Importance of the ICRU bladder point dose on incidence and persistence of urinary frequency and incontinence in locally advanced cervical cancer: An EMBRACE analysis

Purpose: To identify patient- and treatment-related risk factors and dose-effects for urinary frequency and incontinence in locally advanced cervical cancer (LACC) treated with radio(chemo)therapy and image-guided adaptive brachytherapy (IGABT). Material and methods: Physician-assessed (CTCAE) and patient-reported (EORTC) frequency and incontinence recorded in the EMBRACE-I study were analysed. Risk factors analysis was performed in patients without bladder infiltration and with baseline morbidity available. Cox regression was used for CTCAE grade (G) >= 3 and G >= 2 and for EORTC very much and quite a bit or worse. Logistic regression was used for late persistent morbidity defined when CTCAE G >= 1 or EORTC >= quite a bit were scored in at least half of follow-ups. Results: Longitudinal data on 1153 and 884 patients were available for CTCAE and EORTC analysis, respectively. Median follow-up was 48[3-120] months. Crude incidence rates of G >= 2 were 13% and 11% for frequency and incontinence, respectively. Baseline morbidity and overweight-obesity were risk factors for both symptoms. Elderly patients were at higher risk for incontinence. Patients receiving conformal-radiotherapy were at higher risk for frequency. ICRU bladder point (ICRU-BP) dose was a stronger predictor for incontinence than bladder D-2cm3. The 5-year actuarial estimate of G >= 2 incontinence increased from 11% to 20% with ICRU-BP doses > 75 Gy compared to <= 65 Gy. Frequency showed weaker associations with dose. Conclusion: ICRU-BP dose, in addition to clinical parameters, is a risk factor for urinary incontinence and shows a dose-effect after radio(chemo)therapy and IGABT. ICRU-BP dose should be monitored during treatment planning alongside volumetric parameters. Frequency seems associated with larger irradiated volumes. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study on locally advanced cervical cancer patients revealed that baseline morbidity and overweight/obesity are risk factors for urinary frequency and incontinence. Additionally, elderly patients are more prone to incontinence, while patients receiving conformal-radiotherapy are more likely to experience frequency.