Hines Katherine, Nieto Karina, Dezarn William, Greven Kathryn, Krol Bridget, Matthews Catherine, Parker-Autry Candace
Wake Forest Department of Urology, Division of Female Pelvic Health, Winston-Salem, NC, USA.
Wake Forest Department of Radiation Oncology, Winston-Salem, NC, USA.
Int Urogynecol J. 2023 Apr;34(4):929-935. doi: 10.1007/s00192-022-05363-7. Epub 2022 Oct 1.
Female survivors of endometrial and rectal cancers have increased risk of urinary incontinence. Survivors with prior radiation therapy are counseled against mesh incontinence surgery. We hypothesize that urethral radiation dose varies based on modality which may influence surgical risks. We aimed to demonstrate urethral radiation dose differences between vaginal brachytherapy (VBT) and external beam radiation therapy (EBRT).
This is a retrospective cohort study of women exposed to VBT for endometrial cancer and EBRT for rectal cancer. The urethra was contoured on CT imaging to calculate radiation doses in centigray (cGy). The primary outcome was the percent of treatment radiation dose estimated to be received by the urethra based on the volume dose to 0.2 cc of urethra. Secondary outcomes were point doses to the bladder neck, mid-urethra, and total mean urethral dose. Descriptive statistics described demographic characteristics. Bivariate analyses compared urethral radiation dose based on radiation modality.
Between 2014-2017, 32 women treated were included: 18 with VBT and 14 with EBRT. Mean ± SD urethral volume doses were lower in VBT (1266 cGy ± 533, 42.2% of prescribed treatment dose) compared to EBRT (5051 cGy ± 192, 100.2% of prescribed treatment dose), p < 0.0001. VBT also had significantly lower mean total urethral dose and point doses to bladder neck and mid- urethra compared to EBRT (p < 0.0001).
The female urethra is exposed to significantly less radiation in VBT compared to EBRT. These data highlight that modality of pelvic radiation should be considered in treatment counseling on urinary incontinence in women.
子宫内膜癌和直肠癌的女性幸存者尿失禁风险增加。对于曾接受过放射治疗的幸存者，不建议进行网状物治疗尿失禁手术。我们假设尿道辐射剂量因治疗方式而异，这可能会影响手术风险。我们旨在证明阴道近距离放射治疗（VBT）和外照射放疗（EBRT）之间的尿道辐射剂量差异。
这是一项对接受子宫内膜癌VBT和直肠癌EBRT治疗的女性进行的回顾性队列研究。在CT成像上勾勒出尿道轮廓，以计算以厘戈瑞（cGy）为单位的辐射剂量。主要结局是根据尿道0.2 cc的体积剂量估计尿道接受的治疗辐射剂量百分比。次要结局是膀胱颈、尿道中段的点剂量以及尿道总平均剂量。描述性统计描述人口统计学特征。双变量分析比较基于放疗方式的尿道辐射剂量。
2014年至2017年期间，纳入了32名接受治疗的女性：18名接受VBT，14名接受EBRT。与EBRT（5051 cGy±192，规定治疗剂量的100.2%）相比，VBT的平均±标准差尿道体积剂量较低（1266 cGy±533，规定治疗剂量的42.2%），p<0.0001。与EBRT相比，VBT的平均尿道总剂量以及膀胱颈和尿道中段的点剂量也显著较低（p<0.0001）。
与EBRT相比，VBT中女性尿道受到的辐射明显更少。这些数据表明，在女性尿失禁治疗咨询中应考虑盆腔放疗方式。
