Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Int J Radiat Oncol Biol Phys. 2013 Feb 1;85(2):363-9. doi: 10.1016/j.ijrobp.2012.03.061. Epub 2012 May 30.
Local-regional failures (LFs) after cystectomy with or without chemotherapy are common in locally advanced disease. Adjuvant radiation therapy (RT) could reduce LFs, but toxicity has discouraged its use. Modern RT techniques with improved normal tissue sparing have rekindled interest but require knowledge of pelvic failure patterns to design treatment volumes.
Five-year LF rates after radical cystectomy plus pelvic node dissection with or without chemotherapy were determined for 8 pelvic sites among 442 urothelial bladder carcinoma patients. The impact of pathologic stage, margin status, nodal involvement, and extent of node dissection on failure patterns was assessed using competing risk analysis. We calculated the percentage of patients whose sites of LF would have been completely encompassed within various hypothetical clinical target volumes (CTVs) for postoperative radiation.
Compared with stage ≤pT2, stage ≥pT3 patients had higher 5-year LF rates in virtually all pelvic sites. Among stage ≥pT3 patients, margin status significantly altered the failure pattern whereas extent of node dissection and nodal positivity did not. In stage ≥pT3 patients with negative margins, failure occurred predominantly in the iliac/obturator nodes and uncommonly in the cystectomy bed and/or presacral nodes. Of these patients in whom failure subsequently occurred, 76% would have had all LF sites encompassed within CTVs covering only the iliac/obturator nodes. In stage ≥pT3 with positive margins, cystectomy bed and/or presacral nodal failures increased significantly. Only 57% of such patients had all LF sites within CTVs limited to the iliac/obturator nodes, but including the cystectomy bed and presacral nodes in the CTV when margins were positive increased the percentage of LFs encompassed to 91%.
Patterns of failure within the pelvis are summarized to facilitate design of adjuvant RT protocols. These data suggest that RT should target at least the iliac/obturator nodes in stage ≥pT3 with negative margins; coverage of the presacral nodes and cystectomy bed may be necessary for stage ≥pT3 with positive margins.
在局部晚期疾病中，膀胱切除术加或不加化疗后的局部区域失败（LFs）很常见。辅助放疗（RT）可以降低 LFs，但毒性使其应用受到阻碍。具有改善正常组织保护的现代 RT 技术重新引起了人们的兴趣，但需要了解盆腔失败模式以设计治疗体积。
在 442 例尿路上皮膀胱癌患者中，确定了根治性膀胱切除术加盆腔淋巴结清扫术加或不加化疗后 8 个盆腔部位的 5 年 LF 率。使用竞争风险分析评估病理分期、切缘状态、淋巴结受累和淋巴结清扫范围对失败模式的影响。我们计算了各个假设的术后放射治疗临床靶区（CTV）内完全包含 LF 部位的患者百分比。
与 pT2 期相比，pT3 期及以上患者在几乎所有盆腔部位的 5 年 LF 率都更高。在 pT3 期及以上患者中，切缘状态显著改变了失败模式，而淋巴结清扫范围和淋巴结阳性与否则没有。在切缘阴性的 pT3 期及以上患者中，失败主要发生在髂/闭孔淋巴结，而在膀胱切除术床和/或骶前淋巴结中则很少发生。在随后发生失败的这些患者中，76%的患者的所有 LF 部位都包含在仅覆盖髂/闭孔淋巴结的 CTV 中。在切缘阳性的 pT3 期患者中，膀胱切除术床和/或骶前淋巴结的失败明显增加。只有 57%的此类患者的所有 LF 部位都在仅包括髂/闭孔淋巴结的 CTV 内，但当切缘阳性时将膀胱切除术床和骶前淋巴结包括在 CTV 中可将包含的 LF 比例提高到 91%。
总结了盆腔内的失败模式，以方便辅助 RT 方案的设计。这些数据表明，对于切缘阴性的 pT3 期患者，RT 应至少靶向髂/闭孔淋巴结；对于切缘阳性的 pT3 期患者，可能需要包括骶前淋巴结和膀胱切除术床。
