Guy's and St Thomas' first in London to use radiotherapy for heart condition

Guy’s and St Thomas’ has become the first NHS trust in London to use a pioneering radiotherapy procedure to treat a woman’s dangerously abnormal heartbeat.

Stereotactic ablative radiotherapy, or SABR, is a precise form of radiotherapy that is usually used to treat different types of cancer.

Radiotherapy for cancer treatment uses high-energy x-ray radiation called photons. SABR uses many smaller, thin beams of radiation. The beams are directed from different angles that meet at the tumour. This allows extremely precise targeting and means that the tumour gets a high dose of radiation, whilst sparing surrounding normal tissue.

Sue Simons, from Bromley in south east London, was the first patient to receive the treatment at the Cancer Centre at Guy’s for ventricular tachycardia, a type of abnormal heartbeat in which the heart beats too fast.

Heartbeat is controlled by electrical signals that travel through the heart and make the heart muscle contract in a co-ordinated way. In ventricular tachycardia, faulty electrical signals in the ventricles (the lower chambers of the heart) cause it to beat faster than normal. This is potentially very dangerous and can be life threatening.

Sue has had heart disease for 30 years and suffered a cardiac arrest in 2009. She has received two heart valve replacements, a double bypass, and was fitted with an implantable cardioverter defibrillator which delivers paced beats and is able to shock the heart back into a normal rhythm.

Despite having all the known conventional treatments available for her condition, Sue continued to experience episodes of ventricular tachycardia which could last between five and 15 minutes and see her heart race up to 200 beats per minute.

A team of cardiologists, cardiac electrophysiologists, clinical oncologists, radiologists, therapeutic radiographers and physicists at Guy’s and St Thomas’ worked together over several months to plan Sue’s SABR treatment. She underwent various imaging scans and tests so they could map out her heart and pinpoint the abnormal tissue that causes the ventricular tachycardia. This area was then treated with SABR to stop it forming the faulty electrical signal.

Sue, a retired HR director, said: “I have two mechanical valves in my heart so catheter ablation was not an option for me, there was no alternative. If I didn’t have the SABR treatment the ventricular tachycardia would damage the function of my heart even more.”

The 69-year-old added: “Although this is an experimental treatment I thought it was worth trying as it was the only hope of slowing my heartbeat down. It’s still early days, but I haven’t had any episodes of ventricular tachycardia since the treatment.”

SABR is delivered during one appointment and is given by a machine called a linear accelerator. Although the treatment only takes around 15 minutes, the whole procedure can take more than an hour as the patient needs careful accuracy and precision checks before delivering the dose.

Around 100 people worldwide have received SABR for ventricular tachycardia, with 12 in the UK.

Dr Shahreen Ahmad, a consultant clinical oncologist at Guy’s and St Thomas’, said: “SABR is a tried and tested treatment for cancer and has proved to be safe and potentially curative in this setting. Cardiac SABR for ventricular tachycardia has been investigated in preclinical and clinical research studies as a new way of treating this condition when conventional treatments have failed. We have consulted with other teams in the UK and USA in order to deliver this treatment safely and it is a testament to great collaborative working amongst colleagues in the NHS and beyond.

“I have immense admiration for Sue’s bravery and trusting her doctors to do the best for her by undergoing this pioneering treatment. We hope cardiac SABR will be used to help many more patients like her in the future and enable them to have a better life.”

Professor Mark O’Neill, consultant cardiologist and professor of cardiac electrophysiology at Guy’s and St Thomas’, said: “This treatment is not suitable for everyone with ventricular tachycardia and many people with this particular heart rhythm disturbance will benefit from proven, conventional treatments including medication and catheter ablation.

“In a small population of patients however, where conventional options have either failed or cannot safely be offered, this new treatment could be the way forward. SABR allows us to treat parts of the heart which cannot be reached with catheters and also to treat patients who may otherwise be too frail or unwell to have catheter ablation.”