Analysis of treatment outcome
Patients were followed for disease related parameters and adverse side effects every 3 months in the first 2 years, in 6 month intervals for the next 3 years and then annually. MRI was done every 6 months in the first 5 years. Complete response (CR) was defined as total resolution of clinically visible and/or palpable tumor of the cervix and vagina. Treatment failures were classified according to the site(s) of first tumor relapse and were defined as primary (cervix, uterine corpus, vagina, parametrium), pelvic node, or distant metastases. Time intervals for disease free survival (DFS), local recurrence free survival (LRFS), metastasis recurrence-free survival (MRFS) and cancer specific survival (CSS) rates were calculated from the date of diagnosis to the date of event or last follow-up appointment. Acute toxicities were defined as those occurring within 90 days after the last treatment date, and late toxicities were defined as those that occurred more than 90 days after the last treatment date.
Late toxicity was graded according to site and severity using the National Cancer Institute CTCAE v4.03 (Common Terminology Criteria for Adverse Events version 4.03) guidelines. Cox regression models were used to analyze the association between predictors and time-to-event outcomes. The Kaplan–Meier test was used to calculate survival curves. All analyses were performed using SPSS software, version 21 of the SPSS System for Windows.