PP.09.26] RADIATION-INDUCED VASCULAR DAMAGE IN HODGKIN LYMPHOMA SURVIVORS

Abstract

Objective: New chemotherapeutic drugs and radiation therapy have significantly improved cancer patient's survival, although the cardiovascular (CV) side effects of cancer treatment are increasingly important. In previous studies, an increased risk of cerebrovascular complications such as stroke and transient ischemic attack was described in patients undergoing neck radiotherapy. Aim of our study was to evaluate vascular carotid structural (IMT, plaque) and functional (carotid stiffness) damage, and changes in arterial stiffness (Carotido-femoral pulse wave velocity; cf-PWV) in Hodgkin Lymphoma survivors previously treated with radiotherapy. Design and method: We enrolled 206 Hodgkin lymphoma survivors (mean age 54 ± 14 years, 51% males, mean follow-up of 9 ± 6 years). CV risk factors were investigated and atherosclerotic carotid damage was assessed by standard carotid ultrasound evaluation for intima-media thickness (IMT) measurement (MeanMax-IMT, CBMax, Tmax; n = 167); in 141 patients radiofrequency-based carotid stiffness analysis (distensibility; distensibility coefficient, DC; compliance coefficient; CC)was also performed. Cf-PWV measurement were obtained in 154 patients. Results: a significant correlation between radiotherapy dose and: MeanMax-IMT (r = 0.20; p < 0.05),Tmax (r = 0.20; p < 0.05), distensibility (r = 0.24; p < 0.05),DC (r = 0.24; p < 0.05),CC (r = 0.24; p < 0.05)was observed. Patients were divided into 4 groups according to radiotherapy dose (Dose: 20–30; 31–36; 37–42; >42 Gy). An increase in Tmax (1.27 ± 0.61, 1.35 ± 0.59, 1.46 ± 0.69, 1.76 ± 1.12 mm, p for trend < 0.05) and in the prevalence of carotid plaque (29%, 31%, 47% and 55%, p for trend < 0.05) was observed as related to dose-category. One-hundred-seventeen patients received neck irradiation (67 bilateral;50 unilateral). In unilaterally irradiated patients, MeanMaxIMT was greater in the irradiated side as compared to unirradiated carotid artery and the difference reached statistical significance in the group of patients who received a high radiotherapy dose (0.97 ± 0.35 vs 0.92 ± 0.34 p < 0.05). Cf-PWV was significantly greater only in patients that received high dose (>42 Gy), as compared to all the other dose groups (9.7 ± 2.3 vs 8.3 ± 2.2, 8.0 ± 1.5 and 8.3 ± 1.4, p < 0.05). Conclusions: In this large number of Hodgkin Lymphoma survivors, carotid IMT, plaque prevalence and aortic and carotid stiffness were significantly related with radiotherapy doses. Carotid IMT, carotid and aortic stiffness were significantly higher in the irradiated carotid arteries, but only at doses >42 Gy, suggesting that there may be a dose threshold for radiotherapy-induced carotid wall damage.