Radiation Carcinogenesis: Time-Dose Relationships

• Published in: Radiation research 1987-07, Vol.111 (1), p.179-184
• Main Authors: Ullrich, R. L., Jernigan, M. C., Satterfield, L. C., Bowles, N. D.
• Format: Article
• Language: English
• Subjects: Adenocarcinoma; Adenocarcinoma - etiology; Animals; Correspondence; Data ranges; Dosage; Dose response relationship; Dose-Response Relationship, Radiation; Female; Fractions; Gamma Rays; Irradiation; Lung Neoplasms - etiology; Lungs; Mammary Neoplasms, Experimental - etiology; Mice; Mice, Inbred BALB C; Modeling; Neoplasms, Radiation-Induced - etiology; Radiation Dosage; Radiation dose response relationship; Tumors
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3577031

The present studies were undertaken to examine the time-dose relationships for the induction of lung adenocarcinomas and mammary adenocarcinomas in female BALB/c mice following γ irradiation. Twelve-week-old female BALB/c/An NBd mice were irradiated with 137 Cs γ rays, and lifetime tumor incidences following high-dose-rate, low-dose-rate, or fractionated exposure regimens were compared. Analysis of the results indicated that the data could be fitted by linear-quadratic dose-response models for the induction of both tumors following acute doses and a linear model with a slope similar to that for the linear portion of the linear quadratic following low-dose-rate exposure regimens. When doses were fractionated the response was dependent upon the dose per fraction. If the dose per fraction was a dose which was predominantly on the linear portion of the acute dose response curve, then the response was linear and similar to that after low-dose-rate exposures. If the dose per fraction was in a region where the quadratic portion of the acute dose-response was significant, then the tumor incidence was higher than that following low-dose-rate exposures.