Partial irradiation of the heart

Area of Science:

• Cardiology
• Radiation Oncology
• Medical Physics

Background:

• Radiation-induced heart disease (RIHD) encompasses conditions like pericarditis, ischemic heart disease, and myocardial infarction, posing fatal risks.
• Increased survival from radiotherapy, particularly for left-sided breast cancer, can be offset by excess deaths from RIHD.
• Subclinical cardiac effects post-irradiation are documented in breast and Hodgkin's lymphoma treatments.

Purpose of the Study:

• To review dose-volume response relationships for cardiac complications in radiotherapy.
• To evaluate biological models like the Lyman-Kutcher-Burman (LKB) and Källman's relative seriality models for predicting cardiac events.
• To discuss strategies for reducing heart irradiation and the importance of accurate cardiac definition in modeling.

Main Methods:

• Review of studies on pericarditis (Martel et al.) and cardiac mortality (Gagliardi et al.).
• Analysis of dose-volume response relationships using biological models.
• Evaluation of anatomical and functional heart definitions impacting dosimetrical data for modeling.

Main Results:

• Dose-volume response relationships for pericarditis and cardiac mortality have been studied using biological models.
• Accurate anatomical and functional heart definition is crucial for reliable dosimetrical input in cardiac modeling.
• Several treatment strategies aimed at decreasing heart irradiation have been reviewed.

Conclusions:

• Left-sided breast cancer patients undergoing radiotherapy should consistently utilize 3-dimensional (3D) dose planning.
• Minimizing heart irradiation is critical to prevent potentially fatal complications and ensure radiotherapy's survival benefits.
• Further research into cardiac modeling and treatment strategies is essential for improving patient outcomes.