Publications by authors named "James Tsui"

Purpose: High dose rate (HDR) prostate brachytherapy (BT) procedure requires image-guided needle insertion. Given that general anesthesia is often employed during the procedure, minimizing overall planning time is crucial. In this study, we explore the clinical feasibility and time-saving potential of artificial intelligence (AI)-driven auto-reconstruction of transperineal needles in the context of ultrasound (US)-guided prostate BT planning.

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Background: Coronary artery disease is the most common form of cardiovascular disease. It is caused by excess plaque along the arterial wall, blocking blood flow to the heart (stenosis). A percutaneous coronary intervention widens the arterial wall with the inflation of a balloon inside the lesion area and leaves behind a metal stent to prevent re-narrowing of the artery (restenosis).

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Purpose: We aimed to determine if ultrahypofractionated radiation therapy (UHYPO-RT) delivering 6 Gy x 5 fractions yields similar tumor necrosis compared with conventional radiation therapy (CONV-RT) with 2 Gy x 25 fractions in soft tissue sarcoma. The clinical significance of tumor necrosis on loco-regional recurrence-free survival (LRFS), distant disease-free survival (DDFS), and overall survival (OS) were assessed.

Methods And Materials: Patients with localized soft tissue sarcoma treated with CONV-RT or UHYPO-RT followed by surgery were included.

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Article Synopsis
  • The study investigates how AI-generated measurements of intraprostatic tumor volume from MRI scans can predict the risk of metastasis in prostate cancer patients treated with either radiation therapy or radical prostatectomy.
  • A total of 732 patients were involved, with findings indicating that a larger tumor volume significantly correlated with increased rates of metastasis during the follow-up periods, which averaged 6.9 years for radiation therapy and 5.5 years for surgery.
  • The research highlighted that the AI-based volume measurements provided independent prognostic information, outperforming traditional risk categorization methods in predicting long-term metastasis.
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Serous endometrial carcinoma (SEC) is a high-risk subtype of endometrial cancer. The effectiveness of multiple adjuvant therapies, namely chemotherapy (CT), radiotherapy (RT), and sequential/concurrent chemotherapy with radiotherapy (CRT), have previously been investigated. However, optimal management of early-stage SEC remains unclarified.

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This review article focuses on the applications of deep learning with neural networks and multimodal neural networks in the orthopaedic domain. By providing practical examples of how artificial intelligence (AI) is being applied successfully in orthopaedic surgery, particularly in the realm of imaging data sets and the integration of clinical data, this study aims to provide orthopaedic surgeons with the necessary tools to not only evaluate existing literature but also to consider AI's potential in their own clinical or research pursuits. We first review standard deep neural networks which can analyze numerical clinical variables, then describe convolutional neural networks which can analyze image data, and then introduce multimodal AI models which analyze various types of different data.

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Purpose: The delineation of dominant intraprostatic gross tumor volumes (GTVs) on multiparametric magnetic resonance imaging (mpMRI) can be subject to interobserver variability. We evaluated whether deep learning artificial intelligence (AI)-segmented GTVs can provide a similar degree of intraprostatic boosting with external beam radiation therapy (EBRT) as radiation oncologist (RO)-delineated GTVs.

Methods And Materials: We identified 124 patients who underwent mpMRI followed by EBRT between 2010 and 2013.

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Article Synopsis
  • The study evaluates the safety of moderate hypofractionated radiation therapy (HF RT) compared to standard fractionation (SF RT) in high-risk prostate cancer patients, based on the hypothesis that HF RT may offer advantages due to prostate cancer's sensitivity to radiation.
  • From February 2012 to March 2015, 329 high-risk patients participated in a trial, with participants randomized into HF and SF groups, both receiving androgen deprivation therapy, and researchers primarily focused on monitoring acute and delayed toxicity.
  • Results indicated that while there were initially more acute gastrointestinal (GI) events in the HF group, this significance diminished over time; ultimately, no major differences in delayed GI-related adverse events were observed
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Background And Purpose: Breast cancer locoregional (LR) radiation in the elderly requires careful consideration between the benefits of aggressive treatment and its potential toll on these patients. Extreme weekly LR hypofractionated radiation (HFRT), delivering >5 Gy per fraction, may be better suited in such a population. It represents a good compromise between RT omission and exhaustive daily radiation.

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Article Synopsis
  • Long-term androgen deprivation therapy in men with high-risk prostate cancer is linked to a decrease in bone mineral density, but this does not significantly increase the risk of fractures.
  • A study analyzed the bone mineral density changes after 28 months of therapy and supplementation with calcium and vitamin D in patients, revealing an average decrease of -3.2% across multiple sites without significant classification changes for most patients.
  • The findings suggest that while there is a slight reduction in bone mineral density, calcium and vitamin D supplementation is generally effective in managing bone health for these patients on long-term therapy.
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Following radical prostatectomy, prostate bed radiotherapy (PBRT) has been combined with either long-term androgen deprivation therapy (LT-ADT) or short-term ADT with pelvic lymph node radiotherapy (PLNRT) to provide an oncological benefit in randomized trials. McGill 0913 was designed to characterize the efficacy of combining PBRT, PLNRT, and LT-ADT. It is the first study to do so prospectively.

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Purpose: Radiation oncology is often overlooked in US medical school curricula, with few opportunities for most students to learn about the specialty or the value of radiation therapy in cancer care. Tumor boards represent a potential avenue not only to increase students' exposure to radiation oncologists but also to provide a fundamental understanding of the multidisciplinary nature of cancer care and effective collaboration in clinical practice.

Methods And Materials: In this study, we evaluated a novel radiation oncologist-driven tumor board shadowing experience at 3 medical schools in the United States and Canada.

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Purpose: In this prospective phase II study, we investigated whether cone beam computed tomography scan was a superior method of image-guided radiotherapy relative to 2D orthogonal kilovoltage images in the post-radical prostatectomy setting.

Methods: A total of 419 treatment fractions were included in this analysis. The shifts required to align the patient for each treatment were performed using 3D matching between cone beam computed tomography scans and the corresponding computed tomography images used for planning.

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Article Synopsis
  • Esophageal cancer treatment complicates radiation delivery due to the esophagus's location and potential radial spread, necessitating various techniques to optimize target coverage and minimize damage to surrounding organs.
  • An analysis of 15 advanced esophageal cancer cases evaluated four different radiation methods, including conformal and volumetric modulated arc therapies, each administering a total dose of 50.4 Gy.
  • Results showed that all techniques provided adequate target coverage, but Method 2 demonstrated the best organ-sparing effects for the lungs, heart, liver, and spinal cord compared to other methods.
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In this case report, we present the clinical course of a woman with locally advanced mucosal melanoma of the oral cavity. She was initially treated with surgery with adjuvant local radiation of 50 Gy in 20 fractions. She quickly relapsed with an aggressive regional recurrence of the disease on the neck and with numerous pulmonary metastases.

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Neurons throughout the visual system have receptive fields with both excitatory and suppressive components. The latter are responsible for a phenomenon known as surround suppression, in which responses decrease as a stimulus is extended beyond a certain size. Previous work has shown that surround suppression in the primary visual cortex depends strongly on stimulus contrast.

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Nervous systems adapt to the prevailing sensory environment, and the consequences of this adaptation can be observed in the responses of single neurons and in perception. Given the variety of timescales underlying events in the natural world, determining the temporal characteristics of adaptation is important to understanding how perception adjusts to its sensory environment. Previous work has shown that neural adaptation can occur on a timescale of milliseconds, but perceptual adaptation has generally been studied over relatively long timescales, typically on the order of seconds.

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Neurons in the primate extrastriate cortex are highly selective for complex stimulus features such as faces, objects, and motion patterns. One explanation for this selectivity is that neurons in these areas carry out sophisticated computations on the outputs of lower-level areas such as primary visual cortex (V1), where neuronal selectivity is often modeled in terms of linear spatiotemporal filters. However, it has long been known that such simple V1 models are incomplete because they fail to capture important nonlinearities that can substantially alter neuronal selectivity for specific stimulus features.

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The dorsal pathway of the primate visual cortex is involved in the processing of motion signals that are useful for perception and behavior. Along this pathway, motion information is first measured by the primary visual cortex (V1), which sends specialized projections to extrastriate regions such as the middle temporal area (MT). Previous work with plaid stimuli has shown that most V1 neurons respond to the individual components of moving stimuli, whereas some MT neurons are capable of estimating the global motion of the pattern.

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A method for the trace analysis of antifouling agent Irgarol 1051 and its decyclopropylated degradation product in seawater was developed by using reversed-phase LC-MS with quadrupole time-of-flight mass spectrometry detection. Atrazine-d(5) was used as the internal standard for the LC-MS determination. Irgarol 1051 and the major degradation product were detected at trace levels in seawater samples collected from several marinas in Hong Kong.

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