Shannen Doherty says breast cancer spread to her brain, expresses "fear" and "turmoil"

"Charmed" and "Beverly Hills, 90210" actor Shannen Doherty said on Instagram Tuesday that her breast cancer, which she was first diagnosed with in 2015, has spread to her brain. 

The news was shared with an emotional video of Doherty, 52, crying as she underwent radiation. The process entails patients wearing a custom-made mask that keeps the head still during the treatment so that the lasers can hit the tumor as accurately as possible. 

"On January 5th, my ct scan showed Mets in my brain," Doherty said. "...January 12 the first round of radiation took place. My fear is obvious."