Real-Time Elastography Superior for Identifying Prostate Cancer
VIENNA—Real-time elastography has significantly better predictive accuracy for identifying prostate cancer (PCa) lesions compared with contrast-enhanced magnetic resonance imaging (MRI), researchers reported here at the 26th Annual Congress of the European Association of Urology. Biopsy studies need to confirm these results, however.
Jochen Walz, MD, of the Institut Paoli-Calmettes, Marseille, France, and colleagues studied 28 PCa patients who underwent real-time elastography and contrast-enhanced MRI prior to radical prostatectomy at least six weeks after a prostate biopsy.
During the biopsy, each prostate was partitioned into 12 sectors (anterior, posterior, left, right, base, middle gland, and apex), for a total of 336 sectors. Suspect zones were identified and their locations recorded. For each imaging modality, investigators compared preoperative suspicions for cancer lesions and pathologic results.
The clinical stage was T1c for 78.5% of patients. The pathologic stage was pT2a in 14.3%, pT2b in 10.7%, pT2c in 64.2%, and pT3b in 10.7%, according to researchers. The median prostate volume was 30 grams (range 10-63 grams), and the median diameter of the main cancer lesion was 2.5 cm.
In all, 88 cancer lesions could be identified in the prostatectomy specimen. For real time elastography vs. MRI, the sensitivity and specificity for correct cancer identification were, respectively, 73.4% vs. 31.2% and 79.0% vs. 90.5%, the researchers stated. The negative and positive predictive values for elastography vs. MRI were, respectively, 83.4% vs. 69.2% and 67.4% vs. 66.1%. The accuracy for correct identification of the tumor lesion was 76.5% for elastography and 68.5% for MRI 68.5%, a significant difference between modalities.
In a separate study presented at the conference, Marko Brock, MD, and collaborators at Ruhr University Bochum in Herne, Germany, demonstrated that real-time elastography, compared with conventional gray-scale ultrasound, significantly improves the PCa-detection sensitivity of 10-core prostate biopsies.
The study included 373 men suspected of having PCa. Researchers randomly assigned 178 men to undergo real-time elastography or gray-scale ultrasound prior to prostate biopsy. After a digital rectal examination (DRE), a 10-core systematic biopsy was performed. Stiffer blue-colored lesions on elastography and hypoechoic lesions on ultrasonography prompted suspicion of PCa. The two groups did not differ with respect to age, PSA level, prostate volume, and DRE findings.
PCa was detected in 160 men (45.3%). The detection rate was significantly better in the elastography than the ultrasonography group (51.1% vs. 39.4%). Overall, the sensitivity and specificity for predicting PCa were 60.8% and 68.4%, respectively, for elastography and 15% and 92.3% for ultrasonography.