LOS ANGELES -- Actress Shannen Doherty says she has received a "miracle" treatment nearly 10 years into her battle with breast cancer.
Doherty, 52, revealed on her podcast, "Let's Be Clear with Shannen Doherty," that a new treatment she is undergoing appears to be working after the cancer spread to her brain.
"I'm on a new cancer infusion ... after the sixth, seventh treatment, we really saw it breaking down the blood brain barrier," Doherty said. "So I call that a miracle? Yeah. For me that happens to be a miracle"
The "Charmed" and "Beverly Hills, 90210" actress was first diagnosed with breast cancer in 2015, after which she underwent a mastectomy, chemotherapy and radiation. In 2017, Doherty announced she was in remission.
Three years later, Doherty announced her breast cancer had returned and was stage 4. Last year, she revealed that the cancer had spread to her bones and her brain, and that she had undergone surgery to get a tumor removed from her brain.
The blood-brain barrier is a physical membrane that surrounds the brain and acts as a gatekeeper to determine what substances are allowed in the brain, according to StatPearls, an online library published in the National Library of Medicine.
Dr. Leah Croll, a board-certified neurologist, said that in the past, it has been difficult to find treatments that treat brain tumors because of the blood-brain barrier.
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"That means that not every medication can cross that barrier and get into the brain, and it's a big problem we have with treating neurologic diseases of all kinds," Croll told "Good Morning America." "Many of the chemotherapeutic agents that we have available to us actually do not cross that blood-brain barrier, which makes treating brain tumors a real challenge."
Doherty did not say on her podcast exactly what infusion she is receiving.
In addition to the infusion, the actress said she is also undergoing radiation treatments, beams of intense energy meant to destroy tumor cells. Research shows that long-term side effects of radiation can sometimes include mood or cognitive changes, as well as memory issues.
Doherty described being scared of potential side effects of the radiation treatments she is receiving, saying, "I was petrified of, you know, is it going to change who I am?"
The severity of side effects a patient experiences from radiation varies by several factors, including the number of treatments, the dose of the radiation and a person's overall health and age.
Croll noted also that radiation therapy continues to evolve and improve.
"Luckily, as the technologies we use for radiation treatments are getting more and more advanced, fewer and fewer people are having to deal with those long-term side effects," Croll said.