Elastography allows prostate cancer detection in fewer cores than systemic biopsy
MedWire News: Real-time elastography (RTE)-targeted prostate biopsy can detect the presence of prostate cancer using fewer cores than are needed with systematic biopsy in men with a prostate-specific antigen (PSA) level between 1.25 and 4.00 ng/ml, say researchers.
The team compared the results of a 5-core RTE-targeted prostate biopsy with those of a 10-core systematic biopsy in the same patients, and observed an almost five-fold higher cancer detection rate per core using the RTE method.
"We believe that image targeted biopsy has great potential for diagnosing [prostate cancer], especially when the number of biopsy cores needed for cancer diagnosis can be decreased," write Friedrich Aigner from the Medical University of Innsbruck in Austria, and co-authors.
"This may have a significant impact on patients' morbidity associated with biopsy," they add in the Journal of Urology.
The study cohort included 94 men who were scheduled for a prostate biopsy on the basis of a raised PSA level (mean=3.20 ng/ml).
Patients underwent RTE to the peripheral zone, where most prostate cancers originate, and hard areas of tissue were considered suspicious for disease. The men received a 5-core biopsy based on the results of RTE, followed by a standard 10-core systematic biopsy.
Overall, 27 prostate cancer cases were identified. RTE-targeted biopsy detected cancer in 20 patients, while the systematic method detected cancer in 18.
RTE-targeted biopsy cores were also more frequently positive for cancer compared with systematic cores, at 24.0% versus 5.1% of cases, giving a 4.7-fold greater probability that an RTE-identified core was cancer positive compared with a systematic biopsy core.
The researchers note that, unfortunately, RTE-guided biopsy had a false-positive finding rate of 39%: in four men with suspicious findings, RTE failed to detect prostate cancer when systematic biopsy did, and three men with normal findings on RTE had prostate cancer on systematic biopsy. However, the method had high sensitivity and negative predictive values, at 74% and 93% respectively.
The high negative predictive value in particular may spare patients from unwarranted prostate biopsy when PSA is used as the indication, remark Aigner et al.
"Further multicenter studies are desirable to determine whether these results can be reproduced in different populations and different countries," concludes the team.
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By Sarah Guy