Imaging of local recurrence in prostate cancer.

Diagnosis of prostate cancer (PCa) recurrence after therapy with curative intent currently depends primarily on biochemical serum analyses. When recurrence is suspected, further treatment decisions rely heavily on the confirmation of disease presence and determination of its extent. This is complicated by the fact that benign conditions can mimic biochemical recurrence, and serum studies do not reliably discriminate between local and distant recurrence. This review discusses the contemporary imaging paradigm for the evaluation of local PCa recurrence. The multidisciplinary implications for urologists, radiation oncologists and radiologists are examined. Emerging techniques and future directions of PCa imaging research are discussed.

MRI of the epididymis: can the outcome of vasectomy reversal be predicted preoperatively?

OBJECTIVE: The purpose of this study is to describe the MRI findings seen with tubular ectasia of the epididymis and investigate whether MRI may predict vasal/epididymal tubular occlusion before vasectomy reversal. MATERIALS AND METHODS: First, we compared epididymal T1 signal intensity (measured as percentage change relative to ipsilateral testis) in 24 patients with sonographically established tubular ectasia compared with 22 control patients (sonographically normal epididymides). Second, in a subset of patients with tubular ectasia who subsequently underwent surgery to restore fertility (n = 10), we examined the relationship between epididymal T1 signal intensity and surgical outcome. Vasovasostomy (simple vas deferens reanastomosis with high success rate) was possible when viable sperm were detected in the vas deferens intraoperatively. When no sperm were detected, vasal/epididymal tubular occlusion was inferred and vasoepididymostomy (vas deferens to epididymal head anastomosis, a technically challenging procedure with poorer outcome) was performed. RESULTS: In tubular ectasia, we found increased epididymal T1 signal intensity (0-77%) compared with normal epididymides (-27 to 20%) (p < 0.0001). In patients with tubular ectasia who underwent surgery (n = 10), we found higher T1 epididymal signal intensity in cases of vasal/epididymal occlusion (0-70%) relative to cases in which vasal/epididymal patency was maintained (0-10%) (p = 0.01). By logistic regression, relative epididymal T1 signal intensity increase above 19.4% corresponded to greater than 90% probability of requiring vasoepididymostomy. CONCLUSION: Increased epididymal T1 signal intensity (likely due to proteinaceous material lodged within the epididymal tubules) at preoperative MRI in patients undergoing vasectomy reversal suggests vasal/epididymal tubular occlusion and requirement for vasoepididymostomy rather than vasovasostomy.

Increased risk of vincristine neurotoxicity associated with low CYP3A5 expression genotype in children with acute lymphoblastic leukemia.

BACKGROUND: This study evaluates the relationship between cytochrome P450 (CYP) 3A5 genotype and vincristine-induced peripheral neuropathy (VIPN) in children with precursor B cell acute lymphoblastic leukemia (preB ALL). We have shown in vitro that vincristine is metabolized significantly more efficiently by CYP3A5 than by CYP3A4. We also found that vincristine neurotoxicity is less common in African-Americans (70% express CYP3A5) than in Caucasians. We test the hypothesis that CYP3A5 expressers experience less vincristine neuropathy than do CYP3A5 non-expressers. PROCEDURE: This study of pharmacogenetics of vincristine neuropathy in children with preB ALL was completed at Indiana University Simon Cancer Center. Whole blood for DNA extraction and genotyping was collected as well as plasma from a single time-point for analysis of vincristine and primary metabolite (M1) concentrations. Vincristine neuropathy was captured via chart review and graded per the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0. RESULTS: Eighty-nine percent of CYP3A5 expressers experienced neurotoxicity versus 100% of non-expressers (P = 0.03). The proportion of treatment months with neurotoxicity was significantly different between the expressers and non-expressers (16% vs. 27%, P = 0.0007). Limited pharmacokinetic data suggest different rates of vincristine metabolism between CYP3A5 genotype groups with higher primary metabolite (M1) plasma concentrations (P = 0.0004) and lower metabolic ratios ([vincristine]/[M1]) (P = 0.036) in the CYP3A5 expressers compared to the CYP3A5 non-expressers. M1 concentration was also inversely related to severity of neuropathy (P = 0.0316). CONCLUSIONS: In children with preB ALL, CYP3A5 expressers experience less VIPN, produce more M1, and have lower metabolic ratios compared to CYP3A5 non-expressers.

Effect of race on vincristine-associated neurotoxicity in pediatric acute lymphoblastic leukemia patients.

BACKGROUND: This report examines the association between race and vincristine-associated neurotoxicity in pediatric patients with precursor B cell acute lymphoblastic leukemia (preB ALL). Given that in vitro vincristine is metabolized more efficiently by cytochrome P450 (CYP) 3A5 than by CYP3A4 and that 70% African-Americans (vs. 20% of Caucasians) express CYP3A5, one may hypothesize that African-Americans metabolize vincristine more efficiently resulting in lower vincristine exposure and associated-toxicity. PROCEDURE: A retrospective analysis of vincristine-related side effects in pediatric patients treated for preB ALL was performed. Data were compared between Caucasians (n = 92) and African-Americans (n = 21) to examine the relationship between race and vincristine-associated neurotoxicity thus using race as a surrogate for CYP3A5 genotype. Race, age, gender, disease subtype, highest grade of vincristine-associated neurotoxicity (per NIH Common Terminology Criteria for Adverse Events version 3.0), number of omitted and reduced vincristine doses, cumulative vincristine dose, and disease outcome were captured. RESULTS: 34.8% of Caucasians experienced symptoms consistent with vincristine-related neurotoxicity compared to 4.8% of African-Americans (P = 0.007). The average grade of neurotoxicity for Caucasians was 2.72 versus grade 1 neurotoxicity in the African-American (P < 0.0001). Four percent of total doses administered to Caucasian patients were reduced due to vincristine-related neurotoxicity compared to 0.1% given to African-Americans (P < 0.0001). 1.2% of all protocol-indicated doses for Caucasians were held due to severe vincristine-associated toxicity compared to 0.1% of doses for African-Americans (P < 0.01). CONCLUSIONS: The data support the hypothesis pharmacogenetic polymorphisms in CYP3A5 expression contribute to variability in vincristine metabolism and neurotoxicity.

Restriction spectrum imaging improves MRI-based prostate cancer detection.

PURPOSE: To compare the diagnostic performance of restriction spectrum imaging (RSI), with that of conventional multi-parametric (MP) magnetic resonance imaging (MRI) for prostate cancer (PCa) detection in a blinded reader-based format. METHODS: Three readers independently evaluated 100 patients (67 with proven PCa) who underwent MP-MRI and RSI within 6 months of systematic biopsy (N = 67; 23 with targeting performed) or prostatectomy (N = 33). Imaging was performed at 3 Tesla using a phased-array coil. Readers used a five-point scale estimating the likelihood of PCa present in each prostate sextant. Evaluation was performed in two separate sessions, first using conventional MP-MRI alone then immediately with MP-MRI and RSI in the same session. Four weeks later, another scoring session used RSI and T2-weighted imaging (T2WI) without conventional diffusion-weighted or dynamic contrast-enhanced imaging. Reader interpretations were then compared to prostatectomy data or biopsy results. Receiver operating characteristic curves were performed, with area under the curve (AUC) used to compare across groups. RESULTS: MP-MRI with RSI achieved higher AUCs compared to MP-MRI alone for identifying high-grade (Gleason score greater than or equal to 4 + 3=7) PCa (0.78 vs. 0.70 at the sextant level; P < 0.001 and 0.85 vs. 0.79 at the hemigland level; P = 0.04). RSI and T2WI alone achieved AUCs similar to MP-MRI for high-grade PCa (0.71 vs. 0.70 at the sextant level). With hemigland analysis, high-grade disease results were similar when comparing RSI + T2WI with MP-MRI, although with greater AUCs compared to the sextant analysis (0.80 vs. 0.79). CONCLUSION: Including RSI with MP-MRI improves PCa detection compared to MP-MRI alone, and RSI with T2WI achieves similar PCa detection as MP-MRI.

Routine repeat head CT may not be indicated in patients on anticoagulant/antiplatelet therapy following mild traumatic brain injury.

INTRODUCTION: Evaluation recommendations for patients on anticoagulant and antiplatelet (ACAP) therapy that present after mild traumatic brain injury (TBI) are controversial. At our institution, an initial noncontrast head computed tomography (HCT) is performed, with a subsequent HCT performed six hours later to exclude delayed intracranial hemorrhage (ICH). This study was performed to evaluate the yield and advisability of this approach. METHODS: We performed a retrospective review of subjects undergoing evaluation for ICH after mild TBI in patients on ACAP therapy between January of 2012 and April of 2013. We assessed for the frequency of ICH on both the initial noncontrast HCT and on the routine six-hour follow-up HCT. Additionally, chart review was performed to evaluate the clinical implications of ICH, when present, and to interrogate whether pertinent clinical and laboratory data may predict the presence of ICH prior to imaging. We used multivariate generalized linear models to assess whether presenting Glasgow Coma Score (GCS), loss of consciousness (LOC), neurological or physical examination findings, international normalized ratio, prothrombin time, partial thromboplastin time, platelet count, or specific ACAP regimen predicted ICH. RESULTS: 144 patients satisfied inclusion criteria. Ten patients demonstrated initial HCT positive for ICH, with only one demonstrating delayed ICH on the six-hour follow-up HCT. This patient was discharged without any intervention required or functional impairment. Presenting GCS deviation (p<0.001), LOC (p=0.04), neurological examination findings (p<0.001), clopidogrel (p=0.003), aspirin (p=0.03) or combination regimen (p=0.004) use were more commonly seen in patients with ICH. CONCLUSION: Routine six-hour follow-up HCT is likely not indicated in patients on ACAP therapy, as our study suggests clinically significant delayed ICH does not occur. Additionally, presenting GCS deviation, LOC, neurological examination findings, clopidogrel, aspirin or combination regimen use may predict ICH, and, in the absence of these findings, HCT may potentially be forgone altogether.

Role of interventional radiology in the management of acute gastrointestinal bleeding.

Acute gastrointestinal bleeding (GIB) can lead to significant morbidity and mortality without appropriate treatment. There are numerous causes of acute GIB including but not limited to infection, vascular anomalies, inflammatory diseases, trauma, and malignancy. The diagnostic and therapeutic approach of GIB depends on its location, severity, and etiology. The role of interventional radiology becomes vital in patients whose GIB remains resistant to medical and endoscopic treatment. Radiology offers diagnostic imaging studies and endovascular therapeutic interventions that can be performed promptly and effectively with successful outcomes. Computed tomography angiography and nuclear scintigraphy can localize the source of bleeding and provide essential information for the interventional radiologist to guide therapeutic management with endovascular angiography and transcatheter embolization. This review article provides insight into the essential role of Interventional Radiology in the management of acute GIB.

PET/CT appearance of acute pyelonephritis.

An 18-year-old male patient with a history of Ewing sarcoma originally involving the right ilium was evaluated with an FDG PET/CT scan to evaluate the effect of salvage therapy after standard treatment failed and disease progressed to involve the right T12 pedicle. Autologous stem cell transplantation and cyberknife therapy resulted in mixed tumor response, with incidental note made of prominent areas of cortical FDG avidity in the right kidney. These regions demonstrated focal hypoenhancement on the corresponding diagnostic contrast-enhanced CT, which additionally demonstrated peripheral enhancement spanning the length of the right ureter. Clinical workup produced a diagnosis of acute pyelonephritis.

PowerPoint: know your medium.

To make the most of PowerPoint in professional presentations, presenters need to understand some basic principles that transcend the software. These include a thorough grasp of the message a presenter wants to convey; the backgrounds, interests, and needs of the audience; and the best approaches to fitting the medium of delivery to the content of the material. PowerPoint is a useful tool, but like any tool, whether a stethoscope, a scalpel, or a CT scanner, it can be used well or ill. Using it to its full capabilities requires that we regard it less as a crutch that can compensate for our deficiencies and more as a springboard with which to vault our presentations higher. At its best, PowerPoint can serve us just as brushes and pigments serve an artist, but it can never substitute for a fertile imagination and a discerning eye.