A convenient method of interstitial radiation therapy can be quickly and easily accomplished using absorbable Vicryl-125I sutures which offer these general advantages: long shelf life, 60 day half-life; low energy, 28 kilo electron volts, permitting patients to leave the hospital; good geometric and anatomic distribution of 125I seeds which remain in place after implantation; less radiation exposure to the operating and attending personnel due to this low energy plus the reduced exposure time provided by quick implantation; removal unnecessary, reducing exposure time; implantation using minor surgical equipment; dosage determination easily calculated; hospitalization, from the standpoint of radioactivity, unnecessary.