Publications by authors named "Michael Sherar"

The respondents all raised valuable, informative points in response to our Invited Essay. There was convergence around the need to alter governance structures at the same time as payment arrangements for physicians to achieve higher-performing health systems within Canada. At the same time, there were different views on how best to address the disconnect between levels of physician remuneration and accountability for healthcare performance and delivery.

View Article and Find Full Text PDF

Physician compensation has been a rapidly growing segment of healthcare costs in Canada since the late 1990s. In comparative terms, Canadian physicians are now well compensated compared to physicians in other high-income countries. This has caused provincial governments to begin constraining physician remuneration.

View Article and Find Full Text PDF

Introduction: Radiofrequency ablation (RFA) and percutaneous vertebroplasty (PVP) are used independently and in combination to treat metastatically involved vertebrae with the aim of relieving pain, reducing tumour burden and providing bony mechanical stabilization.

Purpose: The aim of this work was to characterize the effect of two bone-targeted RFA devices, alone and in combination with PVP, to improve strength and mechanical stability in vertebrae with osteolytic metastatic disease.

Methods: Simulated spinal metastases (n = 12) were treated with one of two bone-targeted RFA devices (bipolar cooled or bone coil RF electrodes), followed by PVP.

View Article and Find Full Text PDF

Background Context: Radiofrequency ablation (RFA) is emerging as a complementary treatment for vertebral metastases. Traditional RFA induces frictional heating leading to local tissue necrosis but often yields small, incomplete, and inhomogeneous zones of ablation in bone. We have developed a new bone-specific RFA electrode that uses a nontraditional frequency (27.

View Article and Find Full Text PDF

Clinical integration based on care paths and clinical information at the patient level is critical to ensure quality care. Moreover, effective clinical integration can occur in non-integrated health delivery systems. However, one of the challenges of a lack of integration at the system level is that no one organization or provider is responsible for an individual patient's journey.

View Article and Find Full Text PDF

Since 2004, Cancer Care Ontario (CCO) has played a leadership role in linking funding to quality of care, and in using evidence and administrative and clinical data to drive performance and quality improvement. This article describes how CCO has used its cancer and renal health system strategies to establish an environment of continuous health system improvement. The article also describes how CCO's Corporate Strategy is driving organizational improvement: evolving CCO's capacity and capability to drive quality and value across healthcare settings, and its ability to advance broader health system transformation in support of cancer and renal patients.

View Article and Find Full Text PDF

The stage of a patient's cancer at diagnosis is essential to predict the prognosis and plan the treatment. Since 2008, stage data have been collected on all Ontario patients with breast, colorectal, lung and prostate cancers and are linked to other data collected by Cancer Care Ontario. Here, an analysis of such data is presented.

View Article and Find Full Text PDF

Background: Regionalization of the practice of thoracic surgery into designated centers was carried out in Ontario to manage volume, improve outcomes, and facilitate comprehensive care. This article describes the process used by Cancer Care Ontario (CCO) to regionalize thoracic surgery practice and reports early results.

Methods: A thoracic surgery standard was created by CCO, specifying criteria for level I (tertiary) and level II (secondary) thoracic surgery centers based on current volumes and projected population growth and referral patterns, and then implemented the standard using various incentives and disincentives.

View Article and Find Full Text PDF

Purpose: Various radiofrequency (RF) ablation electrode designs have been developed to increase ablation volume. Multiple heating cycles and electrode positions are often required, thereby increasing treatment time. The objective of this study was to evaluate the performance of a high-frequency monopolar induction coil designed to produce large thermal lesions (>3 cm) with a single electrode insertion in a treatment time of less than 10 minutes.

View Article and Find Full Text PDF

Background: Good governance, clinician engagement, and clear accountabilities for achieving specific outcomes are crucial components for improving the quality of care at both an organizational and health system level.

Methods: This article describes the benefits and results reported by Cancer Care Ontario (CCO) in transforming from a direct provider of cancer services to an organization whose responsibilities include improving the quality of care across the province's cancer system. The significant challenges in establishing accountability in the absence of direct operational authority are discussed.

View Article and Find Full Text PDF

With the development of new photosensitizers that are activated by light at longer wavelengths, interstitial photodynamic therapy (PDT) is emerging as a feasible alternative for the treatment of larger volumes of tissue. Described here is the application of PDT treatment planning software developed by our group to ensure complete coverage of larger, geometrically complex target volumes such as the prostate. In a phase II clinical trial of TOOKAD vascular targeted photodynamic therapy (VTP) for prostate cancer in patients who failed prior radiotherapy, the software was used to generate patient-specific treatment prescriptions for the number of treatment fibres, their lengths, their positions and the energy each delivered.

View Article and Find Full Text PDF

A technique for Golay coded B-flow imaging, called fast B-flow imaging, has been developed. This technique improves the frame rate of Golay coded B-flow imaging. In this technique, three instead of four input pulses are used to produce each scan line.

View Article and Find Full Text PDF

We present a technique that uses Golay phase encoding, pulse inversion, and amplitude modulation (GPIAM) for microbubble contrast agent imaging with ultrasound. This technique improves the contrast-to-tissue ratio (CTR) by increasing the time-bandwidth product of the insonating waveforms. A nonlinear pulse compression algorithm is used to compress the signal energy upon receive.

View Article and Find Full Text PDF

Strongly focused large aperture transducers used in high-intensity focused ultrasound treatments are prone to manufacturing defects and degradation. Current methods for evaluating transducer quality measure only bulk physical changes of transducers. We have determined the pressure distribution at the transducer surface, using the angular spectrum method, to detect defects of the transducer.

View Article and Find Full Text PDF

We have developed a novel, thermal therapy device designed to improve local control of large solid tumours using heat in the range 55-90 degrees C. The device is a helical coil designed to be loosely wound inside a tumour and excited with radiofrequency energy at 27.12 MHz.

View Article and Find Full Text PDF

We have developed a novel, radiofrequency thermal therapy device designed to improve local control of large solid tumours using heat in the range 55-90 degrees C. The device is a solenoid or helical coil designed to be loosely wound inside a tumour and excited with radiofrequency energy. Typically, we associate a uniform axially directed magnetic field with a solenoid coil, which when time varying, results in an electric field inside the coil, which lies mainly in the circumferential direction.

View Article and Find Full Text PDF

Background And Objectives: Fluoroptic sensors are used to measure interstitial temperatures but their utility for monitoring laser interstitial thermal therapy (LITT) is unclear because these sensors exhibit a measurement artefact when exposed to the near-infrared (NIR) treatment light. This study investigates the cause of the artefact to determine whether fluoroptic sensors can provide reliable temperature measurements during LITT.

Study Design/materials And Methods: The temperature rise measured by a fluoroptic sensor irradiated in non-absorbing media (air and water) was considered an artefact.

View Article and Find Full Text PDF

Currently the only method to assess liver preservation injury is based on liver appearance and donor medical history. Previous work has shown that high-frequency ultrasound could detect ischemic cell death due to changes in cell morphology. In this study, we use high-frequency ultrasound integrated backscatter to assess liver damage in experimental models of liver ischemia.

View Article and Find Full Text PDF

Thermal therapy is used to kill tumors by heating them to temperatures >50 degrees C for an extended period of time. Cell death results from thermal coagulation. The energy sources available for this approach include radiofrequency electrodes, microwave antennas, laser fiberoptics, and ultrasound transducers.

View Article and Find Full Text PDF

We have developed a system to measure the changes due to heating to high temperatures in the dielectric properties of tissues in the radio-frequency range. A two-electrode arrangement was connected to a low-frequency impedance analyser and used to measure the dielectric properties of ex vivo porcine kidney and fat at 460 kHz. This frequency was selected as it is the most commonly used for radio-frequency thermal therapy of renal tumours.

View Article and Find Full Text PDF

Thermal therapy is an experimental treatment to destroy solid tumours by heating them to temperatures ranging from 55 degrees C to 90 degrees C, inducing thermal coagulation and necrosis of the tumour. We are investigating the feasibility of interstitial microwave thermal therapy as a salvage treatment for prostate cancer patients with local recurrence following failed brachytherapy. Due to the electrical and thermal conductivity of the brachytherapy seeds, we hypothesized that the seeds could scatter the microwave energy and cause unpredictable heating.

View Article and Find Full Text PDF

Urethral cooling catheters are used to prevent thermal damage to the urethra during thermal therapy of the prostate. Quantification of a catheter's heat transfer characteristics is necessary for prediction of the catheter's influence on the temperature and thermal dose distribution in periurethral tissue. Two cooling catheters with different designs were examined: the Dornier Urowave catheter and a prototype device from BSD Medical Corp.

View Article and Find Full Text PDF

Temperature inhomogeneity in hyperthermia treatments often limits the total thermal dose that can be delivered to the tumour region. To reduce such inhomogeneities, a prototype dynamically modifiable square array of saline-filled patches which attenuate microwave energy was developed for superficial treatments that use external microwave applicators. The array was situated inside the coupling water bolus that is often used with external applicators.

View Article and Find Full Text PDF

Impractically long treatment times are required for highly focused spherical transducers to destroy large tumours because thermal lesions generated by these transducers are small and a large number of such lesions are required. Moderately focused spherical transducers and multi-focus acoustic lens/transducer systems can generate larger thermal lesions compared to those produced by highly focused spherical transducers, and therefore shorter treatment times can be expected. The decrease in total treatment time by the use of moderately focused spherical transducers and acoustic lens/transducer systems was quantified in this study.

View Article and Find Full Text PDF