Publications by authors named "Leonard Marks"

Purpose: Men on active surveillance (AS) for prostate cancer are extremely interested in dietary changes or supplements to prevent progression of their disease. We sought to determine whether a high omega-3, low omega-6 fatty acid diet with fish oil capsules (D + FO) decreases proliferation (Ki-67) in prostate biopsies in men with prostate cancer on AS over a 1-year time period.

Methods: In this phase II, prospective randomized trial, men (N = 100) with grade group 1 or 2 prostate cancer who elected AS were randomly assigned to the D + FO or a control group.

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Objective: The objective of this study is to compare detection rates of extracapsular extension (ECE) of prostate cancer (PCa) using artificial intelligence (AI)-generated cancer maps versus MRI and conventional nomograms.

Materials And Methods: We retrospectively analysed data from 147 patients who received MRI-targeted biopsy and subsequent radical prostatectomy between September 2016 and May 2022. AI-based software cleared by the United States Food and Drug Administration (Unfold AI, Avenda Health) was used to map 3D cancer probability and estimate ECE risk.

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Micro-ultrasound has recently been introduced as a low-cost alternative to multi-parametric MRI for imaging prostate cancer. Early clinical studies have demonstrated promising results; however, robust validation via comparison with whole-mount pathology has yet to be achieved. Due to micro-ultrasound probe design and tissue deformation during scanning, it is difficult to accurately correlate micro-ultrasound imaging planes with ground truth whole-mount pathology slides.

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The current prostate cancer (PCa) screen test, prostate-specific antigen (PSA), has a high sensitivity for PCa but low specificity for high-risk, clinically significant PCa (csPCa), resulting in overdiagnosis and overtreatment of non-csPCa. Early identification of csPCa while avoiding unnecessary biopsies in men with non-csPCa is challenging. We built an optimized machine learning platform (ClarityDX) and showed its utility in generating models predicting csPCa.

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Background: Testosterone replacement therapy is known to improve sexual function in men younger than 40 years with pathological hypogonadism. However, the extent to which testosterone alleviates sexual dysfunction in older men and men with obesity is unclear, despite the fact that testosterone is being increasingly prescribed to these patient populations. We aimed to evaluate whether subgroups of men with low testosterone derive any symptomatic benefit from testosterone treatment.

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Article Synopsis
  • Scientists created a special score called the PRI-MUS anterior score to help predict if a person has significant prostate cancer in a specific area of the prostate.
  • They tested this score by showing prostate videos to seven doctors and asking them to rate the chance of cancer using a simple scale.
  • The study showed that micro-ultrasound can find cancer in the prostate, and the new scoring system could be used in hospitals after more testing.
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Background: Magnetic resonance imaging (MRI) underestimation of prostate cancer extent complicates the definition of focal treatment margins.

Objective: To validate focal treatment margins produced by an artificial intelligence (AI) model.

Design Setting And Participants: Testing was conducted retrospectively in an independent dataset of 50 consecutive patients who had radical prostatectomy for intermediate-risk cancer.

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Focal therapy of prostate cancer (PCa) is currently of great interest, but a metric of success. other than biopsy, is not yet available. In a patient with a repeatedly negative MRI and negative systematic biopsies, a scan employing the radioisotope Ga-PSMA-11 PET/CT identified a PSMA-avid hotspot in the prostate.

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Background: Partial gland ablation (PGA) is a new option for treatment of prostate cancer (PCa). Cryotherapy, an early method of PGA, has had favorable evaluations, but few studies have employed a strict protocol using biopsy endpoints in men with clinically significant prostate cancer (csPCa).

Methods: 143 men with unilateral csPCa were enrolled in a prospective, observational trial of outpatient PGA-cryotherapy.

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Prostate biopsy and image-guided treatment procedures are often performed under the guidance of ultrasound fused with magnetic resonance images (MRI). Accurate image fusion relies on accurate segmentation of the prostate on ultrasound images. Yet, the reduced signal-to-noise ratio and artifacts (e.

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Objective: To evaluate the near-term clinical and pathological effects of repeat partial gland ablation (PGA) in men with intermediate-risk prostate cancer (PCa).

Materials And Methods: One hundred seventy men with focal lesions of PCa (all GG2 or GG3) underwent PGA with high-intensity focused ultrasound (HIFU) or cryotherapy (CRYO) in prospective trials. Residual PCa in or near the ablation zone was found in 37 men after a first PGA; 30 went on to receive a second PGA and were the subjects of study.

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Background: Testosterone is the standard treatment for male hypogonadism, but there is uncertainty about its cardiovascular safety due to inconsistent findings. We aimed to provide the most extensive individual participant dataset (IPD) of testosterone trials available, to analyse subtypes of all cardiovascular events observed during treatment, and to investigate the effect of incorporating data from trials that did not provide IPD.

Methods: We did a systematic review and meta-analysis of randomised controlled trials including IPD.

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Focal laser ablation is a minimally invasive method of treating cancerous lesions in organs such as prostate, liver and brain. Oncologic control is achieved by inducing hyperthermia throughout the target while minimizing damage to surrounding tissue. Consequently, successful clinical outcomes are contingent upon achieving desired ablation volumes.

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Background: Systematic prostate biopsies add to the cancer detection rate of targeted biopsies, but the explanation for that increased sensitivity is not yet clear.

Objective: To determine and quantify the utility of perilesional biopsies in the detection of clinically significant prostate cancer (csPCa).

Design, Setting, And Participants: Participants were 2048 men with magnetic resonance imaging (MRI) lesions (grades 3-5) who underwent targeted and systematic prostate biopsy via MRI/ultrasound fusion at University of California Los Angeles and Cornell between 2011 and 2019.

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Purpose: Our goal was to review the pathway and pertinent materials leading to approval of prostate-specific membrane antigen (PSMA) scanning by the U.S. Food and Drug Administration (FDA).

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Article Synopsis
  • Men with low-risk prostate cancer are increasingly choosing active surveillance (AS) instead of immediate treatment, but many later switch to active treatment.
  • A multi-institutional study analyzed genetic data from over 5,000 prostate cancer patients who opted for AS to identify genetic factors that might predict those likely to switch to treatment.
  • The study found 18 genetic variants related to the decision to change treatment and established a link between certain genetic risk scores and the likelihood of converting from AS to active treatment, suggesting that genetics could personalize monitoring and treatment decisions for these patients.
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Thermal ablation is a form of hyperthermia in which oncologic control can be achieved by briefly inducing elevated temperatures, typically in the range 50-80°C, within a target tissue. Ablation modalities include high intensity focused ultrasound, radiofrequency ablation, microwave ablation, and laser interstitial thermal therapy which are all capable of generating confined zones of tissue destruction, resulting in fewer complications than conventional cancer therapies. Oncologic control is contingent upon achieving predefined coagulation zones; therefore, intraoperative assessment of treatment progress is highly desirable.

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In order to evaluate the diagnostic accuracy of high-resolution ultrasound (HRUS) for detection of prostate cancer, it must be validated against whole-mount pathology. An ex-vivo HRUS scanning system was developed and tested in phantom and human tissue experiments to allow for in-plane computational co-registration of HRUS with magnetic resonance imaging (MRI) and whole-mount pathology. The system allowed for co-registration with an error of 1.

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Purpose: The underlying premise of prostate cancer active surveillance (AS) is that cancers likely to metastasize will be recognized and eliminated before cancer-related disease can ensue. Our study was designed to determine the prostate cancer upgrading rate when biopsy guided by magnetic resonance imaging (MRGBx) is used before entry and during AS.

Materials And Methods: The cohort included 519 men with low- or intermediate-risk prostate cancer who enrolled in prospective studies (NCT00949819 and NCT00102544) between February 2008 and February 2020.

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Background: Micro-ultrasound (microUS) is a novel ultrasound-based imaging modality which has demonstrated the ability to visualize prostate cancer. Multiparametric MRI/ultrasound (mpMRI/US) fusion has recognized advantages for the performance of prostate biopsy, however, it encompasses additional cost, time and technical expertise to performing prostate biopsy in comparison to conventional trans-rectal ultrasound biopsy. MicroUS may simplify and optimize this pathway.

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Article Synopsis
  • The study aims to evaluate a deep learning model (Textured-DL) for classifying prostate cancer (PCa) and compares its performance to the established PI-RADS classification system.
  • Textured-DL showed better accuracy with an AUC of 0.85 versus 0.73 for PI-RADS-CLA, indicating it is more effective at distinguishing clinically significant PCa from non-significant cases.
  • The model exhibited higher specificity in detecting suspicious lesions, particularly in the peripheral zone of the prostate, which could lead to improved patient diagnosis and treatment.
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Introduction: A functional tool to optimize patient selection for magnetic resonance imaging (MRI)-guided prostate biopsy (MRGB) is an unmet clinical need. We sought to develop a prostate cancer risk calculator (PCRC-MRI) that combines MRI and clinical characteristics to aid decision-making for MRGB in North American men.

Methods: Two prospective registries containing 2354 consecutive men undergoing MRGB (September 2009 to April 2019) were analyzed.

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