MR-guided radiation therapy offers hope for pancreatic cancer

Pancreatic ductal adenocarcinoma remains one of the most challenging cancers for patients and caregivers, with approximately 67,000 new diagnoses and 51,900 deaths each year. Survival is limited for many patients, particularly for those who are not candidates for surgery. Because a significant number of patients experience local tumor progression, an important factor that can affect overall survival, research has increasingly focused on improving local therapies such as radiation.¹

Radiation therapy has had a longstanding role in treatment for pancreatic cancer and can be used before or after surgery or combined with chemotherapy in patients who are unable to have surgery. Radiation therapy can be delivered in several ways, including conventional external beam radiation therapy and stereotactic body radiation therapy (SBRT). Traditional external beam therapy can range from 15-30 daily treatments, while SBRT condenses treatment into just five sessions or fewer, delivering higher doses each time.

Benefits of MRI guidance

Technological advances have greatly improved how radiation therapy is delivered. The development of the magnetic resonance imaging linear accelerator (MRI-linac) combines the high-contrast imaging of MRI with the precision of a modern radiation therapy machine.

MRI offers superior soft-tissue contrast compared with CT scans, allowing physicians to visualize the pancreas and surrounding organs with far greater clarity. This enhanced view enables more accurate tumor targeting while sparing nearby structures such as the stomach, bowel and duodenum. Because the pancreas moves with breathing, MRI guidance also provides continuous visualization during treatment. Real-time motion management allows the machine to “gate” radiation, delivering dose only when the tumor is correctly positioned. This level of precision is difficult to achieve using conventional CT-based systems, which cannot visually monitor anatomy continuously during treatment.

Adapting treatment in real time

Another benefit of MRI guidance is its ability to adapt treatment in real time. Before each daily fraction, a new MRI scan is performed. If the tumor or surrounding anatomy has shifted due to bowel or stomach changes, the plan can be adjusted on the spot while the patient is on the table to better treat the pancreatic tumor and avoid normal organs.

During treatment, continuous MRI monitoring tracks the tumor. If the cancer moves out of position, the machine automatically stops. After pausing the treatment, the patient's positioning can be adjusted, or the treatment plan can be further adapted to account for anatomic changes. This prevents unintended radiation from being delivered to normal organs, further reducing treatment toxicity. In standard CT-based treatments, these anatomic changes during treatment would not be detected, as there is no live imaging, possibly resulting in the dose being delivered to normal organs.

Reduction in toxicities

The SMART trial evaluated MR-guided SBRT for pancreatic cancer and illustrated the clinical advantages of this technology.² Researchers reported a 1-year local control rate of 83% from the time of treatment and 90% from the time of diagnosis. Notably, the rate of severe (grade 3 or higher) gastrointestinal toxicity determined to be probably related to treatment was only 2.2%. By comparison, published toxicity rates for conventional CT-based SBRT have reached 30% or more in some series.³

These findings highlight the value of real-time visualization, motion tracking and adaptive planning in reducing harm while maintaining excellent tumor control.

Looking ahead

MRI-guided radiation represents a promising new frontier in pancreatic cancer care. By combining real-time imaging, adaptive planning and precision targeting, MRI-guided therapy offers the potential for improved local control with fewer side effects when compared to traditional CT-guided treatments.

As Pancreatic Cancer Awareness Month reminds us, advancements in treatment are about more than technology—they are about providing hope, improving quality of life and expanding options for patients facing a difficult diagnosis. Ongoing and future research will continue to progress in MRI-guided SBRT and explore ways to improve outcomes, making radiation therapy both safer and more effective for patients.

Learn more about the Liver & Pancreas Program at Northside Hospital Cancer Institute.

References: 

1. American Cancer Society. 2025. “Key Statistics for Pancreatic Cancer.” American Cancer Society. Last revised January 16, 2025. https://www.cancer.org/cancer/types/pancreatic-cancer/about/key-statistics.html. [cancer.org]
2. Chuong, Michael D., et al. 2024. “Stereotactic MR-Guided On-Table Adaptive Radiation Therapy (SMART) for Borderline Resectable and Locally Advanced Pancreatic Cancer: A Multi-Center, Open-Label Phase 2 Study.” Radiotherapy and Oncology 191: 110064. https://doi.org/10.1016/j.radonc.2024.110064. [scribbr.com]
3. Shouman, M. A., F. Fuchs, F. Walter, S. Corradini, C. B. Westphalen, M. Vornhülz, G. Beyer, D. Andrade, C. Belka, M. Niyazi, and P. Rogowski. 2024. “Stereotactic Body Radiotherapy for Pancreatic Cancer—A Systematic Review of Prospective Data.” Clinical and Translational Radiation Oncology, January 2024. https://doi.org/10.1016/j.ctro.2023.100123.