1. 1. Chen YP, Chan ATC, Le QT, et al. (2019) Nasopharyngeal carcinoma. Lancet, 394(10192): 64-80. [DOI:10.1016/S0140-6736(19)30956-0]

2. Tang LL, Chen YP, Chen CB, et al. (2021) The Chinese Society of Clinical Oncology (CSCO) clinical guidelines for the diagnosis and treatment of nasopharyngeal carcinoma. Cancer Commun (Lond), 41(11): 1195-227. [DOI:10.1002/cac2.12218]

3. Sun XS, Li XY, Chen QY, Tang LQ, Mai HQ (2019) Future of radiotherapy in nasopharyngeal carcinoma. Br J Radiol, 92(1102): 20190209. [DOI:10.1259/bjr.20190209]

4. Kong L, Wang L, Shen C, et al. (2016) Salvage intensity-modulated radiation therapy (IMRT) for locally recurrent nasopharyngeal cancer after definitive IMRT: A novel scenario of the modern era. Sci Rep, 6: 32883. [DOI:10.1038/srep32883]

5. Dawson LA, Anzai Y, Marsh L, et al. (2000) Patterns of local-regional recurrence following parotid-sparing conformal and segmental intensity-modulated radiotherapy for head and neck cancer. Int J Radiat Oncol Biol Phys, 46(5): 1117-26. [DOI:10.1016/S0360-3016(99)00550-7]

6. Zhang X, Luo J, Gao L, Xu G (2011) Mastoid recurrence after radiotherapy for nasopharyngeal carcinoma: two case studies. Head Neck, 33(10): 1535-8. [DOI:10.1002/hed.21391]

7. Autorino R, Miccichè F, Dinapoli N, et al. (2012) Recurrence in region of spared parotid gland in patient receiving definitive intensity-modulated radiotherapy for nasopharyngeal cancer: a case report. Acta Oncol, 51(8): 1095-9. [DOI:10.3109/0284186X.2012.673735]

8. Cao CN, Luo JW, Gao L, et al. (2013) Clinical characteristics and patterns of failure in the parotid region after intensity-modulated radiotherapy for nasopharyngeal carcinoma. Oral Oncol, 49(6): 611-4. [DOI:10.1016/j.oraloncology.2013.02.001]

9. Chow JCH, Tam AHP, Cheung KM, et al. (2020) Second primary cancer after intensity-modulated radiotherapy for nasopharyngeal carcinoma: A territory-wide study by HKNPCSG. Oral Oncology, 111: 105012. [DOI:10.1016/j.oraloncology.2020.105012]

10. Zhang LL, Li GH, Li YY, et al. (2019) Risk assessment of secondary primary malignancies in nasopharyngeal carcinoma: a big-data intelligence platform-based analysis of 6,377 long-term survivors from an endemic area treated with intensity-modulated radiation therapy during 2003-2013. Cancer Res Treat, 51(3): 982-91. [DOI:10.4143/crt.2018.298]

11. Ng WT, Lee MC, Chang AT, et al. (2014) The impact of dosimetric inadequacy on treatment outcome of nasopharyngeal carcinoma with IMRT. Oral Oncol, 50(5): 506-12. [DOI:10.1016/j.oraloncology.2014.01.017]

12. Ng WT, Lee MC, Hung WM, et al. (2011) Clinical outcomes and patterns of failure after intensity-modulated radiotherapy for nasopharyngeal carcinoma. Int J Radiat Oncol Biol Phys, 79(2): 420-8. [DOI:10.1016/j.ijrobp.2009.11.024]

13. Lee AW, Ng WT, Pan JJ, et al. (2018) International guideline for the delineation of the clinical target volumes (CTV) for nasopharyngeal carcinoma. Radiother Oncol, 126(1): 25-36. [DOI:10.1016/j.radonc.2017.10.032]

14. Ng WT, Chow JCH, Beitler JJ, et al. (2022) Current radiotherapy considerations for nasopharyngeal carcinoma. Cancers (Basel), 14(23): 5773. [DOI:10.3390/cancers14235773]

15. Chan JY, Wong ST, Wei WI (2014) Whole-organ histopathological study of recurrent nasopharyngeal carcinoma. Laryngoscope, 124(2): 446-50. [DOI:10.1002/lary.24218]

16. Wang HZ, Cao CN, Luo JW, et al. (2016) High-risk factors of parotid lymph node metastasis in nasopharyngeal carcinoma: a case-control study. Radiat Oncol, 11(1): 113. [DOI:10.1186/s13014-016-0691-x]