PIMS/AMI Seminar: Biological Modeling in Radiation Oncology: Past, Present and Future

Studies of the biological effect of ionizing radiation on tissues started almost as soon as the x-ray was discovered by Roentgen in 1895. The need for these studies was also motivated by the early adoption of radiation to treat cancers. Great strides in understanding the effects of radiation dose were achieved with the first survival plot of mammalian cells in the 1950s. More recently, biological modeling has looked at the effect of fractionation, and estimates of tumour control and normal tissue complication probability. In the past decade, however, the technology that is now routinely available for radiotherapy has significantly improved such that the radiation dose can now be finely targeted to the tumour with much less exposure to the normal tissues. This has allowed dose escalation in several tumour sites. In order to better understand the biological effect of modern radiation oncology, improved models of dose volume effects in normal tissues will be needed.