RESUMO
BACKGROUND AND PURPOSE: To investigate early vascular changes related to carotid atherosclerotic injury post-radiation therapy (RT), we studied carotid intima-media thickness (IMT) and vascular cellular adhesion molecule (VCAM)-1 at two time-points after RT and compared local and remote irradiation effects in patients with head and neck (HNC) and prostate cancer (PC), respectively. MATERIAL AND METHODS: We prospectively studied patients beginning RT for HNC or PC, performing carotid ultrasound before RT, early after and six months after treatment to measure carotid IMT. Blood samples were simultaneously collected to study VCAM-1 by ELISA. RESULTS: We studied 19 patients with HNC and 24 with PC. Patients with HNC were younger (55 ± 10 years) than PC patients (68 ± 8 years). Early post-RT only HNC patients had an increase in IMT compared to baseline measurements (0.73 ± 0.04 mm vs. 0.80 ± 0.05 mm, p=0.029). On the other hand, VCAM-1 levels decreased in PC patients, remaining unchanged in HNC patients. Late post-RT (six months from previous assessment), neither IMT nor VCAM-1 values changed in both groups. CONCLUSION: Local and remote RT seem to exert differential early effects regarding vascular-related changes: (1) local RT seems to affect vascular structure and increase IMT and (2) RT for PC is associated with reduction in VCAM levels, suggesting systemic modulation of cancer-related factors.