RAMB Março/Abril 2016

ardiovascular

effects

radiotherapy

the

patient

with

cancer

ssoc

ras

2016; 62(2):192-196

195

smaller than 2 mm of common carotids and proximal in-

ternal sections of the carotid artery. However, the clinical

significance of these changes is unclear, which could be an-

swered in future long term follow-up studies.

Neverthe-

less, patients with severe carotid obstructive disease referred

for surgery and a history of cervical radiation therapy of-

ten represent a challenge for the vascular surgeon since

there is abnormal adherence of the

intima

and all layers,

obliterating anatomical plans and making endarterecto-

my technically difficult. Therefore, stent implant angio-

plasty is increasingly frequent in these patients.

Another late-onset sequela associated with cervical ra-

diation is chronic failure of the baroreflex manifested by la-

bile hypertension and orthostatic intolerance. Histopatho-

logical studies have shown atherosclerotic changes,

perivascular fibrosis and thickening in the carotid sinus af-

ter cervical radiation. Chronic failure of the baroreflex has

been attributed to these changes.

Diffuse calcification of the thoracic aorta and stenot-

ic lesions of the subclavian arteries have also been report-

ed. These are late-onset sequelae attributed to adjuvant

RT, and it has become well-known that all arteries are

sensitive to the late-onset effects of radiation.

14,15,41-43

CHART 2

Cardiovascular lesions secondary to

radiotherapy in cancer patients.

Cardiovascular

structures

irradiated

Major clinical presentations

Pericardium Pericardial thickening

Pericardial effusion

Cardiac tamponade

Constrictive pericarditis

Coronary artery

disease

Obstructive lesion in the anterior descending artery

Obstructive lesion in the coronary ostia

Myocardium Asymptomatic left ventricular diastolic dysfunction

Valves

Valvular thickening without hemodynamic

repercussions

Aortic stenosis

Cardiac electrical

and conduction

disorders

Right bundle branch block (more frequent)

Left bundle branch block

Complete atrioventricular block

T-wave flattening or inversion

Great vessels of

the chest

Increased carotid

intima

-media thickness

Chronic baroreflex failure: labile hypertension or

orthostatic hypotension

Aortic calcification

Stenotic lesions of the subclavian arteries

onclusion

It is evident that chest and cervical radiation has an im-

pact on cardiovascular morbidity and mortality. Despite

the major developments in the improvement of radio-

therapy techniques and better knowledge and mastery of

radiation in recent decades, it has not yet been possible

to completely exclude important areas of the cardiovas-

cular system from irradiation fields. More effective and

less toxic therapy should be sought. Guidelines must be

created for strict monitoring of patients who have had

exposure of the cardiovascular system to radiation, espe-

cially when it comes to young people with a long life ex-

pectancy, given that cardiovascular damage is treated with

limited results.

esumo

Efeitos cardiovasculares da radioterapia no paciente com

câncer

A incidência de câncer (CA) tem aumentado globalmen-

te e a radioterapia (RT) é um componente vital do trata-

mento. As lesões cardiovasculares induzidas pela RT no

tratamento de CA torácicos e cervicais geram problemas

à prática clínica há décadas e estão entre os efeitos adver-

sos mais graves da RT experimentados pelo crescente nú-

mero de sobreviventes de CA. Neste artigo, realiza-se re-

visão nas bases Lilacs, Scielo e Pubmed das principais

lesões cardiovasculares secundárias à RT, os mecanismos

fisiopatológicos, as apresentações clínicas, os tratamen-

tos e as propostas de prevenção. Dentre as lesões pela RT,

destacam-se as doenças do pericárdio, a doença arterial

coronariana, a doença valvular, a doença do miocárdio

com disfunção sistólica e diastólica, os distúrbios de con-

dução, a doença das artérias carótidas e dos grandes va-

sos. A irradiação torácica e cervical aumentam a morbi-

mortalidade cardiovascular. Apesar da grande evolução

no aprimoramento das técnicas de RT, ainda não foi pos-

sível excluir totalmente áreas nobres do sistema cardio-

vascular dos campos de irradiação. Faz-se necessária a ins-

tituição de diretrizes para monitoramento, diagnóstico

e tratamento dos pacientes com CA submetidos à RT.

Palavras-chave:

radioterapia, lesões por radiação, doen-

ças cardiovasculares.

eferences

Kumar V, Abbas AK, Fausto N, Aster JC. Robbins and Cotran Patologia.

Bases patológicas das doenças. 8.ed. São Paulo: Elsevier, 2010.