Radiotherapy or chemotherapy for lung cancer can cause damage to the heart, and this issue is of increasing concern as patients survive longer after radiotherapy for lung cancer. 2012, the European Society for Medical Oncology (ESMO) issued guidelines to guide physicians on how to assess, monitor, and manage The ESMO guidelines are designed to guide physicians in assessing, monitoring, and managing cardiac damage due to radiotherapy.
Heart damage from radiotherapy can manifest as coronary artery disease, heart valve disease, myocardial disease, and cardiac conduction system abnormalities. Depending on whether the damage can be reversed, there are two types of damage: type I is permanent damage; type II is reversible damage.
What is radiation therapy-related heart damage?
What is radiation therapy-related heart damage?
Acute cardiac damage from radiation therapy is often “subclinical,” that is, changes in cardiac metabolism and function that manifest as electrocardiographic abnormalities but are not yet clearly symptomatic. The main abnormalities in the ECG are ST-T segment changes, followed by premature beats, atrial fibrillation, sinus tachycardia or bradycardia, while atrioventricular block and abnormal Q waves are rare. If you already have previous ECG abnormalities, they may worsen after radiation therapy. The risk is higher in older adults.
Radiotherapy-related heart damage includes:
- Coronary atherosclerosis
- Acute pericarditis and chronic pericardial exudate (may or may not be symptomatic, usually 6 to 12 months after radiation therapy)
- Myocarditis and chronic congestive heart failure
- Heart valve stenosis and regurgitation (usually in the mitral and aortic valves)
- Cardiac conduction system pathology, causing complete or incomplete conduction block, affecting the normal pulsation of the heart
What conditions are more likely to present with heart damage?
- Irradiation dose: Dose greater than 30-35 Gy (Gy is the unit of absorbed dose of radiotherapy, Gorée in Chinese); dose greater than 2 Gy per split
- Radiation range: larger portion of the heart irradiated
- Age: the younger you are at the time of radiation therapy and the longer you have survived, the greater the chance of advanced cardiac damage
- Combination with other treatments that damage the heart: such as treatment with cytotoxic chemotherapy drugs, endocrine therapy, or trastuzumab
- Other risk factors: having diabetes, hypertension, dyslipidemia, obesity, or smoking.
How to prevent?
The higher the dose of radiation therapy, the higher the incidence of heart injury. The main way to reduce heart damage is to reduce the radiation dose to the heart.
There are also some “black technologies” to help doctors achieve more precise and controlled radiation therapy to reduce heart damage, such as:
- Dose calculation via dose-volume histogram-based 3D treatment;
- Calculating the radiation dose received by normal tissue by normal tissue complication probability;
- Using intensity modulated radiation therapy (IMRT) technology, which adjusts the dose of radiation therapy as required within the radiation field.
How is follow-up done?
Detection of cardiac damage from radiation therapy depends on long-term follow-up, most critically the assessment and monitoring of cardiac function. The main tests include the following, and you should follow up and review them regularly as prescribed by your doctor:
- Coronary artery disease
- Coronary artery disease: review of lipid levels, electrocardiogram, echocardiogram, radionuclide testing, and coronary angiography;
- Pericardial disease: review of ECG, echocardiography, radionuclide examination and coronary angiography;
- Arrhythmias: review ECG and 24-hour ambulatory ECG;
- Valvular lesions: review echocardiography and cardiac catheterization.
If you want to learn about heart damage from chemotherapy for lung cancer, read this article:
Co-authors: Guangdong Provincial People’s Hospital Guangdong Lung Cancer Institute Dr. Peixin Tan Dr. Chang Lu