ABSTRACT
The quality of the data is paramount in normal tissue complication probability modeling. Models quantifying the relationship between dose-volume parameters and normal tissue complications were developed on a large scale once three-dimensional radiotherapy became available in the 1990s. Collecting dose and complication data for a defined group of patients treated with radiotherapy can be considered as an observational cohort study. Clinical symptoms may affect daily functioning of the patient in terms of physical, social, and mental wellbeing of the patient, deteriorating the quality of life of the patient. In order to create a high-quality database, data recording and collection procedures are critical. The dimensions of data quality may have consequences for both the internal and external validity of obtained study results. Depending on the quality of the image guidance scans, the deformable image registration algorithms used, and the organs at risks of interest, methods may be more or less accurate.
