CLINICAL-PATIENT STUDY Radio-induced gliomas: 20-year experience and critical review of the pathology Maurizio Salvati Æ Alessandro D’Elia Æ Graziella Angelina Melone Æ Christian Brogna Æ Alessandro Frati Æ Antonino Raco Æ Roberto Delfini Received: 9 October 2007 / Accepted: 25 February 2008 / Published online: 20 June 2008 Ó Springer Science+Business Media, LLC. 2008 Abstract The authors report their personal experience with a surgical series of 16 cases of cerebral radiation- induced gliomas, defining diagnostic criteria and surgical and clinical characteristics. There were ten males and six females, with a median age of 45.9 years. Irradiation had initially been given for acute lymphoblastic leukemia (ALL) in six cases, tinea capitis in four cases, scalp hemangioma in three cases, cutaneous hemangioma, cav- ernous angioma, and medulloblastoma in one case each. There were 14 cases of glioblastoma (grade IV WHO) and 2 cases of astrocytoma (grade II WHO), with a mean latency time of 17 years (range: 6–26 years). For glio- blastomas mean survival time was 10.4 months, account- ing for 1–3% of all the glioblastomas treated. A thorough revision of the pertinent literature revealed some clinical– biological peculiarities. Keywords High grade Á Low grade Á Radiation-induced gliomas Á Radiosurgery Á Radiotherapy Introduction Radiotherapy and, until recently, radiosurgery have repre- sented very important therapeutic instruments for treating various intra- and extracranial pathologies. Although they are not entirely free of immediate and long-term side effects, they have been extensively employed worldwide [41]. Such complications include radionecrosis or the onset of new tumors [41]. Although epidemiological evidence indicates sarcomas and meningiomas as being the most frequent tumors to develop as a side effect of radiation [17, 33], there have also been consistent reports on gliomas, mainly malignant, arising in the previously irradiated region [1–77]. The etiological role of radiation in tumor induction was questioned in early 1902 by Frieben [56]. More evidence was subsequently provided by Lacassagne and coworkers in 1933 from their experiments on guinea pigs [32], while the first cases observed in humans were described in the early 1960s [23, 54]. Since then, a total number of 129 radiation-induced gliomas has been reported, including the patients of our series. In the present study, besides a review of the pertinent literature, 16 cases of radiation-induced glioma treated in our institution from 1970 to 2006, 10 of which were reported in a previous article [57], are described. Two cases of low-grade glioma and one case of c-knife 60 Co radio- surgery-induced glioblastoma are particularly interesting, given their rarity. Finally, we attempted to define the fre- quency of radiation-associated glioblastomas not from the irradiation source registry, as previously performed, but from a neurosurgical point of view. Materials and methods We reviewed all cases of intracranial glioma with a posi- tive anamnesis of previous cranial irradiation. All cases M. Salvati Department of Neurosurgery, INM Neuromed IRCCS, Pozzilli, Is, Italy M. Salvati (&) Via Cardinal Agliardi, 15, 00165 Rome, Italy e-mail: salvati.maurizio@libero.it A. D’Elia Á G. A. Melone Á C. Brogna Á A. Frati Á A. Raco Á R. Delfini Department of Neurological Sciences, Neurosurgery, University of Rome ‘‘Sapienza’’, Policlinico Umberto I, Rome, Italy 123 J Neurooncol (2008) 89:169–177 DOI 10.1007/s11060-008-9565-x