title: A simple dose-response relationship for modeling secondary cancer incidence after radiotherapy.
abstract: Estimates of secondary cancer risk after radiotherapy are becoming more important for comparative treatment planning. There is great uncertainty concerning the dose-response relationship for radiation-induced carcinogenesis at doses higher than 4 Gy. The purpose of this report is to determine a simple dose-response relationship for secondary cancer incidence after radiotherapy treatment which can be used for comparative treatment planning. In this report a simple one-parameter model to estimate the complication probability of secondary cancer was fitted to literature data on secondary cancer incidence after radiotherapy. The results showed a linear dose-response relationship in the low-dose part and an exponentially decreasing one after a maximum at around 10 Gy. The observed dose-response relationship and the literature data used to fit the dose-response indicate that cell death effects are important for the explanation of secondary cancer incidence. Even using a dose and dose-rate effectiveness factor (DDREF) of two (instead of one), a cancer incidence maximum is observed at around 10 Gy, with decreasing incidence at higher doses.
authors.affiliation: Division of Medical Physics, Department of Radiation Oncology and Nuclear Medicine, City Hospital Triemli, Zürich, Switzerland. uwe.schneider@psi.ch
authors.forename: Uwe
authors.initials: U
authors.lastname: Schneider
authors.forename: Barbara
authors.initials: B
authors.lastname: Kaser-Hotz
mesh_terms: D004307:Dose-Response Relationship, Radiation; D006801:Humans; D015994:Incidence; D009369:Neoplasms / Q000453:epidemiology / Q000401:mortality / Q000532:radiotherapy*; D011878:Radiotherapy / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D012008:Recurrence; D016019:Survival Analysis