Radiotherapy in the Management of Nasopharyngeal Carcinoma: A Retrospective Analysis of Long-Term Outcomes and Toxicity in 459 Patients

Background: Nasopharyngeal carcinoma (NPC) represents a therapeutic challenge due to its unique pathological behavior, complex anatomical location, and high incidence in endemic regions such as the Maghreb. Advances in radiotherapy techniques, particularly intensity-modulated radiotherapy (IMRT), combined with chemotherapy have improved tumor control and reduced toxicity. Methods: We conducted a retrospective study of 459 patients with NPC treated at the Radiotherapy–brachytherapy Department of CHU Hassan II, Fès, Morocco, between January 2014 and December 2022. All patients underwent biopsy with histopathological confirmation and staging investigations. Treatment protocols included induction chemotherapy followed by concomitant chemoradiotherapy (68%), exclusive concomitant chemoradiotherapy (30%), or radiotherapy alone (2.2%). IMRT was used in all cases. Survival outcomes were estimated with the Kaplan–Meier method, and toxicities graded according to CTCAE v5. Results: The mean age was 48.3 years, with a male/female ratio of 1.94. Undifferentiated carcinoma of nasopharyngeal type (UCNT) was predominant (94.8%). Most patients presented at advanced stages (III–IV: 72.4%). Acute toxicities included mucositis (61.7%, grade ≥3 in 11%), radiodermatitis (40.8%, grade ≥3 in 2%), and hematologic toxicity (32.3%). Late toxicities included xerostomia (68%), hearing loss (29.8%), trismus (10.7%), and cervical fibrosis (4.5%). At a median follow-up of 5 years, overall survival was 81% at 5 years and 71% at 8 years, while metastasis-free survival was 77% and 73%, respectively. Nodal stage significantly impacted prognosis, with 5-year OS ranging from 91.1% (N0) to 43.2% (N3, p<0.001). Conclusion: Our findings confirm that IMRT-based concurrent chemoradiotherapy, with or without induction chemotherapy, achieves high rates of tumor control and survival in an endemic population, with manageable toxicity. Nodal involvement remains the strongest prognostic factor. These results support the need for multidisciplinary, personalized strategies and ongoing refinement of therapeutic protocols for NPC in the Maghreb region.