Improved long-term results of intensity-modulated radiotherapy for a non-endemic European nasopharyngeal carcinoma cohort: single-center retrospective study.

Purpose: Report our matured outcomes of European nasopharyngeal carcinoma (NPC) treatment from a non-endemic region in the IMRT era.

Methods: We reviewed 109 consecutive patients with biopsy proven NPC treated between 2009 and 2013. All received IMRT as per RTOG 0615. Toxicity was scored accordingly to CTCAE 4.03. Platinum-based chemotherapy was delivered following the Intergroup 0099.

Results: Median age of 53 years; 97% Caucasian; 74% male; 72% WHO grade III; 43% T1; 14% T2; 18% T3, 25% T4; 17% N0; 17% N1; 39% N2; 27% N3. Compliance to adjuvant chemotherapy was 88%. With a median follow up of 56 months, the 4-year local control was 90.2% (88.6% for T1; 100% for T2; 85% for T3; and 91.7% for T4), the 4-year distant metastases-free survival was 86% and an overall survival rate was 77%. Local control and survival were better in G3 (p < 0.001 and p = 0.032, respectively). Xerostomia was the most frequent late toxicity in 55% (n = 60). Hypothyroidism requiring hormonal reposition occurred in 15.5% (n = 17). From the 36 deaths, 20 were due to distant metastases, 3 grade 5 toxicity, 2 from local progression, 5 non-cancer deaths and unknown cause in the remaining 6. On multivariable analysis, age (p = 0.017), local recurrence and distant metastases were associated with death (p < 0.001, both).

Conclusion: Our matured data from the IMRT era showed a major improvement from our 3D cohort series reaching excellent local and regional control, even in T4. Local recurrences, despite few, and distant metastases were correlated with the risk of death.