ABSTRACT
Alan Nahum
and Gerald Kutcher
* Alan Nahum wishes to acknowledge many useful and interesting discussions with Dr. Giovanna Gagliardi (Como
and Stockholm) on the subject of NTCP modelling.
Physicists working in radiotherapy spend a lot of their time measuring doses in
phantoms and then calculating the dose distributions in patients due to a particular
arrangement of beams. This is because, according to the present state-of-the-art practice,
the radiation oncologist prescribes the treatment in terms of a (uniform) dose to the target
volume accompanied by some sort of constraint on the dose to one or more organs-at-risk.
However, the endpoints in radiotherapy that are truly of relevance are not dose distri-
butions but the probability of local control, also known as the Tumour Control Probability
(TCP) and the Probability of Normal-Tissue Complications (NTCP). This chapter deals with
the modelling of TCP and NTCP with the emphasis on the spatial distribution of the
absorbed dose within the target volume.
