Christina Pfannenberg MD, Abstract Co-Author: Nothing to Disclose

Michael Brosi, Abstract Co-Author: Nothing to Disclose

Sergios Gatidis MD, Presenter: Nothing to Disclose

Cornelia Brendle MD, Abstract Co-Author: Nothing to Disclose

Bernhard Klumpp MD, Abstract Co-Author: Nothing to Disclose

Nina Schwenzer MD, Abstract Co-Author: Nothing to Disclose

Claus Detlef Claussen MD, Abstract Co-Author: Nothing to Disclose

Daniel Zips, Abstract Co-Author: Nothing to Disclose

Arndt-Christian Muller, Abstract Co-Author: Nothing to Disclose

Matthias Reimold MD, Abstract Co-Author: Nothing to Disclose

To evaluate the accuracy of 11C-Choline PET/CT for preoperative lymph-node (LN) staging in patients (pts) with prostate cancer (PCA) or PSA relapse and to compare it with histological results after extended lymph-node dissection (eLND).

Retrospective analysis of 22 pts (mean 64y, range 51-75y) with histologically proven primary PCA (n=16, 13 high risk, 2 intermediate risk, 1 low risk) and 29% risk of nodal involvement (Roach formula) or biochemical relapse (n=6). All pts underwent preoperative 11C-Choline PET/CT with a standard protocol (600 Mbq, uptake time 5 min, 3min/bed, contrast-enhanced CT) and a short term eLND or selective LND (mean interval 36d, range 7-90d). PET/CT images were analyzed blindly regarding surgical results in consensus (nuclear physician and radiologist) for localization, size and 11C-Choline uptake (visually and SUVmax) of suspected lesions. The reference standard was given by histopathology of removed LN and further follow-up.

A total of 490 LN’s were removed and evaluated histologically, per-patient 19 (median, range 4-64). 64 LN’s in 10 pts (5 primary PCA, 5 relapse) were histologically positive. 12 pts had no LN metastases. 11C-Choline PET/CT was true-positive in 8 pts (39 LN’s), false-negative in 2 pts (25 LN’s), true-negative in 9 pts and false-positive in 3 pts (7 LN’s). For primary PCA the calculated values for sensitivity, specificity, PPV, NPV and accuracy were 60%/73%/50%/80% and 69% in the per-patient and 63%/96%/59%/98% and 94% in the per-node analysis. The respective numbers for the recurrent PCA were 100%/100%/100%/100% and 100% in the per-patient and 60%/100%/100%/27% and 65% in the per-node analysis. The mean diameter of true-positive LN’s was 14.7 (range 5-25mm) and in the same range as false-positive LN’s (mean 14.9, range 6-20 mm). The mean SUVmax of LN metastases was 3,4 (range 1,8-5,7).

11C-Choline PET/CT shows a high PPV and high specificity in LN staging of pts with biochemical relapse of PCA providing a basis for further therapy decisions. However sensitivity and NPV of the method are limited, especially in the case of small volume disease.

Choline PET/CT has a higher accuracy than CT and MRI for LN staging in PCA, but the value of this method is still under debate because of divergent results and often lack of histological verification.

Pfannenberg, C, Brosi, M, Gatidis, S, Brendle, C, Klumpp, B, Schwenzer, N, Claussen, C, Zips, D, Muller, A, Reimold, M, Value of 11C-choline PET/CT for Lymph-node Staging in Patients with High and Intermediate Risk Primary Prostate Cancer or Biochemical Relapse: A Retrospective Analysis with Histopathological Correlation.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044383.html