Radiation can lead to the symptoms you are describing (odynophagia - or pain when swallowing). It doesn't happen in everyone, but it is certainly possible.
Testing the upper GI tract with an upper GI series or upper endoscopy can be considered to look for any further anatomical obstruction.
Delayed gastric emptying is also a more uncommon disorder that can lead to these symptoms - a gastric emptying scan can be ordered.
Other causes would be liver or gallbladder disease - which can be evaluated with an ultrasound.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
http://www.straightfromthedoc.com