External radiation finished 6 days ago and chemo about 2 weeks ago. Ever since about 1/2 way through rads, Ive been experiencing a tight feeling in my sacral area and now a bit of sciatica in my right leg. My Dr isnt concerned but reading posts here say it can be caused by tumor spread? My Dr says its impossible especially since the radiation is still working. Have my brachy planning MRI this evening and I'm just really worried. 

I had really bad leg pain a few weeks after treatment finished, I felt like a 90 year old at times! It eased off after about a month x