Between December 2018 and June 2021, the medical data of patients in our institutions who were classified as FIGO stage IB-IIA disease were retrospectively reviewed. The inclusion criteria were as follows: negative nucleic acid detection of COVID-19; FIGO stage IB-IIA cervical cancer; received radical surgery; pathologically confirmed any of the following high-risk factors: lymph node metastasis, parametrial invasion, or positive resection margin; and treated with postoperative CCRT. The policy of wearing a mask was required for every person entering hospitals since the beginning of the COVID-19 pandemic after December 2019. The patients were required to wear a mask, which included surgical masks or N95 respirators, during the entire radiotherapy procedure and at every visit. According to the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia (Trial Version Seven), radiotherapy was suspended or postponed for patients with fever. The patients were required to undergo nucleic acid tests once a week. When the result of nucleic acid detection was negative, patients could continue radiotherapy. The study was approved by the Institution Ethics Committee. All medical information was anonymous, and informed consent was waived due to the retrospective nature of this study.
Radiotherapy and chemotherapy
Patients (mask wearing, freely breathing) underwent computer tomography (CT) simulation in the supine position using intravenous and oral contrast agents. A cylindrical radio-opaque virginal marker was used before CT simulation. The rectum of patients remained empty during CT simulation and daily treatment. In an attempt to achieve day-to-day reproducibility in bladder filling, the patients were asked to empty the bladder and then asked to drink 500 ml of water 1 hour prior to the planning CT scan and each external beam radiotherapy treatment fraction. External beam radiation therapy was applied using an intensity-modulated radiotherapy (IMRT) technique, including conventional fixed-field IMRT (FF-IMRT) or helical tomotherapy (HT). The clinical target volume (CTV) covered regional lymph node regions (obturator, common iliac, internal iliac, external iliac, and presacral regions) and the upper 2.0 cm of the vagina and paravaginal soft tissue lateral to the vagina. The external, internal, and common iliac nodal volumes were based on the contrast-enhanced vessels with a 0.7- to 1-cm circumferential margin. The planning target volume (PTV) was defined as the CTV expanded to a 0.8- to 1-cm margin with FF-IMRT and a 0.6- to 0.8-cm margin with HT. The pelvic field was prescribed 50.4 Gy in 28 fractions. Weekly cone-beam CT procedures were conducted for patients with FF-IMRT, and daily on-board megavoltage CT procedures were conducted for patients who were received HT before treatment. High-dose rate (HDR) intracavitary brachytherapy was administered to patients with a positive resection margin or if the tumor was adjacent (<5 mm) to the surgical margin of the vagina. The prescription dose was 20 Gy/4 fractions and was delivered to a depth of 5 mm below the vaginal mucosa.
The common concurrent chemotherapy regimen was cisplatin 40 mg/m2 weekly for 4-6 cycles. Some patients with renal comorbidities received paclitaxel 60 mg/m2/week.
Follow-up and statistical analysis
After treatment completion, all patients were evaluated after 1 month, followed by evaluations at 3-month intervals for 2 years. The routine follow-up evaluation included gynecological examination, laboratory testing, and abdomen and pelvic MRI/CT. Acute toxicities, measured from the initiation of treatment to 90 days after completion, were graded according to the National Cancer Institute’s Common Terminology Criteria for Adverse Events, version 3.0. Statistical analysis was performed using Statistical Package for Social Sciences, version 26.0 (SPSS, Chicago, IL). The chi-square test and the Fisher’s exact test were used to compare the toxicity of different groups. Continuous variables were analyzed using the Student’s t-test or the Mann-Whitney U test. A level of P < 0.05 was considered to be significant.