Title: Optimisation and Individualisation of Heart-Sparing Breast Radiotherapy Techniques: The HeartSpare Study
Funder: Department of Health (England)

Abstract: Background Breast radiotherapy (RT) has contributed to a halving of breast cancer (BC) mortality over the last 2 decades despite rising incidence (1). About 30,000 women with early stage BC receive RT every year in the UK. Off-setting the benefits, RT for women with left-sided tumours delivers significant dose to underlying heart tissue causing 1-2% cardiac deaths. Breast RT is normally delivered with the patient lying supine and both arms raised above the head. Techniques that reduce heart dose, including treatment during breath-hold in deep inspiration, are not yet in routine use in the UK owing to poor patient selection criteria, lack of reproducibility, resource issues and lack of experience. These issues need urgently to be addressed before heart-sparing breast RT can become a standard of care. Aims 1) To identify the best technique of deep inspiratory breath-hold (DIBH) for heart-sparing breast RT: specifically, to test if voluntary deep-inspiratory breath-hold (v_DIBH, a low-cost technique) is as good as activated-breathing-controlled DIBH (ABC_DIBH, a resource-intensive technique) in terms of reproducibility and heart sparing. 2) To test whether the best technique of DIBH in the standard supine position is as good as an alternative prone (face-down) technique in larger-breasted women. 3) To test whether roll-out of the best DIBH technique in the context of a HTA-funded multicentre trial of breast radiotherapy fractionation confirms effective heart-sparing. Plan of Investigation Stage IA (in women of all breast volumes): A single-centre randomised controlled trial (RCT) of v_DIBH versus ABC_DIBH in women undergoing left breast RT. Stage IB (in women with large breast volumes only): A single-centre RCT of optimised supine DIBH versus prone position. Patients in both RCTs will be randomised to have the first half of their RT fractions using one technique and the second half using the other technique (crossover design). Stage II: A multicentre non-randomised intervention study of optimised supine DIBH in centres participating in the National Cancer Research Network (NCRN) FAST-Forward trial. Potential Impact There are currently >500,000 UK breast cancer survivors (1), >70% of whom have received RT. 15-year cardiac mortality after breast RT, mostly due to coronary artery disease, is 1-2%, so heart-sparing breast RT has the potential to save hundreds of lives per year. Establishing v_DIBH as a low-cost equivalent to ABC_DIBH is expected to lead to the immediate adoption of DIBH as a standard of care for at least 15,000 UK women per year, representing all those with left-sided tumours. Identifying women with the most to gain from one or other heart-sparing technique will ensure maximum gains in long-term survival and quality of life. Implementation in an ongoing multicentre UK clinical trial ensures high quality collaboration and rapid adoption of research results.


Research activity codes: 5.5 RADIOTHERAPY AND OTHER NON-INVASIVE THERAPIES
Health categories: CANCER AND NEOPLASMS;CARDIOVASCULAR