Department for Radiation Oncology, Charité-University Medicine Berlin, Campus Virchow-Clinic, Augustenburger Platz 1, 13353, Berlin, Germany.
Department for Radiation Oncology, Helios Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany.
Strahlenther Onkol. 2019 Jun;195(6):517-525. doi: 10.1007/s00066-018-1398-8. Epub 2018 Nov 15.
To evaluate the effect of changes in bladder volume during high-dose intensity-modulated-radiotherapy (IMRT) of prostate cancer on acute genitourinary (GU) toxicity and prospectively evaluate a simple biofeedback technique for reproducible bladder filling with the aim of reducing acute GU toxicity.
One hundred ninety-three patients were trained via a biofeedback mechanism to maintain a partially filled bladder with a reproducible volume of 200-300 cc at planning CT and subsequently at each fraction of radiotherapy. We prospectively analyzed whether and to what extent the patients' ability to maintain a certain bladder filling influenced the degree of acute GU toxicity and whether cut-off values could be differentiated.
We demonstrated that the ability to reach a reproducible bladder volume above a threshold volume of 180 cc and maintain that volume via biofeedback throughout treatment predicts for a decrease in acute GU toxicity during curative high-dose IMRT of the prostate. Patients who were not able to reach a partial bladder filling to that cut-off value and were not able to maintain a partially filled bladder throughout treatment had a significantly higher risk of developing ≥grade 2 GU acute toxicity.
Our results support the hypothesis that a biofeedback training for the patient is an easy-to-apply, useful, and cost-effective tool for reducing acute GU toxicity in high-dose IMRT of the prostate. Patients who are not able to reach and maintain a certain bladder volume during planning and treatment-two independent risk factors-might need special consideration.
评估前列腺癌高剂量强度调制放射治疗（IMRT）过程中膀胱容量的变化对急性泌尿生殖（GU）毒性的影响，并前瞻性评估一种简单的生物反馈技术，以实现可重复的膀胱充盈，从而降低急性 GU 毒性。
通过生物反馈机制对 193 例患者进行培训，使他们在计划 CT 时以及随后的每次放疗时，将膀胱维持在 200-300cc 的部分充盈状态，且具有可重复性。我们前瞻性分析了患者维持一定膀胱充盈的能力是否以及在何种程度上影响急性 GU 毒性的程度，以及是否可以区分截止值。
我们证明，通过生物反馈达到可重复的膀胱体积阈值（180cc）以上的能力，并在整个治疗过程中维持该体积，可预测在前列腺根治性高剂量 IMRT 中急性 GU 毒性的降低。那些无法达到该截止值的部分膀胱充盈，并且无法在整个治疗过程中保持部分膀胱充盈的患者，发生≥2 级 GU 急性毒性的风险显著增加。
我们的结果支持这样一种假设，即对患者进行生物反馈训练是一种易于应用、有用且具有成本效益的工具，可降低前列腺高剂量 IMRT 中的急性 GU 毒性。那些在计划和治疗过程中无法达到并维持一定膀胱容量的患者——两个独立的危险因素——可能需要特别考虑。
