Harriet C. Thoeny

PI-RADS Prostate Imaging – Reporting and Data System: 2015, Version 2

The Prostate Imaging - Reporting and Data System Version 2 (PI-RADS™ v2) is the product of an international collaboration of the American College of Radiology (ACR), European Society of Uroradiology (ESUR), and AdMetech Foundation. It is designed to promote global standardization and diminish variation in the acquisition, interpretation, and reporting of prostate multiparametric magnetic resonance imaging (mpMRI) examination, and it is based on the best available evidence and expert consensus opinion. It establishes minimum acceptable technical parameters for prostate mpMRI, simplifies and standardizes terminology and content of reports, and provides assessment categories that summarize levels of suspicion or risk of clinically significant prostate cancer that can be used to assist selection of patients for biopsies and management. It is intended to be used in routine clinical practice and also to facilitate data collection and outcome monitoring for research.

Twenty years experience with an ileal orthotopic low pressure bladder substitute--lessons to be learned

PURPOSE We present the long-term results of a large consecutive series of patients undergoing ileal orthotopic bladder substitution following radical cystectomy. MATERIALS AND METHODS Between April 1985 and 2005 orthotopic bladder substitution with an ileal low pressure reservoir was performed in 482 patients (including 40 women) after radical and, if possible, nerve sparing cystectomy. In 447 cases the procedure was combined with an afferent ileal isoperistaltic tubular segment. The patients were followed prospectively. RESULTS In the 482 patients 61 early (less than 30 days) diversion related complications requiring prolonged hospital stay or readmission were noted and 115 late complications required treatment. At 1 year continence was good in 92% of patients during the day and in 79% at night. At last followup 93% of patients could void spontaneously. Of 442 evaluable men 99 (22.4%) reported having erections without and 68 (15.4%) with medical assistance. Ureteroileal stenosis was observed in 12 of 447 (2.7%) patients. Urethral recurrence was detected in 25 of 482 (5%) patients. A total of 15 (5%) patients received vitamin B12 substitution. Renal parenchyma decreased only in patients with preoperative or postoperative ureteral obstruction. After 10 years patients with normal renal function had no long-term acidosis and in 20 patients the incidence of osteoporosis resembled that of the normal population. CONCLUSIONS Ileal orthotopic bladder substitution combined with an afferent ileal tubular segment allows for good long-term functional results provided patients are restrictively selected, postoperative instructions are followed carefully, and typical complications such as outlet obstruction and hernias are treated early.

Extracranial applications of diffusion-weighted magnetic resonance imaging

Diffusion-weighted MRI has become more and more popular in the last couple of years. It is already an accepted diagnostic tool for patients with acute stroke, but is more difficult to use for extracranial applications due to technical challenges mostly related to motion sensitivity and susceptibility variations (e.g., respiration and air-tissue boundaries). However, thanks to the newer technical developments, applications of body DW-MRI are starting to emerge. In this review, we aim to provide an overview of the current status of the published data on DW-MRI in extracranial applications. A short introduction to the physical background of this promising technique is provided, followed by the current status, subdivided into three main topics, the functional evaluation, tissue characterization and therapy monitoring.

Predicting and Monitoring Cancer Treatment Response with Diffusion-Weighted MRI

An imaging biomarker that would provide for an early quantitative metric of clinical treatment response in cancer patients would provide for a paradigm shift in cancer care. Currently, nonimage based clinical outcome metrics include morphology, clinical, and laboratory parameters, however, these are obtained relatively late following treatment. Diffusion‐weighted MRI (DW‐MRI) holds promise for use as a cancer treatment response biomarker as it is sensitive to macromolecular and microstructural changes which can occur at the cellular level earlier than anatomical changes during therapy. Studies have shown that successful treatment of many tumor types can be detected using DW‐MRI as an early increase in the apparent diffusion coefficient (ADC) values. Additionally, low pretreatment ADC values of various tumors are often predictive of better outcome. These capabilities, once validated, could provide for an important opportunity to individualize therapy thereby minimizing unnecessary systemic toxicity associated with ineffective therapies with the additional advantage of improving overall patient health care and associated costs. In this report, we provide a brief technical overview of DW‐MRI acquisition protocols, quantitative image analysis approaches and review studies which have implemented DW‐MRI for the purpose of early prediction of cancer treatment response. J. Magn. Reson. Imaging 2010.

Synopsis of the PI-RADS v2 Guidelines for Multiparametric Prostate Magnetic Resonance Imaging and Recommendations for Use

Department of Radiology and Nuclear Medicine Radboudumc, Nijmegen, The Netherlands; Yale School of Medicine, New Haven, CT, USA; University of Cincinnati, Cincinnati, OH, USA; Harvard University, Boston, MA, USA; University Hospital of Bern, Bern, Switzerland; AdMeTech Foundation, Boston, MA, USA; g Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex, UK; University of California, Los Angeles, CA, USA; i Johns Hopkins University, Baltimore, MD, USA; University of Toronto, Sunnybrook Health Sciences Centre, Toronto, Canada; Rene Descartes University, Paris, France; National Institutes of Health, Bethesda, MD, USA

Diffusion-weighted MR Imaging in the Head and Neck

Extracranial applications of diffusion-weighted (DW) magnetic resonance (MR) imaging are gaining increasing importance, including in head and neck radiology. The main indications for performing DW imaging in this relatively small but challenging region of the body are tissue characterization, nodal staging, therapy monitoring, and early detection of treatment failure by differentiating recurrence from posttherapeutic changes. Lower apparent diffusion coefficients (ADCs) have been reported in the head and neck region of adults and children for most malignant lesions, as compared with ADCs of benign lesions. For nodal staging, DW imaging has shown promise in helping detect lymph node metastases, even in small (subcentimeter) nodes with lower ADCs, as compared with normal or reactive nodes. Follow-up of early response to treatment is reflected in an ADC increase in the primary tumor and nodal metastases; whereas nonresponding lesions tend to reveal only a slight increase or even a decrease in ADC during follow-up. Optimization and standardization of DW imaging technical parameters, comparison of DW images with morphologic images, and increasing experience, however, are prerequisites for successful application of this challenging technique in the evaluation of various head and neck pathologic conditions.

Potential and Limitations of Diffusion-Weighted Magnetic Resonance Imaging in Kidney, Prostate, and Bladder Cancer Including Pelvic Lymph Node Staging: A Critical Analysis of the Literature

CONTEXT Diagnosis, staging, and treatment monitoring are still suboptimal for most genitourinary tumours. Diffusion-weighted magnetic resonance imaging (DW-MRI) has already shown promise as a noninvasive imaging modality in the early detection of microstructural and functional changes in several pathologies of various organs. OBJECTIVE To assess the potential and limitations of DW-MRI in the management of patients with kidney, prostate, and bladder cancer. EVIDENCE ACQUISITION A nonsystematic literature search using the Medline/PubMed and Embase databases for full-length papers reporting on DW-MRI for kidney, prostate, and bladder cancer was performed up to August 1, 2011. Only those articles with complete data reporting on DW-MRI applications with potential implications in solving commonly encountered clinical challenges relating to tumour detection, staging, and treatment monitoring were finally examined. EVIDENCE SYNTHESIS For kidney tumours DW-MRI is a reasonable alternative to conventional cross-sectional imaging to detect and characterise focal renal lesions, especially in patients with impaired renal function. For prostate cancer, DW-MRI applied in addition to conventional T2-weighted and contrast-enhanced magnetic resonance imaging (MRI) improves tumour detection and localisation. In addition, it has shown promise for the assessment of tumour aggressiveness and for treatment monitoring during active surveillance, radiation therapy, and focal therapy. For bladder cancer, DW-MRI may improve the performance of conventional T2-weighted and contrast-enhanced MRI in the work-up of bladder cancer, helping to differentiate non-muscle-invasive from muscle-invasive tumours. For pelvic lymph nodes, initial results showed the potential to improve nodal staging of prostate and bladder cancer compared with conventional cross-sectional imaging. CONCLUSIONS DW-MRI holds promise to ameliorate the management of patients with kidney, prostate, and bladder cancer including pelvic lymph node staging. Current limitations include the lack of standardisation of the technique across multiple centres and the still limited expertise.

Diffusion-weighted MR Imaging of Native and Transplanted Kidneys

Applications of diffusion-weighted (DW) magnetic resonance (MR) imaging outside the brain have gained increasing importance in recent years. Owing to technical improvements in MR imaging units and faster sequences, the need for noninvasive imaging without contrast medium administration, mainly in patients with renal insufficiency, can be met successfully by applying this technique. DW MR imaging is quantified by the apparent diffusion coefficient (ADC), which provides information on diffusion and perfusion simultaneously. By using a biexponential fitting process of the DW MR imaging data, these two entities can be separated, because this type of fitting process can serve as an estimate of both the perfusion fraction and the true diffusion coefficient. DW MR imaging can be applied for functional evaluation of the kidneys in patients with acute or chronic renal failure. Impairment of renal function is accompanied by a decreased ADC. Acute ureteral obstruction leads to perfusion and diffusion changes in the affected kidney, and renal artery stenosis results in a decreased ADC. In patients with pyelonephritis, diffuse or focal changes in signal intensity are seen on the high-b-value images, with increased signal intensity corresponding to low signal intensity on the ADC map. The feasibility and reproducibility of DW MR imaging in patients with transplanted kidneys have already been demonstrated, and initial results seem to be promising for the assessment of allograft deterioration. Overall, performance of renal DW MR imaging, presuming that measurements are of high quality, will further boost this modality, particularly for early detection of diffuse renal conditions, as well as more accurate characterization of focal renal lesions.

Combined Ultrasmall Superparamagnetic Particles of Iron Oxide–Enhanced and Diffusion-weighted Magnetic Resonance Imaging Facilitates Detection of Metastases in Normal-sized Pelvic Lymph Nodes of Patients with Bladder and Prostate Cancer

BACKGROUND Conventional cross-sectional imaging with computed tomography and magnetic resonance imaging (MRI) has limited accuracy for lymph node (LN) staging in bladder and prostate cancer patients. OBJECTIVE To prospectively assess the diagnostic accuracy of combined ultrasmall superparamagnetic particles of iron oxide (USPIO) MRI and diffusion-weighted (DW) MRI in staging of normal-sized pelvic LNs in bladder and/or prostate cancer patients. DESIGN, SETTING, AND PARTICIPANTS Examinations with 3-Tesla MRI 24-36 h after administration of USPIO using conventional MRI sequences combined with DW-MRI (USPIO-DW-MRI) were performed in 75 patients with clinically localised bladder and/or prostate cancer staged previously as N0 by conventional cross-sectional imaging. Combined USPIO-DW-MRI findings were analysed by three independent readers and correlated with histopathologic LN findings after extended pelvic LN dissection (PLND) and resection of primary tumours. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Sensitivity and specificity for LN status of combined USPIO-DW-MRI versus histopathologic findings were evaluated per patient (primary end point) and per pelvic side (secondary end point). Time required for combined USPIO-DW-MRI reading was assessed. RESULTS AND LIMITATIONS At histopathologic analysis, 2993 LNs (median: 39 LNs; range: 17-68 LNs per patient) with 54 LN metastases (1.8%) were found in 20 of 75 (27%) patients. Per-patient sensitivity and specificity for detection of LN metastases by the three readers ranged from 65% to 75% and 93% to 96%, respectively; sensitivity and specificity per pelvic side ranged from 58% to 67% and 94% to 97%, respectively. Median reading time for the combined USPIO-DW-MRI images was 9 min (range: 3-26 min). A potential limitation is the absence of a node-to-node correlation of combined USPIO-DW-MRI and histopathologic analysis. CONCLUSIONS Combined USPIO-DW-MRI improves detection of metastases in normal-sized pelvic LNs of bladder and/or prostate cancer patients in a short reading time.

Do Patients Benefit from Routine Follow-up to Detect Recurrences After Radical Cystectomy and Ileal Orthotopic Bladder Substitution?

BACKGROUND The need for and intensity of follow-up to detect disease recurrence after radical cystectomy (RC) for transitional cell carcinoma (TCC) remains a matter for debate. OBJECTIVE To determine whether diagnosis of asymptomatic recurrence after RC by routine follow-up investigations confers a survival benefit versus symptomatic recurrence. DESIGN, SETTING, AND PARTICIPANTS Retrospective analysis of 479 patients with nonmetastatic bladder TCC receiving no neoadjuvant chemotherapy/radiation therapy and prospectively followed with a standardised protocol for a median 4.3 yr (range: 0.3-20.9) after RC at an academic tertiary referral centre. INTERVENTION RC and extended pelvic lymph node dissection with ileal orthotopic bladder substitution. MEASUREMENTS Cancer-specific survival (CSS) and overall survival (OS) probability for asymptomatic and symptomatic recurrent patients were estimated using the Kaplan-Meier method. The effects of age, nerve-sparing surgery, pathologic tumour stage, lymph node status, adjuvant chemotherapy, mode of recurrence diagnosis, and recurrence site on survival were assessed with multivariable Cox regression models. RESULTS AND LIMITATIONS Of the 174 of 479 patients (36.3%) with tumour recurrence, 87 were diagnosed by routine follow-up investigations and 87 by symptoms. Routine follow-up mostly detected lung metastases and urethral recurrences, while symptoms were predominantly the result of bone metastases and concomitant pelvic/distant recurrences. Of 24 patients with urethral recurrences, 13 had carcinoma in situ (CIS). Of these, 12 were successfully managed with urethra-sparing treatment, and 6 are still alive with no evidence of disease. Most other recurrent long-term survivors had lung and extrapelvic lymph node metastases. Cumulative 5-yr survival rates of the entire cohort were 69.8% (95% confidence interval [CI], 65.5-74.3%) for CSS and 61.9% (95% CI, 57.4-66.7%) for OS. In multivariable analysis, mode of recurrence diagnosis and site of initial recurrence were the only independent predictors of CSS and OS. Patients with recurrences detected by routine follow-up investigations and with secondary urothelial tumours as site of recurrence had a slightly but significantly higher survival probability. CONCLUSIONS Patients diagnosed with asymptomatic recurrences during our routine follow-up after RC had a slightly higher survival than patients with symptomatic recurrences. Routine follow-up appears particularly effective in early detection of urethral CIS, which can be treated conservatively. In addition, the predominance of lung and extrapelvic lymph node metastases in survivors may justify the use of routine cross-sectional imaging.