Analysis of the efficacy of intensity-modulated radiotherapy and two-dimensional conventional radiotherapy in nasopharyngeal carcinoma with involvement of the cervical spine.

The aim of the present study was to retrospectively analyze the clinical efficacy and side-effects of two-dimensional conventional radiotherapy (2D-CRT) and intensity-modulated radiotherapy (IMRT) in 53 NPC patients with cervical spine involvement, without distant metastases. In total, 53 patients were enrolled in the present study, with 24 being treated with IMRT and 29 being treated with 2D-CRT. All 53 patients received platinum-based concurrent chemotherapy and 4-6 cycles of adjuvant chemotherapy subsequent to radiation. The patients were clinically staged according to the seventh edition of the UICC and AJCC staging systems. Overall survival (OS), local progression-free survival (LPFS) and distant metastasis-free survival (DMFS) rates were calculated. The 3- and 5-year OS rates were 87.7% and 45.5% in the IMRT-treated group and 65.5% and 9.1% in the 2D-CRT-treated group (P=0.01). The 3- and 5-year LPES rates were 87.4% and 69.9% in the IMRT-treated group compared with 49.4% and 9.4% in the 2D-CRT-treated group, respectively (P=0.00). The 3- and 5-year DMFS rates were 94.4 and 40.8% in the IMRT-treated group and 79.8 and 30.4% in the 2D-CRT-treated group (P=0.13). N stage (P=0.00) and radiotherapy methods (P=0.01) were relevant to the OS and LPFS rates, it also revealed a significant difference when the DMFS rates were analyzed in N stage. The incidence of dry mouth in the IMRT group was significantly lower (P=0.01), but there was no statistically significant difference in acute oropharyngeal mucositis or myelosuppression. IMRT had significant advantages in local control and OS compared with conventional 2D-CRT, but IMRT failed to reduce the incidence of distant metastasis.