Joseph H. Yacoub

Imaging-guided Prostate Biopsy: Conventional and Emerging Techniques

Transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations owing to the operators inability in most cases to directly visualize and target prostate lesions. Magnetic resonance (MR) imaging of the prostate overcomes many of these limitations by directly depicting areas of abnormality and allowing targeted biopsies. Accuracy in the detection of prostate cancer is improved by the combined use of standard T2-weighted MR imaging and advanced MR imaging techniques such as diffusion-weighted imaging, dynamic contrast-enhanced imaging, and MR spectroscopy. Suspicious-appearing regions of the prostate seen on MR images can be targeted at real-time transrectal US-guided biopsy to improve the diagnostic yield. MR imaging also can be performed for real-time guidance of transrectal prostate biopsy. Studies among patients who underwent at least one transrectal US-guided biopsy with a negative result before undergoing an MR imaging-guided biopsy showed improved detection rates with MR imaging-guided biopsy in comparison with the detection rates achieved with a repeat transrectal US-guided biopsy; however, MR imaging-guided biopsy is a more time-consuming procedure. A technique known as fused MR imaging- and transrectal US-guided biopsy, which relies on the coregistration of previously acquired MR images with real-time transrectal US images acquired during the procedure, shows promise but is limited by deformation of the prostate; this limitation is the subject of ongoing investigation. Another technique that is currently under investigation, MR imaging-guided prostate biopsy with robotic assistance, may one day help improve the accuracy of biopsy needle placement.

Evolving role of MRI in Crohn's disease

MR enterography is playing an evolving role in the evaluation of small bowel Crohns disease (CD). Standard MR enterography includes a combination of rapidly acquired T2 sequence, balanced steady‐state acquisition, and contrast enhanced T1‐weighted gradient echo sequence. The diagnostic performance of these sequences has been shown to be comparable, and in some respects superior, to other small bowel imaging modalities. The findings of CD on MR enterography have been well described in the literature. New and emerging techniques such as diffusion‐weighted imaging (DWI), dynamic contrast enhanced MRI (DCE‐MRI), cinematography, and magnetization transfer, may lead to improved accuracy in characterizing the disease. These advanced techniques can provide quantitative parameters that may prove to be useful in assessing disease activity, severity, and response to treatment. In the future, MR enterography may play an increasing role in management decisions for patients with small bowel CD; however, larger studies are needed to validate these emerging MRI parameters as imaging biomarkers. J. Magn. Reson. Imaging 2013;37:1277–1289.

MR Imaging of the Prostate

Multiparametric magnetic resonance (MR) imaging of the prostate is gaining acceptance in the management of prostate cancer. Emerging indications of prostate MR imaging may expand its use in the work-up of localized prostate cancer. Improvements in the standardization of prostate MR imaging techniques and reporting are needed for further establishment of the emerging roles of prostate MR imaging. This article describes the prostate MR imaging techniques and provides an approach for interpretation of prostate MR imaging studies. Established and emerging indications for prostate MR imaging are also reviewed.

New Magnetic Resonance Imaging Modalities for Crohn Disease

Magnetic resonance (MR) enterography has an increasing role in the evaluation of the small bowel in patients with Crohn disease. MR enterography is accurate for disease assessment and can influence the choice of therapy. Functional sequences may increase the role of MR enterography in Crohn disease. Techniques such as high-resolution MR enterography, diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, magnetization transfer, and MR motility imaging may allow better assessment of disease extent, activity, and severity. Quantitative analysis using these advanced techniques as well as the standard techniques may provide methods for evaluating and following the disease in the future.

How one institution overcame the challenges to start an MRI-based brachytherapy program for cervical cancer

Purpose Adaptive magnetic resonance imaging (MRI)-based brachytherapy results in improved local control and decreased high-grade toxicities compared to historical controls. Incorporating MRI into the workflow of a department can be a major challenge when initiating an MRI-based brachytherapy program. This project aims to describe the goals, challenges, and solutions when initiating an MRI-based cervical cancer brachytherapy program at our institution. Material and methods We describe the 6-month multi-disciplinary planning phase to initiate an MRI-based brachytherapy program. We describe the specific challenges that were encountered prior to treating our first patient. Results We describe the solutions that were realized and executed to solve the challenges that we faced to establish our MRI-based brachytherapy program. We emphasize detailed coordination of care, planning, and communication to make the workflow feasible. We detail the imaging and radiation physics solutions to safely deliver MRI-based brachytherapy. The focus of these efforts is always on the delivery of optimal, state of the art patient care and treatment delivery within the context of our available institutional resources. Conclusions Previous publications have supported a transition to MRI-based brachytherapy, and this can be safely and efficiently accomplished as described in this manuscript.

ACR Appropriateness Criteria Staging of Testicular Malignancy

Testicular cancer represents only 1% of all malignancies occurring in men. However, it is the most frequent malignancy in men between the ages of 20 and 34 years, accounting for 10% to 14% of cancer incidence in that age group. In most instances, the diagnosis of testicular tumors is established with a carefully performed physical examination and scrotal ultrasonography. Tumor markers are useful for determining the presence of residual disease. Cross-sectional imaging studies (CT, MRI) are useful in determining the location of metastases. Chest radiography and CT are used to assess pulmonary disease. Fluorine-18-2-fluoro-2-deoxy-d-glucose (FDG) PET scans have slightly higher sensitivity than CT, but their role in staging testicular cancer has not been determined in a large study. FDG PET may play a role in the follow-up of higher stage seminoma after chemotherapy. Bone scans are useful in the absence of FDG PET scans and should be used when bone metastases are suspected. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (the RAND/UCLA Appropriateness Method and the Grading of Recommendations Assessment, Development, and Evaluation) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Evaluation of the gallbladder and cystic duct patency with gadoxetate disodium enhanced MR cholangiography: prospective comparison of patients with normal gallbladder function and acute cholecystitis.

Background Using hepatocyte-specific magnetic resonance imaging (MRI) contrast agents such as gadoxetate disodium, MRI can provide functional information regarding the patency of the cystic duct similar to hepatobiliary scintigraphy in addition to anatomic images. Purpose To describe the gadoxetate disodium enhanced MR cholangiography (GDE-MRC) findings in patients with acute cholecystitis and to compare them with findings in patients without acute cholecystitis and with normal hepatobiliary scintigraphy. Material and Methods This study was HIPAA compliant and institutional review board approved. Twenty-three patients (n = 14 diagnosed with acute calculous cholecystitis based on ultrasound [US] or computed tomography [CT]; n = 9 controls with normal hepatobiliary scintigraphy) were prospectively enrolled. All patients underwent GDE-MRC within 2 days of the US, CT, or hepatobiliary scintigraphy. GDE-MRC included axial gradient echo T1-weighted images before and 3, 10, 20, 30, and 60 min after injection of 10 mL of gadoxetate disodium. If excretion of contrast into the gallbladder was not noted at 60 min, intravenous morphine was administered (0.04 mg/kg) and images were acquired 30 min later. Results In all nine controls, gadoxetate disodium was excreted into the gallbladder within 60 min (7/9 in <30 min). Twelve out of 14 patients with acute cholecystitis completed the study. Six out of 12 (50%) patients demonstrated contrast in their gallbladder within 1 h of administration similar to the control group (2/6 in <30 min). In the remaining 6/12 patients, contrast was not present in the gallbladder within 1 h from injection. Following morphine augmentation, contrast was subsequently noted in the gallbladder in 2/6 patients. Conclusion GDE-MRC can assess the patency of the cystic duct. Delayed (>60 min) or lack of filling of the gallbladder during GDE-MRC supports the diagnosis of acute cholecystitis. However, filling of the gallbladder with contrast in <60 min does not exclude the diagnosis of acute calculous cholecystitis.

PD55-09 ROLE OF MPMRI PSA DENSITY AND PIRADS SCORE IN PREDICTING UPSTAGING IN MEN ON ACTIVE SURVEILLANCE

Abstract Purpose Using a combination of magnetic resonance imaging of the prostate and prostate specific antigen density, we aim to determine which men on active surveillance are at risk of being upstaged, and which men could avoid repeat biopsy while remaining on surveillance. Methods We reviewed 110 men on active surveillance with Gleason 6 disease who underwent magnetic resonance imaging followed by Uronav-fusion biopsy. Using univariable and multivariable logistic regression analyses, we examined the effect of age, race, prostate specific antigen, prostate specific antigen density, prostate volume, Prostate Imaging - Reporting and Data System (PI-RADS) score, number and size of target lesions, and time on surveillance to determine the likelihood of upstaging to Gleason ≥7 disease. Results A total of 33 men, or 30%, were upstaged. On multivariable analysis, prostate specific antigen density and PI-RADS score were significant predictors of upstaging with adjusted odds ratios of 3.97 for prostate specific antigen density of ≥0.16 (CI 1.31-12.00, p Conclusion A combination of PI-RADS score and prostate specific antigen density predicts patients at risk of being upstaged at surveillance biopsy. Conversely, this combination may help determine which men may safely forgo biopsy.

Providing MR Imaging for Cervical Cancer Brachytherapy: Lessons for Radiologists

Brachytherapy (BT), the use of a locally placed or implanted radioactive source for treatment of an adjacent tumor, is an important component in the treatment of patients with both early- and advanced-stage cervical cancer and is increasingly part of the standard treatment protocol. When it is feasible, many radiation oncologists choose to include a magnetic resonance (MR) imaging examination for planning BT treatment (ie, an MR imaging examination after placement of the applicator but before radiation dosing). MR imaging provides excellent soft-tissue contrast and allows radiation oncologists to individualize the radiation dose to the target volume and minimize the dose to adjacent organs that are at risk for radiation damage. However, traditionally, the radiology department has not performed imaging studies for planning, and the requirements are different compared with those of standard diagnostic imaging. In addition, many applicators are available for use in BT treatment of cervical cancer, and each must considered separately to determine MR safety and to define the best imaging parameters. Starting and supporting a robust gynecologic BT program includes implementing imaging protocols that are helpful to both radiation oncologists and diagnostic radiologists. By becoming more familiar with this treatment modality and the logistics of imaging patients undergoing BT, radiologists can provide imaging support for colleagues in the radiation oncology department and better care for patients. ©RSNA, 2018.

MP14-16 ANTERIOR PROSTATE LESIONS AND CANCER DETECTED BY MRI IN AFRICAN AMERICAN MEN

INTRODUCTION AND OBJECTIVES: African American (AA) men tend to present with higher risk prostate cancer (CaP) with poorer prognosis than a non-AA cohort. It has been postulated that the burden of anterior prostate lesions (APL) may be greater and more aggressive in AA men leading to CaP evasion of detection and increased mortality. We aim to compare the rates and grade of APLs in AA and non-AA males. METHODS: A retrospective database was established including 463 men (64 AA, 399 non-AA) at an academic hospital who underwent prostate biopsy following MRI from to June 2014 to September 2016. Thesepatientsdidnot carry adiagnosisofCaP.Multiparametricmagnetic resonance imaging (mpMRI) was used to identify lesions suspicious for CaP. A 3-Tesla MRI machine and Invivo software was utilized for fusion. RESULTS: The AA male population studied showed no significant difference in age (p1⁄40.92), or gland volume (p1⁄40.73). However, median prostate specific antigen (PSA) (7.9 vs. 6.3; p<0.001) and PSA density (PSAD) (.134 vs.111; p<0.03) were significantly higher in the AA population. Despite this, there were fewer AA men with anterior lesions (15/64, 23.4%) then non-AA men (112/399, 28.1%). Additionally, there was no significant difference in maximum lesion size from the AA group to the control. When these lesions were biopsied, the ratios of both APLs and total lesions shown to be Gleason 7 or higher were equivalent for both populations. CONCLUSIONS: AA men were slightly less likely to have an anterior lesion mpMRI, but had equivalent total lesions and maximal lesion dimensions. Despite higher PSAD, AA men were equally likely to have clinically significant APLs and CaP in general. These findings contradict conventional hypotheses in urology and may implicate a more complex multifactorial cause for the prognostic disparity observed.