Alexandra Rink, PhD, MCCPM

Patient Dosimetry
Radiotherapy treatments have become very sophisticated due to advances in technology and the increased complexity of the processes themselves. A robust, real-time patient radiation dosimeter is an important safety system for catching errors that cannot be detected by human vigilance and other quality assurance and quality control methods. My research involves investigating various materials for use with fibre-optical readout for real-time patient dosimetry, as well as probe and system design. An important component of this work is the ability to implement the dosimetric device on patients and accurately predict real-time dose from a linear accelerator or remote brachytherapy afterloader to create a quality control tool. Immediate treatment interruption upon the detection of a threshold error is critical to avoid potential health consequences and can only be achieved with real-time data feedback and comparison against the expected. Additionally, implementing a large-scale patient dosimetry program would provide the radiotherapy community with the statistics on treatment delivery deviations, including those not resulting in severe complications.

Improvement in Brachytherapy Patient Care
The paradigm of radiotherapy delivery is scan, plan and treat. The quality of treatment depends on the applicability of the scan to the time of treatment. While the standard practice in external beam radiotherapy is to account for planning and treatment uncertainties, this is rare in high dose-rate brachytherapy. Oedema from implant and organ filling and motion are just few of the factors that can contribute to a deviation from intended dose distribution. Understanding these factors and finding methods to account for these uncertainties, for example through implementation of planning margins or by following an organ filling protocol, can help improve the quality of patients’ brachytherapy treatment. Non-dosimetric factors, such as the time it takes between patient scan and treatment, or the number of treatment catheters used in brachytherapy, also play an important part in the quality of patients’ brachytherapy treatment. My research explores methods to improve these factors, including image guidance and navigation for interstitial catheter positioning. Other opportunities include assisted contouring of targets and organs. My goal is to minimize the patient’s time from scan to treatment and ensure interventions performed are necessary for optimal dose delivery.

For a list of Dr. Rink's publications, please visit PubMed or Scopus.

Medical Physicist, Radiation Medicine Program, Princess Margaret Cancer Centre
Associate Professor, Department of Radiation Oncology, University of Toronto
Assistant Professor, Department of Medical Biophysics, University of Toronto