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Objective: The utility of 11 C-choline positron emission tomography/computed tomography for determining treatment response as compared with prostate-specific antigen response and prognosis prediction in castration-resistant prostate cancer patients was investigated., Methods: Eighty-four 11 C-choline-positron emission tomography/computed tomography scans before/after treatments with abiraterone (n = 12 patients), enzalutamide (n = 3), docetaxel (n = 9), cabazitaxel (n = 5), radiation therapy alone (n = 3), radiation therapy, enzalutamide, and/or abiraterone (n = 5), radium-223 (n = 4), and radiofrequency ablation (n = 1) in 42 castration-resistant prostate cancer patients were retrospectively examined. Prostate-specific antigen values were determined before and after treatment. Using the Kaplan-Meier method, the correlation of Positron Emission Tomography Response Criteria In Solid Tumors with prostate-specific antigen response and prognostic impact was evaluated., Results: Pretreatment 11 C-choline-positron emission tomography/computed tomography findings identified local, lymph node, bone, and visceral metastasis in 12, 12, 29, and five patients, respectively. Following treatments, complete metabolic response was noted in one, partial metabolic response in eight, stable metabolic disease in 13, and progressive metabolic disease in 20. Mean prostate-specific antigen change for complete metabolic response, partial metabolic response, stable metabolic disease and progressive metabolic disease was -48.9%, -55.0% (range -92.4% to -19.1%), -4.2% (-33.2% to 35.1%), and 142.7% (30.7% to 373.8%), respectively, significantly greater in the progressive metabolic disease cases (P < 0.01). Positron Emission Tomography Response Criteria In Solid Tumors was well correlated with prostate-specific antigen change. Patients with no progression (complete metabolic response/partial metabolic response/stable metabolic disease) showed significantly longer cancer-specific survival than progressive metabolic disease (P < 0.005). Using pretreatment 11 C-choline-positron emission tomography/computed tomography results to divide into three groups; (a) local and/or lymph node metastasis without bone metastasis (n = 10), (b) <6 bone metastasis sites (n = 16), (c) ≥6 bone metastasis sites and/or visceral metastasis (n = 16), cancer-specific survival showed significant stratification (P < 0.001)., Conclusions: 11 C-choline-positron emission tomography/computed tomography may reflect castration-resistant prostate cancer metastatic lesion activity for treatment response and prognosis evaluations., (© 2022 The Japanese Urological Association.)

Since the inline positron emission tomography (PET)/magnetic resonance imaging (MRI) system appeared in clinical, more than a decade has passed. In this article, we have reviewed recently-published articles about PET/MRI. There have been articles about staging in rectal and breast cancers by PET/MRI using fluorodeoxyglucose (FDG) with higher diagnostic performance in oncology. Assessing possible metastatic bone lesions is considered a proper target by FDG PET/MRI. Other than FDG, PET/MRI with prostate specific membrane antigen (PSMA)-targeted tracers or fibroblast activation protein inhibitor have been reported. Especially, PSMA PET/MRI has been reported to be a promising tool for determining appropriate sites in biopsy. Independent of tracers, the clinical application of artificial intelligence (AI) for images obtained by PET/MRI is one of the current topics in this field, suggesting clinical usefulness for differentiating breast lesions or grading prostate cancer. In addition, AI has been reported to be helpful for noise reduction for reconstructing images, which would be promising for reducing radiation exposure. Furthermore, PET/MRI has a clinical role in neuroscience, including localization of the epileptogenic zone. PET/MRI with new PET tracers could be useful for differentiation among neurological disorders. Clinical applications of integrated PET/MRI in various fields are expected to be reported in the future., (© 2022. The Author(s) under exclusive licence to The Japanese Society of Nuclear Medicine.)

Objective: To evaluate diffusion-weighted magnetic resonance imaging (DWI), 11 C-choline positron emission tomography (PET), and fluorine-18-fluorodeoxyglucose ( 18 F-FDG) PET for predicting Gleason score in prostate cancer patients., Subjects and Methods: The study cohort included 11 patients with biopsy-proven prostate cancer who underwent DWI, 11 C-choline PET, and 18 F-FDG PET examinations before treatment. The correlations of Gleason score with those findings were determined using Spearman's test. Multi-technique imaging performance for separating higher Gleason score (≥8) cases was also examined., Results: Both diffusion coefficient (ADC) map and 11 C-choline PET/computed tomography (CT) findings showed prostate cancer in all 11 patients, while 18 F-FDG PET/CT was only successful in 6 (54.5%) cases, thus no further evaluations of that modality were performed. A moderately negative correlation was observed between Gleason score and ADC value for the primary tumor shown by DWI, though the difference was not significant (r=-0.49, P=0.13). In contrast, a strongly significant positive correlation was observed between Gleason score and maximum standardized uptake value (SUVmax) for the primary tumor in 11 C-choline PET findings (r=0.85, P=0.0010). Sensitivity, specificity, and accuracy for separating higher (≥8) from lower (≤7) Gleason score were 87.5%, 33.3%, and 72.7%, respectively, with a best cut-off value of 0.78 for ADC map, and 87.5%, 100%, and 90.9%, respectively, with a best cut-off value of 6.0 for 11 C-choline PET., Conclusion: Carbon-11-choline PET was found have a greater correlation with Gleason score than DWI and is considered to be more useful to predict a higher score in patients with prostate cancer. Fluorine-18-FDG PET was limited because of low sensitivity.

We investigated the effectiveness of 11C-choline-positron emission tomography/computed tomography (PET/CT) for evaluating treatment response in patients with prostate cancer or renal cell carcinoma. We performed 34 11C-choline PET/CT scans before/after a combined total of 17 courses of treatment in 6 patients with prostate cancer and 2 with renal cell carcinoma. The 17 treatments including hormonal therapy, radiotherapy, chemotherapy, radium-223, molecular target therapy, radiofrequency ablation, transcatheter arterial embolization, and cancer immunotherapy yielded 1 (5.9%) complete metabolic response (CMR), 3 (17.6%) partial metabolic responses (PMRs), 2 (11.8%) stable metabolic diseases (SMDs), and 11 (64.7%) progressive metabolic diseases (PMDs). Target lesions were observed in bone (n=14), lymph nodes (n=5), lung (n=2), prostate (n=2), and pleura (n=1), with CMR in 4, PMR in 10, SMD in 8 and PMD in 2 lesions. SUVmax values of the target lesions before and after treatment were 7.87±2.67 and 5.29±3.98, respectively, for a mean reduction of -35.4±43.6%. The response for the 8 prostate cancer-treatment courses was PMD, which correlated well with changes in serum prostatic specific antigen (PSA) (7 of 8 cases showed increased PSA). 11C-choline-PET/CT may be an effective tool for detecting viable residual tumors and evaluating treatment response in prostate cancer and renal cell carcinoma patients., Competing Interests: No potential conflict of interest relevant to this article was reported.

We compared 11C-choline and FDG PET/CT scan findings for the staging and restaging of prostate cancer. Twenty Japanese prostate cancer patients underwent 11C-choline and FDG PET/CT before (n=5) or after (n=15) treatment. Using a five-point scale, we compared these scanning modalities regarding patient- and lesion-based diagnostic performance for local recurrence, untreated primary tumor, and lymph node and bony metastases. Of the 20 patients, documented local lesions, and node and bony metastases were present in 11 (55.0%), 9 (45.0%), and 13 (65.0%), respectively. The patient-based sensitivity/specificity/accuracy/area under the receiver-operating-characteristic curve (AUC) values for 11C-choline-PET/CT for diagnosing local lesions were 90.9% /100%/ 95.0% / 1.0, whereas those for FDG-PET/CT were 45.5% /100%/ 75.0% / 0.773. Those for 11C-choline-PET/CT for node metastasis were 88.9% /100%/ 95.0% / 0.944, and those for FDG-PET/CT were 44.4%/100%/75.0%/0.722. Those for 11C-choline-PET/CT for bone metastasis were 84.6%/100%/90.0%/0.951, and those for FDG-PET/CT were 76.9% /100%/ 85.0% / 0.962. The AUCs for local lesion and node metastasis differed significantly (p=0.0039, p=0.011, respectively). The lesion-based detection rates of 11C-choline compared to FDG PET/CT for local lesion, and node and bone metastases were 91.7% vs. 41.7%, 92.0% vs. 32.0%, and 94.8% vs. 83.0% (p=0.041, p=0.0030, p<0.0001), respectively. 11C-choline-PET/CT is more useful for the staging and restaging of prostate cancer than FDG-PET/CT in Japanese men., Competing Interests: No potential conflict of interest relevant to this article was reported.

Purpose: To investigate the impact of three-dimensional (3D) T2-weighted turbo spin-echo imaging (TSE-T2WI) with tissue-specific variable refocusing flip angle (TS-VRFA) on image quality and prostate cancer (PCa) detection and extraprostatic extension (EPE) evaluation compared to 2D TSE-T2WI and conventional 3D TSE-T2WI with volume isotropic TSE acquisition (VISTA)., Materials and Methods: Image data sets of 40 patients who underwent 3-T MRI before prostatectomy, including multiplane 2D T2WI, 3D T2WI with TS-VRFA and VISTA, and diffusion-weighted images were independently evaluated by two radiologists. The detectability of PCa and EPE of each sequence was assessed using areas by the receiver operating characteristic curve (AUC) analysis. Image quality measures and contrast ratios (CR) between cancerous lesions and non-cancerous regions for each T2WI were also evaluated., Results: Overall image quality of TS-VRFA was better than that of VISTA and equivalent to 2D. The highest CR was obtained with TS-VRFA (P < 0.05). For both readers, no significances were observed in detectability for PCa detection between three sequences (P > 0.05). For both readers, there were no significant differences in AUC for EPE evaluation between three sequences (P > 0.05)., Conclusion: 3D T2 WI using TS-VRFA could potentially replace multiplane 2D T2 WI for prostate cancer diagnosis with better image quality than VISTA.

The aim of this study was to compare 11C-choline PET/CT and bone scintigraphy (BS) for detection of bone metastases in patients with prostate cancer. Twenty-one patients with histologically proven prostate cancer underwent 11C-choline PET/CT and BS before (n = 4) or after (n = 17) treatment. Patient-, region-, and lesion-based diagnostic performances of bone metastasis of both 11C-choline PET/CT and BS were evaluated using a five-point scale by two experienced readers. Bone metastases were present in 11 (52.4%) of 21 patients and 48 (32.7%) of 147 regions; 111 lesions were found to have bone metastases. Region-based analysis showed that the sensitivity, specificity, accuracy, and area under the receiver-operating-characteristic curves (AUC) of 11C-choline PET/CT were 97.9%, 99.0%, 98.6%, and 0.9989, respectively; those of BS were 72.9%, 99.0%, 90.5%, and 0.8386, respectively. Sensitivity, accuracy, and AUC significantly differed between the two methods (McNemar test, p = 0.0015, p = 0.0015, and p < 0.0001, respectively). 11C-choline PET/CT detected 110/111 metastatic lesions (99.1%); BS detected 85 (76.6%) (p < 0.0001). According to the CT morphological type, the visualization rates of 11C-choline-PET/BS were 100%/90.3% for the blastic type, 91.7%/8.3% for the lytic type, 100%/100% for the mixed type, and 100%/53.3% for the invisible type, respectively. Significant differences in blastic, lytic, and invisible types were observed between the two methods (p = 0.013, p = 0.0044, and p = 0.023, respectively). In conclusion, 11C-choline PET/CT had greater sensitivity and accuracy than BS for detection of bone involvement in patients with prostate cancer.

Digital rectal examination, serum prostate-specific antigen screening and transrectal ultrasound-guided biopsy are conventionally used as screening, diagnostic and surveillance tools for prostate cancer. However, they have limited sensitivity and specificity. In recent years, the role of multiparametric magnetic resonance imaging has steadily grown, and is now part of the standard clinical management in many institutions. In multiparametric magnetic resonance imaging, the morphological assessment of T2-weighted imaging is correlated with diffusion-weighted imaging, dynamic contrast-enhanced imaging perfusion and/or magnetic resonance spectroscopic imaging. Multiparametric magnetic resonance imaging is currently regarded as the most sensitive and specific imaging technique for the evaluation of prostate cancer, including detection, staging, localization and aggressiveness evaluation. This article presents an overview of multiparametric magnetic resonance imaging, and discusses the current role of multiparametric magnetic resonance imaging in the different fields of prostate cancer management., (© 2016 The Japanese Urological Association.)

Background: To evaluate more detailed information noninvasively through on diffusion and perfusion in prostate cancer (PCa) using triexponential analysis of diffusion-weighted imaging (DWI)., Methods: Sixty-three prostate cancer patients underwent preoperative 3.0 Tesla MRI including eight b-values DWI. Triexponential analysis was performed to obtain three diffusion coefficients (Dp , Df , Ds ), as well as fractions (Fp , Ff , Fs ). Each diffusion parameter for cancerous lesions and normal tissues was compared and the relationship between diffusion parameters and Gleason score (GS) was assessed. K(trans) , Ve , and the ratios of intracellular components measured in histopathological specimens were compared with diffusion parameters., Results: Dp was significantly greater for cancerous lesions than normal peripheral zone (PZ) (P < 0.001), whereas Dp in transition zone (TZ) showed no significant difference (P = 0.74, 95% confidence interval (CI) = -4.69-6.48). Ds was significantly smaller for each cancerous lesions in PZ and TZ (P < 0.001, respectively). There was no significant difference in Df between cancerous lesions and normal tissues in PZ and TZ (P = 0.07, 95% CI = -0.29-0.12 and P = 0.53, 95% CI = -3.51-2.29, respectively). D obtained with biexponential analysis were significantly smaller in cancerous lesions than in normal tissue in PZ and TZ (P < 0.001 for both), while D* in PZ and TZ showed no significant difference (P = 0.14, 95% CI = -1.60-0.24 and P = 0.31, 95% CI = -3.43-1.16, respectively). Dp in PZ and TZ showed significant correlation with K(trans) (R = 0.85, P < 0.001; R = 0.81, P < 0.001, respectively), while D(*) in PZ obtained with biexponential analysis showed no such correlation (P = 0.08, 95% CI = -0.14-0.30). Fs was significantly correlated with intracellular space fraction evaluated in histopathological specimens in PZ and TZ cancer (R = 0.41, P < 0.05; R = 0.59, P < 0.001, respectively). Ff and Fs correlated significantly with GS in PZ and TZ cancer (PZ: R = -0.44, P < 0.05; R = 0.37, P < 0.05, TZ: R = -0.59, P < 0.05; R = 0.57, P < 0.05, respectively)., Conclusion: Triexponential analysis is a noninvasive approach that can provide more detailed information regarding diffusion and perfusion of PCa than biexponential analysis., (© 2015 Wiley Periodicals, Inc.)

Objective: The purpose of this study was to assess the utility of DWI and dynamic contrast enhancement (DCE) in MRI at 3 T with an endorectal coil in identifying local prostate cancer recurrence after radical prostatectomy., Materials and Methods: Eighty men underwent MRI for suspected local recurrence. The reference standards were histopathologic result, decrease in prostate-specific antigen level after salvage radiation therapy, and follow-up findings. Using a 5-point scoring system, two reviewers independently interpreted T2-weighted images alone (protocol A), a combination of T2-weighted and DW images (protocol B), a combination of T2-weighted and DCE images (protocol C), and a combination of T2-weighted, DW, and DCE images (protocol D). ROC analysis was used to compare the four protocols., Results: Local recurrence was found in 57 of the 80 patients (71.3%). The ROC AUCs for protocols A, B, C, and D were 0.71, 0.72, 0.90, and 0.89 for reader 1 and 0.65, 0.62, 0.84, and 0.83 for reader 2. Protocols C and D had statistically better performance than protocols A and B for both readers (p < 0.001). For local recurrence lesions with a long-axis diameter less than 10 mm visualized with protocol C, protocol B had detection rates of 25.0-29.4% and for lesions measuring 10 mm or greater, 67.9-69.0%. The rates of detection of local recurrence with protocol C or D were 76.5-82.4% for prostate-specific antigen levels less than 0.4 ng/mL, 60-73.3% for 0.4-1.0 ng/mL, and 80-88.0% for greater than 1.0 ng/mL., Conclusion: Addition of DCE to T2-weighted imaging in 3-T MRI with an endorectal coil improves the accuracy of detection of local cancer recurrence after radical prostatectomy. The addition of DWI is of limited incremental value for detection, especially of small lesions.

Objective: To evaluate the influence of the combinations of b-values on computed diffusion-weighted images (cDWIs) for prostate cancer (PCa) detection at b = 2000 s mm(-2)., Methods: Diffusion-weighted imaging (DWIs) for 31 patients with PCa (65.2 ± 7.1 years) were obtained pre-operatively at different b-values (0, 100, 500, 1000 and 2000 s mm(-2)) on a 3-T MRI. cDWIs at b = 2000 were generated by using six b-value combinations: 0-100 s mm(-2) (cDWI0-100); 0-500 s mm(-2) (cDWI0-500); 100-500 s mm(-2) (cDWI100-500); 0-1000 s mm(-2) (cDWI0-1000); 100-1000 s mm(-2) (cDWI100-1000); and 500-1000 s mm(-2) (cDWI500-1000). These cDWIs and measured DWIs with b = 2000 s mm(-2) (mDWI2000) were evaluated in this setting. To assess image quality for each DWI, contrast ratios (CRs) of cancerous and non-cancerous lesions were evaluated. To compare the detectability of PCa for each DWI, receiver operating characteristic analysis was used., Results: CRs of all cDWIs were significantly higher than those of mDWI2000 (p < 0.05). Areas under the curve of cDWI0-100 (0.62) and cDWI0-500 (0.65) were significantly smaller (p < 0.05) than those of others (cDWI100-500, 0.72; cDWI0-1000, 0.73; cDWI100-1000, 0.71; cDWI500-1000, 0.74; mDWI2000, 0.72)., Conclusion: The combinations of b-values influenced image quality and diagnostic ability of cDWIs for PCa detection. The combinations of b ≥ 100 and b ≥ 500 s mm(-2), as well as b = 0 and b = 1000 s mm(-2), were optimal in this study., Advances in Knowledge: For generating the useful cDWI for PCa detection, radiologists should take care of the combination of b-values when including low b-values.

Purpose: The purpose was to evaluate whether the diffusion tensor imaging (DTI) technique can visualize changes in the numbers of periprostatic nerve fibers before and after nerve-sparing and non-nerve-sparing prostatectomy., Method: Fifty-two prostate cancer patients underwent 3-T magnetic resonance imaging including DTI before and after prostatectomy., Results: After non-nerve-sparing prostatectomy, the numbers of tracts were significantly decreased at base (218.8±198.8 vs. 60.5±88.7), midgland (124.1±134.5 vs. 32.5±45.7), and apex (103.1±127.4 vs. 29.1±57.1). However, after nerve-sparing prostatectomy, the numbers of tracts were not changed significantly at base (170.5±139.7 vs. 127.7±146.0), midgland (134.3±140.8 vs. 83.7±58.3), and apex (64.1±68.4 vs. 62.3±61.9)., Conclusion: DTI technique may be feasible for visualization of periprostatic nerve fibers., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Unlabelled: The aim of this study was to compare (11)C-choline PET/CT with pelvic multiparametric MR imaging for detection of recurrent prostate carcinoma in patients with suspected recurrence after radical prostatectomy and to identify an optimal imaging method to restage these patients., Methods: This was a retrospective, single-institution study of 115 prostatectomy patients with suspected tumor recurrence who underwent both (11)C-choline PET/CT and multiparametric MR imaging with endorectal coil. The reference standard included histopathology, treatment change, and imaging follow-up for determination of locally recurrent tumor, lymph node (LN) metastases, and skeletal metastases. Two nuclear medicine and 2 genitourinary radiologists independently and in a masked manner reviewed PET/CT and multiparametric MR imaging, respectively. The reviewers assessed for local recurrence in the prostatectomy bed as well as LN and bone metastases, rating their diagnostic confidence with a 5-point scoring system for each location. Receiver-operating-characteristic analysis was used to compare the 2 modalities., Results: The standard of reference (either positive or negative) for the diagnosis of local recurrence and pelvic LN and bone metastases was met in 87, 70, and 95 patients, respectively. Documented local recurrence and pelvic LN and bone metastases was present in 61 of 87 (70.1%), 50 of 70 (71.4%), and 16 of 95 (16.8%) patients, respectively. Patient-based area under the receiver-operating-characteristic curves of multiparametric MR imaging versus PET/CT for the diagnosis of local recurrence and pelvic LN and bone metastases were 0.909 versus 0.761 (P = 0.0079), 0.812 versus 0.952 (P = 0.0064), and 0.927 versus 0.898 (P = 0.69), respectively. Among 61 patients with local recurrence, 32 patients (52.4%) were correctly diagnosed as having local recurrence by both multiparametric MR imaging and PET/CT, 22 (36.1%) were correctly diagnosed by multiparametric MR imaging only, 6 (9.8%) could not be diagnosed by either modality, and 1 (1.6%) was correctly diagnosed by PET/CT only. The patient-based sensitivity, specificity, and accuracy of multiparametric MR imaging for diagnosing local recurrence were 88.5% (54/61), 84.6% (22/26), and 87.4% (76/87) whereas those of PET/CT for detecting body LN or bone metastases were 92.3% (72/78), 100% (18/18), and 93.8% (90/96), respectively., Conclusion: Multiparametric MR imaging with endorectal coil is superior for the detection of local recurrence, PET/CT is superior for pelvic LN metastasis, and both were equally excellent for pelvic bone metastasis. (11)C-choline PET/CT and pelvic multiparametric MR imaging are complementary for restaging prostatectomy patients with suspected recurrent disease.

Prostate cancer is the most common non-cutaneous malignancy among men in the Western world, and continues to be a major health problem. Imaging has recently become more important in the clinical management of prostate cancer patients, including diagnosis, staging, choice of optimal treatment strategy, treatment follow up and restaging. Positron emission tomography, a functional and molecular imaging technique, has opened a new field in clinical oncological imaging. The most common positron emission tomography radiotracer, 18F-fluorodeoxyglucose, has been limited in imaging of prostate cancer. Recently, however, other positron emission tomography tracers, such as 11C-acetate and 11C- or (18) F-choline, have shown promising results. In the present review article, we overview the potential and current use of positron emission tomography or positron emission tomography/computed tomography imaging employing the four most commonly used positron emission tomography radiotracers, 18F-fluorodeoxyglucose, 11C-acetate and 11C- or 18F-choline, for imaging evaluation of prostate cancer., (© 2013 The Japanese Urological Association.)

Objective: To assess the efficacy of computed diffusion-weighted images (cDWIs) of b = 2000 s/mm(2) (cDWI2000) generated from DWIs of b = 0 and 1000 for prostate cancer (PCa) diagnosis in comparison with that of measured original DWIs of b = 1000 (mDWI1000) and b = 2000(mDWI2000) using 3-T MRI., Methods: Eighty patients who underwent a preoperative MRI examination, including T2WI and DWI (b = 0, 1000, 2000 s/mm(2)), were enrolled in this study. Four combinations of images, protocol A (T2WI alone), B (T2WI + mDWI1000), C (T2WI + mDWI2000) and D (T2WI + cDWI2000), were assessed for their diagnostic capability. Areas under the receiver operating characteristic curve (Az) and diagnostic performance were evaluated, as well as contrast ratios (CR) between cancerous and non-cancerous lesions for each DWI., Results: The highest CR was obtained with cDWI2000 (0.29 ± 0.16). Sensitivity, specificity, accuracy, and Az of the protocols were: A: 66.3 %, 59.4 %, 63.0 %, 0.67; B: 82.6 %, 62.0 %, 72.5 %, 0.80; C: 84.1 %, 66.5 %, 75.5 %, 0.86; D: 83.2 %, 70.0 %, 76.6 %, and 0.84, respectively The specificities and accuracies of protocol C and D were significantly higher than those of protocol B (P < 0.05)., Conclusion: cDWI2000 appears to be more effective than mDWI1000, and at least as effective as mDWI2000 for PCa diagnosis.

Objective: To investigate the usefulness of apparent diffusion coefficient (ADC) values in predicting true Gleason scores from radical prostatectomy specimen (tGS), compared with systematic transrectal ultrasound (TRUS)-guided biopsy GS (bGS)., Materials and Methods: One hundred and five patients with biopsy-proven prostate cancer underwent preoperative DWI (b-values of 0, 1000, and 2000s/mm(2)) of 3-T MRI. The mean and minimum ADCs of visible tumors were calculated for either of a pair of b-values: 0 and 1000s/mm(2) (ADC1000), or 0 and 2000s/mm(2) (ADC2000), and relationships between the four ADC parameters and tGS evaluated for the peripheral zone (PZ) and transition zone (TZ). For multiple tumors, the dominant tumor's GS and ADCs were estimated for cancer aggressiveness assessment by computing ROC curves., Results: Significant negative correlations were observed between tGS and mean ADC1000, mean ADC2000, minimum ADC1000, and minimum ADC2000 (r=-0.41, -0.39, -0.39, and -0.37, respectively) of 100 visible PZ tumors and 66 visible TZ tumors (r=-0.40, -0.42, -0.29, and -0.21, respectively). For distinguishing high-grade from low/intermediate-grade PZ lesions, the areas under the curve (AUCs) of mean ADC1000 (0.751), mean ADC2000 (0.710), minimum ADC1000 (0.768), and minimum ADC2000 (0.752) were similar to that of the highest bGS (0.708) (p=0.61, p=0.98, p=0.47, and p=0.60, respectively). For distinguishing high-grade from low/intermediate-grade TZ lesions, AUCs of mean ADC1000 (0.779), and mean ADC2000 (0.811) were similar to that of the highest bGS (0.805) (p=0.83 and p=0.97)., Conclusion: Tumor ADCs obtained with high b-values could predict prostate cancer aggressiveness as effectively as systematic TRUS-guided biopsy., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Whole-body positron emission tomography/computed tomography (PET/CT) with [(11)C]- and [(18)F]-labeled choline derivates has emerged as a promising molecular imaging modality for the evaluation of prostate cancer. (11)C- and (18)F-choline PET/CT are used successfully for restaging prostate cancer in patients with biochemical recurrence of disease after definitive therapy, especially when the serum prostate-specific antigen level is >1.0 ng/mL. (11)C- and (18)F-choline PET/CT have more limited roles for the initial staging of prostate cancer and for the detection of tiny lymph node metastases due to the low spatial resolution inherent to PET. Overall, these modalities are most useful in patients with a high pre-test suspicion of metastatic disease. The following is a review of the current clinical roles of (11)C- and (18)F-choline PET/CT in the management of prostate cancer.

Purpose: To determine, with histopathological findings of radical prostatectomy as reference, whether diffusion-weighted imaging (DWI) using b = 2000 s/mm(2) for 3-T magnetic resonance imaging (MRI) is superior to the use of b = 1000 s/mm(2) for prostate cancer detection., Materials and Methods: This study evaluated 73 patients with biopsy-proven prostate cancer. All patients underwent preoperative 3-T MRI using T2-weighted imaging (T2WI) and DWI (b = 0, 1000, 2000 s/mm(2) ). The following three sets of images were evaluated separately by two radiologists: protocol A (T2WI alone), protocol B (T2WI and DWI with b = 1000 s/mm(2) ), and protocol C (T2WI and DWI with b = 2000 s/mm(2) ). For estimation of diagnostic capability, area under the receiver operating characteristic (ROC) curve (AUC) was calculated., Results: A total of 341 cancer foci were found in the prostectomy specimens of 73 patients. Reader 1 rated AUCs of the three sets as; A 0.66, B 0.77, C 0.80. ROC analysis showed significant differences among the three protocols (A vs. B vs. C: P < 0.0001, A vs. B: P < 0.0001, B vs. C: P < 0.0001)., Conclusion: The use of b = 2000 s/mm(2) for DWI with 3-T MRI is diagnostically superior to that of b = 1000 s/mm(2) for prostate cancer detection., (Copyright © 2012 Wiley Periodicals, Inc.)

We previously reported on the accumulation of a substantial amount of free N-acetylneuraminic acid (Neu5Ac)-containing complex-type N-glycans in human pancreatic cancer cells (Yabu M, Korekane H, Takahashi H, Ohigashi H, Ishikawa O, Miyamoto Y. 2013. Accumulation of free Neu5Ac-containing complex-type N-glycans in human pancreatic cancers. Glycoconj J, 30(3):247-256). In the present paper, we further extend our cancer glycomic study of human prostate cancer. Specifically, we demonstrate that, in addition to the free Neu5Ac-containing N-glycans, significant amounts of free deaminoneuraminic acid (KDN, 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid)-containing N-glycans had accumulated in the prostate cancer tissues from four of five patients. Indeed, in one of the four cases, the free KDN glycans accumulated as major components in prostate cancer tissue. The structures of the KDN-containing free oligosaccharides were analyzed by a variety of methods. Specifically, we used fluorescent labeling with aminopyridine combined with two-dimensional mapping, KDNase digestion and mass spectrometry to facilitate identification. The analysis also utilized newly synthesized KDN-linked oligosaccharides as standards. The prostate-specific glycans were composed of five species having the following sequence, KDN-Gal-GlcNAc-Man-Man-GlcNAc (α2,6-KDN-linked glycans being the dominant form). The most abundant free KDN-containing N-glycan was KDNα2-6Galβ1-4GlcNAcβ1-2Manα1-3Manβ1-4GlcNAc followed by KDNα2-6Galβ1-4GlcNAcβ1-2Manα1-6Manβ1-4GlcNAc. This is the first study to show unequivocal chemical evidence for the occurrence of KDN glycoconjugates in human tissues together with their detailed structures. These oligosaccharides might be developed as tumor markers, especially for prostate cancer.

Purpose: To determine whether the apparent diffusion coefficient (ADC) obtained using b = 2000 s/mm(2) upon 3 Tesla (T) diffusion-weighted MRI is superior to b = 1000 s/mm(2) for discriminating malignant from normal prostate tissue and predicting the aggressiveness of prostate cancer, using histopathological findings of radical prostatectomy as a reference., Materials and Methods: Eighty prostate cancer patients underwent preoperative 3T MRI including diffusion weighted imaging with b-values of 0, 1000, and 2000 s/mm(2) . ADCs were measured for malignant lesions and normal sites on three sets of ADC maps calculated with monoexponential fitting between b = 0 and 1000, 0 and 2000, and 1000 and 2000, respectively. The relationship between the ADC and Gleason score was evaluated., Results: The areas under the ROC curves for b = 0,1000, b = 0,2000, and b = 1000,2000 were 0.896, 0.937, and 0.857, respectively, in the peripheral zone (PZ) and 0.877, 0.889, and 0.731, respectively, in the transition zone (TZ). The difference between b = 0,1000 and b = 0,2000 was significant in PZ (P = 0.033), but not in TZ (P = 0.84). Weak but significant negative correlations were identified between ADCs and Gleason score in both PZ and TZ cancer at b = 0,1000 and b = 0,2000 (r = -0.323 to -0.341)., Conclusion: For 3T MRI, ADCs using b = 0,2000 are more accurate than b = 0,1000 for diagnosing PZ cancer, and as accurate for TZ cancer., (Copyright © 2012 Wiley Periodicals, Inc.)

Purpose: To evaluate the diagnostic ability of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCEI) in combination with T2-weighted imaging (T2WI) for the detection of prostate cancer using 3 T magnetic resonance imaging (MRI) with a phased-array body coil., Materials and Methods: Fifty-three patients with elevated serum levels of prostate-specific antigen (PSA) were evaluated by T2WI, DWI, and DCEI prior to needle biopsy. The obtained data from T2WI alone (protocol A), a combination of T2WI and DWI (protocol B), a combination T2WI and DCEI (protocol C), and a combination of T2WI plus DWI and DCEI (protocol D) were subjected to receiver operating characteristic (ROC) curve analysis., Results: The sensitivity, specificity, accuracy, and area under the ROC curve (Az) for region-based analysis were: 61%, 91%, 84%, and 0.8415, respectively, in protocol A; 76%, 94%, 90%, and 0.8931, respectively, in protocol B; 77%, 93%, 89%, and 0.8655, respectively, in protocol C; and 81%, 96%, 92%, and 0.8968, respectively in protocol D. ROC analysis revealed significant differences between protocols A and B (P = 0.0008) and between protocols A and D (P = 0.0004)., Conclusion: In patients with elevated PSA levels the combination of T2WI, DWI, DCEI using 3 T MRI may be a reasonable approach for the detection of prostate cancer.

Purpose: To determine whether the apparent diffusion coefficient (ADC) obtained using a high b-value (2,000 s/mm2) is superior to that using a standard b-value (1,000 s/mm2) for discriminating malignant from normal peripheral tissue in the prostate., Methods: Twenty-six patients with biopsy-proven prostate cancer underwent 1.5T magnetic resonance (MR) imaging including single-shot, echo-planar diffusion-weighted imaging (DWI) with repetition time/echo time, 3500/88 ms; 4-mm slice thickness; 1-mm interslice gap; 144x128 matrix; field of view, 250x250 mm; number of excitations, 10; and b-values, 0, 1,000, and 2,000 s/mm2. For each patient, ADC values were obtained for malignant and normal tissue using b=1,000 and 2,000 in a monoexponential model. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios in DWI were also evaluated., Results: At b=1,000, the mean ADC (x10(-3) mm2/s) for malignant tissue was 0.82+/-0.27 (range 0.43-1.29) and for normal tissue, 1.69+/-0.23 (1.31-2.18). At b=2000, the mean ADC for malignant tissue was 0.61+/-0.19 (0.30-0.94) and for normal tissue, 1.01+/-0.14 (0.73-1.35). Significant ADC overlap between the malignant and normal tissue was recognized at b=2000. As b-value increased, the mean SNR within malignant tissue decreased by 21.6%, and mean CNR decreased 17.3%., Conclusions: Under the same imaging conditions, measuring ADC using a high b-value (2,000 s/mm2) in a monoexponential model has little diagnostic advantage over using the standard b-value (1,000 s/mm2) in discriminating malignant from normal prostate tissue.

The magnetic resonance imaging findings in 2 patients pathologically proven to have pure leiomyoma of the prostate are reported.

The present study was designed to investigate the efficacy of various combinations of chemotherapeutic agents in the treatment of prostatic cancer in a group refractory to antiandrogenic therapy (Group 1) and in a previous untreated group (Group 2). Therapeutic combinations of Estracyt (E) + Peplomycin (P) + Doxorubicin (Do) and P + Do + 5 FU (F) in Group 1 and E + P, Honvan (Ds) + P and E in Group 2 were carried out. The main objectives of this study were estimations of the efficacy of E and P in relation to the refractory cases of Group 1 and the efficacy of the combination E + P, in Group 2. This is the first such prospective, randomized, controlled study to be carried out in Japan in relation to prostatic cancer. The results obtained in the present study indicated that chemotherapeutic regimens including E provide some enhanced efficacy, but that the efficacy with regard to refractory cases is poor (23.1-27.3%), as has been reported of studies conducted in the USA and Europe. With regard to previously untreated cases, the E + P regimen achieved a relatively higher response rate than the other treatments (72.7 vs 44.5 or 50.0%). In the comparison of survival times and survival curves, there were no statistically significant differences among the various treatment subgroups. A comparison of survival curves revealed the interesting finding that the PAP-related response showed a clear correlation to the survival curves of Group 2 patients.

The purpose of this study is to demonstrate the localization and distribution of keratin-positive cells (KPC) in the various pathological types of prostatic cancer, and to investigate the correlation between the basal cell and KPC. The localization of keratin was immunohistochemically investigated in 20 benign prostatic hyperplasia (BPH) and 33 human prostatic adenocarcinomas by the indirect immunoperoxidase technique, using anti human keratin rabbit serum on frozen sections. In BPH, strongly positive staining for keratin was detected in the cytoplasm of basal cells. Glandular epithelial cells were positive. In the cancer sections, no KPC was observed in all 6 cases of the large acinar type, all 10 cases of the small acinar type and all 12 cases of the column and cord type. On the other hand, KPC remained around the cancer cell populations in all 10 cases of the cribriform type. In the fused gland type, KPC was localized in 3 of 9 cases and in the medullary type 3 of 7 cases. If KPC was regarded as the marker of the basal cell as shown in BPH, it would be speculated that the absence of KPC occurred in some type of prostatic cancer showed the disappearance of basal cell. That is, KPC could not be detected in large acinar, small acinar and column and cord type, while KPC remained completely or partially in the cribriform, fused gland and medullary type. These histochemical alteration would suggest the different degree of malignancy in the various histological type of prostatic cancer.

The interrelationship among localization of tumor, local extension, lymph node metastasis and various histological grades was investigated in 31 consecutive series of prostate cancer treated by radical prostatectomy. Surgical specimens were examined by step sections cut perpendicular to the urethra. Each tumor was graded histologically in accordance with WHO-Mostofi grading (evaluated by nuclear anaplasia and structural differentiation), Gleason's and M.D. Anderson's grading systems. The areas of the prostate was divided into 4 quadrants delimited vertically along the urethral axis and transversely at the level of utricle, i.e. anterior/superior, anterior/inferior, posterior/superior and posterior/inferior quadrants. Topographical localization and extension of each tumor was examined in accordance with the above area subdivision. Every tumor was growing at least in the posterior/inferior area. All cases with tumor progression to the anterior/superior area also revealed extensive tumor growth in the other two or three quadrants. Therefore, prostate cancer appears to be originated from the posterior/inferior area of the prostate and terminated in the anterior/superior area as local extension. In 31 cases examined, capsular invasion was noted in 22, seminal vesicle invasion in 16, and lymph node metastasis in 12 cases. All cases with seminal vesicle invasion also showed capsular invasion. None of the cases without capsular and/or seminal vesicle invasion had lymph node metastasis. Thus, it is inferred that prostate cancer is initially growing locally, extending to the capsule and seminal vesicle and then metastasizes to the pelvic lymph nodes. As for the histological grading, higher grade tumors tended to show higher incidence of capsular and seminal vesicle invasion and lymph node metastasis.(ABSTRACT TRUNCATED AT 250 WORDS)