Screening for Lymphedema
What is lymphedema?
A swollen arm, hand, or tightening of a ring following breast cancer diagnosis or treatment is often indicative of lymphedema. This occurs secondary to the accumulation of lymph in the extremity on the side where the breast cancer was diagnosed.
Lymph is a collection of fluid which lies between the cells of the body. Normally it accumulates within lymphatic channels where it is transported to lymph nodes, and finally empties into the right or left subclavian vein re-entering the bloodstream of the body.
Patients who have breast cancer, may develop a blockage of the lymph nodes under their arms. This can occur as a result of the spread of cancer blocking the nodes, or treatment. Treatment may be in the form of surgical sampling, removal of the nodes (axillary dissection) or radiation therapy. Much like a traffic jam, which would result in highway congestion, if the pathway of lymphatic travel is blocked, the fluid cannot advance resulting in swelling of the limb.
Lymphedema may cause aching, increased risk of infection, limitation of mobility, and pain. Screening can afford early detection, and therefore treatment.
Screening for lymphedema
Patients should be educated about the symptoms of lymphedema. A set of printed questions addressing arm swelling, tightness, or redness may alert the health care team to lymphedema.
A common method of testing for lymphedema is measuring the circumference of the upper extremity. A flexible tape measure is used to measure both arms before and after treatment. These are done at multiple sites, including the hand, wrist, forearm, and upper arm. Increased circumferences reflect swelling of the arm. This method is operator dependent.
Perometry (optoelectronic volumetry):
With this method a device uses infrared light to calculate the volume of the arm. The arm is placed in a device where infrared beams from different angles intercept the arm. A computer uses the information to calculate the arm volume.
Bioimpedence detects the amount of fluid in the arm. It is done by measuring the resistance to a small electric current passed through the arm. This is done at multiple sites along the arm. The higher the interstitial fluid, the lower the resistance. This is very sensitive and may detect lymphedema before it is clinically apparent.
In this test a radioactive substance is injected into the lower arm. It is taken up by the lymphatics and can be followed as it travels up the arm. This may give information as to how well the lymph is traveling.
Results of screening:
Breast cancer survivors are living longer than in the past. Prolonged quality of life is important. Screening for lymphedema will result in earlier detection. This may allow treatment that will halt or slow the progression of lymphedema and its symptoms.