Fig 1: AP Picture showing stent on an x-ray film.
The esophagus and gall bladder are part of the gastrointestinal system. The treatment of these cancers is similar in that they are both treated using "intralumenal" catheters. ( A lumen is the hollow space in the center of a tube). The patient is treated on an outpatient basis. Both treatment courses require 3 to 4 treatments.
With biliary intralumenal treatments, the patient comes to our clinic with a stent that has been placed in the bile duct by the surgeon. This stent, visible on x-ray, keeps the duct open, allowing the HDR treatment catheter to be positioned accurately. Once the localization x-ray films are taken and the computerized treatment plan completed, the initial treatment is given. Each of the successive treatments is preceded by x-ray films to ensure that the treatment catheter is in the same position as the first treatment.
Esophageal HDR treatments involve inserting a 1cm to 1.3cm diameter tube into the esophagus which most patients can do without much difficulty. Referring to CT and diagnostic radiographs, the physician indicates on the localization x-ray films where the tumor is, the treatment length and treatment radius. After the position of the treatment catheter has been approved by the physician, the computerized treatment plan is quickly done as there is only one catheter involved in esophageal treatments. The time required for the source to deliver the prescribed dose is between 5 and 10 minutes. Using HDR brachytherapy for these types of cancers ensures a very high radiation dose directed at the tumor. Because the radiation is delivered internally, a much smaller volume of normal tissue is irradiated.