Analysis of dose-effect relationship between DVH parameters and clinical prognosis of definitive radio(chemo)therapy combined with intracavitary/interstitial brachytherapy in patients with locally advanced cervical cancer: A single-center retrospective study

Abstract

PurposeThe purpose of the study was to explore the dose-effect relationship between dose-volume histogram parameters and clinical prognosis of definitive radio(chemo)therapy followed by intracavitary/interstitial brachytherapy in locally advanced cervical cancer. Methods and MaterialsA retrospective analysis was performed on 110 patients with locally advanced cervical cancer who underwent external beam radiotherapy combined with intracavitary/interstitial brachytherapy with or without chemotherapy from July 2010 to September 2018. We reported D100, D98, and D90 for high-risk clinical target volume (HR-CTV) and intermediate-risk clinical target volume, D2cm³ for organs at risk. Multivariate Cox regression was used to screen independent factors. Dose-volume parameters screened by the Cox regression were incorporated into the probit model for investigating its relationship with survival. ResultsThe median followup time was 72.33 months. Multivariate Cox regression analysis showed that HR-CTV D100, HR-CTV D98, and HR-CTV D90 were independent factors, affecting the 5-year overall survival (OS), cancer-specific survival (CSS), and local control (LC) rates. The probit model showed that HR-CTV D98 had predictive values for the 5-year OS, CSS, and LC, and HR-CTV D100 had predictive values for the 5-year OS, CSS, whereas HR-CTV D90 had a predictive value only for the 5-year OS. The HR-CTV D98 corresponding to OS ED90, CSS ED90, and LC ED90 was 86.8, 85.6, and 78.6 Gy, respectively. ConclusionsA significant dependence of OS, CSS, and LC on D98 for HR-CTV was found. When the long-term OS, CSS, and LC rate of the patient was >90%, HR-CTV D98 > 86.8 Gy EQD2, 85.6 Gy EQD2, and 78.6 Gy EQD2 were required.