Contrastive study on the treatment of locally recurrent nasopharyngeal carcinoma with large segmentation gamma knife and large segmentation conformal retransmission radiotherapy

Abstract

Objective To compare the efficacy and adverse reactions of large segmentation gamma knife and large segmentation conformal retransmission radiotherapy for locally recurrent nasopharyngeal carcinoma. Methods One hundred and twenty-one patients with locally recurrent nasopharyngeal carcinoma from January 2009 to June 2012 were selected. The patients were divided into large segmentation conformal retransmission radiotherapy group (control group, 61 cases) and large segmentation gamma knife retransmission radiotherapy group (study group, 60 cases) according to the propensity score matching method. The radiation injury, quality of life, short-term efficacy and long-term efficacy were observed. Results In the recent radiation injury, the incidences of maxillofacial skin reaction and fatigue in study group were significantly higher than those in control group: 28.3% (17/60) vs. 13.1% (8/61) and 48.3% (29/60) vs. 29.5% (18/61), and there were statistical differences (P 0.05). In the long-term radiation injury, the incidences of deafness and difficulty in opening mouth in study group were significantly lower than those in control group: 33.3% (20/60) vs. 52.5% (32/61) and 58.3% (35/60) vs. 73.8% (45/61), the incidence of maxillofacial muscle fibrosis in control group was significantly higher than that in control group: 43.3% (26/60) vs. 26.2% (16/61), and there were statistical differences (P 0.05). In the actual long-term radiation injury, the incidences of dry mouth, deafness and difficulty in opening mouth in study group were significantly lower than those in control group: 66.7% (40/60) vs. 86.9% (53/61), 31.7% (19/60) vs. 50.8% (31/61) and 43.3% (26/60) vs. 67.2% (41/61), the incidence of maxillofacial muscle fibrosis in study group was significantly higher than that in control group: 41.7% (25/60) vs. 23.0% (14/61), and there were statistical differences (P 0.05). There were no significant differences in Karnofsky performance scale (KPS) score and body weight change before treatment and at the end of treatment, and at the end of treatment and 3 months after treatment between 2 groups (P > 0.05). For the short-term efficacy, the local control rates of 3, 6, 9 and 12 months after treatment in study group were significantly higher than those in control group: 75.0% (45/60) vs. 54.1% (33/61), 86.7% (52/60) vs. 62.3% (38/61), 90.0% (54/60) vs. 67.2% (41/61) and 91.7% (55/60) vs. 68.9% (42/61), and there were statistical differences (P 0.05). Conclusions Large-segment gamma knife and large-segment conformal reconstitution radiotherapy are effective for the short-term curative effect and long-term curative effect of locally recurrent nasopharyngeal carcinoma. They can reduce radiation damage and have better safety. Large segmentation gamma knife reconstitution radiotherapy is more advantageous in reducing the long-term radiation injury and improving the local control than large segmentation conformal retransmission radiotherapy. Key words: Nasopharyngeal neoplasms; Radiotherapy, conformal; Gamma rays; Radiation injuries; Treatment outcome