Crossing and looping methods in radical interstitial therapy for lateral and posterior oro-, hypopharyngeal tumors.

192Ir looping and crossing methods as a means of megavoltage tumor dose boosting have been applied for Stage II and III lateral and posterior oro-, hypopharyngeal tumors. A megavoltage and interstitial combined dose in excess of 9000 rad resulted in a soft tissue injury in two patients. Nevertheless, all five patients are alive without residual tumor at 8-38 months. We believe that a megavoltage dose of 5200 rad plus interstitial doses of 3000-3500 rad with a four week rest period intervening may improve cure rate at an acceptable injury rate.