Can Botox be used to slim down the deltoid muscle?

Hello, I was pole dancing for more than 5 years. My arm /shoulders became overgrown. rounded "man" shape, although I stopped all exercises for upper part the shoulders are still "rounded" . I do not feel good with this shape. I am slim and I do not want to gain fat only to hide that. Is that possible that botox can reduce those muscles? Thank you in advance