12. Presti, J. C., Jr., O’Dowd, G. J., Miller, M. C., Mattu, R. andVeltri, R. W.: Extended peripheral zone biopsy schemes in-crease cancer detection rates and minimize variance in pros-tate specific antigen and age related cancer rates: results of acommunity multi-practice study. J Urol, 169: 125, 2003

13. Prostate. In: AJCC Cancer Staging Manual, 6th ed. Edited byF. L. Greene, D. L. Page, I. D. Fleming, A. G. Fritz, C. M.Balch, D. G. Haller et al. New York: Springer-Verlag, partIX, chapt. 34, pp. 309–316, 2002

14. Montironi, R., van der Kwast, T., Boccon-Gibod, L., Bono, A. V.and Boccon-Gibod, L.: Handling and pathology reporting ofradical prostatectomy specimens. Eur Urol, 44: 626, 2003

15. Kundel, H. L. and Polansky, M.: Measurement of observeragreement. Radiology, 228: 303, 2003

16. Breeuwsma, A. J., Pruim, J., Jongen, M. M., Suurmeijer, A. J.,Vaalburg, W., Nijman, R. J. et al: In vivo uptake of[11C]choline does not correlate with cell proliferation inhuman prostate cancer. Eur J Nucl Med Mol Imaging, 32:668, 2005

17. Sutinen, E., Nurmi, M., Roivainen, A., Varpula, M., Tolvanen,T., Lehikoinen, P. et al: Kinetics of [11C]choline uptake inprostate cancer: a PET study. Eur J Nucl Med Mol Imaging,31: 317, 2004

18. Bott, S. R., Young, M. P., Kellett, M. J., Parkinson, M. C. andContributors to the UCL Hospitals’ Trust Radical Prosta-tectomy Database: Anterior prostate cancer: is it more dif-ficult to diagnose? BJU Int, 89: 886, 2002

EDITORIAL COMMENT

Conventional 18F-fluorodeoxyglucose-PET is known to havelittle use in newly diagnosed prostate cancer and there issubstantial interest in alternative radiopharmaceuticalmarkers. The authors have presented a promising investi-gation of 11C-choline as such a marker, which combined thePET study with CT (which should improve anatomical local-ization), and included comparisons with TRUS and MRI.However, caution must be exercised in the interpretation oftheir data. Their patients had a relatively high risk profile.For example, mean PSA was 12.0 ng/ml compared to 7.8ng/ml in a recent comparable series of 48 North Americanpatients.1 11C-choline PET/CT only detected 1 of 23 tumorfoci 5 mm or less in diameter. The clinical relevance of suchsmall tumor foci in the prostate is questionable, but argu-ably the extension of the 11C-choline PET/CT technique tonodal imaging (where most tumor deposits would be small)would likely be of limited sensitivity.

Fergus CoakleyDepartment of Radiology

University of California, San FranciscoSan Francisco, California

1. Hom, J. J., Coakley, F. V., Simko, J. P., Qayyum, A., Lu, Y.,Schmitt, L. et al: Prostate cancer: endorectal MR imagingand MR spectroscopic imaging—distinction of true-positiveresults from chance-detected lesions. Radiology, 238: 192,2006

REPLY BY AUTHORS

In patients with newly diagnosed prostate cancer knowl-edge of lymph node metastasis is of key importance forappropriate treatment planning but conventional imaging(CI) techniques have not been shown to have any role inthis setting.1 Although many nomograms have been de-veloped to quantify the risk of extraprostatic disease,2

difficulties arise in the selection of the most appropriatenomogram with the optimal cutpoint for the single pa-tient. Pelvic lymph node dissection (PLND) remains thegold standard for N staging. Furthermore the clinicalbenefit and extent of PLND in patients with prostatecancer are still under discussion. Thus, new imaging ap-proaches would be welcome.

11C-choline PET/CT has demonstrated good results forre-staging in patients with recurrent prostate cancer butlittle is known about its potential role for N staging.3 Weare now performing a prospective study to assess theaccuracy of 11C-choline PET/CT compared to CI beforeradical prostatectomy and extended PLND. Our prelimi-nary results show low sensitivity (approximately 65%) buthigh specificity and positive predictive value with thistechnique. The main drawback is the limited spatial res-olution of PET/CT scanners (approximately 4 to 5 mm)which hampers the recognition of micrometastasis. Fur-ther studies including an accurate cost-effectiveness anal-ysis are needed but PET/CT may be helpful in the decisionto abort ineffective surgical treatment and to enhancespecificity of CI.

1. Flanigan, R. C., McKay, R. C., Olson, M., Shankey, T. V., Pyle,J. and Waters, W. B.: Limited efficacy of preoperative com-puted tomographic scanning for the evaluation of lymphnode metastasis in patients before radical prostatectomy.Urology, 48: 428, 1996

2. Briganti, A., Chun, F. K., Salonia, A., Zanni, G., Scattoni, V.,Valiquette, L. et al: Validation of a nomogram predicting theprobability of lymph node invasion among patients undergo-ing radical prostatectomy and an extended pelvic lymphad-enectomy. Eur Urol, 49: 1019, 2006

3. de Jong, I. J., Pruim, J., Elsinga, P. H., Vaalburg, W. andMensink, H. J.: Preoperative staging of pelvic lymph nodesin prostate cancer by 11C-choline PET. J Nucl Med, 44: 331,2003

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