The Beverly Hills, 90210 star shaved her head and shared the experience with a beautiful photo series.
Shannen Doherty, 45, has been open with fans about her ongoing battle with breast cancer since she first went public with her diagnosis last year.
In the first image of the series, titled 'Step 1', Shannen is seen hugging her mother, Rosa Elizabeth.
With the support of her friend, model Anne Marie Kortright, Shannen then cuts her hair and shaves her head.
While Shannen did not provide much commentary on the photos, her friend shared a touching message of support.
"I couldn't be prouder of you today. Your strength and courage is so inspiring and I am so very lucky to have you in my life," Anne wrote on Instagram. "Thank you for blindly trusting me today to help you with such a big step. I will forever be there for you no matter what. #fuckcancer"
Shannen was reportedly diagnosed with cancer in March 2015, but didn't go public with the sad news until August.
"Yes, I have breast cancer, and I am currently undergoing treatment," the actress said in a statement to PEOPLE at the time.
"I am continuing to eat right, exercise and stay very positive about my life. I am thankful to my family, friends and doctors for their support and, of course, my fans who have stood by me."
The actress' diganosis came to light after filing a lawsuit against her former business manager who failed to re-enrol her in health insurance.