A novel treatment approach using hypofractionated proton beam therapy, guided by advanced imaging techniques, is showing promise in extending the lives of older patients diagnosed with glioblastoma, the most aggressive form of brain cancer. The phase 2 study, conducted at Mayo Clinic, offers a potential improvement in overall survival while maintaining patients' quality of life.
The study, led by Dr. Sujay Vora, a radiation oncologist at Mayo Clinic, involved patients over the age of 65 with newly diagnosed, malignant glioblastoma. The results, published in The Lancet Oncology, indicated that 56% of participants were alive after 12 months, with a median overall survival of 13.1 months. This is a significant improvement compared to historical data, where similar patient populations had a median survival of only six to nine months.
Precision Targeting with Advanced Imaging
The innovative approach combines 18F-DOPA PET and contrast-enhanced MRI to map the target area in the patient's brain. "Combining advanced imaging allowed us to determine the most metabolically active, or aggressive, regions of the glioblastoma," Dr. Vora explained. This precise mapping enables clinicians to target the most aggressive areas of the tumor while minimizing radiation exposure to surrounding healthy brain tissue.
Short-Course Hypofractionated Proton Beam Therapy
Unlike traditional radiation therapy, which can last three to six weeks, the hypofractionated proton beam therapy was completed in just one to two weeks. Proton beam therapy uses charged heavy particles to destroy cancer cells with targeted precision, reducing collateral damage to healthy tissue. According to Dr. Vora, this method delivers "a lot less collateral radiation."
Clinical Impact and Future Directions
The improved survival rates and shorter treatment duration offer a significant benefit to patients and their families. "Anything we can do to help reduce that burden, is a good thing," Dr. Vora noted, highlighting the importance of minimizing the impact of long and demanding treatment schedules.
Building on these promising results, a larger, randomized clinical trial (NCT05781321), known as SAGA, is now underway at Mayo Clinic. This trial aims to compare the short-course hypofractionated proton beam therapy regimen with standard-of-care treatment in adults of all ages with newly diagnosed glioblastoma. Dr. William Breen, radiation oncologist and principal investigator of the current study, stated, "Our goal is to transform the way we treat glioblastoma using shorter courses of radiation to minimize the burden on patients and their families and help them complete safe and effective treatment in a shorter amount of time."
The study was funded by Mayo Clinic Marley Endowment Funds and the Lawrence W. and Marilyn W. Matteson Fund in Cancer Research.
