ABSTRACT
PURPOSE: To investigate the dose-effect relationship between the dose-volume parameters of residual gross tumor volume (GTVres) and clinical prognosis in MRI image-guided adaptive brachytherapy (IGABT) of patients with locally advanced cervical cancer in our center. MATERIALS AND METHOD: The clinical data of 93 patients with locally advanced cervical squamous cell cancer who received external beam radiotherapy (EBRT) combined with IGABT⯱ chemotherapy in our center were retrospectively analyzed. The disease stage, overall treatment time (OTT), chemotherapy, and the dose-volume parameters D90, D98, and D100 of GTVres, the intermediate-risk clinical target volume (CTVIR), and the high-risk clinical target volume (CTVHR) of the patients were statistically analyzed. Kaplan-Meier and uni- and multivariable Cox regression analyses were used to analyze 2year overall survival (OS), progression-free survival (PFS), and local control rate (LC). A probit model was employed to assess the dose-effect relationship between the volume and dose-volume parameters of GTVres and 2year OS, PFS, and LC. RESULTS: The median follow-up time was 19.6 months and 2year OS, PFS, and LC were 79.6%, 68.8%, and 94.6%, respectively. CTVHR D90 was an independent influencing factor for 2year PFS (Pâ¯= 0.041); GTVresBT1 volume was an independent factor for 2year OS, PFS, and LC (Pâ¯< 0.001). The probit model showed that at GTVresBT1 volumeâ¯< 32.86â¯cm3, the expected 2year LC wasâ¯> 90%; at GTVres D98â¯> 129.12 GyEQD2, the expected 2year OS wasâ¯> 90%. CONCLUSION: Both the volume and dose-volume parameters of GTVres are promising predictors in assessment of IGABT prognosis of cervical cancer.