Multimodality Imaging for Cardiac Surveillance of Cancer Treatment in Children

Publication Date: December 1, 2023

Last Updated: December 6, 2023

Introduction

During cancer treatment inclusive of cardiotoxic medications, echocardiographic screening for early detection of subclinical cardiac dysfunction is recommended. The frequency of screening will depend on doses used and other coexisting risk factors.
Current criteria for defining early cardiac dysfunction are based on decreased FS or EF that have been poorly validated in prospective studies. Withholding cancer treatment requires multidisciplinary decision-making and must be made cautiously.
After completion of treatment, cardiac surveillance is recommended at least every 2 years for high-risk and every 5 years for moderate-risk patients. The cost-benefit for low-risk patients is questionable, and evidence-based recommendations for cardiac surveillance after novel treatments have not been established.

Serial assessment of LV chamber size and wall thickness must be included when evaluating children with cancer before, during, and after treatment.
Linear dimensions of the LV cavity, interventricular septum, and posterior wall can be measured either by M-mode echocardiography or by 2D echocardiography. Consistency in the method used for measuring linear dimensions is crucial for interpreting serial changes. The measurements should be corrected for body size, and Z scores should be included in the reports.
Left ventricle volume and mass measured by 2D echocardiography using the method of disks or the area-length method can provide additional and more detailed information on LV size.
Three-dimensional echocardiography is an emerging technique in pediatrics for assessing LV volume and mass without geometric assumptions.

We recommend the use of EF and not FS for monitoring LV function in children with cancer.
For measuring EF by 2D echocardiography, we recommend using the biplane method of disks for serial follow-up. If apical 2-chamber views are limited, the area-length method is a reasonable alternative, especially in young children. When available, 3D echocardiography-based EF calculations are preferable in adolescents and young adults.
Each laboratory should consistently utilize a single method for serial assessment of LV function. The method used should be identified in the report.
Normal EF is ≥55%. An EF value between 50% and 54% is borderline function and should be confirmed by a second echocardiogram acquired within 1 to 2 weeks (during treatment) or within 6 months (after treatment). In case of borderline LV function, assessment of LV function by other imaging modalities, such as cardiac MRI, can be considered. When EF is <50% a cardio-oncology consultation is recommended.

Measurement of GLS by STE is a reproducible measurement of LV function that should be included in the assessment of LV function.
Given intervendor variability, the use of either a single-vendor or a vendor-neutral strain analysis software is recommended for serial follow-up.
Values of GLS equal to or more negative than −18% are considered normal, of −16% to −17% are considered borderline normal, and less negative than −16% are considered abnormal. The predictive value of an early decrease in GLS during treatment and in long-term survivors is uncertain in the presence of preserved EF.
If LVEF is >55% but GLS is > –18%, more frequent follow-up could be considered.

Despite their limitations, assessment of LV diastolic parameters should be considered an essential part of LV functional assessment.
We recommend serial assessment of mitral inflow velocities, tissue Doppler velocities at the septal and lateral mitral annulus, LA volume by the biplane method, and peak tricuspid regurgitation velocity.
Serial assessment of these parameters can help to identify development of diastolic abnormalities. Diastolic dysfunction remains poorly defined in children, as no specific guidelines have been developed.
Left atrial volume assessment is a more stable parameter of LV diastolic function in children. Progressive LA dilatation without obvious explanation could indicate increased LV stiffness and LV filling pressures.
Left atrial strain is a promising measure of LA function that requires further validation in children exposed to cancer treatment.

Multimodality Imaging for Cardiac Surveillance of Cancer Treatment in Children