Cardiac
Prevention
Radiation Therapy (RT) Related Damage
Over time, the total dose of RT given to Hodgkin Lymphoma (HL) patients has decreased, the fraction size has decreased and techniques have changed so that RT is better planned (less likely to have very high dose areas with the treatment more evenly spread out).
In summary, methods to reduce the risk of cardiac damage in RT include:
- Reducing the total RT dose (in pediatric HL this has been done successfully)
- Reducing the treatment volume and not including so much cardiac tissue in the RT field (moving from mantle field to involved field RT in pediatric HL still allows for effective therapy and spares more normal tissue)
- Improved RT planning with 3-D conformal planning (such as weighting anterior and posterior fields equally).
- Decreasing daily RT fraction size
- Anthracycline therapy is not given concurrently with RT to the chest.
Chemotherapy Related Damage
There is limited and suboptimal therapy for anthracycline-induced cardiomyopathy, so prevention is an important area of research.
Treatment regimens that restrict the amount of anthracycline given and reduce RT dose and volumes are likely to decrease the incidence of cardiomyopathy. But, anthracyclines are very effective agents for many pediatric pediatric patients with sarcomas and high-risk hematologic malignancies.
Cardioprotective agents:
Dexrazoxane:
- A derivative of EDTA.
- Dexrazoxane chelates iron, but the precise mechanism by which it protects the heart from anthracyclines is not known3.
- Dexrazoxane appears to protect against doxorubicin-induced depolarization of the myocyte mitochondrial membrane and possible prevent myocyte specific iron-based oxidative damage to mitochondria3.
- It also has effects on inhibiting topoisomerase II which could be another route in which cardioprotection against anthracyclines is derived3.
- Hydrolysis products of dexrazoxane have been shown to chelate both free and bound intracellular iron, including iron that is bound in anthracycline complexes, thereby preventing the generation of cardiotoxic reactive oxygen species3.
- Clinical trials of dexrazoxane in children show encouraging evidence of short-term cardioprotection5.
- The long-term reduced risk of cardiotoxicity by using this drug still needs to be determined3.
Life style:
- Education and counselling can help to ensure that other risk factors are reduced and don’t add to the problem.
- Diet
- Healthy ideal body weight should be maintained as obesity is a major preventable coronary risk factor associated with increased morbidity and mortality9.
- A diet low in saturated fats can be recommended along with a sodium intake of less than 2.5g/day9.
- Exercise
- Regular aerobic exercise should be promoted8
- Intensive isometric exercise, such as weight lifting, has anecdotally been reported to cause cardiac decompensation, thus patients should be discourage to participate unless under direct supervision of a cardiologist and exercise physiologist7.
- Monitoring for and treatment of elevated serum lipids and hypercholesterolemia.
