Peter L Choyke

NCI-Frederick, Фредерик, Maryland, United States

Are you Peter L Choyke?

Claim your profile

Publications (749)3237.47 Total impact

  • The Journal of Urology 04/2013; 189(4):e897. DOI:10.1016/j.juro.2013.02.2096 · 3.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Active surveillance (AS) is an attempt to avoid overtreatment of clinically insignificant prostate cancer (PCa); however, patient selection remains controversial. Multiparametric prostate magnetic resonance imaging (MP-MRI) may help better select AS candidates. We reviewed a cohort of men who underwent MP-MRI with MRI/Ultrasound fusion-guided prostate biopsy and selected potential AS patients at entry using Johns Hopkins criteria. MP-MRI findings were assessed, including number of lesions, dominant lesion diameter, total lesion volume, prostate volume, and lesion density (calculated as total lesion volume/prostate volume). Lesions were assigned a suspicion score for cancer by MRI. AS criteria were reapplied based on the confirmatory biopsy, and accuracy of MP-MRI in predicting AS candidacy was assessed. Logistic regression modeling and chi-square statistics were used to assess associations between MP-MRI interpretation and biopsy results. Eighty-five patients qualified for AS with a mean age of 60.2 years and mean prostate-specific antigen level of 4.8 ng/mL. Of these, 25 patients (29%) were reclassified as not meeting AS criteria based on confirmatory biopsy. Number of lesions, lesion density, and highest MRI lesion suspicion were significantly associated with confirmatory biopsy AS reclassification. These MRI-based factors were combined to create a nomogram that generates a probability for confirmed AS candidacy. As clinicians counsel patients with PCa, MP-MRI may contribute to the decision-making process when considering AS. Three MRI-based factors (number of lesions, lesion suspicion, and lesion density) were associated with confirmatory biopsy outcome and reclassification. A nomogram using these factors has promising predictive accuracy for which future validation is necessary. Cancer 2013. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
    Cancer 04/2013; 119(18). DOI:10.1002/cncr.28216 · 4.90 Impact Factor
  • The Journal of Urology 04/2013; 189(4):e911. DOI:10.1016/j.juro.2013.02.2130 · 3.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To describe clinical technique of laser ablation of prostate cancer using MRI guidance as well as ultrasound guidance. To show feasibility in phantoms of using a novel fusion guided platform to ablate prostate cancer using real time ultrasound guidance fused to pre-procedural multi-parametric MRI.Materials and Methods Water cooled laser ablation was performed in patients with Gleason 6 or Gleason 7 prostate cancer that was focal and well visualized by MRI. Focal ablation was performed using MRI guidance and MRI thermometry feedback. Laser ablations were performed in prostate phantoms using a custom ultrasound to MRI fusion software platform.Custom phantom materials (CIRS, Norfolk, VA) were used that show ablated regions with CT, ultrasound, and MRI.ResultsFocal laser ablation was performed safely in 10 patients with prostate cancer using MRI guidance. Follow-up imaging at day one, 6 months, and one year post-ablation was performed. Biopsy was performed in patients one year post-ablation. Ultrasound to MRI fusion was used to guide laser fibers to targets predefined with pre-procedural MRI, without requiring the presence of the MRI gantry.Conclusion Focal prostate laser ablation of image-able prostate cancer may be safely performed in patients undergoing active surveillance or watchful waiting for non-aggressive prostate cancers. MRI + ultrasound fusion guidance may be used to guide laser fibers to targets identified on prior MRI, without requiring the physical presence of the MRI gantry.
    Journal of Vascular and Interventional Radiology 04/2013; 24(4):S99. DOI:10.1016/j.jvir.2013.01.242 · 2.15 Impact Factor
  • Peter L Choyke, Baris Turkbey
    Oncology (Williston Park, N.Y.) 04/2013; 27(4):274, 276. · 2.98 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have recently developed a cancer-specific therapy, photoimmunotherapy, which uses an antibody-IR700 (phototoxic phthalocyanine dye) conjugate to bind to the cell membrane and near-infrared light to induce immediate and highly specific tumor killing in vivo. For monitoring the acute cytotoxic effects of photoimmunotherapy before the tumor begins to shrink, we used (18)F-FDG PET before and after this intervention in mice. METHODS: Photoimmunotherapy was performed by binding panitumumab (anti-HER1)-IR700 to HER1-positive tumor cells (A431), followed by near-infrared light irradiation in vitro and in vivo. The uptake of (18)F-FDG in the tumor after photoimmunotherapy was evaluated in cellular uptake studies and PET imaging studies. Serial histologic analyses were conducted after photoimmunotherapy. RESULTS: The in vitro cellular uptake of (18)F-FDG was reduced as the dose of light increased, and at high light dose (2 J/cm(2)) the uptake was reduced by more than 99% within 1 h after photoimmunotherapy. In vivo (18)F-FDG PET imaging showed that the accumulation of radioactivity in the treated tumors decreased 76% at 75 min after photoimmunotherapy and did not change for 24 h. In contrast, no significant changes were demonstrated in nontreated tumors. None of tumors changed size within 24 h after photoimmunotherapy, although diffuse necrosis was observed in photoimmunotherapy-treated tumors. CONCLUSION: Immediate cytotoxic effects induced by photoimmunotherapy were clearly detected by decreased glucose uptake using (18)F-FDG PET even before changes in tumor size became evident. (18)F-FDG allows the clinical assessment of the therapeutic effects of photoimmunotherapy earlier than anatomic methods that rely on tumor size.
    Journal of Nuclear Medicine 03/2013; 54(5). DOI:10.2967/jnumed.112.112110 · 5.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose:To determine whether multiparametric magnetic resonance (MR) imaging can help identify patients with prostate cancer who would most appropriately be candidates for active surveillance (AS) according to current guidelines and to compare the results with those of conventional clinical assessment scoring systems, including the D'Amico, Epstein, and Cancer of the Prostate Risk Assessment (CAPRA) systems, on the basis of findings at prostatectomy.Materials and Methods:This institutional review board-approved HIPAA-compliant retrospectively designed study included 133 patients (mean age, 59.3 years) with a mean prostate-specific antigen level of 6.73 ng/mL (median, 4.39 ng/mL) who underwent multiparametric MR imaging at 3.0 T before radical prostatectomy. Informed consent was obtained from all patients. Patients were then retrospectively classified as to whether they would have met AS eligibility criteria or were better served by surgery. AS eligibility criteria for prostatectomy specimens were a dominant tumor smaller than 0.5 mL without Gleason 4 or 5 patterns or extracapsular or seminal vesicle invasion. Conventional clinical assessment scores (the D'Amico, Epstein, and CAPRA scoring systems) were compared with multiparametric MR imaging findings for predicting AS candidates. The level of significance of difference between scoring systems was determined by using the χ2 test for categoric variables with the level of significance set at P < .05.Results:Among 133 patients, 14 were eligible for AS on the basis of prostatectomy results. The sensitivity, positive predictive value (PPV), and overall accuracy, respectively, were 93%, 25%, and 70% for the D'Amico system, 64%, 45%, and 88% for the Epstein criteria, and 93%, 20%, and 59% for the CAPRA scoring system for predicting AS candidates (P < .005 for all, χ2 test), while multiparametric MR imaging had a sensitivity of 93%, a PPV of 57%, and an overall accuracy of 92% (P < .005).Conclusion:Multiparametric MR imaging provides useful additional information to existing clinicopathologic scoring systems of prostate cancer and improves the assignment of treatment (eg, AS or active treatment).© RSNA, 2013Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121325/-/DC1.
    Radiology 03/2013; 268(1). DOI:10.1148/radiol.13121325 · 6.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Sorafenib targets multiple pathways thought to be crucial in growth of plexiform neurofibroma (PN) in children with neurofibromatosis type 1 (NF1). Sorafenib has been tolerated with manageable toxicities in adults and children with refractory cancer. We conducted a separate study in this population. Monitoring long-term toxicities such as effects on growth and obtaining additional pharmacokinetic data were of importance due to the young age and long duration of therapy seen in previous phase I trials in children with NF1. PROCEDURE: Children ≥3 and ≤18-year-old with NF1 and inoperable PN were eligible. Sorafenib was administered orally twice daily for consecutive 28-day cycles. Maximum tolerated dose (MTD) was determined from toxicities observed during the first three cycles. RESULTS: Nine children enrolled, median age 8 (6-12) years. At the starting 115 mg/m(2) /dose (n = 5), two experienced dose-limiting grade 3 pain in their PN. At the de-escalated 80 mg/m(2) /dose (n = 4), approximately 40% of the pediatric solid tumor MTD, two had dose-limiting toxicity (grade 3 rash and grade 4 mood alteration), exceeding the MTD. At 80 mg/m(2) /dose, the median AUC(0-12 hours) at steady-state was 39.5 µg hours/ml. Toxicities appeared to correspond with decreases in quality of life (QOL). No tumor shrinkage was observed. CONCLUSIONS: Children with NF1 and PN did not tolerate sorafenib at doses substantially lower than the MTD in children and adults with malignant solid tumors. Future trials with targeted agents for children with NF1 may require a more conservative starting dose and separate definitions of dose limiting toxicities (DLT) than children with cancer. Pediatr Blood Cancer © 2012 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 03/2013; 60(3). DOI:10.1002/pbc.24281 · 2.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Predictive biomarkers are needed to triage patients to best therapy. We prospectively planned examination of sequential blood, biopsy, and functional imaging with which to confirm mechanism and identify potential predictive biomarkers in a phase Ib clinical trial expansion cohort of solid tumor patients receiving sorafenib/bevacizumab. The maximally-tolerated doses of sorafenib 200mg twice daily with bevacizumab 5mg/kg every other week were given to biopsiable patients. Patients were randomized to receive either sorafenib or bevacizumab monotherapy for the first 28 day cycle with the second drug added with cycle 2. Biopsies, dynamic contrast-enhanced MRI, and FDG-PET were done pre-therapy, and at 2, and 6 weeks (2 weeks into combination therapy). Tumor and serum proteomics, Ras/Raf mutational analysis, and functional imaging results were examined individually and across the dataset to identify potential changes predictive of response to therapy and those which confirm biochemical drug mechanism(s). Therapy with sorafenib/bevacizumab resulted in clinical benefit in 45% of this mixed solid tumor group. ERK activation and microvessel density were decreased with monotherapy treatment with sorafenib or bevacizumab, respectively; whereas, decreased signal over the group of total AKT, phospho(p)-VEGF receptor2, p-endothelial nitric oxide synthase, BRAF and cleaved PARP was associated with earlier progression of disease. Tumor metabolic activity decreased in those patients with clinical benefit lasting longer than 4 months, and increased with progressive disease. Cleavage of caspase 3 and PARP were increased, and Ki67 expression decreased in patients with prolonged clinical benefit, consistent with decreased proliferation and increased apoptosis. The conglomerate analysis, incorporating pharmacodynamic and tumor biochemistry, demonstrated sorafenib/bevacizumab targeted vascular activity in the tumor. Results suggest potential biomarkers for which changes, as a group, during early therapeutic exposure may predict clinical benefit.
    Molecular &amp Cellular Proteomics 02/2013; DOI:10.1074/mcp.M112.026427 · 7.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Recent advances in the treatment of metastatic castration-resistant prostate cancer (CRPC) have resulted in improved outcomes; however, the effects have not proved to be long term, highlighting the need for new therapies, particularly in patients with docetaxel-refractory metastatic CRPC. Angiogenesis has been shown to play an important role in the development and progression of prostate cancer. Although targeting angiogenesis appears to be a rational and therapeutic approach for metastatic CRPC, identifying the appropriate subgroups that may benefit from anti-angiogenic therapy remains a challenge. The study demonstrates the potential use of dynamic contrast-enhanced (DCE)-MRI variables as pharmacodynamic endpoints in predicting the clinical outcomes associated with anti-angiogenic agents such as cediranib. Further investigation into the potential predictive value of DCE-MRI variables as biomarkers for antiangiogenic therapy is warranted. OBJECTIVE: To assess the efficacy and toxicity of cediranib, a highly potent inhibitor of vascular endothelial growth factor receptor tyrosine kinases, in patients with metastatic castration-resistant prostate cancer (CRPC) previously treated with docetaxel-based therapy. PATIENTS AND METHODS: The study used a Simon two-stage trial design, which required at least two of 12 patients in the first cohort to be progression-free at 6 months. We enrolled a total of 35 evaluable patients who all received cediranib 20 mg orally daily. In a second cohort, 23 additional patients received prednisone 10 mg daily with cediranib. Endpoints included tumour response, progression-free survival (PFS), overall survival (OS), vascular permeability via dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and toxicity. RESULTS: A total of 59 patients were enrolled, of whom 67% had received two or more previous chemotherapy regimens. Six of 39 patients with measurable disease had confirmed partial responses and one had an unconfirmed partial response. At 6 months, 43.9% of patients were progression-free; the median PFS and OS periods for all patients were 3.7 months and 10.1 months, respectively. We found that the DCE-MRI variables baseline transport constant (K(trans) ) and rate constant at day 28 were significantly associated with PFS in univariate analyses, but only baseline K(trans) remained significant when considered jointly. The most frequent toxicities were hypertension, fatigue, anorexia and weight loss; the addition of prednisone reduced the incidence of constitutional toxicities. CONCLUSION: This study demonstrated that cediranib was generally well tolerated with some anti-tumour activity in highly pretreated patients with metastatic CRPC who had progressive disease after docetaxel-based therapy.
    BJU International 02/2013; 111(8). DOI:10.1111/j.1464-410X.2012.11667.x · 3.13 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: INTRODUCTION: We describe a prototype positron projection imager (PPI) for visualizing the whole-body biodistribution of positron-emitting compounds in mouse-size animals. The final version of the PPI will be integrated into the MONICA portable dual-gamma camera system to allow the user to interchangeably image either single photon or positron-emitting compounds in a shared software and hardware environment. METHODS: A mouse is placed in the mid-plane between two identical, opposed, pixelated LYSO arrays separated by 21.8-cm and in time coincidence. An image of the distribution of positron decays in the animal is formed on this mid-plane by coincidence events that fall within a small cone angle perpendicular to the two detectors and within a user-specified energy window. We measured the imaging performance of this device with phantoms and in tests performed in mice injected with various compounds labeled with positron-emitting isotopes. RESULTS: Representative performance measurements yielded the following results (energy window 250-650keV, cone angle 3.5°): resolution in the image mid-plane, 1.66-mm (FWHM), resolution ±1.5-cm above and below the image plane, 2.2-mm (FWHM), sensitivity: 0.237-cps/kBq (8.76-cps/μCi) (18)F (0.024% absolute). Energy resolution was 15.9% with a linear-count-rate operating range of 0-14.8MBq (0-400μCi) and a corrected sensitivity variation across the field-of-view of <3%. Whole-body distributions of [(18)F] FDG and [(18)F] fluoride were well visualized in mice of typical size. CONCLUSION: Performance measurements and field studies indicate that the PPI is well suited to whole-body positron projection imaging of mice. When integrated into the MONICA gamma camera system, the PPI may be particularly useful early in the drug development cycle where, like MONICA, basic whole-body biodistribution data can direct future development of the agent under study and where logistical factors (e.g., available imaging space, non-portability, and cost) may be limitations.
    Nuclear Medicine and Biology 02/2013; DOI:10.1016/j.nucmedbio.2012.12.003 · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: There is limited data regarding the role of 18F-Fluorodeoxyglucose positron emission tomography ([18F]-FDG PET) imaging in management of patients with thymic epithelial tumors (TET). The primary objective of this study was to assess the usefulness of early [18F]-FDG PET to monitor treatment efficacy and its correlation with Response Evaluation Criteria in Solid Tumors (RECIST) in patients with TETs. EXPERIMENTAL DESIGN: [18F]-FDG PET/CT scans were performed at baseline and after six weeks of treatment in patients enrolled in two phase II and one phase I/II clinical trials. Based on data from other solid tumors, metabolic response was defined as a reduction of [18F]-FDG uptake by more than 30% as assessed by average standardized uptake values (SUV) of up to five most metabolically active lesions. RESULTS: Fifty six patients with unresectable Masaoka stage III or IV TETs were included. There was a close correlation between early metabolic response and subsequent best response using RECIST (P <0.0001 to 0.0003): sensitivity and specificity for prediction of best response were 95% and 100% respectively. Metabolic responders had significantly longer progression-free survival (median 11.5 vs. 4.6 months, P = 0.044) and a trend towards longer overall survival (median 31.8 vs. 18.4 months, P = 0.14) than non-responders. [18F]-FDG uptake was significantly higher in thymic carcinoma compared with thymoma (P= 0.0004 to 0.0010). CONCLUSIONS: In patients with advanced TETs, early metabolic response closely correlates with outcome of therapy. [18F]-FDG PET may be used to monitor treatment efficacy and assess histological differences in patients with advanced TETs.
    Clinical Cancer Research 02/2013; 19(6). DOI:10.1158/1078-0432.CCR-12-2929 · 8.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: There has been a resurgent interest in intravoxel incoherent motion (IVIM) MR imaging to obtain perfusion as well as diffusion information on lesions, in which the diffusion was modeled as Gaussian diffusion. However, it was observed that this diffusion deviated from expected monoexponential decay at high b-values and the reported perfusion in prostate is contrary to the findings in dynamic contrast-enhanced (DCE) MRI studies and angiogenesis. Thus, this work is to evaluate the effect of different b-values on IVIM perfusion fractions (f) and diffusion coefficients (D) for prostate cancer detection. The results show that both parameters depended heavily on the b-values, and those derived without the highest b-value correlated best with the results from DCE-MRI studies; specifically, f was significantly elevated (7.2% vs. 3.7%) in tumors when compared with normal tissues, in accordance with the volume transfer constant (K(trans) ; 0.39 vs. 0.18 min(-1) ) and plasma fractional volume (v(p) ; 8.4% vs. 3.4%). In conclusion, it is critical to choose an appropriate range of b-values in studies or include the non-Gaussian diffusion contribution to obtain unbiased IVIM measurements. These measurements could eliminate the need for DCE-MRI, which is especially relevant in patients who cannot receive intravenous gadolinium-based contrast media. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
    Magnetic Resonance in Medicine 02/2013; 69(2). DOI:10.1002/mrm.24277 · 3.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We propose a new method for prostate cancer classification based on supervised statistical learning methods by integrating T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI images with targeted prostate biopsy results. In the first step of the method, all three imaging modalities are registered based on the image coordinates encoded in the DICOM images. In the second step, local statistical features are extracted in each imaging modality to capture intensity, shape, and texture information at every biopsy target. Finally, using support vector machines, supervised learning is conducted with the biopsy results to train a classification system that predicts the pathology of suspicious cancer lesions. The algorithm was tested with a dataset of 54 patients that underwent 164 targeted biopsies (58 positive, 106 negative). The proposed tri-modal MRI algorithm shows significant improvement over a similar approach that utilizes only T2-weighted MRI images (p= 0.048). The areas under the ROC curve for these methods were 0.82 (95% CI: [0.71, 0.93]) and 0.73 (95% CI: [0.55, 0.84]), respectively.
    Proceedings of SPIE - The International Society for Optical Engineering 02/2013; DOI:10.1117/12.2007927 · 0.20 Impact Factor
  • Article: Reply.
    Journal of Nuclear Medicine 02/2013; 54(2):326-7. · 5.56 Impact Factor
  • Journal of Nuclear Medicine 02/2013; 54(2):326-327. DOI:10.2967/jnumed.112.114454 · 5.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Context:Nephrocalcinosis is a complication of hypoparathyroidism and other metabolic disorders. Imaging modalities include ultrasonography (US) and computed tomography (CT). Few studies have compared these modalities, and standard clinical practice is not defined.Objective:The objective of the study was to determine the preferred method for assessing nephrocalcinosis.Design:The design of the study was a retrospective, blinded analysis.Setting:The study was conducted at a clinical research center.Patients:Twenty-two hypoparathyroid subjects and 7 controls participated in the study.Interventions:Contemporaneous renal US and CT images were reviewed in triplicate by 4 blinded radiologists. Nephrocalcinosis was classified using a 0-3 scale with 0 meaning no nephrocalcinosis and 3 meaning severe nephrocalcinosis.Main Outcome Measures:Intraobserver, interobserver, and interdevice agreements were measured.Results:Intraobserver agreement was high, with an overall weighted kappa of 0.83 for CT and 0.89 for US. Interobserver agreement was similar between modalities, with kappas of 0.74 for US and 0.70 for CT. Only moderate agreement was found between US and CT scores, with an intermodality kappa of 0.47 and 60% concordance. Of discordant pairs, 81% had higher US scores and only 19% had higher CT scores. Of nephrocalcinosis seen on US and not CT, 45%, 46%, and 9% were grades 1, 2, and 3, respectively. Overall, US scores were higher than CT with a cumulative odds ratio (95% confidence interval) of 5.97 (2.60, 13.75) (P < .01). In controls, 100% of US ratings were 0, and 95% of CT ratings were 0.Conclusions:US is superior to CT for assessment of mild to moderate nephrocalcinosis in patients with hypoparathyroidism. This finding, in combination with its low cost, lack of radiation, and portability, defines US as the preferred modality for assessment of nephrocalcinosis.
    The Journal of Clinical Endocrinology and Metabolism 01/2013; 98(3). DOI:10.1210/jc.2012-2747 · 6.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose:To evaluate the potential of anti-human epidermal growth factor receptor (HER)1- and anti-HER2-targeted radiolabeled antibodies and magnetic resonance (MR) imaging for imaging of orthotopic malignant pleural mesothelioma (MPM) in mouse models.Materials and Methods:Animal studies with 165 mice were performed in accordance with National Institutes of Health guidelines for the humane use of animals, and all procedures were approved by the institutional Animal Care and Use Committee. Flow cytometry studies were performed to evaluate HER1 and HER2 expression in NCI-H226 and MSTO-211H mesothelioma cells. Biodistribution and single photon emission computed tomography (SPECT)/computed tomography (CT) imaging studies were performed in mice (four or five per group, depending on tumor growth) bearing subcutaneous and orthotopic MPM tumors by using HER1- and HER2-targeted indium 111 ((111)In)- and iodine 125 ((125)I)-labeled panitumumab and trastuzumab, respectively. Longitudinal MR imaging over 5 weeks was performed in three mice bearing orthotopic tumors to monitor tumor growth and metastases. SPECT/CT/MR imaging studies were performed at the final time point in the orthotopic models (n = 3). The standard unpaired Student t test was used to compare groups.Results:Orthotopic tumors and pleural effusions were clearly visualized at MR imaging 3 weeks after tumor cell inoculation. At 2 days after injection, the mean (111)In-panitumumab uptake of 29.6% injected dose (ID) per gram ± 2.2 (standard error of the mean) was significantly greater than the (111)In-trastuzumab uptake of 13.6% ID/g ± 1.0 and the (125)I-panitumumab uptake of 7.4% ID/g ± 1.2 (P = .0006 and P = .0001, respectively). MR imaging fusion with SPECT/CT provided more accurate information about (111)In-panitumumab localization in the tumor, as the tumor was poorly visualized at CT alone.Conclusion:This study demonstrates the utility of radiolabeled anti-HER1 antibodies in the imaging of MPM in preclinical models.© RSNA, 2013Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12121021/-/DC1.
    Radiology 01/2013; DOI:10.1148/radiol.12121021 · 6.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The lymphatic system is essential for fluid regulation and for the maintenance of host immunity. However, in vivo lymph flow is difficult to track in real time, because of the lack of an appropriate imaging method. In this study, we combined macro-zoom fluorescence microscopy with quantum-dot (Qdot) optical lymphatic imaging to develop an in vivo real-time optical lymphatic imaging method that allows the tracking of lymph through lymphatic channels and into lymph nodes. After interstitial injection of Qdots in a mouse, rapid visualization of the cervical lymphatics and cervical lymph nodes was achieved. Real-time monitoring of the injected Qdots revealed that the cortex of the node enhanced first followed by a net-like pattern in the central portion of the node. Histology revealed that the rim and net-like enhancing regions corresponded to the subcapsular sinuses and medullary sinuses respectively. Additionally, multiplexed two-color real-time lymphatic tracking was performed with two different Qdots. With this real-time imaging system, we successfully tracked microscopic lymphatic flow in vivo. This method could have a potential impact for lymphatic research in visualizing normal or abnormal functional lymphatic flows. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
    Contrast Media & Molecular Imaging 01/2013; 8(1):96-100. DOI:10.1002/cmmi.1487 · 3.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose Patients with an enlarged prostate and suspicion of prostate cancer pose a diagnostic dilemma. The prostate cancer detection rate of systematic 12-core transrectal ultrasound guided biopsy is between 30% and 40%. For prostates greater than 40 cc this decreases to 30% or less. Magnetic resonance-ultrasound fusion biopsy has shown superior prostate cancer detection rates. We defined the detection rate of magnetic resonance-ultrasound fusion biopsy in men with an enlarged prostate gland. Materials and Methods We retrospectively analyzed the records of patients who underwent multiparametric prostate magnetic resonance imaging followed by magnetic resonance-ultrasound fusion biopsy at our institution. Whole prostate volumes were calculated using magnetic resonance imaging reconstructions. Detection rates were analyzed with respect to age, prostate specific antigen and whole prostate volumes. Multivariable logistic regression was used to assess these parameters as independent predictors of prostate cancer detection. Results We analyzed 649 patients with a mean ± SD age of 61.8 ± 7.9 years and a median prostate specific antigen of 6.65 ng/ml (IQR 4.35–11.0). Mean whole prostate volume was 58.7 ± 34.3 cc. The overall detection rate of the magnetic resonance-ultrasound fusion platform was 55%. For prostates less than 40 cc the detection rate was 71.1% compared to 57.5%, 46.9%, 46.9% 33.3%, 36.4% and 30.4% for glands 40 to 54.9, 55 to 69.9, 70 to 84.9, 85 to 99.9, 100 to 114.9 and 115 cc or greater, respectively (p <0.0001). Multivariable logistic regression showed a significant inverse association of magnetic resonance imaging volume with prostate cancer detection, controlling for age and prostate specific antigen. Conclusions Transrectal ultrasound guided and fusion biopsy cancer detection rates decreased with increasing prostate volume. However, magnetic resonance-ultrasound fusion biopsy had a higher prostate cancer detection rate compared to that of transrectal ultrasound guided biopsy in the literature. Magnetic resonance-ultrasound fusion biopsy represents a promising solution for patients with suspicion of prostate cancer and an enlarged prostate.

Publication Stats

21k Citations
3,237.47 Total Impact Points

Institutions

  • 2005–2015
    • NCI-Frederick
      • Laboratory of Pathology
      Фредерик, Maryland, United States
  • 1990–2015
    • National Institutes of Health
      • • Center for Cancer Research
      • • Branch of Radiation Oncology
      • • Center for Clinical Research
      베서스다, Maryland, United States
  • 1970–2015
    • National Cancer Institute (USA)
      • • Molecular Imaging Program
      • • Surgery Branch
      베서스다, Maryland, United States
  • 2014
    • Vascular and Interventional Radiology
      Chicago, Illinois, United States
  • 2003–2014
    • Northern Inyo Hospital
      BIH, California, United States
    • The Ohio State University
      • Department of Radiology
      Columbus, OH, United States
    • Robert Wood Johnson University Hospital
      New Brunswick, New Jersey, United States
  • 2012
    • Aarhus University Hospital
      • Department of Nuclear Medicine & PET-Centre
      Århus, Central Jutland, Denmark
  • 2011
    • Conselleria de Sanidade
      La Corogne, Galicia, Spain
  • 2010
    • National Human Genome Research Institute
      Maryland, United States
    • Boston Children's Hospital
      Boston, Massachusetts, United States
  • 2004–2008
    • Virginia Polytechnic Institute and State University
      • Department of Electrical and Computer Engineering
      Blacksburg, VA, United States
    • The Children's Hospital of Philadelphia
      Filadelfia, Pennsylvania, United States
    • Hebrew University of Jerusalem
      Yerushalayim, Jerusalem, Israel
  • 1992–2008
    • National Eye Institute
      베서스다, Maryland, United States
  • 2007
    • University of South Dakota
      Vermillion, South Dakota, United States
    • Virginia State University
      Petersburg, Virginia, United States
    • The University of Tokyo
      Tōkyō, Japan
    • SAIC
      Фредерик, Maryland, United States
    • Fred Hutchinson Cancer Research Center
      Seattle, Washington, United States
    • Howard Hughes Medical Institute
      Ashburn, Virginia, United States
  • 2006
    • George Washington University
      Washington, Washington, D.C., United States
  • 2000–2004
    • Uniformed Services University of the Health Sciences
      • • Department of Radiology & Radiological Sciences
      • • Department of Radiobiology
      Maryland, United States
  • 1986–2004
    • Georgetown University
      • • Department of Radiology
      • • Department of Surgery
      Washington, D. C., DC, United States
  • 2002
    • National Institute of Allergy and Infectious Diseases
      베서스다, Maryland, United States
  • 1998–2002
    • Leidos Biomedical Research
      Maryland, United States
    • Washington University in St. Louis
      • Department of Pediatrics
      San Luis, Missouri, United States
  • 2001
    • GE India Industrial Pvt. Ltd.
      New Dilli, NCT, India
  • 1999
    • General Electric
      Fairfield, California, United States
  • 1997
    • National Center for Genome Resources
      Santa Fe, New Mexico, United States
  • 1996
    • University of Alabama in Huntsville
      • Department of Computer Science
      Huntsville, Alabama, United States
  • 1985
    • Hospital of the University of Pennsylvania
      • Department of Radiology
      Philadelphia, Pennsylvania, United States