Cancer patient first in Canada to be treated with a rare radioisotope

A team at London Health Sciences Center Research Institute (LHSCRI) is the first in Canada to treat a patient with neuroendocrine tumors (NETs)—a rare form of cancer—using a radioisotope (an atom that releases radiation) called actinium-225 DOTATATE.

The treatment is a type of therapy called theranostics, which combines advanced diagnostic imaging technologies and radioisotopes to precisely locate tumors and then eradicate them by releasing radioactive energy.

The treatment, called actinium-225 DOTATATE therapy, is being offered as part of an international clinical trial that is assessing whether this specific isotope can treat NETs and enhance patient outcomes. LHSC is one of only three centers in Canada where patients are participating in the trial.

The trial will compare actinium-225 DOTATATE to standard-of-care therapies (called everolimus, Sutent or increased somatostatin therapy) in patients who have progressed in the disease following conventional therapy with lutieum-177 DOTATATE. The study aims to assess the efficacy and safety of actinium-225 DOTATATE which uses a more potent form of radiation called alpha particles.

These alpha particles are highly energetic and deposit much of their energy within a short distance, making them potentially highly suited to destroying cancer cells.

"Introducing a new treatment option to patients is a big win in the fight against cancer," said Dr. David Laidley, Researcher at LHSCRI and Nuclear Oncologist at LHSC.

"While the study is still in its early phase and requires more assessment, we're seeing patients tolerate the therapy well with little to no side effects and we are hopeful this treatment may extend patients' quality of life and life expectancy."

Neuroendocrine tumors are rare and occur in endocrine cells that help regulate functions in the body like growth, metabolism and reproduction. They can be found anywhere in the body, but the most common places are in the small bowel, pancreas, and lungs.

Depending on the stage of cancer and progression, some patients have exhausted all their cancer treatment options. With actinium-225 DOTATATE, patients could have a new form of treatment.

"Given the significant clinical need for new therapies in the treatment of patients with progressive NETs, LHSCRI has been extremely active in recruiting patients to the research trial," said Dr. Laidley. "It's our hope that we can show the treatment to be effective in improving patient outcomes."

The study is estimated to be complete in 2026. There are currently five patients from across Ontario participating in this trial at LHSCRI and more are being recruited.

While the team is studying actinium-225 DOTATATE for neuroendocrine tumors, they also see potential for using this form of therapy to treat other cancers like prostate cancer, breast cancer and lymphoma. The team is also exploring several other multicentre trials that will evaluate novel theranostic therapies.

Provided by London Health Sciences Centre Research Institute