Childhood cancer is now a treatable disease, with more than three quarters of patients surviving at least five years from diagnosis. There is a population of some 26,000 childhood cancer survivors in the UK today, a number that increases by around 1,000 every year.
Anthracyclines are a class of drug used in the treatment of many childhood cancers, including leukaemia and Wilms’ tumour. They are one of the most effective anti-cancer treatments but have a variety of adverse effects including toxicity to heart muscle cells.
The death of individual heart muscle cells after chemotherapy results in increased space between the surviving cells, which is known as ‘extracellular volume fraction’. If severe, over time the damage results in breathlessness and can ultimately cause heart failure and death. Susceptibility to this cardiac toxicity varies between individuals and cannot be predicted.
Although conventional cardiac MRI scanning can measure the heart in a number of ways, there has historically been no non-invasive way of accurately measuring the amount of cell loss or predicting poor heart function before heart failure occurs.
A new method of scanning, developed by the project team, enables measurement of the extracellular volume fraction through use of an intravenous contrast that collects in the space outside the cells and shows up on the scan. This technique has been previously used to investigate other types of cardiac problems but so far there have been no systematic studies of patients following anthracycline chemotherapy.
Additionally, rapid cardiac MRI techniques developed by the project team enable measurement of the effects of simple exercise, thereby assessing heart muscle reserve. This new methodology may reveal damage that cannot be detected with normal, resting, cardiac MRI techniques or normal heart ultrasound.