Associate Professor

Robert Weersink

PhD, University of Toronto

Princess Margaret Cancer Centre
700 University Avenue, Medical Physics Floor 7-214 OPG, Toronto, Ontario Canada M5G 1X6
Research Interests
Biomedical Imaging, Image-Guided Therapy and Device Development

At a Glance

  • Image guided therapies, in particular the intersection of biophotonics with surgery and radiation therapies.
  • Integrating optical imaging with 3D radiological imaging using navigation technologies and computer vision methods
  • Planning and monitoring photothermal and photodynamic therapies (PDT and PTT) for clinical treatments in prostate, head and neck and lung.
  • Board certification, radiation oncology physics (M-CCPM)

Short Bio

Robert Weersink is Scientist at the Princess Margaret Cancer Centre, University Health Network, and Assistant Professor in the Depts. of Radiation Oncology, Medical Biophysics, and at the Institute of Biomaterials and Biomedical Engineering. Dr. Weersink earned a PhD in Chemical Physics at the University of Toronto. He worked as a staff scientist and manager of the Laboratory for Applied Biophotonics (Princess Margaret Hospital), then manager of the Guided Therapeutics (GTx) Program at UHN. He gained his certification as a Clinical Physicist in 2012 and has been a member of the brachytherapy team at Princess Margaret Cancer Centre since then. His research focus is on developing new technologies in image-guided therapy with clinical applications in radiation medicine and surgery.

Research Synopsis

Dr. Weersink and his team have two main research areas:

Image Guidance for Ablative Therapies

Photodynamic and photothermal therapies are increasingly translated into clinical use. We are developing new treatment planning, delivery and monitoring methods for both modalities with a strong focus on clinical translation into treating prostate, lung and head and neck. We are developing optically-based methods for response monitoring in these indications such as trans-rectal diffuse optical tomography (TR-DOT) for monitoring prostate treatments and photoacoustic imaging. These methods rely on changes in tissue properties as measurements of treatment response, such as optical scattering, absorption and fluorescence.

Registration of Optical and Radiological Imaging

Radiological imaging is the primary data set used in planning and guiding procedures in image-guided surgery, radiation therapy and interventional radiology, providing exact spatial information of disease location. Non-volumetric information, such as endoscopy, needle positioning and pathology also provide important clinical information that is typically disconnected from the spatial mapping provided by the radiological imaging. We are developing methods of spatially mapping and integrating this non-volumetric information with the standard radiological imaging as an aid in image-guided surgery and radiation treatment planning. For endoscopic imaging, we have developed methods of image-based registration between the optical imaging and CT imaging, comparing real and virtual endoscopic views. This quantitative endoscopy is being evaluated as a method to improve the contouring of mucosal disease in head and neck cancers being treated with radiation therapy. More recently, we have been applying these methods for applications in lung and esophagus brachytherapy, where definition of the disease and the applicator insertion is based on optical visualization. We are investigating new methods of 3D endoscopy using a combination of MEMs-based fiber scanning probes and optical coherence tomography.

Recent Publications

  1. Wilson BC, Weersink RA, “The Yin and Yang of PDT and PTT”, Photochemistry and Photobiology, 2019, doi: 10.1111/php.13184.
  2. Weersink RA, J Qiu, D Martinez, et al., "Feasibility Study of Navigated Endoscopy for the Placement of High Dose Rate Brachytherapy Applicators in the Esophagus and Lung," Med. Phys. 2019, 47(3):917-926, doi: 10.1002/mp.13997.
  3. He J, Li CL, Wilson BC, Fisher CJ, Ghai S, Weersink RA, “A Clinical Prototype Transrectal Diffuse Optical Tomography (TRDOT) System for In vivo Monitoring of Photothermal Therapy (PTT) of Focal Prostate Cancer”, IEEE Transactions on Biomedical Engineering, 2019, doi: 10.1109/TBME.2019.2955354.
  4. Weersink RA, Patterson, S, Ballantyne H, Di Tomasso A, Borg J, Vitkin A, Rink A., Beiki-Ardakani A, “An Improved Treatment Planning and Quality Assurance Process for COMS Eye Plaque Brachytherapy”, Brachytherapy, 2019, 18(5), p 658-667.
  5. Verhaegen F, Dubois L, Gianolini S, Hill MA, Karger CP, Lauber K, Prise KM, Sarrut D, Thorwarth D, Vanhove C, Vojnovic B, Weersink R, Wilkens JJ, and Georg D, "ESTRO ACROP: Technology for precision small animal radiotherapy research: Optimal use and challenges". Radiotherapy and Oncology, 2018. 126(3): p. 471-478.
  6. Weersink RA, Chaudhary S, Mayo K, He J, and Wilson BC, "Shape-based reconstruction for transrectal diffuse optical tomography monitoring of photothermal focal therapy of prostate cancer: simulation studies". Journal of Biomedical Optics, 2017. 22(4): p. 45004.
  7. Weersink RA, Ansell S, Wang A, Wilson G, Shah D, Lindsay PE, and Jaffray DA, "Integration of optical imaging with a small animal irradiator". Medical Physics, 2014. 41(10).
  8. Ng KK, Shakiba M, Huynh E, Weersink RA, Roxin A, Wilson BC, and Zheng G, "Stimuli-Responsive Photoacoustic Nanoswitch for in Vivo Sensing Applications". Acs Nano, 2014. 8(8): p. 8363-8373.
  9. McVeigh PZ, Sacho R, Weersink RA, Pereira VM, Kucharczyk W, Seibel EJ, Wilson BC, and Krings T, "High-Resolution Angioscopic Imaging During Endovascular Neurosurgery". Neurosurgery, 2014. 75(2): p. 171-17
  10. He J, Wilson BC, Piao D, and Weersink RA, "Diffuse optical tomography to monitor the photocoagulation front during interstitial photothermal therapy: numerical simulations and measurements in tissue-simulating phant". Photonics and Lasers in Medicine, 2014. 3(3): p. 241-254.
  11. Qiu J, Hope AJ, Cho BCJ, Sharpe MB, Dickie CI, DaCosta RS, Jaffray DA, and Weersink RA, "Displaying 3D radiation dose on endoscopic video for therapeutic assessment and surgical guidance". Physics in Medicine and Biology, 2012. 57(20): p. 6601-6614.
  12. Weersink RA, Qiu J, Hope AJ, Daly MJ, Cho BCJ, DaCosta RS, Sharpe MB, Breen SL, Chan H, and Jaffray DA, "Improving superficial target delineation in radiation therapy with endoscopic tracking and registration". Medical Physics, 2011. 38(12): p. 6458-6468.

Graduate Students

Theodore Husby