Objective: The use of elastography is limited for prostate cancer detection because of the difficulty in obtaining stable and reproducible images. To overcome these limitations, we developed a new technique called real-time balloon inflation elastography (RBIE); with RBIE, balloon inflation and deflation are used in place of manual compression. We present the accuracy and feasibility of the RBIE technique for detecting prostate cancer.
Materials and methods: The results of a pathologic analysis of 55 prostatectomy specimens were compared with elastographic moving images obtained at the time of biopsy of the prostate.
Results: The RBIE technique generated stable and repeatable elastographic moving images. The percentage of images affected by artifact due to slippage in the compression plane was reduced to 1% using the RBIE method compared with 32% using the manual compression method. With regard to tumor location, elastographic moving images obtained using the RBIE technique were in complete agreement with clinicopathologic evaluation of tumor location in eight cases (15%), showed partial agreement in 43 cases (78%), and disagreed in four cases (7%). In three different regions of the prostate, 84% of anterior tumors, 85% of middle tumors, and 60% of posterior tumors were detected. The tumor detection rates by Gleason score were 60% in tumors with a Gleason score of 5 or 6, 73% in tumors with a Gleason score of 7, 72% in tumors with a Gleason score of 8, and 74% in tumors with a Gleason score of 9 or 10.
Conclusion: The RBIE method improved the quality of elastographic moving images compared with the manual compression method. High-grade tumors and tumors of impalpable regions of the prostate were more frequently detected using RBIE. We conclude that RBIE is a promising method with which to detect prostate cancer.