2Department of Radiation Oncology, Bağcılar Training and Research Hospital, İstanbul-Türkiye
3Vocational School of Health Services, İstanbul University-Cerrahpaşa Radiotherapy Program, İstanbul-Türkiye
4Department of Public Health, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, İstanbul-Türkiye DOI : 10.5505/tjo.2025.4605 OBJECTIVE
This study aimed to assess the incidence and dosimetric predictors of radiation-induced lower cranial nerve (CN 9-12) palsy in patients with nasopharyngeal carcinoma (NPC), treated with intensity-modulated radiotherapy (IMRT) ± chemotherapy.
METHODS
A total of 125 patients with histologically confirmed NPC who underwent radiotherapy (RT) with or
without chemotherapy between 2010 and 2024 were retrospectively reviewed. Lower cranial nerves (CN
9-12) were contoured, and dose-volume parameters including Dmax, Dmean, D2cc, D1cc, and D0.5cc were analyzed.
Statistical analyses were conducted using the Mann-Whitney U test and Cox regression to assess
associations between clinical features, radiation dose, and the incidence of nerve palsy.
RESULTS
Median follow-up was 44 months. Cranial nerve palsy was observed in 8 patients (6.4%), all involving
CN 12, with concomitant CN 9-11 involvement in 5 cases. No statistically significant correlation was
found between palsy and patient characteristics or dosimetric parameters.
CONCLUSION
Although our study did not demonstrate statistically significant associations, likely due to limited sample
size, contouring and sparing of lower cranial nerves in radiotherapy planning are crucial. These
nerves play a vital role in preserving long-term quality of life, and their protection should be integrated
into routine clinical practice.