Table 4. Risk factors for radiation-induced heart disease (RIHD).

RISK FACTORS FOR RIHD
	< 50 years of age
	Cumulative radiation dose > 30 Gy
	High fractional doses of radiation > 2 Gy/day
	Presence and extent of a tumor close to the heart
	Concomitant use of chemotherapy agents (mainly anthracyclines)
	Risk factors for cardiovascular disease (hypertension, DM, dyslipidemia, smoking)
	Preexisting cardiovascular disease
	Inadequate cardiac protection
	Irradiation in the anterior region or left hemithorax
Definition of high risk: exposure to thoracic radiotherapy in the anterior or left chest region in addition to at least one of the listed factors

DM: diabetes mellitus.