Beam angle manipulation to reduce cardiac dose during breast radiotherapy

Area of Science:

• Oncology
• Radiotherapy
• Cardiovascular Health

Background:

• Standard radiotherapy after breast-conserving surgery (BCS) can irradiate the heart, specifically the left ventricle and left anterior descending coronary artery (LAD).
• Increased interest exists in minimizing radiation dose to cardiac structures to reduce cardiovascular morbidity.

Purpose of the Study:

• To test the hypothesis that manipulating beam angles during radiotherapy can achieve significant cardiac sparing.
• To evaluate if accepting lower doses in specific breast areas can reduce cardiac irradiation compared to standard plans.

Main Methods:

• A study of 12 patients undergoing radiotherapy after left-sided BCS.
• Development of "institutional" plans with manipulated beam angles to minimize cardiac irradiation.
• Generation of "hypothetical standard" plans for comparison in seven patients based on published guidelines.

Main Results:

• Institutional plans showed lower doses to the LAD and myocardium in seven patients compared to standard plans.
• In five patients, standard plans already achieved minimal cardiac doses, aligning with the institutional approach.
• The institutional plan, involving careful beam angle manipulation, was effective in reducing cardiac radiation exposure.

Conclusions:

• Careful manipulation of beam angles is a simple yet effective technique for minimizing cardiac radiation dose in patients undergoing radiotherapy after BCS.
• This approach demonstrates potential for reducing radiation-induced cardiovascular risks in breast cancer patients.