Science Made Simple: Understanding Brain Cancer with Professor Rachel Grossman

Cancer research can be complex, but understanding why it matters should not be. Science Made Simple brings insights from leading physicians and researchers directly to our community, breaking down important advances in cancer research into clear, accessible language.

We recently spoke with Professor Rachel Grossman, ICRF Project Grant recipient, Rambam Health Care Campus, about her research into glioblastoma and a new approach that could provide a “window into the brain” through a blood test. Using MRI-guided focused ultrasound to temporarily open the blood-brain barrier, her team hopes to detect tumor and immune-related biomarkers in the bloodstream and better understand how glioblastoma responds to treatment over time.

Can you describe your research in simple terms and explain why it is important?

My research focuses on finding better ways to understand how glioblastoma responds to treatment and how we can monitor what is happening inside the tumor over time. One of the major challenges in treating glioblastoma is that it is very difficult to assess the biological changes occurring inside the brain without surgery. The brain is protected by the blood-brain barrier (BBB), which limits the movement of molecules from the brain into the bloodstream. As a result, important signals produced by the tumor or by the immune system may remain largely hidden from routine blood tests.

In this study, we use MRI-guided focused ultrasound to temporarily and precisely open the BBB around the tumor. We take blood samples immediately before and after opening the barrier and look for tumor- and immune-related biomarkers that may otherwise remain trapped within the brain. In effect, we are trying to create a “window into the brain” through a simple blood test.

We apply this approach in patients receiving standard glioblastoma treatment together with Tumor Treating Fields (TTFields), a non-invasive therapy that uses low-intensity electrical fields to interfere with tumor cell growth and may also influence the immune response against the tumor.

This research is important because today we rely heavily on MRI scans to determine whether glioblastoma treatment is working, but imaging does not always reflect what is happening biologically within the tumor. By repeatedly measuring blood biomarkers during treatment, we hope to detect changes in the tumor and its immune environment earlier and more accurately. Ultimately, our goal is to develop a blood-based method for monitoring glioblastoma in real time, allowing us to better understand treatment response, identify which patients are benefiting from therapy, and ultimately guide more personalized treatment strategies.

How could your research change the way brain cancer is detected, diagnosed, or treated in the future?

One of the major challenges in brain cancer is that we have very limited ways to understand what is happening inside the tumor site during treatment. We mainly rely on MRI, but imaging does not always reflect the biological changes occurring within the tumor.

Our research aims to create a kind of “window into the brain” through a blood test. By temporarily and safely opening the BBB with MRI-guided focused ultrasound, we hope to release tumor- and immune-related signals into the bloodstream, where they can be measured using liquid biopsy.

In the future, this could allow us to monitor how a tumor is responding to treatment in real time, potentially identify treatment failure earlier, and select therapies based on the biology of an individual patient’s tumor rather than relying primarily on imaging. In this study, we are particularly interested in understanding the immune response to TTFields, which may ultimately help us identify which patients benefit most and how this treatment approach could be combined with immunotherapy.

How will ICRF funding help advance your research or accelerate your next steps?

ICRF funding is extremely important because it allows us to move an innovative concept from the laboratory toward patients. We already have encouraging preclinical data showing that focused ultrasound can open the BBB in a controlled and reproducible way and enhance the release of biomarkers into the circulation.

The ICRF support will allow us to take the next critical step: a proof-of-concept clinical study in patients with glioblastoma. We will combine MRI-guided BBB opening with repeated blood sampling during TTFields treatment and examine whether we can detect and follow immune- and tumor-related biomarkers over time.

This type of early translational research is essential for generating the evidence needed to develop larger clinical trials. Ultimately, the goal is to establish a platform that could be used not only for TTFields, but potentially for monitoring many different treatments for brain tumors.

How does your work as both a physician and researcher shape your approach to understanding brain cancer?

In treating patients with brain tumors, I regularly encounter situations where the information we have is not enough to guide treatment decisions. These clinical gaps often become the starting point for my research.

Glioblastoma is a good example. Surgery gives us access to tumor tissue and allows us to study its biology in detail, but it provides information from only one point in time. Once treatment begins, the tumor continues to change, while our ability to follow these biological changes is very limited. Repeated surgery just to obtain tissue is not a good option.

This limitation led us to explore whether temporarily opening the BBB, combined with serial blood sampling, could provide biological information about the tumor during treatment. The goal is to understand not only what the tumor looks like on MRI, but also how it is changing and responding at a biological level.

My work with patients helps me identify the most relevant clinical questions, while research allows me to investigate them systematically and, hopefully, translate the findings back into better patient care.

What has your experience been like as a woman leading the Brain Tumor Center at Rambam, and what do you believe is needed to encourage more women to pursue leadership roles in science?

Neurosurgery has traditionally been a male-dominated field, so building a career in academic neurosurgery and eventually leading a Brain Tumor Center has certainly involved challenges. At the same time, I have been fortunate to work with excellent colleagues and collaborators, and I believe that leadership should ultimately be defined by professional excellence, commitment, and the ability to build strong teams.

I think one of the most important ways to encourage more women to pursue leadership positions is to make those career paths visible and achievable. Young women need role models, but they also need mentorship, access to research opportunities, and institutional environments that actively support their professional development.

We also have to recognize that becoming a neurosurgeon, scientist, and leader is a long process, often during the same years in which people are building families. Ensuring that women have equal opportunities for mentorship, promotion, funding, and leadership can make an enormous difference.

I hope that seeing more women leading clinical departments, research programs, and major scientific collaborations will gradually make this less exceptional. Leadership should be a realistic career option for talented women in medicine and science, rather than a path that still feels unusual or exceptional.

What advice would you give to the next generation of young women who aspire to become scientists, physicians, or research leaders?

My advice would be to stay curious and be prepared to work hard across several areas at the same time. Be deeply involved in your clinical work, but remain curious about the questions that arise from it. Learn how to turn those questions into research, seek out people with complementary expertise, and actively create collaborations rather than waiting for them to happen.

Some of the most interesting opportunities come from working with people outside your immediate field and being open to ideas you had not initially considered. It is also important to take responsibility and to be willing to invest the time and effort required to move projects forward.

Work hard, stay curious, build strong collaborations, and don’t limit yourself too early to one direction. Over time, the combination of clinical experience, research, and collaboration can create opportunities that would not have been possible through any one of them alone.

Learn more about Professor Rachel Grossman.