Radiation therapy is integral to the management of most cancers, including the three most common cancers globally, breast, prostate and lung cancer. About 50-60 percent of cancer patients receive radiation therapy, making it one of the most common treatment options.
The Elekta MR-linac, a new advance in radiation therapy technology, is bringing this pillar of cancer therapy into the age of personalized, precision medicine. MR-linac is designed to address a decades-long clinical need in radiation therapy: the ability to “see while you treat” in real time and in any plane. MR-linac is the first system that integrates precision radiation therapy delivery with real-time high-field 1.5 Tesla (T) MR imaging.
With high-field 2D MR imaging at a rate of at least five frames per second, tumors can now be precisely located, their movement tracked and treatment delivery adapted in real-time in response to changes in tumor position, shape, biology and the relationship to sensitive organs over time. This is essential for improving efficacy and safety, and developing personalized treatment regimens that can improve patient outcomes.
Addressing a critical unmet need in radiation therapy Tumors change shape and size and their position relative to surrounding tissue over the course of treatment and during individual treatment sessions. This results in uncertainty about the location of tumor and normal tissue during treatment, and necessitates increased planned treatment volume (PTV) margins in order to ensure complete dosing of the tumor. Larger PTV margins increase the amount of normal tissue that is dosed, which causes more widespread or more severe toxicity that can lead to acute and long-term side effects and reduced quality of treatment outcomes.
The ability to see and monitor radiation dosing in real time could substantially reduce uncertainty about where radiation is being delivered, allowing PTV margin reductions that could better spare healthy tissue. Smaller PTVs may enable delivery of higher doses to the tumor, which could improve efficacy, while minimizing toxicity.
Real-time dose monitoring also allows calculation of the total amount of radiation accumulated in the tumor or surrounding tissue at any point over the course of therapy. Subsequent treatments can then be adjusted to ensure that the actual dose delivered is consistent with the planned dose, which is critical for optimizing outcomes.
