Cardiovascular complications of radiation therapy for thoracic malignancies: the role for non-invasive imaging for detection of cardiovascular disease

Abstract

Radiation exposure to the thorax is associated with substantial risk for the subsequent development of cardiovascular disease. Thus, the increasing role of radiation therapy in the contemporary treatment of cancer, combined with improving survival rates of patients undergoing this therapy, contributes to a growing population at risk of cardiovascular morbidity and mortality. Associated cardiovascular injuries include pericardial disease, coronary artery disease, valvular disease, conduction disease, cardiomyopathy, and medium and large vessel vasculopathy-any of which can occur at varying intervals following irradiation. Higher radiation doses, younger age at the time of irradiation, longer intervals from the time of radiation, and coexisting cardiovascular risk factors all predispose to these injuries. The true incidence of radiation-related cardiovascular disease remains uncertain due to lack of large multicentre studies with a sufficient duration of cardiovascular follow-up. There are currently no consensus guidelines available to inform the optimal approach to cardiovascular surveillance of recipients of thoracic radiation. Therefore, we review the cardiovascular consequences of radiation therapy and focus on the potential role of non-invasive cardiovascular imaging in the assessment and management of radiation-related cardiovascular disease. In doing so, we highlight characteristics that can be used to identify individuals at risk for developing post-radiation cardiovascular disease and propose an imaging-based algorithm for their clinical surveillance.

Kardiotoksisitas Akibat Terapi Radiasi

“…Namun, radiasi juga dapat menyebabkan komplikasi kardiovaskuler pada pasien yang menjalani terapi. [1][2][3] Dalam suatu penelitian rektrospektif yang dilakukan di Stanford University pada pasien yang mendapatkan terapi radiasi untuk kasus limfoma hodgkin, didapatkan risiko relatif infark miokard sebesar 41,5 dibandingkan dengan populasi umum. 4 Penelitian tesebut juga melaporkan bahwa risiko henti jantung meningkat pada pasien yang mendapat terapi radiasi mediastinal dengan dosis >30 Gy dan meningkat seiring dengan peningkatan dosis.…”

“…Fibrosis pada miokard dapat menyebabkan kardiomiopati restrikstif dan gagal jantung diastolik. 2 Kerusakan jantung akibat radiasi dapat terjadi secara akut maupun kronis dan dampaknya terjadi secara makrovaskuler dan mikrovaskuler. 10 Dalam beberapa menit setelah terpapar radiasi, kerusakan seluler akan menyebabkan terjadinya vasodilatasi dan peningkatan permeabilitas vaskuler.…”

“…4,13 Penebalan perikardial ≥4 mm pada CT ataupun magnetic resonance imaging (MRI) sugestif terhadap perikarditis konstriktif, namun 20% dari pasien perikarditis konstriktif yang telah menjalani operasi terbukti tidak mengalami penebalan perikard pada gambaran MRI. 2 Transthoracic echocardiography (TTE) dapat menunjukkan gambaran velositas puncak E' yang lebih tinggi pada septal dibandingkan dengan lateral anulus katup mitral. 2 Intraventricular septal bounce pada TTE ataupun MRI adalah gambaran yang paling sensitif dan spesifik untuk menunjukkan adanya perikarditis konstriktif, dengan sesitifitas yang tercatat pada echocardigrafi sebanyak 62-81% dan spesifisitas 93-100%.…”

Noninvasive Assessment of Coronary Arteries in Patients with Hematologic Disorders

“…8,11 Groacher et al created an algorithm for screening patients with non-Hodgkin lymphoma (NHL), who received mediastinal/thoracic radiotherapy. 13 In patients with signs/symptoms of constrictive pericarditis transthoracic echocardiography (TTE) ± CT or magnetic resonance imaging (MRI) is recommended. In case of patients with acute coronary syndrome (ACS) and suspected coronary artery involvement, invasive coronary angiography and/ or functional angiogram is the recommended investigation.…”

“…Groacher et al recommend a low threshold for screening with noninvasive imaging methods, for identifying coronary lesions at early stages where an opportune intervention may reduce cardiovascular morbidity and mortality in malignancy survivors. 13 …”