Glioblastoma multiforme after microsurgery for acoustic neuroma without radiotherapy: limitations of the Cahan criteria.

摘要

In 1948 Calran and others reported 11 cases of sarcoma that arose in radiated bone, mostly in children treated for tuberculosis. They studied only cases that met certain inclusion criteria: 1) there must have been histologic or radiographic evidence of the nonmalignant nature of the initial condition; 2) the sarcoma that arose must have arisen in the area included in the radiotherapeutic beam; 3) there must have been a relatively long, asymptomatic period of latency between radiation and development of the sarcoma; and 4) the sarcoma must be proved histologically. Since Cahan's report, these criteria have often been cited as requirements for considering a case to represent radiation-induced malignancy.Since the 1980s there has been considerable interest in stereotactic radiosurgery and other forms of focused radiation therapy for nonmalignant conditions. One of the concerns raised by radiation treatments for acoustic neuroma, which has somewhat limited their use, is the potential for radiation to induce other intracranial tumors, including malignancies. Because such cases are rare, it has been difficult to establish a reliable estimate of their occurrence to guide selection of treatment and patient counseling. We report a case that we feel should be taken into consideration when estimating the risk of radiation-induced malignancy. Institutional Review Board approval was obtained.