I am very shy about my body but I have found the echoes fine.
I do have to take my clothes off from the waist up, but they give me a private part of the room with the curtains closed, and a gown to wear (opening at the front).
I've done 4 or 5 echoes, all with male staff, but they have been really kind and gentle, very discreet. I felt completely at ease and comfortable each time.
My first was before I started cancer treatment, then the next two while on chemo. Then one soon after surgery when I had a seroma from the mastectomy, and the most recent after radiotherapy.
I realised my surgery wound that had been stretched by seroma then made red by radiotherapy would be unsightly for them to see, but I am sure they've seen far far more mutilated bodies than mine and it doesn't phase them at all. I found it just made the most recent person even more caring and he checked several times whether it was ok (I had promised I'd tell him if it hurt, which it didn't).
They have been so thoughtful about making me feel comfortable, I don't feel stressed at all when I know I've got an echo appointment.