Betatron therapy for unresectable pancreatic cancer. A preliminary report.

Nineteen-patients with unresectable but localized ductal adenocarcinoma of the pancreas were treated with definitive high dose, small volume, external beam radiotherapy with promising results. The tumors of all patients were histologically confirmed. A 45 MV betatron was used for radiation of the clipped tumor volume plus a 1 to 2 cm margin. Fourteen patients were treated by a three-field technic with the use of opposed lateral photon beams and an anterior mixed photon-electron beam. Five patients were treated with either a four-field "box" or a three-field photon technic. Tumor doses of 5,900 to 6,700 r were delivered over seven to nine weeks. The twelve month survival rate after diagnosis is 53%. This compares favorably with published reports of patients treated surgically for cure. Four patients are alive 18.5 to 64 months after diagnosis. Three are clinically free of disease. Treatment has been well tolerated and there have been no significant radiation complications.