The heart is moderately sensitive to radiation injury, as well as chemotherapy injuries. All components are susceptible to injury that can manifest as late effects. Adriamycin is dose limited for cardiac damage, and high lifetime doses of adriamycin can cause sudden cardiac death. Radiation induced cardiac injury includes CHF, restrictive cardiomyopathy, valvular stenosis CAD, ischemia, infarct and pericarditis. The heart volume identification is a significant problem, in that there is cardiac motion, respiratory motion, the top of the atria are indistinct from the great vessels, adjacent tissue with similar electron density (diaphragm, stomach).
MDACC demonstrated a correlation between a mean dose of > 26 Gy and restrictive pericarditis for volumes greater than 3 to 50 Gy with the strongest associated risk at V30. U Michigan repored a risk of pericardial effusion if dose/fraction was 3.5 Gy and mean dose > 27 Gy with a maximum dose > 47 Gy. Valve disease is associated with younger age of treatment and dose > 30 Gy.
Anthracycline based chemotherapy can exacerbate radiation injury to the heart. Radiation exposure in conjunction with anthracyclines (adriamycin) can decrease EF with a 25 year risk of 7.9%. Other risk factors include CAD and other cardiac diseases.
A V30 to V40 of 30% to 35% is associated with a less than 0.5% risk of excess cardiac death at about 15 years. A mean cardiac dose of > 26 Gy and a V30 > 45% are associated with higher risks of pericarditis. For lymphoma patients, the whole heart upper dose limit is 30 Gy (rt alone) or 15 Gy (with anthracycline based chemotherapy).