Over four months after undergoing emergency spinal surgery, Abby Lee Miller has left her Los Angeles rehabilitation facility, PEOPLE confirms.

In April, one day after undergoing emergency surgery for what was initially thought to be a spinal infection, the reality star — who was released from prison in March — was preliminarily diagnosed with non-Hodgkin’s lymphoma, a cancer that develops in the lymphatic system.

“It was not an infection, it was a type of a non-Hodgkin’s lymphoma — it’s a type of a cancer,” said Dr. Hooman M. Melamed, an orthopedic spine surgeon at Cedar Sinai Marina Del Rey Hospital who treated the star. “We’re getting an oncologist involved and we have to figure out what the next steps are as far as chemotherapy or radiation or more spine surgery. Depending on the tumor type, depending on the sensitivity of the tumor — it just depends the type but I feel more than yes, she will undergo chemotherapy or radiation.”

The doctor added that it was a “preliminary diagnosis pending pathology and oncology results.”

Miller went into the emergency room after she experienced “excruciating neck pain” and weakness in her arm, and after her condition deteriorated over the next couple days, Dr. Melamed performed emergency surgery for a multi-level laminectomy.

“If we didn’t do something, she was going to die,” Dr. Melamed told PEOPLE. “Her blood pressure was bottoming out. She was not doing well.”

Since her diagnosis, the former Dance Moms star has been receiving chemotherapy and has been documenting her journey via social media.

Miller had been living in a halfway house since serving her 366-day sentence for bankruptcy fraud at the Victorville Federal Correctional Institution in California, which she entered in July.

In May, Miller was officially released from the halfway house.

“TIMES UP!!!! ‘Free at last, Free at last, Thank God almighty we are free at last.’ Martin Luther King Jr.,” the 51-year-old wrote alongside a black-and-white photo of herself sporting a wide smile as she pointed to a watch on her wrist.

Last week, Miller shared a picture of herself hitting up a mall in Los Angeles for some shopping.

“Hallelujah! I’m headed to the Mall!” she captioned the post. “I’ve only been once in 13 long painful months. For a lifelong shopper like me that’s absolute torture!!!”

She also shared a photo of herself out and about with two medical professionals who helped with her recovery.

“Seriously, these two female Doctors, @kadeletti and @missoscar22 were such vital parts of my Physical Rehabilitation — I can never thank them enough!” she gushed.