025%); and the proportion of sarcoma was higher in patients who received 3D-CRT (41.667%) than in those who received IMRT (6.818%) and conventional 2D radiotherapy (17.647%). Patients who received surgery for RICs had better survival than those who received no surgery (64.49 vs. 12.42 months). In the univariate and multivariate analyses, surgery was an independent prognostic factor for overall survival.Our results have implications for long-term follow-up of RIC, multidisciplinary management, and patient counseling of RIC after nasopharyngeal carcinoma treatment by treating clinicians.