Has anyone had an endoscopy after radiotherapy which has caused swallowing problems 19 months after treatment still slightly painful when swallowing.

Already had two endoscopy but they couldn't get the camera down so didn't carry on with it. They thought it was too risky . I have lung cancer which was attached to my oesophagus it has been stable for 19 months. My doctor has referred me again to have the endoscopy done again and i am really worried that there could be complications .has anyone had this problem . I'm just worried sick about having it done this time .