Abstract：【Objective】 To investigate the dosimetric characteristics and clinical efficacy of volumetric modulated arc therapy (VMAT) for nasopharyngeal carcinoma. 【Methods】 Total clinical data of 90 patients with nasopharyngeal carcinoma were collected. According to radiotherapy modes, they were divided into the VMAT (volumetric modulated arc therapy) group (n=50) and the sIMRT the (static intensity-modulated radiation therapy) group (n=40). Dosimetric evaluation was performed to compare the target coverage, homogeneity, conformity, efficacy and safety between the two groups. 【Results】 The PCTV (planned clinical target area) indicators: Dmin, D2, D98, Dmean and CI (conformality) in the VMAT group were higher than the sIMRT group, while HI (uniformity index) was lower than the sIMRT group (P<0.05). The PGTV (planned gross tumor target area) indicators: Dmax, Dmin, D2, Dmean and CI in the VMAT group were higher than the sIMRT group (P<0.05). In the VMAT group, Dmax and D1 of the brainstem were higher than those in the sIMRT group (P<0.05), the temporomandibular joint Dmax and laryngeal Dmean were higher than those in the sIMRT group (P<0.05), and the temporal lobe D1 was lower than that in the sIMRT group (P<0.05). The treatment monitor unit (MU) and treatment time of the VMAT group were lower than those of the sIMRT group (P<0.05). The total effective rate of treatment and the incidence of adverse reactions between the two groups were not significantly different (P>0.05). 【Conclusion】 The application of VMAT in patients with nasopharyngeal carcinoma can shorten the time of radiotherapy with high homogeneity and conformity.
2019, Vol. 36 
