The efficacy of intensity-modulated radiotherapy in radical radiotherapy for cervical cancer: a propensity score matching analysis / 中华放射肿瘤学杂志

ABSTRACT

Objective:To compare the clinical efficacy and toxicity of intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) in radical radiotherapy for cervical cancer.Methods:Clinical data of 1002 patients with cervical cancer treated with radical radiotherapy at Zhejiang Cancer Hospital from September 2013 to December 2016 were retrospectively analyzed. All patients were divided into the IMRT group and 3D-CRT group according to the technology of external beam radiation therapy (EBRT). After 1∶1 propensity score matching (PSM), clinical prognosis of patients receiving IMRT or 3D-CRT was compared. Continuous data were expressed as Mean ± SD or median . Categorical data were described by case number (percentage). Quantitative data were compared by t-test. Qualitative data were compared by chi-square test or Fisher's exact test. Survival rates in two groups were calculated by Kaplan-Meier method and log-rank test. Results:The percentage of patients who received pelvic and para-aortic radiotherapy in the IMRT group was significantly higher than that in the 3D-CRT group (14.9% vs. 1.2%, P<0.001). The percentage of patients whose positive lymph nodes dose reached 55 Gy or more in the IMRT group was significantly higher than that in the 3D-CRT group (26.6% vs. 15.5%, P=0.002). In the IMRT group, the 5-year disease-free survival (DFS) rate (74.6% vs. 68.9%, P=0.084) and overall survival (OS) rate (79.4% vs. 74.9%, P=0.270) were slightly higher than those in the 3D-CRT group, but there were no significant differences between two groups. In the IMRT group, the local recurrence (3.0% vs. 6.9%, P=0.020) and distant lymph node metastasis rates (4.2% vs. 9.0%, P=0.013) were significantly lower compared with those in the 3D-CRT group. In terms of acute radiotherapy toxicities, grade 3-4 leukopenia (46.3% vs. 37.9%, P=0.028) and anemia (18.8% vs. 14.0%, P<0.001) occurred significantly more frequently in the IMRT group than in the 3D-CRT group. Conclusions:Both IMRT and 3D-CRT could achieve good therapeutic outcomes in radical radiotherapy of cervical cancer. IMRT can boost the radiation dose of metastatic lymph nodes and has significant advantages in reducing local recurrence and distant lymph node metastasis.