Sangeet Ghai

Efficacy of Embolization in Traumatic Uterine Vascular Malformations

PURPOSE To evaluate the efficacy of embolotherapy in patients with bleeding traumatic uterine arteriovenous malformations (AVMs). MATERIALS AND METHODS A retrospective review of all patients who underwent pelvic arterial embolization at our institution between July 1992 and September 2002 was performed. Fifteen patients were diagnosed with a uterine vascular malformation on duplex ultrasonography and correlative MR imaging. Serial beta-human chorionic gonadotropin levels were measured to exclude gestational trophoblastic neoplasia. All patients underwent transcatheter embolization of the uterine arteries. Embolizations were performed with use of standard 4-5-F catheters and microcatheters when necessary. Embolic agents in the 25 procedures included glue only (n = 13), polyvinyl alcohol (PVA) particles and glue (n = 4), PVA particles (n = 2), Gelfoam (n = 2), coils (n = 1), PVA particles and coils (n = 1), glue and Gelfoam (n = 1), and glue and coils (n = 1). PVA particle size ranged from 350 to 1,000 micro m. Outcomes assessed were cessation of bleeding, persistence or resolution of the AVM, complications, and pregnancy after embolization. These were assessed by chart, laboratory, and imaging reviews. RESULTS A total of 25 embolization procedures were performed in 15 patients. Six patients required repeat embolization (one patient underwent embolization on six occasions; five patients had two embolization procedures each) for recurrence of bleeding. Sixteen procedures were performed on an elective basis and nine were performed on an emergent basis. The technical success rate of embolization was 100%. The clinical success rate was 93%: bleeding was controlled in 14 of 15 patients and one patient underwent a hysterectomy. Four of the 15 patients subsequently had a total of five uneventful intrauterine pregnancies carried to term. The 14 patients who underwent successful embolization had no recurrence of bleeding at a median follow-up of 53 months (range, 3-124 months) after treatment. Three patients were eventually lost to follow-up. One minor complication (0.4%) of non-flow-limiting dissection of the internal iliac artery occurred. CONCLUSION Percutaneous embolotherapy is a safe and effective treatment for traumatic AVMs. This procedure allows for preservation of uterine function with the possibility of future pregnancy and should be considered as a primary treatment option.

The expanding role of MRI in prostate cancer.

OBJECTIVE The purpose of this article is to review the many evolving facets of MRI in the evaluation of prostate cancer. We will discuss the roles of multiparametric MRI, including diffusion-weighted MRI, dynamic contrast-enhanced MRI, and MR spectroscopy, as adjuncts to morphologic T2-weighted imaging in detection, staging, treatment planning, and surveillance of prostate cancer. CONCLUSION Radiologists need to understand the advantages, limitations, and potential pitfalls of the different sequences to provide optimal assessment of prostate cancer.

Feasibility of real time next generation sequencing of cancer genes linked to drug response: results from a clinical trial.

The successes of targeted drugs with companion predictive biomarkers and the technological advances in gene sequencing have generated enthusiasm for evaluating personalized cancer medicine strategies using genomic profiling. We assessed the feasibility of incorporating real‐time analysis of somatic mutations within exons of 19 genes into patient management. Blood, tumor biopsy and archived tumor samples were collected from 50 patients recruited from four cancer centers. Samples were analyzed using three technologies: targeted exon sequencing using Pacific Biosciences PacBio RS, multiplex somatic mutation genotyping using Sequenom MassARRAY and Sanger sequencing. An expert panel reviewed results prior to reporting to clinicians. A clinical laboratory verified actionable mutations. Fifty patients were recruited. Nineteen actionable mutations were identified in 16 (32%) patients. Across technologies, results were in agreement in 100% of biopsy specimens and 95% of archival specimens. Profiling results from paired archival/biopsy specimens were concordant in 30/34 (88%) patients. We demonstrated that the use of next generation sequencing for real‐time genomic profiling in advanced cancer patients is feasible. Additionally, actionable mutations identified in this study were relatively stable between archival and biopsy samples, implying that cancer mutations that are good predictors of drug response may remain constant across clinical stages.

Comparison of CT Histogram Analysis and Chemical Shift MRI in the Characterization of Indeterminate Adrenal Nodules

OBJECTIVE Adrenal nodules having an attenuation of more than 10 H on unenhanced CT are considered indeterminate. The purpose of this study was to compare CT histogram analysis and chemical shift MRI in the characterization of indeterminate adrenal nodules. MATERIALS AND METHODS Thirty-nine adrenal masses that were indeterminate on CT were identified in 37 patients. Histogram analysis was performed on unenhanced CT from a region of interest (ROI) that recorded mean attenuation, number of pixels, and percentage of negative pixels. MR signal intensity drop between the in- and opposed-phase images was measured for the masses. Analyses to determine whether correlations existed among the mean CT attenuation, percentage of negative pixels, and MR signal intensity drop were performed. A final diagnosis was obtained by pathology results, follow-up of more than 6 months, or adrenal washout CT findings. RESULTS Negative pixels were present in 25 of 28 adenomas and nine of 11 nonadenomas. A threshold of more than 10% negative pixels for the diagnosis of adenoma provided a sensitivity of 46% and specificity of 100%. A threshold of more than 20% MR signal intensity drop yielded a sensitivity of 71% and specificity of 100%. An increase in the percentage of negative pixels was correlated with a decrease in mean CT attenuation. Using MRI, observers characterized seven additional nodules as adenomas compared with CT histogram analysis (McNemar test, chi2 = 5.1429; p = 0.023). CONCLUSION CT histogram analysis with a threshold of a 10% negative pixel presence increases sensitivity for the characterization of adenomas compared with analysis of the mean CT attenuation alone. The use of chemical shift MRI with a threshold of 20% signal intensity drop results in a higher sensitivity than CT histogram analysis.

Split-Bolus MDCT Urography: Upper Tract Opacification and Performance for Upper Tract Tumors in Patients With Hematuria

OBJECTIVE Our purpose was to assess upper urinary tract opacification and the performance of split-bolus MDCT urography for upper tract tumors in patients with hematuria. MATERIALS AND METHODS Between January 2004 and December 2006, we identified 200 patients (119 men, 81 women; median age, 58 years, age range, 18-89 years) who underwent MDCT urography for hematuria. MDCT urography included unenhanced and combined nephrographic and excretory phase imaging of the urinary tract. Images were independently reviewed by two radiologists blinded to the final diagnosis. The degree of upper urinary tract opacification and the diagnosis were recorded. Prospective interpretations were also reviewed. The standard of reference included all available clinical, imaging, and laboratory data for up to 12 months after MDCT urography. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated for upper tract tumors for prospective and retrospective interpretations. RESULTS For reviewers 1 and 2, 85.1% and 84.5% of segments were at least 50% opacified, respectively. Final diagnoses for hematuria were no cause, 123 (61.5%); urothelial cancer, 27 (13.5%); nonmalignant, 46 (23%) and indeterminate, four patients (2%). There were nine upper tract cancers. Sensitivity, specificity, and accuracy for upper tract cancers for prospective interpretation, reviewer 1 and reviewer 2, were 100%, 99%, 99%; 100%, 99.5%, 99.5%; and 88.9%, 99.0%, 98.5%, respectively. CONCLUSION Split-bolus MDCT urography provided at least 50% opacification of the majority of upper urinary tract segments and had high sensitivity, specificity, and accuracy for the detection of upper urinary tract tumors.

Operator is an Independent Predictor of Detecting Prostate Cancer at Transrectal Ultrasound Guided Prostate Biopsy

PURPOSE We investigated whether interoperator differences exist in the setting of prostate cancer detection by transrectal ultrasound guided prostate biopsy. Our secondary aim was to investigate whether a learning curve exists for prostate cancer detection. MATERIALS AND METHODS A prospective database from 2000 to 2008 including 9,072 transrectal ultrasound guided prostate biopsies at our institution was limited to 4,724 done at initial presentation. Biopsies were performed by 4 uroradiologists. The OR for detecting cancer on transrectal ultrasound guided prostate biopsy was calculated for likely independent prognostic variables, including operator. We also examined the rate of biopsy positivity in increments, comparing the first and last cohorts. The senior radiologist (AT) with the most biopsies (75%) was considered the referent for prostate cancer detection. Univariate and multivariate logistic regression modeling was used to determine significant covariates with p <0.05 deemed relevant. RESULTS Prostate cancer was detected in 2,331 men (49.3%). Operators performed a median of 514 transrectal ultrasound guided prostate biopsies (range 187 to 3,509) with a prostate cancer detection rate of 43.8% to 52.4% (p = 0.001). Other significant covariates were prostate specific antigen, suspicious lesions on ultrasound, nodule on digital rectal examination, smaller prostate volume and increasing patient age. Operator was a significant multivariate predictor of cancer detection (OR 0.67 to 0.89, p = 0.003). No learning curve was detected and biopsy rates were consistent throughout the series. CONCLUSIONS Significant differences in prostate cancer detection exist among operators who perform transrectal ultrasound guided prostate biopsy even in the same setting. The volume of previously performed transrectal ultrasound guided prostate biopsies does not appear to influence the positive prostate cancer detection rate, nor could a learning curve be identified. Differences in prostate cancer detection among operators are likely related to unknown differences in expertise or technique. Further research is needed.

Real-Time MRI-Guided Focused Ultrasound for Focal Therapy of Locally Confined Low-Risk Prostate Cancer: Feasibility and Preliminary Outcomes

OBJECTIVE Focal therapy is an emerging approach to the treatment of localized prostate cancer. The purpose of this study was to report the 6-month follow-up oncologic and functional data of the initial phase 1 trial of patients treated with focal transrectal MRI-guided focused ultrasound in North America. SUBJECTS AND METHODS Four patients with a prostate-specific antigen (PSA) level of 10 ng/mL or less, tumor classification cT2a or less, and a Gleason score of 6 (3 + 3) were prospectively enrolled in the study and underwent multiparametric MRI and transrectal ultrasound-guided prostate systematic biopsy. Under MRI guidance and real-time monitoring with MR thermography, focused high-frequency ultrasound energy was delivered to ablate the target tissue. The incidence and severity of treatment-related adverse events were recorded along with responses to serial quality-of-life questionnaires for 6 months after treatment. Oncologic outcomes were evaluated with multiparametric MRI and repeat transrectal ultrasound-guided biopsy 6 months after treatment. RESULTS Four patients with a total of six target lesions were treated and had complications graded Clavien-Dindo I or less. Quality-of-life parameters were similar between baseline and 6-months. All four patients had normal MRI findings in the treated regions (100%), biopsy showed that three patients (75%) were clear of disease in the treated regions, representing complete ablation of five target lesions (83%). All patients had at least one Gleason 6-positive core outside of the treated zone. CONCLUSION MRI-guided focused ultrasound is a feasible method of noninvasively ablating low-risk prostate cancers with low morbidity. Further investigation and follow-up are warranted in a larger patient series with appropriate statistical analysis of oncologic and functional outcome measures.

Assessment of Urinary Tract Calculi With 64-MDCT: The Axial Versus Coronal Plane

OBJECTIVE The objective of our study was to compare the detection rate, conspicuity, and size measurements of urinary tract calculi on coronal reformations versus the axial plane using 64-MDCT. MATERIALS AND METHODS For this retrospective study, 80 consecutive CT examinations performed for clinical diagnosis of renal colic or for the assessment of known nephrolithiasis were evaluated. All studies were stripped of patient identifiers, and the axial and coronal plane images of each study were randomized and presented to two abdominal radiologists. For each study, the radiologists recorded the number and location of stones, diagnostic confidence and stone conspicuity (subjectively on a 2-point scale), and stone size. The standard of reference was data from a consensus reading with the study coordinator examining the same parameters on images in both planes of each patient. Detection rates were compared between planes using logistic regression with generalized estimating equations to account for multiple stones per patient. RESULTS On consensus reading, 272 stones were identified. For all renal stones, the coronal plane detected more stones as compared with the axial plane (p < 0.001). For stones smaller than 5 mm, a higher proportion received the maximal conspicuity score on the coronal plane than on the axial plane (p < 0.001). Both reviewers better estimated stone size on the coronal plane than the axial plane (p = 0.02); their axial plane measurements underestimated stone size by 13.4% (mean). CONCLUSION The detection of stones and estimation of maximal stone diameter were improved using coronal reformations. The conspicuity of stones and diagnostic confidence in identifying stones smaller than 5 mm in diameter were also improved on the coronal plane.

Focal magnetic resonance guided focused ultrasound for prostate cancer: Initial North American experience

The treatment of low-risk prostate cancer is a common clinical dilemma between standard curative whole gland therapy (and its associated quality of life diminishing side effects) and active surveillance (and its low, but real, risk of progression). The goal of focal therapy in low-risk prostate cancer is to achieve the best balance between cancer control and maintenance of quality of life. Magnetic resonance-guided focused ultrasound (MRgFUS) surgery is a non-invasive thermal ablation method that integrates magnetic resonance imaging for target identification, treatment planning and closed-loop control of thermal deposition and focused ultrasound for thermal ablation of the tumour target. This novel transrectal system allows for tumour localization, targeting and monitoring of tumour target ablation in real time, while simultaneously preserving adjacent normal tissue thereby minimizing the side effects of standard curative surgical or radiation therapy. We report the first North American clinical experience of treatment of localized prostate cancer with focal MR-guided transrectal focused ultrasound (clinicaltrial.gov identifier NCT01226576).

Role of Transrectal Ultrasonography in Prostate Cancer

Transrectal ultrasound and ultrasound guided prostate biopsy is the current standard for detecting prostate cancer. Newer techniques such as elastography and contrast enhanced ultrasound may help in lesion detection and monitoring. Advances are occurring in several areas including multiparametric MRI, understanding of the nature of prostate cancer and new therapies including focal therapy and active surveillance. These changes are creating an increasing role for targeted biopsies following MRI and for use of MRI for treatment monitoring.