Diffusion-weighted imaging of prostate cancer using a statistical model based on the gamma distribution.

Diagnostic efficacy of b value (2000 s/mm2) diffusion-weighted imaging for prostate cancer: Comparison of a reduced field of view sequence and a conventional technique

Aim. To compare the diagnostic performance of diffusion weighted imaging (DWI) using b-values of 1000 s/mm2 and 2000 s/mm2 at 3 Tesla (T) for the evaluation of clinically significant prostate cancer. Matherials and Methods. Seventy-eight prostate cancer patients underwent a 3T MRI scan followed by radical prostatectomy. DWI was performed using b-values of 0, 1000, and 2000 s/mm2 and qualitatively analysed by two radiologists. ADC maps were obtained at b-values of 1000 and 2000 s/mm2 and quantitatively analyzed in consensus. Results. For diagnosis of 78 prostate cancers the accuracy of DWI for the young reader was significantly greater at b = 2000 s/mm2 for the peripheral zone (PZ) but not for the transitional zone (TZ). For the experienced reader, DWI did not show significant differences in accuracy between b-values of 1000 and 2000 s/mm2. The quantitative analysis in the PZ and TZ was substantially superimposable between the two b-values, albeit with a higher accuracy with a b-value of 2000 s/mm2. Conclusions. With a b-value of 2000 s/mm2 at 3T both readers differentiated clinical significant cancer from benign tissue; higher b-values can be helpful for the less experienced readers.

Citrate as an in vivo marker to discriminate prostate cancer from benign prostatic hyperplasia and normal prostate peripheral zone: Detection via localized proton spectroscopy

Although many models have been proposed to interpret non-Gaussian diffusion MRI data in biological tissues, it is often difficult to see the correlation between the MRI data and the histological changes in the tissue. Among these models, so called statistical models, which assume the diffusion coefficient D is distributed continuously within a voxel, are more suitable for interpreting the data in a histological context than others. In this work, we examined a statistical model based on the gamma distribution. First, the proposed gamma model, the bi-exponential model, and the truncated Gaussian model were compared for goodness of fit. To evaluate diagnostic capability, area fractions of certain D ranges were evaluated. The area fraction for D < 1.0 mm2/s (frac < 1) was attributed to small cancer cells with restricted diffusion, and the area fraction for D > 3.0 mm2/s (frac > 3) was considered to reflect perfusion component. A clinical data set of histologically proven prostate cancer cases from previous study was used. For the cancer tissue, the gamma model was better fit than the truncated Gaussian model, and there was no significant difference between the gamma model and the bi-exponential model. For the normal peripheral zone tissue, there was no significant differences among all models. In the 2D scatter plot of frac < 1 vs. frac > 3, Cancer and non-cancer tissues were clearly separated. Using the proposed model, the diffusion MR data was well fit, and histological interpretation of the data appears possible.

Purpose:Prostate cancer management includes identification of clinically significant cancers that may require curative treatment. Statistical models based on gamma distribution can describe diffusion signal decay curves of prostate cancer. The purpose of this study was to evaluate the ability of parameters obtained with the gamma model in differentiating prostate cancers with different Gleason score values.Methods:This study included 155 patients with prostate cancer who underwent multiparametric magnetic resonance imaging prior to prostate biopsy (127 patients) or radical prostatectomy (28 patients) between January 2015 and June 2017; 159 foci of prostate cancer were included in our study. We compared cases scored as Gleason score (GS) 3 + 3 and GS ≥ 3 + 4, and analyzed cases scored as GS ≤ 3+ 4 and GS ≥ 4 + 3 based on the gamma model (Frac < 1.0, Frac < 0.8, Frac < 0.5, Frac < 0.3, and Frac > 3.0), and apparent diffusion coefficient (ADC).Results:Among 159 cancerous lesions in 155 patients, 13 (8.2%) were GS 3 + 3 prostate cancers, 51 (32.0%) were GS 3 + 4 prostate cancers, 30 (18.2%) were GS 4 + 3 cancers, and 65 (40.9%) were GS ≥ 4 + 4 cancers. Frac < 0.3, Frac < 0.5, Frac < 0.8, and Frac < 1.0 were significantly higher and ADC values were significantly lower in GS ≥ 4 + 3 cancers than in GS ≤ 3 + 4 cancers (P < 0.01, P < 0.01, P < 0.01, P = 0.01, and P < 0.01, respectively). With receiver operating characteristic (ROC) analysis, Frac < 0.3 and Frac < 0.5 had significantly greater area under the ROC curve for discriminating GS ≥ 4 + 3 cancers from GS ≤ 3 + 4 cancers than ADC (P = 0.03, P < 0.01, respectively).Conclusion:Frac < 0.3 and Frac < 0.5 showed higher diagnostic performance than ADC for differentiating GS ≥ 4 + 3 from GS ≤ 3 + 4 cancers. The gamma model may add additional value in discrimination of tumor grades.

Purpose: This study examined the significance of tubulin α and βII expression in benign prostatic hyperplasia (BPH) and prostate cancer. Materials and Methods: A total 103 cases diagnosed with either BPH or prostate cancer were divided into 4 groups: BPH (n=25), localized prostate cancer (n=41), locally advanced prostate cancer (n=18), metastatic prostate cancer (n=18). The tissues were taken through a transurethral resection of the prostate, suprapubic prostatectomy, prostatic needle biopsy or radical retropubic prostatectomy. The expression was measured by immunohistochemical staining. The degree of expression was graded on a 4-point scale. The data was compared in terms of stage, the serum prostatic specific antigen (PSA) level and Gleason score. The statistical comparisons were made using one-way ANOVA test and a Fisher's exact test. Results: The levels of tubulin α and βII expression were stronger in the patients with prostate cancer than those with BPH (p 0.05). The level of tubulin α expression was stronger in the patients with a Gleason score ≥8 than in those of Gleason score ≤7 (p<0.05), but there was no such difference in tubulin βII expression. The level of tubulin α and βII expression was stronger in the patients with a serum PSA level ≥4ng/ml than in those with the serum PSA level <4ng/ml (p<0.001). Conclusions: The expression of tubulin α and βII may be associated with the development of prostate cancer. These might be used as useful markers for the diagnosis, prognosis and treatment response. (Korean J Urol 2008; 49:709-714) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏

PurposeOur aim was to investigate the diffusion-weighted Imaging (DWI) appearance and apparent diffusion coefficient (ADC) values of normal prostatic gland, prostate carcinoma (PCa) and benign prostate hyperplasia (BPH) and to determine the utility of DWI in their characterization. Materials and methodsDuring a period of 16months, 40 consecutive patients, with elevated PSA level and 12 healthy volunteers with no clinical symptoms or history of prostate disease were prospectively evaluated with DWI of the prostate. MRI was performed using a 1.5T MR scanner equipped with a pelvic phased array coil. For anatomical imaging, T2W FSE in the three orthogonal planes, and T1WI in axial plane were obtained. DWI with b values of 0, 300, 500 and 800s/mm2 were performed in axial plane. The results were confirmed by TRUS-guided biopsy or prostatectomy. ResultsPatients ranged in age from 45 to 85years (mean 66.6±7.9year). Twenty patients were confirmed to have BPH, whereas 20 patients had PCa. The mean and SD of ADC values for the peripheral zone (PZ), central gland (CG), BPH nodules and PCa were 1.839±0.233, 1.469±0.239, 1.359±0.201 and 0.87±0.13 respectively. The mean ADC value of PCa was significantly lower than that of CG, PZ, and BPH nodule, with p value <0.05. ConclusionDW MR imaging characteristics and ADC values can differentiate PCa and BPH. DWI with ADC may be used as a complementary method to conventional MRI in diagnosis of PCa and BPH.

Comparison of the Clinical Validity of Free Prostate–Specific Antigen, Alpha–1 Antichymotrypsin–Bound Prostate–Specific Antigen and Complexed Prostate–Specific Antigen in Prostate Cancer Diagnosis

Benign prostatic hyperplasia (BPH) and prostate cancer commonly occur together. This suggests that common familial, hormonal, and environmental factors contribute to their development. In men at risk for the development of prostate cancer (at 40 men in 19 families) and aged-matched unrelated controls (n = 46), we have determined whether familial factors, age, and blood hormone concentrations are related to the transition zone (TZ), peripheral zone (PZ), or total volume of the prostate measured by transrectal ultrasound (TRUS). We determined that the influences of age, prostate cancer (n = 15), and familial status did not significantly affect the relationships reported. Therefore, data from all groups were combined for this study. TZ correlated positively with age (P = 0.003) after controlling for family status, but total prostate volume correlated insignificantly with age (P = 0.08). In addition, the ratio of TZ to PZ volumes also correlated significantly with age in the control group (r = 0.27, P = 0.014). Both TZ and PZ volumes correlated highly (r = 0.91, P < 0.0001, n = 86) with total volume. In addition, total volume correlated significantly (r = 0.71, P < 0.001) with the ratio of the TZ/PZ volumes, which also correlated significantly with each other (r = 0.61, P < 0.0001, n = 86). In contrast to the increase of TZ volume related to total prostate volume, PZ volume declined compared with total volume. Prostate volumes up to 50 ml are predominated by the PZ and above 50 ml by the TZ, which may compress and shrink the PZ. Both TZ and total prostate volume correlated positively with serum estrone concentrations (P = 0.04 and P = 0.003, respectively). These results suggest that the risk of prostate cancer does not contribute to generalized overgrowth of the prostate, including the TZ. However, estrogens and age strongly influence TZ but not PZ volume. Both PZ and TZ volumes rise together until the prostate exceeds 50 ml, when the growth of the TZ appears to exceed the PZ and then to compress it.

Expanded Prostate Cancer Index Composite for Clinical Practice: Development and Validation of a Practical Health Related Quality of Life Instrument for Use in the Routine Clinical Care of Patients With Prostate Cancer

: Diffusion tensor magnetic resonance imaging (DTI) measurements of prostate cancer (PCa) were performed in vivo, in patients undergoing radical prostatectomy, and ex vivo, in the same patients' prostatectomy specimens. For the first time, the imaging data were co-registered to histological sections of the prostatectomy specimens, thereby enabling unambiguous characterization of diffusion parameters in cancerous and benign tissues. Through image co-registration and histological analysis, we have shown that increased cellularity, and thence decreased luminal spaces, in peripheral zone PCa leads to about 40 % and 50 % apparent diffusion coefficient (ADC) decrease compared to benign peripheral zone tissues in vivo and ex vivo, respectively. In contrast, no significant diffusion anisotropy differences between the cancerous and noncancerous peripheral zone tissues were observed. The bundled fibromuscular tissues in prostate, such as stromal tissues in benign prostatic hyperplasia (BPH), exhibited high diffusion anisotropy facilitating the differentiation of PCa from BPH in central gland. A tissue classification method, combining DTI and T2w images, was proposed to provide more specific PCa detection. An ADC threshold for PCa was also established to provide unsupervised PCa localization. The PCa identified using this method correlate well with histologically identified PCa foci.

1H-MRSI of prostate cancer: The relationship between metabolite ratio and tumor proliferation

The TOSOH II PA (AIA-PACK PA in the U.S.A.) monoclonal immunoenzyme assay was used and the clinical usefulness of prostate specific antigen (PSA) was evaluated in 39 men with prostatic cancer and 32 men with benign prostatic hyperplasia (BPH) confirmed pathologically. We evaluated the lower limit of detection in this assay by the mean PSA level plue 3 standard deviations in 5 separate experiments with a zero control sera as well as the mean PSA level minus 3 standard deviations in 5 separate experiments with serial dilutions of a known concentration of PSA. PSA concentrations of 0 to 0.25 ng/ml could not be distinguished from the zero control. Therefore, we set the lower limit of detection for the assay as 0.25 ng/ml. At our laboratory, the normal standard value was determined by the mean PSA level plus 3 standard deviations in 79 healthy men as 2.3 ng/ml. Of patients that underwent radical cystoprostatectomy for bladder cancer, all had PSA levels less than 0.25 ng/ml, while only 6% had PAP levels less than 0.11 ng/ml, the lower limit of detection in the TOSOH II PAP assay. We compared TOSOH II PA with Markit PA, a commonly used assay in Japan. Although there was a close linear correlation (r = 0.90) between the TOSOH II PA and Markit PA, the difference of slope in the linear regression lines was great, it was thought due to anti-PSA antibodies in each assay recognizing different epitopes of PSA in the blood.(ABSTRACT TRUNCATED AT 250 WORDS)

PAGE4 Positivity Is Associated with Attenuated AR Signaling and Predicts Patient Survival in Hormone-Naive Prostate Cancer

CCR2 and CCR5 genes polymorphisms in benign prostatic hyperplasia and prostate cancer