Computed tomography and magnetic resonance imaging evaluation of pelvic lymph node metastasis in bladder cancer

Yong Li, Feiyu Diao, Siya Shi, Kaiwen Li, Wangshu Zhu, Shaoxu Wu, Tianxin Lin, Yong Li, Feiyu Diao, Siya Shi, Kaiwen Li, Wangshu Zhu, Shaoxu Wu, Tianxin Lin

Abstract

Background: Accurate evaluation of lymph node metastasis in bladder cancer (BCa) is important for disease staging, treatment selection, and prognosis prediction. In this study, we aimed to evaluate the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) for metastatic lymph nodes in BCa and establish criteria of imaging diagnosis.

Methods: We retrospectively assessed the imaging characteristics of 191 BCa patients who underwent radical cystectomy. The data regarding size, shape, density, and diffusion of the lymph nodes on CT and/or MRI were obtained and analyzed using Kruskal-Wallis test and χ2 test. The optimal cutoff value for the size of metastatic node was determined using the receiver operating characteristic (ROC) curve analysis.

Results: A total of 184 out of 3317 resected lymph nodes were diagnosed as metastatic lymph nodes. Among 82 imaging-detectable lymph nodes, 51 were confirmed to be positive for metastasis. The detection rate of metastatic nodes increased along with more advanced tumor stage (P < 0.001). Once the ratio of short- to long-axis diameter ≤ 0.4 or fatty hilum was observed in lymph nodes on imaging, it indicated non-metastases. Besides, lymph nodes with spiculate or obscure margin or necrosis indicated metastases. Furthermore, the short diameter of 6.8 mm was the optimal threshold to diagnose metastatic lymph node, with the area under ROC curve of 0.815.

Conclusions: The probability of metastatic nodes significantly increased with more advanced T stages. Once lymph nodes are detected on imaging, the characteristic signs should be paid attention to. The short diameter > 6.8 mm may indicate metastatic lymph nodes in BCa.

Keywords: Bladder cancer; Computed tomography; Lymph node metastasis; Magnetic resonance imaging.

Figures

Fig. 1
Fig. 1
Flowchart of selecting patients with bladder cancer
Fig. 2
Fig. 2
Pelvic magnetic resonance (MR) images of a 62-year-old man with bladder cancer (stage pT2b). a Transverse T1-weighted MR image shows a hyperintense lymph node with round shape and a short-axis diameter of about 6.0 mm in the left perivesical region. The fatty hilum shows high signal intensity on the image (yellow arrows). b In out-of-phase MR imaging, the fat signal was suppressed in the lymph node (yellow arrows). This lymph node with fatty hilum was proved to be benign in pathologic diagnosis
Fig. 3
Fig. 3
Pelvic computed tomography (CT) images of a 76-year-old man with bladder cancer (stage pT3a). a CT scan before contrast shows an isodensity oval lymph node with a short-axis diameter of 9.0 mm in the right obturator region (yellow arrows). b In the vein phase after contrast, the necrosis in the center of the lymph node shows annular enhancement (yellow arrows). This lymph node with necrosis was proved to be metastatic in pathologic diagnosis
Fig. 4
Fig. 4
Receiving operating characteristic (ROC) curve of short-axis diameter of metastatic lymph nodes measured on CT and/or MRI (the blue line). A cutoff value of 6.8 mm results in optimal sensitivity (83.0%) and specificity (64.3%) and high Youden index (47.3%). The area under the ROC curve (AUC) is 0.815, and 95% confidence interval is 0.708–0.895

References

    1. Guo P, Huang ZL, Yu P, Li K. Trends in cancer mortality in China: an update. Ann Oncol. 2012;23(10):2755–2762. doi: 10.1093/annonc/mds069.
    1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2016. CA Cancer J Clin. 2016;66(1):7–30. doi: 10.3322/caac.21332.
    1. Zhang ZL, Dong P, Li YH, Liu ZW, Yao K, Han H, et al. Radical cystectomy for bladder cancer: oncologic outcome in 271 Chinese patients. Chin J Cancer. 2014;33(3):165–171. doi: 10.5732/cjc.012.10312.
    1. Leissner J, Ghoneim MA, Abol-Enein H, Thuroff JW, Franzaring L, Fisch M, et al. Extended radical lymphadenectomy in patients with urothelial bladder cancer: results of a prospective multicenter study. J Urol. 2004;171(1):139–144. doi: 10.1097/01.ju.0000102302.26806.fb.
    1. Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D. Global cancer statistics. CA Cancer J Clin. 2011;61(2):69–90. doi: 10.3322/caac.20107.
    1. Saokar A, Islam T, Jantsch M, Saksena MA, Hahn PF, Harisinghani MG. Detection of lymph nodes in pelvic malignancies with computed tomography and magnetic resonance imaging. Clin Imaging. 2010;34(5):361–366. doi: 10.1016/j.clinimag.2009.07.004.
    1. Thoeny HC, Froehlich JM, Triantafyllou M, Huesler J, Bains LJ, Vermathen P, et al. Metastases in normal-sized pelvic lymph nodes: detection with diffusion-weighted mr imaging. Radiology. 2014;273(1):125–135. doi: 10.1148/radiol.14132921.
    1. Triantafyllou M, Studer UE, Birkhauser FD, Fleischmann A, Bains LJ, Petralia G, et al. Ultrasmall superparamagnetic particles of iron oxide allow for the detection of metastases in normal sized pelvic lymph nodes of patients with bladder and/or prostate cancer. Eur J Cancer. 2013;49(3):616–624. doi: 10.1016/j.ejca.2012.09.034.
    1. Fleischmann A, Thalmann GN, Markwalder R, Studer UE. Extracapsular extension of pelvic lymph node metastases from urothelial carcinoma of the bladder is an independent prognostic factor. J Clin Oncol. 2005;23(10):2358–2365. doi: 10.1200/JCO.2005.03.084.
    1. Tilki D, Svatek RS, Karakiewicz PI, Isbarn H, Reich O, Kassouf W, et al. Characteristics and outcomes of patients with pT4 urothelial carcinoma at radical cystectomy: a retrospective international study of 583 patients. J Urol. 2010;183(1):87–93. doi: 10.1016/j.juro.2009.08.145.
    1. Zargar H, Zargar-Shoshtari K, Dundee P, Black PC. Predicting occult lymph node-positive disease at the time of radical cystectomy: a systematic review. Minerva Urol Nefrol. 2016;68(2):112–124.
    1. Stein JP, Lieskovsky G, Cote R, Groshen S, Feng AC, Boyd S, et al. Radical cystectomy in the treatment of invasive bladder cancer: long-term results in 1,054 patients. J Clin Oncol. 2001;19(3):666–675. doi: 10.1200/JCO.2001.19.3.666.
    1. Harisinghani MG, Barentsz J, Hahn PF, Deserno WM, Tabatabaei S, van de Kaa CH, et al. Noninvasive detection of clinically occult lymph-node metastases in prostate cancer. N Engl J Med. 2003;348(25):2491–2499. doi: 10.1056/NEJMoa022749.
    1. Hu B, Satkunasivam R, Schuckman A, Sherrod A, Cai J, Miranda G, et al. Significance of perivesical lymph nodes in radical cystectomy for bladder cancer. Urol Oncol Semin Orig Investig. 2014;32(8):1158–1165. doi: 10.1016/j.urolonc.2014.08.004.
    1. Mir N, Sohaib SA, Collins D, Koh DM. Fusion of high b-value diffusion-weighted and T2-weighted mr images improves identification of lymph nodes in the pelvis. J Med Imaging Radiat Oncol. 2010;54(4):358–364. doi: 10.1111/j.1754-9485.2010.02182.x.
    1. Giannarini G, Petralia G, Thoeny HC. Potential and limitations of diffusion-weighted magnetic resonance imaging in kidney, prostate, and bladder cancer including pelvic lymph node staging: a critical analysis of the literature. Eur Urol. 2012;61(2):326–340. doi: 10.1016/j.eururo.2011.09.019.
    1. Rechichi G, Galimberti S, Oriani M, Perego P, Valsecchi MG, Sironi S. Adc maps in the prediction of pelvic lymph nodal metastatic regions in endometrial cancer. Eur Radiol. 2013;23(1):65–74. doi: 10.1007/s00330-012-2575-2.
    1. Papalia R, Simone G, Grasso R, Augelli R, Faiella E, Guaglianone S, et al. Diffusion-weighted magnetic resonance imaging in patients selected for radical cystectomy: detection rate of pelvic lymph node metastases. BJU Int. 2012;109(7):1031–1036. doi: 10.1111/j.1464-410X.2011.10446.x.
    1. Roy C, Bierry G, Matau A, Bazille G, Pasquali R. Value of diffusion-weighted imaging to detect small malignant pelvic lymph nodes at 3 T. Eur Radiol. 2010;20(8):1803–1811. doi: 10.1007/s00330-010-1736-4.
    1. Nakai G, Matsuki M, Inada Y, Tatsugami F, Tanikake M, Narabayashi I, et al. Detection and evaluation of pelvic lymph nodes in patients with gynecologic malignancies using body diffusion-weighted magnetic resonance imaging. J Comput Assist Tomogr. 2008;32(5):764–768. doi: 10.1097/RCT.0b013e318153fd43.
    1. Uematsu T, Sano M, Homma K. In vitro high-resolution helical CT of small axillary lymph nodes in patients with breast cancer: correlation of CT and histology. AJR Am J Roentgenol. 2001;176(4):1069–1074. doi: 10.2214/ajr.176.4.1761069.
    1. Yang WT, Chang J, Metreweli C. Patients with breast cancer: differences in color Doppler flow and gray-scale US features of benign and malignant axillary lymph nodes. Radiology. 2000;215(2):568–573. doi: 10.1148/radiology.215.2.r00ap20568.
    1. Soave A, John LM, Dahlem R, Minner S, Engel O, Schmidt S, et al. The impact of tumor diameter and tumor necrosis on oncologic outcomes in patients with urothelial carcinoma of the bladder treated with radical cystectomy. Urology. 2015;86(1):92–98. doi: 10.1016/j.urology.2015.03.036.
    1. Koh DM, Brown G, Husband JE. Nodal staging in rectal cancer. Abdom Imaging. 2006;31(6):652–659. doi: 10.1007/s00261-006-9021-3.
    1. Barentsz JO, Engelbrecht MR, Witjes JA, de la Rosette JJ, van der Graaf M. Mr imaging of the male pelvis. Eur Radiol. 1999;9(9):1722–1736. doi: 10.1007/s003300050916.

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