Intensity-modulated radiotherapy (IMRT)/Tomotherapy following neoadjuvant chemotherapy in stage IIB-IVA/B undifferentiated nasopharyngeal carcinomas (UCNT): a mono-institutional experience.

To evaluate the outcome of Undifferentiated Nasopharyngeal Carcinomas (UCNT) treated with intensity-modulated radiation therapy with Simultaneous Integrated Boost (SIB), following induction chemotherapy. Between January 2006 and June 2009, 52 patients with stage II B-IVA/B UCNT were treated either with linac-IMRT or Tomotherapy. All patients were scheduled to receive three cycles of cisplatin based neoadjuvant chemotherapy. With a median follow-up of 38.5 months (range 12.3-64.1), 3 year overall survival (OS), disease-free survival (DFS), and DFS by T2a-2b and T3-T4-stage were 95.0%, 84.6%, 89.0%, and 78.0%, respectively. At multivariate analysis, none of the examined prognostic factors reported statistical significance. N-classification was not a significant predictive factor for either OS or development of distant metastases. T-stage alone had a borderline effect on DFS and development of metastases. No difference between Tomotherapy and linac-IMRT emerged in terms of loco-regional control and development of severe, acute, and late toxicities. The most significant severe, acute toxicities were grade 3 (32.7%) and grade 4 (7.7%) mucositis. No grades 3 and 4 late toxicities were observed. The most commonly observed late effect was xerostomia, 11.5% patients complained grade 2 xerostomia. The severity of grade 2 xerostomia diminished over time with only four patients not improving salivation. IMRT-SIB following neoadjuvant chemotherapy was very satisfactory in terms of local control, regional control, DFS and OS rates in patients with stage IIB to IVB UCNT. In our experience, adding concurrent chemotherapy to IMRT after neoadjuvant chemotherapy in loco-regional widespread disease resulted to be the indicated approach.