C. Ishii

Initial experience of diffusion-weighted magnetic resonance imaging to assess therapeutic response to induction chemoradiotherapy against muscle-invasive bladder cancer.

OBJECTIVES To investigate the feasibility of diffusion-weighted magnetic resonance imaging (DWI) in predicting therapeutic response to low-dose chemoradiotherapy (LCRT) against muscle-invasive bladder cancer (MIBC). Accurate assessment of response to induction therapy is an essential part of bladder-sparing therapeutic protocols against MIBC. However, conventional imaging studies are not useful in evaluating therapeutic response because of their inability to distinguish residual cancer from changes secondary to the treatment. METHODS Twenty patients with clinical T2-4aN0M0 bladder urothelial carcinoma (T2/T3/T4a: n = 10/8/2) who underwent induction LCRT comprising external beam radiotherapy to the bladder (40 Gy) concomitant with 2 cycles of cisplatin administration (20 mg/d for 5 days) followed by partial (n = 13) or radical cystectomy (n = 7) were prospectively enrolled. The patients underwent magnetic resonance imaging examinations with T2-weighted imaging (T2W), dynamic contrast-enhanced T1-weighted imaging (DCE), and DWI after LCRT. A finding of each protocol was compared with a pathologic finding of cystectomy specimen. RESULTS Pathologic examination of cystectomy specimens revealed pathologic complete response in 13 (65%) of the 20 patients. The sensitivity/specificity/accuracy of T2W, DCE, and DWI in predicting pathologic response was 43/45/44%, 57/18/33%, and 57/92/80%, respectively. Despite comparable sensitivity, DWI was significantly superior in specificity and accuracy to T2W (P = .03 and .02, respectively) and DCE (P = .002 for both). CONCLUSIONS This is the first study to show the feasibility of DWI over T2W and DCE for assessing therapeutic response to induction chemoradiotherapy against MIBC. The high specificity of DWI indicates that DWI is useful to accurately predict pathologic complete response, allowing more optimal patient selection in bladder-sparing protocols.

High Diagnostic Ability of Multiparametric Magnetic Resonance Imaging to Detect Anterior Prostate Cancer Missed by Transrectal 12-Core Biopsy

PURPOSE We clarified the diagnostic ability of multiparametric magnetic resonance imaging to reveal anterior cancer missed by transrectal 12-core prostate biopsy based on the results of 3-dimensional 26-core prostate biopsy, which is a combination of transrectal 12-core and transperineal 14-core biopsies. MATERIALS AND METHODS The study population consisted of 324 patients who prospectively underwent prebiopsy multiparametric magnetic resonance imaging and then 3-dimensional 26-core prostate biopsy at a single institution. We defined transrectal 12-core negative cancer as cancer detected by transperineal 14-core but not transrectal 12-core prostate biopsy. We focused on cancer in the anterior region. Any findings suspicious for malignancy in the region anterior to the urethra on multiparametric magnetic resonance imaging were defined as an anterior lesion on imaging. Significant cancer was defined as a biopsy Gleason score of 4 + 3 or greater, a greater than 20% positive core and/or a maximum cancer length of 5 mm or greater. Associations between an anterior lesion on imaging and transrectal 12-core negative cancer were investigated. RESULTS The overall cancer detection rate on 3-dimensional 26-core prostate biopsy was 39% (128 of 324 cases), of which 28% (36 of 128) were transrectal 12-core negative cancers. An anterior lesion on prebiopsy multiparametric magnetic resonance imaging was identified in 20% of men overall (65 of 324). Of men with and without an anterior lesion on imaging 40% (26 of 65) and 3.8% (10 of 259), respectively, had transrectal 12-core negative cancer. Significant transrectal 12-core negative cancer was observed in 0.4% (1 of 259 men) without an anterior lesion on imaging. Prebiopsy multiparametric magnetic resonance imaging revealed an anterior lesion in 92% of cases (11 of 12) of significant transrectal 12-core negative cancer. CONCLUSIONS Prebiopsy multiparametric magnetic resonance imaging has the potential to efficiently select men who could advantageously undergo anterior samplings, in addition to transrectal 12-core prostate biopsy.

Apparent diffusion coefficient value reflects invasive and proliferative potential of bladder cancer.

To elucidate a role of apparent diffusion coefficient (ADC) value as a biomarker of bladder cancer, we investigated its associations with Ki‐67 labeling index (LI) along with classical clinicopathological prognosticators.

Usefulness of Pre-biopsy Multiparametric Magnetic Resonance Imaging and Clinical Variables to Reduce Initial Prostate Biopsy in Men with Suspected Clinically Localized Prostate Cancer

PURPOSE We evaluated the usefulness of pre-biopsy multiparametric magnetic resonance imaging and clinical variables to decrease initial prostate biopsies. MATERIALS AND METHODS We prospectively evaluated 351 consecutive men with prostate specific antigen between 2.5 and 20 ng/ml, and/or digital rectal examination suspicious for clinically localized disease. All men underwent pre-biopsy multiparametric magnetic resonance imaging and initial 14 to 29-core biopsy, including anterior sampling. Three definitions of significant cancer were defined based on Gleason score and cancer volume (percent positive core and/or maximum cancer length). The overall cohort was divided into men at low risk-prostate specific antigen less than 10 ng/ml and normal digital rectal examination, and high risk-prostate specific antigen 10 ng/ml or greater and/or abnormal digital rectal examination. We evaluated the frequency of significant cancer according to magnetic resonance imaging and risk categories. Clinical variables as significant cancer predictors were analyzed using logistic regression. The sensitivity, specificity, and positive and negative predictive values of magnetic resonance imaging were calculated with or without clinical variables for significant cancer. RESULTS The frequency of significant cancer in men with negative vs positive magnetic resonance imaging was 9% to 13% vs 43% to 50% in the low risk group and 47% to 51% vs 68% to 71% in the high risk group. In men at low risk with negative magnetic resonance imaging prostate volume was the only significant predictor of significant cancer. In the low risk group the negative predictive value for significant cancer of a combination of positive magnetic resonance imaging and lower prostate volume (less than 33 ml) was 93.7% to 97.5%. CONCLUSIONS Pre-biopsy multiparametric magnetic resonance imaging along with prostate volume decreases the number of initial prostate biopsies by discriminating between significant cancer and other cancer in men with prostate specific antigen less than 10 ng/ml and normal digital rectal examination.

Initial experience of functional imaging of upper urinary tract neoplasm by diffusion-weighted magnetic resonance imaging

Objectives:  Diffusion‐weighted (DW) magnetic resonance imaging (MRI) provides functional information widely used in the diagnosis of acute cerebral stroke. We reported our initial experience of this imaging technique of upper urinary tract (UUT) urothelial carcinoma (UC).

Computed Tomographic Features of Uterine Myoma

Eighty-three cases of uterine inyoina studied by computed tomography (LT) and subsequently operated on are reviewed, and the CT features of uterine myoma are presented. Postoperative diagnoses were uterine myoma in 63 (76%), uterine adenomyosis in 15 (18%), ovarian tumor in 4 (5%), and abscess in Douglass pouch in 1 (1 %).

Female urethral diverticular abscess clearly depicted by diffusion‐weighted magnetic resonance imaging

Abstract:  Diffusion‐weighted (DW) magnetic resonance imaging (MRI) is a functional imaging to assess molecular diffusion. We report a first case of female urethral diverticular abscess examined by DW MRI. A 49‐year‐old woman presented with perineal pain, pyuria and inflammatory reaction. Conventional MRI revealed urethral diverticulum with the content of slightly lower‐signal‐intensity than urine on T2‐weighted contrast. On DW MRI, the diverticulum was shown as a marked hyperintense lesion with restrained signal background of the surrounding tissue. The low apparent diffusion coefficient value of the diverticulum indicated high viscosity restricting water diffusion. DW MRI could depict urethral diverticular abscess clearly and easily in a non‐invasive manner.