Browsing by Author "Wong, Daniel"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Improved Detection of Higher Risk Prostate Cancer by MRI-Targeted Versus Standard Template Ultrasound-Guided Biopsy(2018-01-23) Wong, Daniel; Shakir, Nabeel; Passoni, NiccoloIMPORTANCE: The majority of new prostate cancer (PCa) diagnoses made in the United States occur via transrectal ultrasound (TRUS) guided systematic template prostate biopsy ("standard biopsy"). Since this modality depends on random sampling of the organ, which may lead to undersampling of aggressive disease in addition to detection of low-risk PCa with concomitant harms of overtreatment, there is a demand for more reliable and accurate diagnostic methods. Multiparametric magnetic resonance imaging (MP-MRI) of the prostate can identify lesions suspicious for PCa, and platforms using software fusion of pre-acquired MRI with real-time TRUS ("MRI-targeted biopsy") are now FDA-approved. OBJECTIVE: To assess whether MRI-targeted biopsy detects a significantly greater proportion of higher-grade, clinically-significant disease as compared to standard biopsy ("upgrading") in patients who underwent both approaches. DESIGN: Prospective cohort study of men undergoing both MRI-targeted and standard biopsy from the National Cancer Institute (NCI) and UT Southwestern from 2007 to 2017. Pathology was categorized by the International Society of Urological Pathology grading scheme and compared between targeted biopsy and concurrent standard biopsy with McNemar's test. Parameters associated with upgrading, determined by threshold p<0.15, were evaluated in multivariable logistic regression models where significance was defined as p<0.05. INTERVENTIONS: Following referral for elevated serum prostate-specific antigen (PSA), patients underwent MP-MRI. Men with lesions suspicious for PCa on MRI underwent a single biopsy session during which targeted biopsy and standard biopsy were performed concurrently. RESULTS: Of 1913 men in the study, 1235 were diagnosed with PCa by either standard or targeted biopsy. Patients between the two centers were matched by age and PSA (Table 1) but differed by history of previous biopsy, MRI prostate volume, and racial distribution. 408 patients had intermediate to high grade prostate cancer diagnosed by either targeted or standard biopsy (Table 2), of whom 194 (47%) had concordant targeted and standard biopsy results. 151 (37%) men had intermediate to high grade disease missed or downgraded relative to targeted biopsy by standard biopsy, and 63 men (15%) were missed or downgraded relative to standard biopsy by targeted biopsy (p<0.0001). On multivariable analysis of upgrading by targeted biopsy, when controlling for potentially confounding factors, increasing age, MRI prostate volume, number of targets and PSA remained significantly associated, whereas the performing center was not predictive. CONCLUSIONS: MRI-targeted prostate biopsy results in greater detection of clinically significant higher-grade PCa as compared to standard biopsy. Whether MRI-targeted biopsy can be performed instead of standard biopsy, versus being performed in selected risk-stratified populations or as a supplemental technique, requires additional study.Item Testing Isogenicity of Recurrent UTI in Postmenopausal Women(2017-01-17) Wong, Daniel; Sarir, Saloomeh; Dao, Ryan; Thomas, Collin; Zimmern, Philippe E.PURPOSE: Due to increase in antibiotic allergies and resistance, the care of older women with recurrent urinary tract infections (UTIs) can be extremely challenging. Antibiotic regimens assume that infections are due to a single genetically identical species or isogen. The aim of this study was to use the classic method of phage typing to test whether the UTI pathogen in a patient is isogenic. Our hypothesis posits that infection may be due to the existence of a complex ecology of simultaneous infection by multiple same-species strains. METHODS: Mid-stream urine samples were taken from postmenopausal women with history of documented recurrent UTIs. Standard urine culture confirmed the presence of Escherichia coli bacterial strain. Urine sample was spread on LB agar plate and incubated for 24hrs at 37 degrees Celsius. 50 separate colonies were picked from the incubated plate and were treated in a patch assay with novel UTI targeting phages from the Rajagopal/Thomas Lab. Transilluminated images where taken with Biorad Image Lab equipment; then sensitivity to each phage was rated. Urine sample from patient 9 was used because our Lab had the most phages specific to lysing it. Phage clearings from the patch were rated on a scale of 0-3 based upon prevailing phage-typing metrics. (Ward et al. year) RESULTS: Differences to phage sensitivity across the 50 colonies numbered 9-1 to 9-50 were noted. Colonies 9-8, 9-44, and 9-46 were notably more resistant to a set of phages that was effective on all the other colonies. DISCUSSION: These findings in one representative older woman with recurrent UTI caused by Escherichia coli may have clinical significance particularly if differential phage sensitivity correlates with virulence, biofilm production, and antibiotic sensitivity variations. Pathogen findings in our urine samples suggest that infection may be an ecology of related, but nonidentical bacteria. CONCLUSION: The observed differences in phage sensitivity suggest there are multiple related, but non isogenic, Escherichia coli in the same bladder, a mechanism possibly contributing to antibiotic resistance and thus leading to UTI recurrence. Next step is to test each colony clone for its antibiotic sensitivity profile to determine if this novel observation could be clinically relevant.