Publications by authors named "Steven Leung"

Introduction: In de novo metastatic hormone-sensitive prostate cancer (mHSPC) treated with upfront intensification using androgen receptor signaling inhibitor or chemotherapy (Docetaxel), achieving a PSA nadir less than 0.2 ng/mL, indicative of superior survival in trials, may often be unattainable in real-world settings. We explored the predictive value of the degree of PSA decline and time to PSA nadir (TTPN) on oncological outcomes.

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Even with the development of advanced catheter-based mapping systems, there remain several challenges in the electrophysiological evaluation and elimination of atrial arrhythmias. For instance, atrial tachycardias with irregular rates cannot be reliably mapped by systems that require stability in order to sequentially gather data points to be organized thereafter. Separately, these arrhythmias often arise following initial ablation for atrial fibrillation, posing logistic challenges.

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The narrower focal zone (FZ) size of modern lithotripter was considered as one of the factors that resulted in suboptimal treatment result of extracorporeal shockwave lithotripsy (SWL). Therefore, we investigate the efficacy and safety of standard narrow or extended (FZ) sizes in SWL for patients with renal stones. In this prospective study conducted between April 2018 and October 2022, patients with renal stones were randomized to receive SWL with either standard or extended FZ.

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Purpose: To investigate the effect of androgen deprivation therapy (ADT) on health-related quality of life (HRQOL) in Asian men with all stages of prostate cancer.

Materials And Methods: READT (real-life evaluation of the effect of ADT in prostate cancer patients in Asia) was a multi-center, prospective observational study involving six sites across four Asian populations. We enrolled eligible prostate cancer patients, who opted for ADT alone or in combination without prior neoadjuvant or adjuvant ADT within 12 months.

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Background: Androgen deprivation therapy (ADT) use in prostate cancer (PCa) has seen a rising trend. We investigated the relationship between ADT and adverse changes in metabolic parameters in an Asian population.

Methods: This is an international prospective multicenter single-arm cohort yielded from the real-life experience of ADT in Asia (READT) registry.

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Focused ultrasound (FUS) is a powerful tool for noninvasive modulation of deep brain activity with promising therapeutic potential for refractory epilepsy; however, tools for examining FUS effects on specific cell types within the deep brain do not yet exist. Consequently, how cell types within heterogeneous networks can be modulated and whether parameters can be identified to bias these networks in the context of complex behaviors remains unknown. To address this, we developed a fiber Photometry Coupled focused Ultrasound System (PhoCUS) for simultaneously monitoring FUS effects on neural activity of subcortical genetically targeted cell types in freely behaving animals.

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Introduction: The use of antibiotics may induce the changes in gut microbiota. Previous studies have shown conflicting results on whether the changed gut microbiota by antibiotics can be recovered. Our study aims to investigate whether the gut microbiota could be recovered after a single dose of oral co-amoxiclav before transrectal ultrasound-guided transperineal prostate biopsy (TPPBx) in 5 weeks' time.

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Transcranial focused ultrasound with the InSightec Exablate system uses thermal ablation for the treatment of movement and mood disorders and blood brain barrier disruption for tumor therapy. The system uses computed tomography (CT) images to calculate phase corrections that account for aberrations caused by the human skull. This work investigates whether magnetic resonance (MR) images can be used as an alternative to CT images to calculate phase corrections.

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Transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) enables the noninvasive treatment of the deep brain. This capacity relies on the ability to focus acoustic energy through the in-tact skull, a feat that requires accurate estimates of the acoustic velocity in individual patient skulls. In current practice, these estimates are generated using a pretreatment computed tomography (CT) scan and then registered to a magnetic resonance (MR) dataset on the day of the treatment.

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Purpose: Androgen deprivation therapy (ADT) use in prostate cancer (PCa) has seen a rising trend. We are looking into the relationship between ADT and development of metabolic diseases in Chinese patients.

Methods: This is a prospective multi-centre cohort yielded from the READT database (Real-life experience of ADT in Asia), in which patients diagnosed of PCa and offered ADT were prospectively recruited since 2016.

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Since 2017, the TrueNTH Global Registry (TNGR) has aimed to drive improvement in patient outcomes for individuals with localized prostate cancer by collating data from healthcare institutions across 13 countries. As TNGR matures, a systematic evaluation of existing processes and documents is necessary to evaluate whether the registry is operating as intended. The main supporting documents: protocol and data dictionary, were comprehensively reviewed in a series of meetings over a 10-month period by an international working group.

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Background: Androgen deprivation therapy (ADT), either by medical or surgical castration, is the backbone for standard treatment of locally advanced or metastatic prostate cancer, yet it is also associated with various metabolic and cardiovascular complications. Recent evidence have shown that obesity, insulin resistance, or metabolic disturbances can be associated with changes in the gut microbiome, while animal studies also show that castration is associated with changes in the gut microbiome. This study aims to investigate whether the fecal microbiota in prostate cancer patients who had undergone prostatectomy or ADT are different, and explore changes in phylogeny and pathways that may lead to side effects from ADT.

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The InSightec Exablate system is the standard of care used for transcranial focused ultrasound ablation treatments in the United States. The system calculates phase corrections that account for aberrations caused by the human skull. This work investigates whether skull aberration correction can be improved by comparing the standard of care InSightec ray tracing method with the hybrid angular spectrum (HAS) method and the gold standard hydrophone method.

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Transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) is gaining significant acceptance as a noninvasive treatment for motion disorders and shows promise for novel applications such as blood-brain barrier opening for tumor treatment. A typical procedure relies on CT-derived acoustic property maps to simulate the transfer of ultrasound through the skull. Accurate estimates of the acoustic attenuation in the skull are essential to accurate simulations, but there is no consensus about how attenuation should be estimated from CT images and there is interest in exploring MR as a predictor of attenuation in the skull.

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Androgen deprivation therapy (ADT) is the standard treatment for advanced prostate cancer, but its effect on cardiovascular and metabolic function in Asian patients is still inconclusive. We prospectively assess the effects of ADT on 36 patients with advanced prostate cancer, with reference to another 24 prostate cancer patients not requiring ADT, for 2 years. Patients' anthropometric, metabolic and vascular parameters were assessed every six-monthly.

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Background: Laser interstitial thermal therapy (LITT) is a minimally invasive therapy for treating medication-resistant mesial temporal lobe epilepsy. Cranial nerve (CN) palsy has been reported as a procedural complication, but the mechanism of this complication is not understood.

Objective: To identify the cause of postoperative CN palsy after LITT.

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Transcranial focused ultrasound is a non-invasive therapeutic modality that can be used to treat essential tremor. Beams of energy are focused into a small spot in the thalamus, resulting in tissue heating and ablation. Here, we report on a rapid 3D numeric simulation framework that can be used to predict focal spot characteristics prior to the application of ultrasound.

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Purpose: In this study we assessed the effects of a ramping protocol in patients undergoing extracorporeal shock wave lithotripsy of renal stones.

Materials And Methods: In this prospective study patients with renal stones were randomized to receive shock wave lithotripsy delivered using a ramping protocol in group 1 (first 1,000 shocks at energy level 5 followed by 1,000 shocks at energy level 6 and 1,000 final shocks at energy level 7) and a fixed voltage protocol in group 2 (all 3,000 shocks at energy level 7). Treatment was administered using a Modulith® SLX-F2.

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Transcranial magnetic resonance-guided focused ultrasound continues to gain traction as a noninvasive treatment option for a variety of pathologies. Focusing ultrasound through the skull can be accomplished by adding a phase correction to each element of a hemispherical transducer array. The phase corrections are determined with acoustic simulations that rely on speed of sound estimates derived from CT scans.

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Introduction And Objective: This prospective study aimed to evaluate the effect of ramping and pause protocols on renal fibrosis, blood pressure control, and renal function in patients receiving extracorporeal shockwave lithotripsy (SWL).

Patients And Methods: This study prospectively recruited 320 patients with solitary radiopaque renal stones <15 mm in size. Patients were randomized to receive one of four shockwave protocols: (1) standard protocol (no ramping or pause); (2) ramping protocol alone; (3) ramping and pause protocols; or (4) pause protocol alone.

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Cardiac implantable electronic device (CIED) infections are complex medical problems that are increasingly encountered. They are associated with significant morbidity and mortality with tremendous economic cost. The current review will emphasize the prevention, diagnosis, and treatment of this clinical entity using the relatively limited evidence that is currently available.

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Patients with adult congenital heart disease are now living longer due to the advancements in medicine. As such, these patients are now experiencing morbidities that are commonly seen in the general population such as myocardial infarction, heart failure, and arrhythmias. Often times these problems can be attributed to the underlying adult congenital heart disease; however, a patient making poor lifestyle choices only compounds their risk for these life-threatening comorbidities.

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