Table 1.

Cardiac-Sparing Radiation Therapy Techniques and Modalities

Cardiac-Sparing Technology/Technique	Description	Cancers Where These Techniques May Be Used
		Lymphoma	Breast Cancer	Esophageal Cancer	Lung Cancer	Pediatric Cancer
Modality
3-dimensional conformal radiation therapy	Photon beams designed using forward planning; minimize low dose bath; less conformality of high dose; can use a “heart block” to eliminate heart from the field using beam edge	✓	✓	✓	✓	✓
Intensity-modulated radiation therapy/volumetric-modulated arc therapy	Inverse planning using multiple photon beams or arcs to achieve conformality of high dose at the cost of increased low-dose exposure	✓	✓	✓	✓	✓
Proton therapy	Particle beam with Bragg peak phenomenon resulting in elimination of exit dose; enables both minimization of low dose and conformality of high dose	✓	✓	✓	✓	✓
Cardiac Displacement and motion management techniques
Deep-inspiration breath hold	Using a device to measure depth of inspiration, patient is guided to hold breath for 10-20 seconds to displace thoracic anatomy from the heart	✓	✓
Gating	Using an external abdominal device to gauge respiration, the beam is delivered during a set phase of the respiratory cycle when the heart is farthest from the target, and the beam shuts off when the patient exits this portion of the respiratory cycle	✓	✓	✓	✓
Prone positioning	Displaces the target anatomy from the heart in many patients		✓
Image-guided radiation therapy
Cone-beam computed tomography (CT)	Low-dose CT obtained in treatment vault permits alignment based on visualization of internal anatomy	✓	✓	✓	✓	✓
Surface alignment	Uses surface anatomy for patient positioning; cannot visualize internal anatomy; no radiation exposure for this alignment technique		✓