Treatment includes surgery, radiation, chemotherapy, targeted therapy or hormonal therapy, likely a combination depending on the individual's disease. Patients with a large breast tumour or palpable lymph nodes often receive chemotherapy first, followed by surgery. During chemotherapy, a doctor performs breast exams and occasional imaging to monitor the tumour and assess how much it is shrinking.
Given that the degree of tumour shrinkage during chemotherapy can predict outcomes and sometimes potentially influence treatment plans, is there a better way to measure the tumour's response to chemotherapy before surgery?
Armed with a new Health Professional-Investigator Award from the Michael Smith Foundation for Health Research, this is the question that a research team led Dr. Jenny Ko, medical oncologist and director of clinical trials at BC Cancer – Abbotsford, is aiming to find out.
From left to right: Dr. Majid Shokoufi, Simon Fraser University, Biomedical Engineering; Dr. Ramani Ramaseshan, Physics, BC Cancer — Abbotsford; Dr. Jenny Ko, Medical Oncology, BC Cancer — Abbotsford; Dr. Thao Nguyen, Medical Oncology, BC Cancer — Abbotsford; Parmveer Atwal, Physics, BC Cancer — Abbotsford
We are collaborating with scientists in the Biomedical Engineering department of Simon Fraser University who have patented a technology called Diffuse Optical Imaging (DOI). It uses light wave lengths that can penetrate the skin and, based on diffraction of that light, can characterize different types of tissues. Based on early results, it is clear that cancer looks different from normal tissue with DOI.
I hypothesize that we can use this technology to see how much a tumour is shrinking in real time over the course of chemotherapy. Currently, we don't have a good technology to do this; the best we have is our hands, to palpate the size and shape of a tumour. This has many limitations, of course. For example, a tumour doesn't necessarily feel shrunken even though cancer cells inside of it may be dying. And imaging technologies like ultrasound and MRI are not done in real time, can be difficult to obtain and may not accurately reflect the actual tumour response during treatment. So, developing bedside real-time imaging technology to visualize a tumour at every contact with a patient is very useful. This technology could help to tell us if chemo is working and has a potential to be able to help clinicians develop a more accurate treatment plan, if the tool can be validated. We also know that patients whose cancer shrinks with chemo prior to surgery do better in the long term, so this technology could help us counsel patients with more accurate prognoses.
Cancer tissue is a lot more disorganized and it's a lot more vascular in some instances, or it's a lot less vascular in other instances. Cancer tissue itself has a very different density, mostly because the water content is different and vascularity is quite different. We can also detect oxyhemoglobin content and other components of a tissue. Based upon all that information we construct a graphical display of what the tissue looks like. In order to validate DOI, we will compare this with information from tumour slides from a patient's surgery and also with ultrasound images that we collect as a standard of care.
Graphic of the handheld DOI technology and display output on a laptop.
Yes. There are cancers that are also accessible for imaging using this probe. Cancers that are more superficial are very relevant, more so than cancers that are deeper within the body. Deeper cancers are difficult to image because the penetrance of the light is superficial, only extending several centimeters into the tissue. You would need a longer range than that for pancreatic or lung cancer, for example. The technology may evolve to penetrate deeper tissues, but right now it can only capture superficial cancers. Our research will take a few years to complete and validate, and if validated in breast cancer, we may be able to examine DOI's ability to image other cancers in the future.
I'm very passionate about patients. It is my daily encounters with them, and in learning about their personal journey through illness, that gives me not only a sense of responsibility but a sense of joy to know that I am able to be there for someone at a vulnerable time in their life. There are also so many different components to cancer care, from acute care and surgery, all the way to palliative care and pain and symptom management, and of course, research. There are also many developments in oncology happening right now, and so many innovative ideas. It's a really exciting time to be in this field.
Communications Officer, BC Cancer
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