Radiation therapy: the response of the hematopoietic system in oncology patients

Radiation therapy: the response of the hematopoietic system in oncology patients

ANSWER

Radiation therapy, occurs when high-energy radiation is directed at cancerous tumors and their surrounding tissues. The hematopoietic system plays a significant role in the response of the bone marrow to radiation therapy.

The hematopoietic system is a collection of blood-forming organs that include bone marrow, lymph nodes, and spleen. Radiation can damage these organs by causing them to swell and leak blood and tissue fluid. The results of radiation therapy often include nausea, fatigue, vomiting, diarrhea, mouth sores from mucositis (damage to mucous membranes), headache and dizziness.

The bone marrow is the site of production and storage of blood cells. During normal physiology, it produces red blood cells, white blood cells and platelets. Furthermore, the bone marrow produces stem cells which can differentiate into either different types of blood cells or other cell types such as fat cells.

When radiation therapy is administered to cancer patients, it may damage or destroy the bone marrow’s ability to produce new blood cells. This can result in anemia (low number/quality of red blood cells), leukopenia (low number/quality of white blood cells), thrombocytopenia (low number/quality of platelets) and pancytopenia (too few all types).

Damage to the hematopoietic system occurs within hours after exposure to ionizing radiation; however, it can take weeks or months for the damage to become apparent on an imaged scan (radiation therapy should be performed with close follow-up).

QUESTION