143 Carotid Intraplaque Neovascularization is Increased in Patients with Prior Ipsilateral Neck Irradiation - A Contrast Enhanced Ultrasound Study. (31st May 2014)

• Record Type: Journal Article
• Authors: Senior, Roxy; Gujral, Dorothy M; Chahal, Navtej S; Harrington, Kevin J; Nutting, Christopher M; Shah, Benoy
• Is Part Of: Heart. Volume 100:(2014)Supplement 3
• Page Start: A84
• Page End: A84
• Publication Date: 2014-05-31
• Subjects: Carotid Artery -- Contrast Ultrasound -- Radiotherapy; Heart -- Diseases -- Treatment -- Periodicals; Cardiology -- Periodicals; 616.12
• DOI: 10.1136/heartjnl-2014-306118.143
• Languages: English
• ISSNs: 1355-6037

Abstract

Abstract : Background: Irradiation of the carotid artery during radiotherapy (RT) for head/neck cancer (HNC) increases intima-media thickness, plaque formation and risk of stroke. However, the effects of RT on plaque composition are unknown. Intraplaque neovascularization (IPN) is a precursor to intraplaque haemorrhage and thus considered to be a marker of plaque instability. Contrast-enhanced ultrasound (CEUS) is a novel method of indirectlyassessing plaque vulnerability by detection of IPN. Methods: B-mode and CEUS carotid ultrasonography were performed in survivors of HNC who had received RT >2 yrs previously and had received >50Gy dose to the ipsilateral neck. Patients with bilateral RT were excluded. Baseline patient demographics were noted. Long and short axis views of the ipsilateral (RT side) and contralateral (non-RT side) carotid arteries were recorded, first in B-mode and then CEUS, using a continuous IV infusion of Sonovue contrast. IPN was graded semi-quantitatively as absent (Grade 0), limited to the adventitia/plaque base (Grade 1) or extensive and/or extending into the plaque body (Grade 2) by a doctor blinded to the laterality of RT. Results: A total of 49 patients were enrolled. Mean age was 57 ± 8yrs, 69% were male and mean BMI was 26 ± 4 kg/m 2 . The mean interval from RT to carotid imaging was 5.3 ± 2.6 years. Plaques were found in 38 (78%) patients, of whom 36 had plaques on the RT vs. 17 on the non-RT side (73 vs. 35%, p < 0.001). IPN was seen in 29/36 patients with RT-side vs. 7/17 patients with non-RT side plaques (81 vs. 41%, p = 0.004). Grade 2 IPN was seen in 14/36 patients with RT-side vs. 2/17 patients with non-RT side plaques (39 vs. 12%, p = 0.04). Conclusions: This is the first study to assess carotid plaque composition in HNC patients treated with RT. IPN, detected non-invasively by CEUS, is more prevalent in plaques from irradiated arteries. These results indicate that the increased risk of stroke in such patients may be due to RT-mediated proliferation of IPN.