High-activity intraluminal 192iridium endocurietherapy for treatment of esophageal cancer.

Intraluminal endocurietherapy (ECT) with high-activity 192Iridium administered via catheter following megavoltage external-beam radiotherapy, allows delivery of 8,000-10,000 rad to the target volume without exceeding the normal tissue radiation tolerances of surrounding vital structures. The endocurietherapy does not require surgery, general or local anesthesia. The technique is accurate, cost-effective, and allows safe delivery of higher radiation doses than could be tolerated by multiple-field external-beam megavoltage radiotherapy techniques alone. In a pilot Phase-1 toxicity study of six patients treated with minimum tumor doses of 8,000 rad, the majority of patients developed benign esophageal stricture 2-6 months following ECT which was managed by dilatation or gastrostomy. No patients developed esophageal perforation. Local tumor control was excellent, but a high proportion of patients developed distant metastatic disease.