Short communication: a technique for delivering carbogen with high dose rate intraluminal brachytherapy in carcinoma of the oesophagus; early results and toxicity.

A technique to deliver carbogen with high dose rate afterloading therapy to the oesophagus is described. Treatment is given using a standard high dose rate (HDR) afterloading catheter which is passed through the tumour-bearing area of the oesophagus within a nasogastric tube. In order to achieve a gas-tight seal, a standard "oxygen" mask used for delivery of carbogen is modified to incorporate the nasogastric tube allowing the treatment catheter to pass through the mask and be connected to the afterloading machine. The technique has proven to be feasible and well tolerated during treatment in four patients treated in this way. Severe acute radiation toxicity, possibly attributable to the carbogen, has been encountered in these patients receiving 1500 cGy at 1 cm via the HDR catheter after 4050 cGy in 27 fractions in 9 days using CHART external beam. Modifications to the radiation scheduling is recommended to enable carbogen to be incorporated in this way.