Long-term follow-up of volumetric modulated arc therapy in definitive radiotherapy for cervical cancer: A single-center retrospective experience

Abstract

ObjectiveTo evaluate the treatment outcomes and toxicity of volumetric modulated arc therapy (VMAT) in definitive radiotherapy for patients with cervical cancer. MethodsMedical records of 440 patients with cervical cancer treated with VMAT in definitive radiotherapy with or without concurrent chemotherapy between January 2010 and June 2015 in our institution were retrospectively reviewed. A dose of 45 ​Gy was prescribed to the planning target volume with VMAT in 25 fractions, followed by high-dose rate intracavitary brachytherapy with 28–36 ​Gy in 4–6 fractions. Survival time was estimated using Kaplan-Meier method. Risk factors for treatment failure were identified using Cox proportional hazards regression model. ResultsThe median follow-up periods were 58.3 months (range: 2.7–112.9 months). The 3- and 5-year survival rates were overall survival (OS) 79.4% and 74.4%, cancer-specific survival (CSS) 81.4% and 77.1%, progression-free survival (PFS) 73.3% and 71.1%, locoregional control (LC) 83.3% and 82% and distant metastasis-free survival (DMFS) 80.8% and 77.7%, respectively. The 5-year OS for patients with different stages was IB1 91.6%, IB2 100%, IIA 82.5%, IIB 74.4%, IIIA 57.1%, IIIB 61.7% and IVB 17.6%, respectively. Of the 124 patients with recurrence, 93 patients (75.0%) experienced distant failure. Multivariate analysis showed that non-squamous cell carcinoma of the cervix (P ​< ​0.001), more advanced stage (P ​= ​0.004), pelvic lymph node metastasis (P ​< ​0.001) and para-aortic lymph node metastasis (P ​= ​0.019) were all independent risk factors of PFS. The incidence of grades 3–4 late bowel toxicities was 2.7%. No grades 3–4 bladder toxicity was observed. ConclusionThis study demonstrated that the use of VMAT in definitive radiotherapy resulted in satisfactory outcomes with acceptable toxicities for patients with cervical cancer. Distant metastasis predominated as the pattern of disease relapse. Further studies are needed to investigate the intensified systemic therapies.