Publications by authors named "Cato Chan"

Objectives: To explore the association between the extent of CT abnormalities by quantitative imaging analysis (QIA) and clinical/physiological disease parameters in patients with antisynthetase syndrome associated interstitial lung disease (ARS-ILD).

Methods: We analysed 20 patients with antisynthetase antibodies and active ILD enrolled in the Abatacept in Myositis-Associated Interstitial Lung Disease study. High-resolution chest CT was obtained at weeks 0, 24 and 48 and QIA scored the extent of ground glass (quantitative score for ground glass), fibrosis (quantitative score for lung fibrosis, QLF) and total ILD (quantitative ILD, QILD).

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Objective: We aimed to evaluate the effectiveness of utilizing artificial intelligence (AI) to quantify the extent of pneumonia from chest CT scans, and to determine its ability to predict clinical deterioration or mortality in patients admitted to the hospital with COVID-19 in comparison to semi-quantitative visual scoring systems.

Methods: A deep-learning algorithm was utilized to quantify the pneumonia burden, while semi-quantitative pneumonia severity scores were estimated through visual means. The primary outcome was clinical deterioration, the composite end point including admission to the intensive care unit, need for invasive mechanical ventilation, or vasopressor therapy, as well as in-hospital death.

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Imaging of Cystic Lung Disease.

Radiol Clin North Am

November 2022

Diffuse cystic lung disease refers to multiple rounded lucencies or low-attenuating areas with well-defined interfaces with normal lung. Parenchymal lucencies, such as cavitary disease, may mimic cystic lung disease. Cystic lung disease generally has a nonspecific presentation.

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Quantitative lung measures derived from computed tomography (CT) have been demonstrated to improve prognostication in coronavirus disease 2019 (COVID-19) patients but are not part of clinical routine because the required manual segmentation of lung lesions is prohibitively time consuming. We aim to automatically segment ground-glass opacities and high opacities (comprising consolidation and pleural effusion). We propose a new fully automated deep-learning framework for fast multi-class segmentation of lung lesions in COVID-19 pneumonia from both contrast and non-contrast CT images using convolutional long short-term memory (ConvLSTM) networks.

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Quantitative lung measures derived from computed tomography (CT) have been demonstrated to improve prognostication in Coronavirus disease 2019 (COVID-19) patients, but are not part of the clinical routine since required manual segmentation of lung lesions is prohibitively time-consuming. We propose a new fully automated deep learning framework for quantification and differentiation between lung lesions in COVID-19 pneumonia from both contrast and non-contrast CT images using convolutional Long Short-Term Memory (LSTM) networks. Utilizing the expert annotations, model training was performed using 5-fold cross-validation to segment ground-glass opacity and high opacity (including consolidation and pleural effusion).

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Purpose: To examine the independent and incremental value of CT-derived quantitative burden and attenuation of COVID-19 pneumonia for the prediction of clinical deterioration or death.

Methods: This was a retrospective analysis of a prospective international registry of consecutive patients with laboratory-confirmed COVID-19 and chest CT imaging, admitted to four centers between January 10 and May 6, 2020. Total burden (expressed as a percentage) and mean attenuation of ground glass opacities (GGO) and consolidation were quantified from CT using semi-automated research software.

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Article Synopsis
  • The study aimed to investigate how epicardial adipose tissue (EAT) seen on chest CT relates to the severity of pneumonia and outcomes for patients with COVID-19.
  • It involved analyzing data from 109 COVID-19 patients to examine the connection between lung abnormalities, EAT volume, EAT attenuation, and various health metrics.
  • The findings revealed that higher EAT volume and attenuation were significant predictors of worse outcomes, such as clinical deterioration or death, in these patients.
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We prospectively investigated the feasibility of IMRT treatment plan optimization based on dosimeter measurements of lateral tongue mucosal dose adjacent to the dental fillings and evaluated dose-toxicity relationship and factors affecting oral mucositis (OM) in head and neck cancer patients. Twenty-nine head and neck cancer patients with metallic dental fillings who were scheduled to undergo fractionated external beam radiation therapy (RT) ± chemotherapy were enrolled. The lateral tongue dose was measured and if the calculated dose for the entire treatment was ≥35 Gy, a re-plan was generated to reduce the lateral tongue mucosal dose.

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Purpose: Radiotherapy can result in lymphopenia, which has been linked to poorer survival. Here, we test the hypothesis that radiotherapy-induced lymphopenia is mediated by a tumor-secreted factor, Galectin-1 (Gal-1), which possesses T-cell proapoptotic activities.

Experimental Design: Matched Gal-1 wild-type (WT) or null mice were implanted with Lewis lung carcinoma (LLC-1) that either expressed Gal-1 or had Gal-1 stably downregulated.

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Background: The purpose of this study was to compare Common Terminology Criteria for Adverse Events (CTCAE), Brock and Chang hearing loss grading in patients with head and neck cancer receiving cis-diamminedichloroplatinum (CDDP). Endpoints were baseline distribution of hearing loss, interobserver consistency, and sensitivity to hearing loss after CDDP treatment.

Methods: Four hundred sixty single ear audiograms in 110 patients with head and neck cancer were graded.

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Objectives: We sought to determine if carbohydrate antigen 19-9 (CA19-9 ) nadir (nCA19-9), time to nadir (TTN), and doubling time (DT) after radiotherapy (RT) correlate with outcomes in pancreatic ductal adenocarcinoma.

Methods: We examined the records of 102 patients treated with RT for primary, nonmetastatic pancreatic ductal adenocarcinoma between August 1998 and July 2011. Of these, 33 patients were treated with postoperative chemoradiotherapy (PORT) and 69 patients with definitive chemoradiotherapy (CRT).

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Background: The purpose of this study was to present our experience utilizing cetuximab and platinum-based concurrent chemoradiotherapy for the definitive treatment of head and neck squamous cell carcinoma (HNSCC).

Methods: Patients (n = 177) who received definitive concurrent chemoradiotherapy for HNSCC were stratified into 3 groups: receiving cetuximab monotherapy (n = 24), cetuximab and chemotherapy combination (n = 33), or platinum-based chemotherapy without cetuximab (n = 120). Primary endpoints were freedom from relapse, event-free survival, and overall survival (OS).

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Article Synopsis
  • Radiation to retropharyngeal nodes (RPN) can lead to higher levels of toxicity in patients.
  • This study explored the factors linked to RPN involvement in 165 patients with oropharynx cancer.
  • Key factors included advanced disease stages (N2c-3 or N2b), having three or more affected cervical lymph nodes, involvement of lymph nodes on the opposite side, or specific tumor locations.
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Purpose: To determine the effect of Alda-89 (an ALDH3 activitor) on (i) the function of irradiated (radiotherapy) submandibular gland (SMG) in mice, (ii) its toxicity profile, and (iii) its effect on the growth of head and neck cancer (HNC) in vitro and in vivo.

Experimental Design: Adult mice were infused with Alda-89 or vehicle before, during, and after radiotherapy. Saliva secretion was monitored weekly.

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Purpose: To report outcomes in patients treated with postoperative radiotherapy for nonadenoid cystic carcinomas of the major salivary glands.

Materials And Methods: From 1998-2011, 37 patients with nonadenoid cystic carcinomas of the major salivary gland underwent postoperative radiotherapy. The median radiation dose was 60 Gy (range, 45-70 Gy).

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Objectives/hypothesis: Postoperative radiation therapy is often used in patients with high-risk salivary gland carcinomas. In this study we evaluated the outcomes and prognostic factors in patients with minor salivary gland cancers treated with adjuvant radiation therapy.

Study Design: Retrospective cohort study.

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Background: It is important to determine the outcomes of retreatment in patients with locally recurrent nasopharyngeal carcinoma.

Methods: We reviewed the records of patients treated for local recurrence at Stanford and Shantou Universities. The end points were local relapse-free survival (LRFS) and overall survival after retreatment.

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