I think I have this too, though couldn't put a name to it.
I have the same symptoms since finishing RT 8 weeks ago.
I checked out telangiectasia/spider veins on Wikipedia and recognised the symptom in the picture, but I had these on my scrotum.
On just checking, I notice the number must have doubled since RT.
If someone had told me I would be disclosing info like this a year ago, I wouldn't have believed them. All in the aid of science and PCa !