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Dive into the research topics where Yoshimasa Jo is active.

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Featured researches published by Yoshimasa Jo.


Journal of Magnetic Resonance Imaging | 2008

Apparent diffusion coefficient values in peripheral and transition zones of the prostate: comparison between normal and malignant prostatic tissues and correlation with histologic grade.

Tsutomu Tamada; Teruki Sone; Yoshimasa Jo; Shinya Toshimitsu; Takenori Yamashita; Akira Yamamoto; Daigo Tanimoto; Katsuyoshi Ito

To investigate the utility of apparent diffusion coefficient (ADC) values for discriminating tumor in patients with prostate cancer from normal prostatic tissues in healthy adult men, and to identify correlations between ADC and histologic grade of prostate cancer.


Radiology | 2008

Prostate Cancer: Relationships between Postbiopsy Hemorrhage and Tumor Detectability at MR Diagnosis

Tsutomu Tamada; Teruki Sone; Yoshimasa Jo; Akira Yamamoto; Takenori Yamashita; Naoto Egashira; Shigeki Imai; Masao Fukunaga

PURPOSE To retrospectively evaluate the influence of postbiopsy hemorrhage on the accuracy of tumor detection at T2-weighted magnetic resonance (MR) imaging, dynamic contrast material-enhanced MR imaging, and diffusion-weighted (DW) MR imaging of prostate cancer, with histologic findings as the reference standard. MATERIALS AND METHODS The institutional review board approved this study and waived the requirement for informed consent. Forty male patients aged 62-84 years (mean age, 71 years) who had prostate cancer underwent MR imaging of the prostate gland after ultrasonographically (US) guided systematic 12-core-specimen biopsy. The mean time between biopsy and MR imaging was 24 days (range, 6-54 days). T1-weighted, T2-weighted, dynamic contrast-enhanced, and DW imaging examinations were performed at 1.5 T. The prostate was divided, according to the biopsy sites, into eight regions on the MR images. Three reviewers in consensus evaluated each region for hemorrhage and prostate cancer. Statistical evaluations were performed with Mann-Whitney U, Ryan, and Spearman rank correlation tests. RESULTS Intraglandular hemorrhage was observed in 38 (95%) patients and significantly more often in the peripheral zone (PZ) than in the transition zone (TZ) (P < .001). Degree of hemorrhage did not correlate significantly (P = .536) with time between biopsy and MR imaging. The sensitivity, specificity, and accuracy of combined T2-weighted, dynamic contrast-enhanced, and DW imaging in the diagnosis of prostate cancer were 69%, 85%, and 78%, respectively. Sensitivity and specificity were lower for the TZ than for the PZ. Degree of hemorrhage was significantly lower in regions of positive biopsy findings than in regions of negative biopsy findings (P = .001) and correlated negatively with tumor size (P = .043). CONCLUSION Interpretation of combined T2-weighted, dynamic contrast-enhanced, and DW MR image findings can yield reasonable diagnostic accuracy in both the PZ (80% [191 of 240 regions]) and the TZ (74% [59 of 80 regions]).


Urology | 2008

Optimal Approach for Prostate Cancer Detection as Initial Biopsy: Prospective Randomized Study Comparing Transperineal Versus Transrectal Systematic 12-Core Biopsy

Ryoei Hara; Yoshimasa Jo; Tomohiro Fujii; Norio Kondo; Teruhiko Yokoyoma; Yoshiyuki Miyaji; Atsushi Nagai

OBJECTIVES Transperineal and transrectal prostate biopsy are both used for prostate cancer detection. However, which approach is superior remains unknown. In this study, we performed a prospective randomized study to compare the efficacy of transperineal versus transrectal 12-core initial prostate biopsy. METHODS From May 2003 to October 2005, a prospective randomized study of transperineal versus transrectal 12-core biopsy (126 and 120 patients, respectively) was conducted in 246 patients with a prostate-specific antigen level of 4.0 to 20.0 ng/mL. All procedures were performed with the patient in the lithotomy position, with the transperineal and transrectal approach performed with spinal anesthesia (0.5% bupivacaine) or a caudal block (1% lidocaine), respectively. With both approaches, eight biopsy specimens were obtained systematically from the peripheral zone, including the apex, and four from the transition zone. RESULTS The cancer detection rate was 42.1% (53 of 126 patients) with the transperineal approach and 48.3% (58 of 120 patients) with the transrectal approach (P = 0.323). For all patients undergoing transperineal and transrectal biopsy, the cancer core rate (cancer core number/biopsy core number) was 13.7% (207 of 1512 cores) and 14.4% (208 of 1440 cores), respectively (P = 0.566). Apart from headache, presumably related to the spinal anesthesia, no significant differences were found in the complications between the two groups. CONCLUSIONS No significant differences were found in the cancer detection rate, cancer core rate, or complications between the two approaches. We believe that the preferred approach as an initial prostate biopsy is the transrectal approach, which does not require spinal anesthesia or another burdensome process.


Prostate Cancer and Prostatic Diseases | 2008

A prospective randomized comparison of diagnostic efficacy between transperineal and transrectal 12-core prostate biopsy.

A Takenaka; Ryoei Hara; T Ishimura; Tomohiro Fujii; Yoshimasa Jo; Atsushi Nagai; Masato Fujisawa

The aim of this study is to elucidate the diagnostic efficacy between transperineal and transrectal 12-core prostate biopsy for prostate cancer. We prospectively randomized 200 consecutive men into two groups to undergo systematic prostate biopsy. Overall positivity for cancer was similar (47% by transperineal and 53% by transrectal; P=0.480). However, in case with ‘gray zone’ PSA (from 4.1 to 10.0 ng/ml), significantly more cores were positive when approach was transperineal, especially among transition zone cores. Therefore, urologist preferences are sufficient for choosing an approach, except for a possible small advantage of transperineal biopsy when PSA is in gray zone.


Journal of Bone and Mineral Metabolism | 2001

Biochemical markers for the detection of bone metastasis in patients with prostate cancer : diagnostic efficacy and the effect of hormonal therapy

Tsutomu Tamada; Teruki Sone; Tatsushi Tomomitsu; Yoshimasa Jo; Hiroyoshi Tanaka; Masao Fukunaga

Abstract In the present study, we investigated the diagnostic effectiveness of biochemical markers of bone turnover for the detection of bone metastasis from prostate cancer and changes in the levels of these markers caused by hormonal therapy. Ninety-five patients with prostate cancer were divided into one of three groups: 26 patients with bone metastasis (BM(+)), 35 patients without bone metastasis on nonhormonal therapy (BM(−)HT(−)) and 34 patients without bone metastasis on hormonal therapy (BM(−)HT(+)). All patients in the BM(+) group had received hormonal therapy. Serum or urinary levels of the following biochemical markers of bone turnover were examined: bone-specific alkaline phosphatase (B-ALP), osteocalcin (OC), type I procollagen C-propeptide (PICP), type I collagen cross-linked C-telopeptide (ICTP), C-telopeptide fragment (CTx), N-telopeptide fragment (NTx), total pyridinoline (T-Pyr), total deoxypyridinoline (T-D-Pyr) and free deoxypyridinoline (F-D-Pyr). The BM(+) group showed significantly higher values than the BM(-)HT(-) group for B-ALP, PICP, NTx, CTx, T-Pyr, T-D-Pyr, and F-D-Pyr. Compared with the BM(−)HT(+) group, the BM(+) group showed significantly higher values for B-ALP, ICTP, NTx, T-Pyr and T-D-Pyr. The levels of B-ALP, NTx, CTx, T-D-Pyr and F-D-Pyr were significantly different between the BM(−)HT(−) and BM(−)HT(+) groups. All markers, except OC and CTx, significantly were correlated with the extent of bone metastasis on bone scintigraphy. Of all markers, receiver operating characteristic (ROC) analyses revealed B-ALP and F-D-Pyr to be the most sensitive and specific for differentiation between the BM(+) and BM(−)HT(−) groups with regard to bone formation and resorption, respectively. In contrast, B-ALP and ICTP were most sensitive and specific for differentiation between the BM(+) and BM(−)HT(+) groups. The results suggest that hormonal therapy greatly affects the efficacy of PICP, CTx and F-D-Pyr in the diagnosis of bone metastasis, whereas its effects on ICTP are small. Although bone metabolic markers would be useful in the diagnosis of bone metastasis from prostate cancer, the effects of hormonal therapy on bone metabolism should be kept in mind in their evaluation.


Journal of Magnetic Resonance Imaging | 2008

Age-related and zonal anatomical changes of apparent diffusion coefficient values in normal human prostatic tissues.

Tsutomu Tamada; Teruki Sone; Shinya Toshimitsu; Shigeki Imai; Yoshimasa Jo; Koji Yoshida; Akira Yamamoto; Takenori Yamashita; Naoto Egashira; Kiyohisa Nagai; Masao Fukunaga

To identify age‐related changes and differences in the diffusion of water molecules within the prostate, through diffusion‐weighted imaging (DWI) of the prostate gland in healthy adult Japanese men.


International Journal of Urology | 2011

Effects of three types of alpha‐1 adrenoceptor blocker on lower urinary tract symptoms and sexual function in males with benign prostatic hyperplasia

Teruhiko Yokoyama; Ryoei Hara; Kazuhiko Fukumoto; Tomohiro Fujii; Yoshimasa Jo; Yoshiyuki Miyaji; Atsushi Nagai; Atsushi Sone

Objectives:  The aim of the present study was to explore the effects of three different types of alpha‐1 adrenoceptor blockers (α1‐blocker) on lower urinary tract symptoms (LUTS), erectile dysfunction (ED) and ejaculatory dysfunction (EjD) in patients with benign prostatic hyperplasia.


American Journal of Roentgenology | 2011

Locally Recurrent Prostate Cancer After High-Dose-Rate Brachytherapy: The Value of Diffusion-Weighted Imaging, Dynamic Contrast-Enhanced MRI, and T2-Weighted Imaging in Localizing Tumors

Tsutomu Tamada; Teruki Sone; Yoshimasa Jo; Junichi Hiratsuka; Atsushi Higaki; Hiroki Higashi; Katsuyoshi Ito

OBJECTIVE The purpose of this article is to retrospectively evaluate the utility of prostate MRI for detecting locally recurrent prostate cancer after high-dose-rate (HDR) brachytherapy. MATERIALS AND METHODS Sixteen men with biochemical failure after HDR brachytherapy for prostate cancer underwent prostate MRI, including T2-weighted imaging, dynamic contrast-enhanced MRI (DCE-MRI), and diffusion-weighted imaging (DWI), using a 1.5-T MRI unit before 12-core-specimen biopsy. Two radiologists in consensus assessed the presence of tumor on each sequence within eight regions of the prostate (six from the peripheral zone [PZ] and two from the transition zone [TZ]) on the basis of biopsy. RESULTS Biopsy revealed locally recurrent prostate cancer in 22 (17 in PZ and five in TZ) of 128 regions (17.2%). The sensitivity, specificity, and accuracy of each MRI method in the detection of recurrent tumor were 27%, 99%, and 87%, respectively, for T2-weighted imaging; 50%, 98%, and 90%, respectively, for DCE-MRI; and 68%, 95%, and 91%, respectively, for DWI. The sensitivity of DWI in detecting recurrent tumor was significantly higher than that of T2-weighted imaging (p = 0.004). Multiparametric MRI achieved the highest sensitivity (77%) but with slightly decreased specificity (92%). CONCLUSION These results indicate that a multiparametric MRI protocol that includes DWI provides a sensitive method to detect local recurrence after HDR brachytherapy.


International Journal of Urology | 2006

Transperineal extended biopsy improves the clinically significant prostate cancer detection rate: a comparative study of 6 and 12 biopsy cores.

Atsushi Takenaka; Ryouei Hara; Yoji Hyodo; Takeshi Ishimura; Yutaka Sakai; Hitoshi Fujioka; Tomohiro Fujii; Yoshimasa Jo; Masato Fujisawa

Background:  We evaluated the improvement in the rate of prostate cancer detection when using a 12‐core transperineal biopsy protocol including transitional zone biopsy.


PLOS ONE | 2014

High b Value (2,000 s/mm2) Diffusion-Weighted Magnetic Resonance Imaging in Prostate Cancer at 3 Tesla: Comparison with 1,000 s/mm2 for Tumor Conspicuity and Discrimination of Aggressiveness

Tsutomu Tamada; Naoki Kanomata; Teruki Sone; Yoshimasa Jo; Yoshiyuki Miyaji; Hiroki Higashi; Akira Yamamoto; Katsuyoshi Ito

Objective The objective of our study was to investigate tumor conspicuity and the discrimination potential for tumor aggressiveness on diffusion-weighted magnetic resonance imaging (DW-MRI) with high b value at 3-T. Materials and Methods The institutional review board approved this study and waived the requirement for informed consent. A total of 50 patients with prostate cancer (69 cancer foci; 48 in the PZ, 20 in the TZ, and one in whole prostate) who underwent multiparametric prostate MRI including DW-MRI (b values: 0, 1000 s/mm2 and 0, 2000 s/mm2) on a 3-T system were included. Lesion conspicuity score (LCS) using visual assessment (1 = invisible for surrounding normal site; 2 = slightly high intensity; 3 = moderately high; and 4 = very high) and tumor-normal signal intensity ratio (TNR) were assessed, and apparent diffusion coefficient (ADC, ×10−3 mm2/s) of the tumor regions and normal regions were measured. Results Mean LCS and TNR at 0, 2000 s/mm2 was significantly higher than those at 0, 1000 s/mm2 (p<0.001 for both). In addition, ADC at both 0, 1000 and 0, 2000 s/mm2 was found to distinguish intermediate or high risk cancer with Gleason score ≥7 from low risk cancer with Gleason score ≤6 (p<0.001 for both). Furthermore, ADC of tumor regions correlated with Gleason score at both 0, 1000 s/mm2 (ρ = −0.602; p<0.001) and 0, 2000 s/mm2 (ρ = −0.645; p<0.001). Conclusions For tumor conspicuity and characterization of prostate cancer on DW-MRI of 3-T MRI, b = 0, 2000 s/mm2 is more useful than b = 0, 1000 s/mm2.

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Ryoei Hara

Kawasaki Medical School

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Teruki Sone

Kawasaki Medical School

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