¹⁸F-Fluoromethylcholine (FCH) PET imaging in patients with castration-resistant prostate cancer: prospective comparison with standard imaging.
OBJECTIVE
The aim of the study was to assess the utility of (18)F-fluorocholine (FCH), compared to standard imaging of bone scan (BS) and contrast-enhanced abdominopelvic computed tomography (CT), in patients with castration-resistant prostate carcinoma.


METHODS
FCH has shown promise as a metabolic imaging agent for prostate carcinoma. Twenty-six patients with castration-resistant prostate carcinoma had FCH, BS and CT imaging within a 2-month period. Individual FCH-positive lesions in bone were compared to the BS and soft tissue lesions were compared to CT. The lesions were then classified as concordant or discordant for the presence or absence of prostate cancer metastases. Discordant bone or soft tissue lesions were followed up with BS or CT, respectively, at 6-month intervals for up to 2 years or until a definitive diagnosis of the discordant lesion could be made.


RESULTS
In 13 (50%) of the patients, all lesions identified were concordant; this included 5 patients in whom no lesions could be identified with any imaging modality. In 21 patients, 183 lesions were observed with 149 being concordant and 34 (19%) being discordant (13 patients). Based on follow-up, FCH correctly identified the presence or absence of disease in 27 of 34 lesions, and in 14 cases FCH-positive lesions, not identified on initial imaging, were confirmed as disease on follow-up. The sensitivity, specificity, accuracy, positive predictive and negative predictive values for lesion detection by FCH are 96% (92-98%), 96% (81-99%), 96% (93-97%), 99% (96-100%) and 81% (64-88%), respectively, with 95% confidence intervals shown in parentheses.


CONCLUSIONS
In this patient cohort, FCH shows good initial concordance (81%) with BS and CT in the detection of metastatic prostate carcinoma. Follow-up of the cases where FCH was initially discordant with subsequent BS or CT shows that FCH was accurate in determining the presence or absence of prostate metastasis in 79% of lesions. While FCH imaging as compared to BS and CT in this patient group has a good sensitivity and specificity for the detection of lesions representing prostate metastasis, further prospective studies are needed to determine its role.
McCarthy
Michael
M
Department of Nuclear Medicine, Royal Perth Hospital, Perth, WA, Australia. Michael.McCarthy@health.wa.gov.au
Siew
Teck
T
Campbell
Andrew
A
Lenzo
Nat
N
Spry
Nigel
N
Vivian
Justin
J
Morandeau
Laurence
L
D000368:Aged; D000369:Aged, 80 and over; D002794:Choline / Q000031:analogs & derivatives*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009919:Orchiectomy; D049268:Positron-Emission Tomography / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
C516370:fluoromethylcholine; D002794:Choline