18F-FECH PET/CT to Assess Clinically Significant Disease in Prostate Cancer: Correlation With Maximum and Total Cancer Core Length Obtained via MRI-Guided Template Mapping Biopsies.
OBJECTIVE
The objective of this study was to detect clinically significant and insignificant prostate cancer on18F-fluoroethylcholine (FECH) PET/CT and to correlate findings with transperineal template-guided prostate mapping (TPM) biopsy.


METHODS
Fifty-six lobes of the prostate were analyzed in 28 men who underwent FECH PET/CT and TPM. Whole-body images and pelvic images were acquired at 60 and 90 minutes after tracer administration. FECH PET/CT findings were correlated with TPM. Sensitivity, specificity, positive predictive values, negative predictive values, and AUC of dual phase FECH PET/CT were calculated.


RESULTS
Mean age of the patients was 68.8 years (range, 53-79 years), and mean prostate-specific antigen level was 12.1 ng/mL (range, 0.6-45 ng/mL). Mean maximum cancer core length was 4.4 mm (median, 4 mm; range, 1-14 mm) and mean total cancer core length, 14.6 mm (median, 14.6 mm; range, 1-82 mm). Prostate cancer was identified in 38 lobes with a Gleason score of 6 in five lobes (13%), 7 in 27 lobes (71%), 8 in four lobes (11%), and 9 in two lobes (5%). FECH PET/CT showed findings of prostate cancer in 46/56 lobes (82%). The ranges for maximum standardized uptake value for 60- and 90-minute FECH PET/CT were 1.3-11.4 and 1.2-10.9, respectively. Clinically significant cancer was seen in 30 of 38 positive lobes; eight had clinically insignificant disease. For 60-minute imaging, the sensitivity, specificity, and ROC AUC were 75%, 75%, and 0.746 (95% CI, 0.612-0.853). For 90-minute imaging, the sensitivity, specificity, and ROC AUC were 73.7%, 58.3%, and 0.646 (95% CI, 0.498-0.776). Overall sensitivity, specificity, positive predictive value, and negative predictive value were 95%, 50%, 82.6%, and 80%, respectively.


CONCLUSIONS
FECH PET/CT can detect prostate cancer and localizes TPM biopsy-proven clinically significant prostate cancer with sensitivity of greater than 89.7%. Of the two imaging durations, 60-minute imaging is more sensitive and specific than 90-minute imaging.
1 Institute of Nuclear Medicine, 5th Fl, Tower Block, University College London NHS Foundation Trust, 235 Euston Rd, London NW1 2BU, UK.|2 St. Bartholomew's Hospital, Barts Health NHS Trust, London, UK.
Athar
A
Haroon
3 Department of Urology, University College Hospital, London, UK.
Hashim U
HU
Ahmed
3 Department of Urology, University College Hospital, London, UK.
Paul
P
Cathcart
1 Institute of Nuclear Medicine, 5th Fl, Tower Block, University College London NHS Foundation Trust, 235 Euston Rd, London NW1 2BU, UK.
Ahmad
A
Almuhaideb
1 Institute of Nuclear Medicine, 5th Fl, Tower Block, University College London NHS Foundation Trust, 235 Euston Rd, London NW1 2BU, UK.
Irfan
I
Kayani
1 Institute of Nuclear Medicine, 5th Fl, Tower Block, University College London NHS Foundation Trust, 235 Euston Rd, London NW1 2BU, UK.
John
J
Dickson
4 Department of Radiology, University College Hospital, London, UK.
Alex
A
Kirkham
5 Department of Pathology, University College Hospital, London, UK.
Alex
A
Freeman
3 Department of Urology, University College Hospital, London, UK.
Mark
M
Emberton
1 Institute of Nuclear Medicine, 5th Fl, Tower Block, University College London NHS Foundation Trust, 235 Euston Rd, London NW1 2BU, UK.
Jamshed
J
Bomanji
D000368:Aged; D002794:Choline / Q000031:analogs & derivatives*; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D015588:Observer Variation; D010865:Pilot Projects; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D047368:Tumor Burden
C448902:fluoroethylcholine; D002794:Choline
MRI; PET/CT; fluoroethylcholine; prostate cancer; template-guided prostate mapping