Mantle radiotherapy was introduced during the 1960s for people with Hodgkin lymphoma whose cancer was confined to lymph glands in the chest, neck or under the arms. The aim of the treatment was to give radiotherapy to all the lymph glands lying above the diaphragm (the muscle which separates the chest from the abdomen),. After the "mantle" phase has been completed, some of the patients will be advised to have additional radiation therapy to the lymph nodes below the diaphragm including the area called the retroperitoneum (central abdomen), spleen (left upper quadrant, or area, of the abdomen), and the pelvis.

The use of mantle radiotherapy transformed the outlook for people with Hodgkin lymphoma. Previously it had been a very difficult  cancer to cure but the new approach to treating wide areas of lymph tissue with radiotherapy resulted in many people being completely cured.

Part or all of the heart is normally included in the area covered by mantle treatments. Over the years, research shows  that there is a risk of some occasional long term side effects from mantle radiotherapy, which often appear many years later. These can include heart damage.

Several types of heart damage have been seen. These include:

• damage to the pericardium:  this is the outer layer of tissue that surrounds the heart and damage here can lead to fluid building up between the pericardium and the heart muscle (the myocardium) which can cause pressure on the heart
• damage to the myocardium: damage to the heart muscle itself can lead to a greater risk of developing heart failure
• damage to the coronary arteries: damage to the blood vessels which supply the heart muscle can lead to a greater risk of heart attacks (myocardial infarction or MI)

Careful study of heart complications after mantle radiotherapy has shown that the risk is greater with higher doses of radiotherapy (which were often used in the early days of mantle treatment) and using the treatment in combination with certain types of chemotherapy.

Doctors who give radiotherapy for Hodgkin lymphoma are well aware of these risks and can adjust the treatment on an individual basis to reduce the likelihood of heart damage to an absolute minimum. This can be done by adjusting the dose of radiation given, or using special treatment techniques to protect or 'shield' the heart.

In your own case, as you have a history of heart disease in the family, it is important that you mention this to the doctor(s) involved in planning your radiotherapy treatment so that they can take this into account.