Kouhei Ogawa, Shinji Hara, Hiroaki Shiina, Hiroaki Yasumoto, Haruki Anjiki, Chiaki Koike, Takeshi Yoshizako, Taichi Nagami, Shigenobu Nakamura, Takeo Hiraoka, Naoko Arichi, Yozo Mitsui, and Masahiro Sumura
INTRODUCTION AND OBJECTIVES: Efficacy in the prostate cancer detection of real-time tissue elastogarpahy (RTE) has been reported. But RTE has a major problem that RTE is highly operator dependent procedure. We hypothesized that the pressure device might decrease the operator dependency and increase the prostate cancer detection rate of RTE. The pressure device run with water pressure was developed for this study, called this procedure real-time balloon inflation elastography (RBIE). The results of targeted prostate biopsy with RBIE was studied for detection of prostate cancer. METHODS: 233 patients and 1978 were enrolled in this study with abnormal findings of digital rectal examination (DRE), PSA and/ or TRUS. Median age was 73 year-old (range 54e89), median PSA was 7.6 ng/mL (range 0.8-2606.0), and median number of biopsy cores taken on each patient was 8 (range 8e10). All of 233 patients were examined with MRI prior to prostate needle biopsy. A total of 1978 specimens obtained by systemic biopsy were studied. The findings of RBIE, RTE, TRUS, PDUS and MRI (T2WI, dynamic contrast enhanced images (DCEI) and diffusion weighted image (DWI)) were compared to the histopathological findings of biopsy specimens. RESULTS: The prostate cancer was detected in 113 of 233 patients (48.5%), and 412 of 1978 specimens (20.8%). Gleason score of 5 to 6, 7 and 8 to 10 tumors was 110, 166 and 138 specimens respectively. Clinical stages of T1c, T2a-c, T3a-b, and T4 were 20, 60, 22 and 11 cases. The sensitivity of RBIE, RTE, TRUS, PDUS, T2WI, DCEI and DWI were 72.1%, 72.1%, 74.5%, 72.8%, 78.2%, 77.2% and 77.2%, the specificity were 94.3%, 93.6%, 85.4% 90.5%, 92.0%, 93.7% and 92.6%, respectively. Both of the sensitivity and the specificity of RBIE were not significantly inferior to those of MRI. The results of targeted biopsy (PPV) of RBIE, RTE, TRUS, PDUS, T2WI, DCEI and DWI were 76.7%, 74.8%, 57.4%, 67.0%, 72.0%, 76.4% and 73.3%. PPV of RBIE was also comparable to those of MRI. CONCLUSIONS: RBIE was low cost and low invasive procedure. The prostate cancer detection capability of RBIE might be not inferior to that of MRI, expensive and time consuming procedure. Furthermore, RBIE reveals prostate in real-time, so RBIE could enhance the prostate cancer detection as a biopsy guidance image.