All you ever wanted to know about Radiation Induced Vascular Disease …
But were too afraid to ask!
Having experienced Radiation Induced Vascular Disease (RIVD) for over three years now and having endured numerous delays and pointless referrals, I have tried to simplify what is a potentially complex explanation of what RIVD is, particularly for the benefit of general vascular surgeons who are often the gatekeepers to its management.
Let me begin by saying what RIVD isn’t. It is not simply Peripheral Artery Disease (PAD) (1), nor is it caused by poor lifestyle choices or lack of exercise. Whilst the presenting symptoms may be similar, on closer examination with the help of CT, MRI or ultrasound scans, you will see that the arterial obstructions are generally much longer than those seen in typical PAD (2) and of course the patient’s medical history will reveal that they have had radiotherapy in the past. But the differences don’t end there.
Unlike PAD, once RIVD presents itself, it will continue to progress throughout the patient’s life with no perceived response to the usual therapy for PAD such as aspirin, statins and of course lifestyle changes or exercise (1,3,4).
So, what causes RIVD?
Unfortunately, whilst radiotherapy is very effective at destroying rapidly dividing cancer cells, like some other cancer treatments, it is unable to distinguish between cancer cells and normal healthy cells and affects them in a variety of ways, especially over time. One of those effects is injury to the irradiated cells. This process is known as radiation fibrosis or scarring (2). Over time these injuries can develop into chronic scarring and thickening of blood vessels in the treated area (5), reducing their flexibility and ability to transport blood and nutrients to organs in the body which may even be outside the radiotherapy area.
How such a side-effect can develop into RIVD years or even decades after arterial radiation exposure is still being debated, however studies indicate that over time the scarring and damage caused to the blood vessels can trigger increased cell production resulting in more cell death, which eventually leads to significant narrowing of the blood vessels (4). Unfortunately, there is no way to stop the progression of this. But there are ways to treat the symptoms and improve the quality of life of most patients affected, by ensuring awareness amongst physicians and providing access to prompt intervention (1, 4, 5).
Fortunately, radiation equipment and techniques have improved over the years, meaning that fewer patients will develop clinically significant radiation damage in the future. Indeed, standard radiotherapy for common cancers such as prostate and breast is now given over a limited area and in doses that are generally well tolerated (1).
However, radiation treatment for other cancers particularly in the past, may produce a much higher risk of developing radiation fibrosis, such as in my case in the 1980’s when I was given a total dose of 51.6 Grays (measurement of radiation exposure), which is the equivalent amount of radiation to 516,000 normal chest x-rays over 20 days. Because I had Non-Hodgkin’s Lymphoma (affecting the lymph-nodes), I was treated over an area called ‘Inverted Y’, which basically includes all the lymph-nodes that surround the aorta, iliac and femoral arteries. Consequently, 3 years ago I began developing symptoms of blockages in those arteries affecting the numerous organs they supply blood to.
Considering the damage that can be caused by radiation to arteries, the preferred treatment approach is to insert stents to try and widen the areas of blockage instead of more invasive surgical interventions such as an arterial bypass (5). However, in my case and as a result of lack of surveillance, my disease, possibly aggravated by the insertion of 14 arterial stents over the past 3 years, has progressed unchecked, into diffuse disease with life-altering side-effects that will now necessitate the more invasive approach of an aorta-bifemoral bypass. This is of course dependent on whether or not the extent of my RIVD will allow the insertion of a man-made arterial graft. Radiation injury of blood vessels was originally described more than a century ago (4), yet despite that, it remains a significant clinical problem today. Whilst there is no cure, there are treatments that can improve the function and quality of life for most patients (5). In order for that to happen and for patients to avoid delays and unnecessary risky intervention, there needs to be widespread awareness amongst the medical profession to ensure prompt and appropriate referral to vascular surgeons who appreciate the uniqueness of this disease. Because, as in my case, many patients present with symptoms long after radiation treatment, it is easy for a doctor to miss the connection, unless of course, adequate attention is paid to the patient’s past medical history, even decades ago.
- Stubblefield, Michael. (2017). Clinical Evaluation and Management of Radiation Fibrosis Syndrome. Physical Medicine and Rehabilitation Clinics of North America. 28. 89-100. 10.1016/j.pmr.2016.08.003. Feb 2017.
- Shichita T, et al. Angiographic characteristics of radiation-induced carotid arterial stenosis. Angiology 2009; 60 pp276-82.
- Treatment Peripheral Arterial Disease NHS. UK https://www.nhs.uk/conditions/peripheral-arterial-disease-pad/treatment/ Last accessed 6 Oct 2019
- Understanding Radiation-Induced Vascular Disease. N L Weintraub, et al. Journal of the American College of Cardiology Vol 55, No 12. pp1237-9. 23 March 2010.
- Primary stenting of bilateral radiation-induced external iliac stenoses. M O Baerlocher, et al. Journal of Vascular Surgery Vol 40, No 5. pp1028-1031. Nov 2004.