RADIOTHERAPY

Radiotherapy is recommended for over 50% of all cancer patients – about 10 million new patients per year.  The number of adverse events has been the subject of ongoing reviews.

Underdosing can result in complications, recurrence or reduced tumour control.

The World Health Organisation (WHO)[1] reports that between 5% to 35% of radiation underdosing is observed in up to 50% of patients being treated with radiation and that this class of patients subsequently developed local recurrences of disease that could be attributed to this error. Such underdosing is less likely to be detected by clinical health-care professionals.

Severe toxicity of the skin because of skin radiation doses exceeding the threshold during an angiogram procedure

Overdosing can result in skin burns and radiation toxicity requiring skin grafts.   About 1% of patients with reported radiotherapy adverse events died due to radiation overdose toxicity[2].

INTERVENTIONAL RADIOLOGY

Almost 20 million people (17.3 million) worldwide die from cardiovascular disease every year and by 2030 that number is predicted to climb to more than 23.6 million per year[3]. In the United States alone there are over one million angiograms performed a year[4].

There are approximately 8 million Interventional radiology procedures of the heart, brain and other organs annually in the US alone[5].

X-ray imaging during interventional procedures carries the potential risk of a patient suffering radiation-induced skin tissue damage and radiation toxicity at basal cell depths, sometimes requiring skin grafts and increasing the risks of free radicals leading to cancer. Contributing factors to these risks are the exposure time to radiation based on the time taken for the procedure.  A patient’s body mass index also influences the amount of radiation that is absorbed with clinically obese patients having up to twice the dose of normal-weight patients with exposure to the operator also doubled.

CT SCANS

Up to 75 million CT scans[6] are performed every year in the United States alone. CT scans emit a powerful dose of radiation. One individual CT scan can be up to the equivalent amount of radiation that most people are exposed to from natural sources over seven years[7]. Such high levels of dosage can, in some cases, fundamentally alter the makeup of human tissue by creating free radicals and can result in cancer. 

Overall, patient exposure to radiation during these procedures can in some cases be as high as the equivalent of approximately 200 chest X-ray plates and, for any given patient exposure, can vary within an institution and between different institutions by up to 121%[8]

There is particular concern for paediatric and pregnant women where the risk of induced cancer is increased because of the remaining life expectancy.

[1] Radiotherapy Risk Profile WHO/IER/PSP/2008.12
[2] Radiotherapy Risk Profile WHO/IER/PSP/2008.12
[3] “2015 Heart Disease and Stroke Statistics – At a glance” – American Heart Association
[4] Coronary Angiography: Definition, Heart Angiogram Test, Procedure, Methods, Risks/Complications, Pros and Cons, Cost
[5] Radiology 2020; 295:418–427
[6] Radiology 2020; 295:418–427
[7] Radiation Risks – The surprising dangers of CT scans and X-rays – March 2015 Consumer Reports
[8] C2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging: Best Practices for Safety and Effectiveness, Journal of the American College of Cardiology May 2018, and Clara Carpeggiani et. al., Variability of radiation doses of cardiac diagnostic imaging tests: the RADIO-EVINCI study, BMC Cardiovascular Disorders, 16 February 2017