Local control of recurrent clival and sacral chordoma after interstitial irradiation with iodine-125: new techniques for treatment of recurrent or unresectable chordomas.

Using new 125I brachytherapy techniques, we were able to deliver safely a tumor volume dose of 16,000 rads to a previous irradiated, large, recurrent sacral chordoma by means of the intraoperative interstitial implantation of 229 low activity 125I seeds and 40,000 rads to a previously irradiated, small, recurrent clival chordoma by means of the transnasal needle implantation of two high activity 125I seeds. Iodine-125 brachytherapy was followed by regression of tumor, lessening of symptoms, and bony recalcification in both cases.