Medical Physics Department, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
Radiation Oncology Department, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
J Appl Clin Med Phys. 2023 Aug;24(8):e14006. doi: 10.1002/acm2.14006. Epub 2023 Apr 25.
To study and analyze the effect of the use of a thin guide-wire instead of a Foley catheter for urethral definition in prostate stereotactic body radiation therapy (SBRT) treatments and to compare treatment parameters in both situations.
Thirty-seven prostate SBRT patients were employed in this study. A Foley catheter was employed in nine of them, and a guide-wire was employed in the other 28 patients. For each of the 28 patients in which the guide-wire was employed, a comparison between urethral positions in both situations was performed, allowing for a margin definition of the urethra when a Foley catheter was employed. Displacements of the prostate during treatment were obtained, allowing for an analysis of prostate positions in both situations. Also, different treatment parameters such as the number of treatment interruptions, couch movements performed, and x-rays needed were gathered.
Large differences between urethral positions can be found in the anterior-posterior (AP) directions compared to those in the lateral (LAT) direction. Differences are also larger in areas closer to the base of the prostate, where margins applied in the case of using a Foley catheter are 16 mm with a mean displacement of 6 mm in the posterior direction. No differences in the treatment parameters were found during treatment in both situations. The difference found in absolute prostate pitch rotations suggests that the Foley catheter provokes a shift of the prostate position, which does not occur when employing the guide-wire.
Foley catheters shift the urethral position, making them a wrong surrogate of the urethra when no catheters are present. The margins needed to assess uncertainties introduced by the use of a Foley catheter are larger than those usually applied. The use of a Foley catheter did not present any additional difficulty during treatment delivery in terms of images employed or interruptions produced.
研究和分析在前列腺立体定向体部放射治疗（SBRT）中使用细导丝代替 Foley 导管进行尿道定义的效果，并比较两种情况下的治疗参数。
本研究纳入了 37 例前列腺 SBRT 患者。其中 9 例使用 Foley 导管，28 例使用导丝。对于使用导丝的 28 例患者中的每例患者，比较了两种情况下的尿道位置，以便在使用 Foley 导管时定义尿道的边缘。获得了前列腺在治疗过程中的位移，从而可以分析两种情况下的前列腺位置。此外，还收集了不同的治疗参数，如治疗中断次数、治疗床移动次数和所需的 X 射线数量。
与侧向（LAT）方向相比，前-后（AP）方向的尿道位置差异较大。靠近前列腺基部的区域差异更大，在该区域使用 Foley 导管时的边缘为 16mm，后向平均位移为 6mm。两种情况下的治疗参数在治疗过程中无差异。绝对前列腺旋转角度的差异表明，Foley 导管会引起前列腺位置的移位，而使用导丝时则不会。
Foley 导管会改变尿道位置，使其成为没有导管时尿道的错误替代物。为评估使用 Foley 导管引起的不确定性而需要的边缘大于通常应用的边缘。就使用的图像或产生的中断而言，在治疗过程中使用 Foley 导管并没有带来任何额外的困难。
