Combined PET/MRI improves diagnostic accuracy in patients with prostate cancer: a prospective diagnostic trial.
OBJECTIVE
The pretherapeutic assessment of prostate cancer is challenging and still holds the risk of over- or undertreatment. This prospective trial investigates positron emission tomography (PET) with [(18)F]fluoroethylcholine (FEC) combined with endorectal magnetic resonance imaging (MRI) for the assessment of primary prostate cancer.


METHODS
Patients with prostate cancer based on needle biopsy findings, scheduled for radical prostatectomy, were assessed by FEC-PET and MRI in identical positioning. After prostatectomy, imaging results were compared with histologic whole-mount sections, and the PET/MRI lesion-based semiquantitative FEC uptake was compared with biopsy Gleason scores and postoperative histology.


RESULTS
PET/MRI showed a patient-based sensitivity of 95% (36/38; 95% confidence interval (CI), 82%-99%). The analysis of 128 prostate lesions demonstrated a sensitivity/specificity/positive predictive value/negative predictive value/accuracy of 67%/35%/59%/44%/54% (P = 0.8295) for MRI and 85%/45%/68%/69%/68% (P = 0.0021) for PET, which increased to 84%/80%/85%/78%/82% (P < 0.0001) by combined FEC-PET/MRI in lesions >5 mm (n = 98). For lesions in patients with Gleason >6 tumors (n = 43), MRI and PET achieved 73%/31%/71%/33%/60% (P = 1.0000) and 90%/62%/84%/73%/81% (P = 0.0010), which were improved to 87%/92%/96%/75%/88% (P < 0.0001) by combined PET/MRI. Applying semiquantitative PET analysis, carcinomas with Gleason scores >6 were distinguished from those with Gleason ≤ 6 with a specificity of 90% and a positive predictive value of 83% (P = 0.0011; needle biopsy 71%/60%, P = 0.1071).


CONCLUSIONS
In a prospective diagnostic trial setting, combined FEC-PET/MRI achieved very high sensitivity in the detection of the dominant malignant lesion of the prostate, and markedly improved upon PET or MRI alone. Noninvasive Gleason score assessment was more precise than needle biopsy in this patient cohort. Hence, FEC-PET/MRI merits further investigation in trials of randomized, multiarm design.
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, AustriaAuthors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria.
Markus
M
Hartenbach
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria.
Sabrina
S
Hartenbach
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria.
Winfried
W
Bechtloff
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria.
Burkhardt
B
Danz
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria.
Klaus
K
Kraft
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria.
Burkhard
B
Klemenz
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria.
Christoph
C
Sparwasser
Authors' Affiliations: Departments of Nuclear Medicine; Pathology; Radiology; Urology, German Armed Forces Hospital, Ulm, Germany; and Division of Nuclear Medicine, Medical University of Vienna, Austria marcus.hacker@meduniwien.ac.at.
Marcus
M
Hacker
D000368:Aged; D002794:Choline / Q000031:analogs & derivatives*; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity
D019275:Radiopharmaceuticals; C448902:fluoroethylcholine; D002794:Choline