No abstract

The histopathology of two patients with radiation-induced neoplasms of the brain following therapeutic irradiation for intracranial malignancies is described. The second neoplasms were an atypical meningioma and a polymorphous cell sarcoma, respectively. They occurred 12 and 23 years after irradiation (4000 rad), within the original field of irradiation. In both cases, the radiation-induced tumors were histologically distinct from the initial medulloblastomas. Both patients were retreated with local irradiation using permanent implantation of radioactive iodine-125 seeds.

Two cases of petroclival meningiomas are reported wherein the tumors were completely destroyed without surgical resection or external-beam irradiation by means of permanent stereotactic implantation of one or two high-activity iodine-125 seeds.

Experience with endocurietherapy of skull base tumors is reviewed. We present our cases of recurrent pituitary hemangiopericytoma, radiation-induced recurrent meningioma, recurrent clival chordoma, recurrent nasopharyngeal cancer involving the cavernous sinus, and recurrent parotid carcinoma of the skull base which were all successfully retreated with high-activity 125iodine (I-125) permanent implantation.

An uncontrolled retrospective analysis of 76 patients with locally advanced Stage III and Stage IV squamous cell carcinoma of the oral cavity, oropharynx, pyriform sinus, supraglottic larynx, glottic larynx, and hypopharynx, who were treated in a uniform manner by surgical resection and 6,600 rad postoperative external beam radiotherapy, revealed relatively high 2-year and 4-year adjusted survival rates of 76% and 68%, respectively. Complication rates were acceptable (8%). The advantages of this treatment approach for locally advanced head and neck cancers compared to treatment by surgery alone are discussed.