Picchio Maria, Treiber Uwe, Beer Ambros J, Metz Stefan, Bössner Patrick, van Randenborgh Heiner, Paul Roger, Weirich Gregor, Souvatzoglou Michael, Hartung Rudolf, Schwaiger Markus, Piert Morand
Department of Nuclear Medicine, IBFM-CNR, Scientific Institute H San Raffaele, Milan, Italy.
J Nucl Med. 2006 Jun;47(6):938-44.
Lymph node involvement is a major prognostic factor in bladder cancer, but the accuracy of conventional imaging modalities for the prediction of regional and distant metastatic diseases is limited. This study was performed to compare the diagnostic accuracies of contrast-enhanced CT and PET with (11)C-choline for the staging of urothelial bladder cancer.
Twenty-seven patients (median age, 69.1 y) who had urothelial bladder cancer and who were referred for radical cystectomy and pelvic lymph node dissection (PLND) on the basis of a histologic evaluation after transurethral resection of bladder cancer (TURB) were studied. PET scanning, using 2 multiring whole-body tomographs, was performed 5 min after intravenous injection of approximately 370-500 MBq of (11)C-choline. In addition, conventional bone scintigraphy and contrast-enhanced CT were performed. After imaging, cystectomy and PLND were performed in all patients. Pathologic (11)C-choline uptake that could not be explained by intestinal activity was noted as a positive result. Node positivity was determined by size on CT: nodes measuring more than 1 cm in the long axis were described as being positive for tumor. Histopathologic findings were used as a reference.
The presence of residual bladder cancer (pTa-pT4) was correctly detected in 21 of 25 histologically tumor-positive patients (84%) by CT and in 24 of 25 patients (96%) by (11)C-choline PET. Lymph node involvement was correctly detected in 4 of 8 patients (50%) by CT and in 5 of 8 patients (62%) by (11)C-choline PET. The median size of the 3 nodes with false-negative PET results was 9 mm (range, 6-21 mm), and the median size of the metastatic lesions within the lymph nodes was 3 mm (range, 1-15 mm). CT resulted in 6 (22%) false-positive lymph nodes, whereas none was demonstrated by (11)C-choline PET; these data indicated a significantly higher accuracy of PET than of CT (P < 0.01). Both modalities missed a small peritoneal metastasis verified by histologic evaluation. No positive results were obtained from bone scintigraphy.
These preliminary data suggest that (11)C-choline PET is comparable to CT for detecting residual bladder cancer after TURB but appears to be superior to CT for the evaluation of potential additional lymph node metastases. (11)C-choline PET should be further evaluated for staging in patients who have bladder cancer and who are scheduled for radical cystectomy.
淋巴结受累是膀胱癌的主要预后因素，但传统成像方式预测局部和远处转移性疾病的准确性有限。本研究旨在比较对比增强CT和（11）C - 胆碱PET对尿路上皮膀胱癌分期的诊断准确性。
对27例（中位年龄69.1岁）尿路上皮膀胱癌患者进行研究，这些患者在经尿道膀胱肿瘤切除术（TURB）后经组织学评估被转诊进行根治性膀胱切除术和盆腔淋巴结清扫术（PLND）。静脉注射约370 - 500 MBq的（11）C - 胆碱后5分钟，使用2台多环全身断层扫描仪进行PET扫描。此外，还进行了传统骨闪烁显像和对比增强CT检查。成像后，所有患者均接受膀胱切除术和PLND。无法用肠道活动解释的病理性（11）C - 胆碱摄取被记录为阳性结果。CT上根据大小确定淋巴结阳性：长轴测量超过1 cm的淋巴结被描述为肿瘤阳性。组织病理学结果用作参考。
在25例组织学肿瘤阳性患者中，CT正确检测出21例（84%）残留膀胱癌（pTa - pT4），（11）C - 胆碱PET正确检测出24例（96%）。CT正确检测出8例患者中的4例（50%）淋巴结受累，（11）C - 胆碱PET正确检测出8例患者中的5例（62%）。PET假阴性结果的3个淋巴结的中位大小为9 mm（范围6 - 21 mm），淋巴结内转移灶的中位大小为3 mm（范围1 - 15 mm）。CT出现6个（22%）假阳性淋巴结，而（11）C - 胆碱PET未显示假阳性；这些数据表明PET的准确性明显高于CT（P < 0.01）。两种检查方式均遗漏了经组织学评估证实的一小处腹膜转移。骨闪烁显像未获得阳性结果。
这些初步数据表明，（11）C - 胆碱PET在检测TURB后残留膀胱癌方面与CT相当，但在评估潜在的额外淋巴结转移方面似乎优于CT。对于计划进行根治性膀胱切除术的膀胱癌患者，（11）C - 胆碱PET的分期应进一步评估。
