Why was 7 September chosen for World Radiotherapy Awareness Day?
- Jul 23
- 4 min read
The remarkable story behind a date that changed cancer treatment forever.
Every year, millions of people around the world receive radiotherapy as part of their cancer treatment. Yet few know that the modern treatment they receive can be traced back to one remarkable day: 7th September 1953.
On that day, the world's first patient was treated using a dedicated clinical linear accelerator (linac) at Hammersmith Hospital in London, now part of Imperial College Healthcare NHS Trust.
That first treatment marked the beginning of a new era in cancer care and is the reason World Radiotherapy Awareness Day (WRAD) was chosen to be celebrated every year on 7th September.
Today, WRAD brings together healthcare professionals, patients, survivors, carers, researchers and advocates from around the world with One Voice for Radiotherapy. It is a day to celebrate progress, raise awareness and help more people understand the life-changing role radiotherapy plays in treating cancer.
A landmark in cancer care
Before the first linear accelerator, clinicians only had the ability to treat cancer using low-energy X-ray machines and radioactive materials such as radium and cobalt. These treatments helped many patients, but they were less able to treat cancers deep inside the body while protecting the healthy tissue around them. The introduction of the linear accelerator was a major breakthrough.
Developed through collaboration between physicists, engineers and clinicians, the machine installed at Hammersmith Hospital became the first linear accelerator designed specifically for medical use. Instead of relying on a radioactive source, it generated high-energy X-rays electrically, allowing clinicians to target tumours more accurately while reducing unnecessary radiation to healthy tissue.
For patients, it offered new hope. For healthcare professionals, it marked the beginning of a new era in cancer treatment and laid the foundations for the radiotherapy technology used around the world today.
In 1956, Gordon Isaacs became the first patient in the United States to receive treatment using a medical linear accelerator developed by Henry Kaplan and Stanford physicists. Gordon had retinoblastoma and his right eye had already been removed after the cancer spread. The linac enabled doctors to precisely target the tumour in his remaining left eye while protecting the surrounding healthy tissue. The treatment saved his sight and he retained normal vision in the treated eye.1
A machine that changed the future
The first linear accelerator was an extraordinary achievement for its time. It introduced innovations that helped improve both treatment quality and patient care, including:
Delivering treatment from different angles
More accurate patient positioning
Better shaping of the radiation beam to protect healthy tissue
Faster and easier dose delivery with automated recording to improve consistency and safety
Many of these ideas continue to form the foundation of the sophisticated radiotherapy systems used in hospitals today.
From one pioneering machine to today's technology
The difference between the first linac and the machines used today is remarkable. Modern linear accelerators combine advanced imaging, sophisticated treatment planning, adaptive radiotherapy, stereotactic techniques and increasingly artificial intelligence to deliver highly personalised care. Although the technology has advanced enormously, the goal has remained the same:
To deliver the right dose of radiation to the tumour while protecting as much healthy tissue as possible.
Every improvement has been driven by one purpose - to improve outcomes and quality of life for patients.
Today, radiotherapy is recommended for around half of all people diagnosed with cancer at some stage during their treatment, making it one of the most important treatments in cancer care.
Why this history still matters
World Radiotherapy Awareness Day is about much more than remembering an important moment in history. It is about recognising how far radiotherapy has come while acknowledging the work that still lies ahead. Millions of people around the world still do not have timely access to radiotherapy because of shortages in equipment, workforce and healthcare resources. At the same time, many patients know very little about radiotherapy before they need it. Misunderstandings and unnecessary fears continue to exist, despite modern radiotherapy being a safe and effective cancer treatment.
By raising awareness, sharing knowledge and celebrating innovation, WRAD aims to help change that.
Honouring the people behind the progress
Radiotherapy is not just about technology. It is about people. Behind every treatment is a team of dedicated professionals, including radiation oncologists, therapeutic radiographers, medical physicists, dosimetrists, engineers, nurses and researchers. Every day, they continue to improve treatment, advance research and provide compassionate care for patients across the world.
Choosing 7th September was never simply about marking the anniversary of a pioneering machine. It was about recognising a moment that transformed cancer treatment and continues to inspire progress today.
Every year, World Radiotherapy Awareness Day brings together the global radiotherapy community to celebrate innovation, recognise the professionals who make treatment possible, share the experiences of patients/consumers and survivors and advocate for better awareness and equitable access to radiotherapy.
Together, we celebrate how far radiotherapy has come and together, we work towards a future where everyone who needs radiotherapy can access it.
If you want to share what you are doing for WRAD, please register your event.
This article is based on the historical development of the first clinical linear accelerator described by P. Howard-Flanders in The Development of the Linear Accelerator as a Clinical Instrument (1954).
Stanford Medicine News Centre (©2026) ‘Medical Linear Accelerator Celerates 50 Years of Treating Cancer.’
