title: The incidence of second brain tumors related to cranial irradiation.
abstract: Secondary brain tumor (SBT) is a devastating complication of cranial irradiation (CI). We reviewed the literature to determine the incidence of SBT as related to specific radiation therapy (RT) treatment modalities. The relative risk of radiation-associated SBT after conventional and conformal RT is well established and ranges from 5.65 to 10.9; latent time to develop second tumor ranges from 5.8 to 22.4 years, depending on radiation dose and primary disease. Theories and dosimetric models suggest that intensity-modulated radiation therapy may result in an increased risk of SBT, but clinical evidence is limited. The incidence of stereotactic radiosurgery-related SBT is low. Initial data suggest that no increased risk from proton therapy and dosimetric models predict a lower incidence of SBT compared with photons. In conclusion, the incidence of SBT related to CI is low. Longer follow-up is needed to clarify the impact of intensity-modulated radiation therapy, proton therapy and other developing technologies.
authors.affiliation: Radiation Oncology Department, Hospital Sírio-Libanês, Rua Dona Adma Jafet 91., Sao Paulo, Sao Paulo 01308-050, Brazil.
authors.forename: Gustavo Nader
authors.initials: GN
authors.lastname: Marta
authors.forename: Erin
authors.initials: E
authors.lastname: Murphy
authors.forename: Samuel
authors.initials: S
authors.lastname: Chao
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Yu
authors.forename: John H
authors.initials: JH
authors.lastname: Suh
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D016371:Cranial Irradiation / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D015994:Incidence; D009381:Neoplasms, Radiation-Induced / Q000473:pathology*; D061766:Proton Therapy / Q000009:adverse effects / Q000379:methods; D011829:Radiation Dosage; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods; D013997:Time Factors
keywords: brain neoplasms; conformal radiotherapy; conventional radiotherapy; intensity-modulated radiation therapy; proton therapy; radiotherapy; second primary neoplasms; stereotactic radiosurgery