Five studies (n=6,908; 2,567 receiving neck radiotherapy, 222 receiving supraclavicular radiotherapy, 4,119 non-irradiated patients) were included in the review. The median follow-up was reported as 7.3 years and ranged from two months to a median of 8.4 years.
Significantly more cardiovascular events were reported in patients receiving neck radiotherapy (66 events) compared to non-irradiated patients (12 events) (OR 9.0, 95% CI: 4.9, 16.7, p<0.0001, five studies).
Forest plots were not presented in the review. There was insufficient evidence on supraclavicular radiotherapy to allow data synthesis.