OBJECTIVES - To evaluate the accuracy of the radiopharmaceutical [(11) C]-acetate combined with positron emission tomography/computer tomography (acetate-PET/CT) in lymph node (LN) staging in newly diagnosed prostate cancer cases. A second aim was to evaluate the potential discriminative properties of acetate-PET/CT in clinical routine.
METHODS - In a prospective comparative study, from July 2010 to June 2013, 53 men with newly histologically diagnosed intermediate- or high-risk prostate cancer underwent acetate-PET/CT investigation at one regional centre before laparoscopic extended pelvic LN dissection (ePLND) at one referral centre. The sensitivity, specificity and accuracy of acetate-PET/CT were calculated. Comparisons were made between true-positive and false-negative PET/CT cases to identify differences in the clinical parameters: PSA level, Gleason status, lymph metastasis burden and size, calculated risk of LN involvement, and curative treatment decisions.
RESULTS - In all, 26 patients had surgically/histologically confirmed LN metastasis (LN+). Acetate-PET/CT was true positive in 10 patients, false positive in one, false negative in 16, and true negative in 26. The individual sensitivity was 38%, specificity 96%, and accuracy 68%. The acetate-PET/CT positive cases had significantly more involved LNs (mean 7.9 vs 2.4, P < 0.001) with larger cancer diameters (14.1 vs 4.9 mm, P = 0.001) and fewer eventually had treatment with curative intent (40% vs 94%, P <0.005), although we lack long-term outcome data.
CONCLUSIONS - Acetate-PET/CT has too low a sensitivity for routine LN staging but the specificity is high. The acetate-PET/CT positive cases have a very high burden of LN spread.
BJU Int. 2015 Jun 13. doi: 10.1111/bju.13202. [Epub ahead of print]
Daouacher G1, von Below C2, Gestblom C3, Ahlström H2, Grzegorek R1, Wassberg C2, Sörensen J2, Waldén M1.
1 Department of Urology, Central Hospital of Karlstad, Karlstad, Sweden.
2 Department of Radiology, Oncology and Radiation Sciences, Uppsala University, Uppsala, Sweden.
3 Department of Pathology, Central Hospital of Karlstad, Karlstad, Sweden.