An imaging agent, developed by Aposense, a molecular imaging and drug development company, used during PET scans to highlight apoptosis (programmed cell death) appears to help oncologists detect the effect of radiation treatment on brain metastases (tumors from elsewhere in the body that have spread to the brain) early in treatment, according to new data presented today at the 56th Annual Meeting of the Society of Nuclear Medicine, taking place June 13-17 in Toronto, Ontario, Canada.
"Patients with brain metastases have a poor prognosis. The sooner we know if a tumor is responding the more we can help these patients. These results have the potential to radically change the way we as oncologists think about monitoring treatment response," said Aaron Allen, MD, a radiation oncologist at the Davidoff Comprehensive Cancer Center of the Rabin Medical Center, in Petach-Tikva, Israel, and the principal investigator on the trial. "By using this imaging agent known as [18F]-ML-10, we might be able to immediately measure the rate of programmed cell death induced by radiation, and evaluate whether treatment is effective early on, whereas standard imaging only allows us to evaluate treatment two or three months after it was completed."
[18F]-ML-10 (ML-10) is a PET tracer developed by Aposense Ltd., the leading developer of agents targeting apoptosis (programmed cell death) for molecular imaging and therapy.
For the study, physicians administered ML-10 radio-labeled with the radio-isotope 18-F to ten patients with brain metastases and performed a PET scan to determine baseline levels of apoptosis, which occurs spontaneously within the pre-treatment tumor. They administered ML-10 and performed another PET scan on day nine or 10 to identify changes in apoptosis as a result of treatment.
Seven patients completed the study and eight tumors were available for evaluation. All tumors demonstrated at baseline clear images of pre-treatment apoptosis, with ML-10 uptake increasing over time within the tumors as compared to the non-target tissue or blood, confirming selective retention of ML-10 in apoptotic regions of the non-treated tumors, as expected given the known presence of spontaneous tumor apoptosis. Following treatment, the signal to background ratio in irradiated tumors increased over time nearly 2-fold and showed a marked enhancement of the accumulation rate of ML-10.
"We are pleased to see additional evidence that imaging treatment induced cell death with ML-10 may provide physicians early indication of the tumor's response to treatment," said Yoram Ashery, CEO of Aposense. "We look forward to presenting additional follow-up data on the clinical response of these patients soon."