Abstract：
OBJECTIVE: We compare urethrogram delineation of the caudal aspect of the anastomosis to the recommended guidelines of post prostatectomy radiotherapy.
BACKGROUND: Level one evidence has established the indications for, and importance of, adjuvant radiotherapy following radical prostatectomy. Several guidelines have recently addressed delineation of the prostate bed target volume including identification of the vesico-urethral anastomosis, taken as the first CT slice caudal to visible urine in the bladder neck. The inferior border of clinical target volume is then variably defined 5-12 mm below this anastomosis or 15 mm cranial to the penile bulb.
METHODS: Thirty-three patients who received adjuvant radiotherapy following radical prostatectomy were reviewed. All underwent planning CT with urethrogram. The authors (MM, JC) independently identified the CT slice caudal to the last slice showing urine in the bladder neck (called the CT Reference Slice), and measured the distance between this and the tip of the urethrogram cone. Five patients also had a diagnostic MRI at the time of CT planning to better visualize the anatomy.
RESULTS: Sixty-six readings were obtained. The mean distance between the Bladder CT Reference Slice and the most cranial urethrogram contrast slice was 16.1 mm (MM 16.4 mm, JC 15.8 mm), range: 6.8-34.2 mm. The mean distance between the urethrogram tip and the ischial tuberosities was 19.9 mm (range 12.5-29.8 mm). The mean distance between the CT Reference Slice and the ischial tuberosities was 36.9 mm (range 28.3-52.4 mm).
CONCLUSIONS: Guidelines for prostate bed radiation post prostatectomy have been developed after publication of the trials proving benefit of such treatment, and are thus untested. The anastomosis is a frequent site of local relapse but is variably defined by the existing guidelines, none of which take into account anatomic patient variation and all of which are at variance with urethrogram data. We recommend the use of planning urethrogram to better delineate the vesico-urethral junction and minimize the potential for geographic misses.
BACKGROUND: Level one evidence has established the indications for, and importance of, adjuvant radiotherapy following radical prostatectomy. Several guidelines have recently addressed delineation of the prostate bed target volume including identification of the vesico-urethral anastomosis, taken as the first CT slice caudal to visible urine in the bladder neck. The inferior border of clinical target volume is then variably defined 5-12 mm below this anastomosis or 15 mm cranial to the penile bulb.
METHODS: Thirty-three patients who received adjuvant radiotherapy following radical prostatectomy were reviewed. All underwent planning CT with urethrogram. The authors (MM, JC) independently identified the CT slice caudal to the last slice showing urine in the bladder neck (called the CT Reference Slice), and measured the distance between this and the tip of the urethrogram cone. Five patients also had a diagnostic MRI at the time of CT planning to better visualize the anatomy.
RESULTS: Sixty-six readings were obtained. The mean distance between the Bladder CT Reference Slice and the most cranial urethrogram contrast slice was 16.1 mm (MM 16.4 mm, JC 15.8 mm), range: 6.8-34.2 mm. The mean distance between the urethrogram tip and the ischial tuberosities was 19.9 mm (range 12.5-29.8 mm). The mean distance between the CT Reference Slice and the ischial tuberosities was 36.9 mm (range 28.3-52.4 mm).
CONCLUSIONS: Guidelines for prostate bed radiation post prostatectomy have been developed after publication of the trials proving benefit of such treatment, and are thus untested. The anastomosis is a frequent site of local relapse but is variably defined by the existing guidelines, none of which take into account anatomic patient variation and all of which are at variance with urethrogram data. We recommend the use of planning urethrogram to better delineate the vesico-urethral junction and minimize the potential for geographic misses.
摘要：
目的：我们将吻合口尾部的尿道造影描绘与前列腺切除术后放疗的推荐指南进行比较。
背景：一级证据已经确立了适应症，和重要性，前列腺癌根治术后的辅助放疗。最近有几项指南解决了前列腺床目标体积的勾画，包括确定膀胱尿道吻合术，作为第一个CT切片，尾部可见膀胱颈部的尿液。然后，将临床目标体积的下边界可变地定义为在该吻合口下方5-12mm或颅骨距阴茎球15mm。
方法：对33例前列腺癌根治术后接受辅助放疗的患者进行回顾性分析。所有患者均接受尿道造影计划CT检查。作者（MM，JC）独立识别了膀胱颈中显示尿液的最后一个切片的CT切片（称为CT参考切片），并测量了它和尿道图锥体尖端之间的距离。五名患者在CT计划时也进行了诊断性MRI，以更好地可视化解剖结构。
结果：获得了66个读数。膀胱CT参考切片与最颅骨尿道造影切片之间的平均距离为16.1mm（MM16.4mm，JC15.8mm),范围：6.8-34.2毫米。尿道图尖端和坐骨结节之间的平均距离为19.9mm（范围12.5-29.8mm）。CT参考切片与坐骨结节之间的平均距离为36.9mm（范围28.3-52.4mm）。
结论：前列腺切除术后前列腺床放疗指南是在证明这种治疗有益的试验发表后制定的，因此未经测试。吻合是局部复发的常见部位，但现有指南对吻合的定义各不相同。其中没有一个考虑到患者的解剖差异，所有这些都与尿道图数据不一致。我们建议使用计划尿道图，以更好地描绘膀胱尿道交界处，并最大程度地减少地理遗漏的可能性。
背景：一级证据已经确立了适应症，和重要性，前列腺癌根治术后的辅助放疗。最近有几项指南解决了前列腺床目标体积的勾画，包括确定膀胱尿道吻合术，作为第一个CT切片，尾部可见膀胱颈部的尿液。然后，将临床目标体积的下边界可变地定义为在该吻合口下方5-12mm或颅骨距阴茎球15mm。
方法：对33例前列腺癌根治术后接受辅助放疗的患者进行回顾性分析。所有患者均接受尿道造影计划CT检查。作者（MM，JC）独立识别了膀胱颈中显示尿液的最后一个切片的CT切片（称为CT参考切片），并测量了它和尿道图锥体尖端之间的距离。五名患者在CT计划时也进行了诊断性MRI，以更好地可视化解剖结构。
结果：获得了66个读数。膀胱CT参考切片与最颅骨尿道造影切片之间的平均距离为16.1mm（MM16.4mm，JC15.8mm),范围：6.8-34.2毫米。尿道图尖端和坐骨结节之间的平均距离为19.9mm（范围12.5-29.8mm）。CT参考切片与坐骨结节之间的平均距离为36.9mm（范围28.3-52.4mm）。
结论：前列腺切除术后前列腺床放疗指南是在证明这种治疗有益的试验发表后制定的，因此未经测试。吻合是局部复发的常见部位，但现有指南对吻合的定义各不相同。其中没有一个考虑到患者的解剖差异，所有这些都与尿道图数据不一致。我们建议使用计划尿道图，以更好地描绘膀胱尿道交界处，并最大程度地减少地理遗漏的可能性。
