Radiation dose and leukaemia risk: general relative risk techniques for dose-response models in a matched case-control study.

Generalized relative risk functions were used to model radiation dose-response information from a large matched case-control study of leukaemia occurring after treatment for cervical cancer. Models suggested by radiobiological theory were investigated and compared to standard analyses of categorical dose-response to the linear model. Local radiation doses to each of fourteen bone marrow compartments for each patient were incorporated into the models, and the corresponding risks were summed. Conditional maximum likelihood methods were used to estimate risk parameters. Unique features of the analysis include modelling both induction and reduction of risk as a function of radiation dose absorbed by different parts of the body within individuals. Detailed statistical aspects of these analyses are presented and discussed.