This is Dr. David
that is called brachytherapy
or intraluminal brachytherapy inside of the esophagus, sometimes it is done with a HDR or high dose rate afterloader
HDR is a description of the rate of the radiation coming from the brachytherapy source.
I am a radiation oncology doctor.
I take it you have had radiation for an esophageal cancer.
you should get another upper endoscopy scope to look down your esophagus to see if the cancer is still blocking the esophagus.
also you can try to swallow a small teaspoon of vegetable oil or canola oil before you eat meals to help food slide down your esophagus better when you eat.
you also might have to change your diet to softer foods and liquid shakes and drinks to get food down easier.
let me know if you have questions.