Purpose: It remains challenging to identify patients at risk of anthracycline-induced cardiotoxicity. To better understand the different risk-stratifying approaches, we evaluated (123)I-metaiodobenzylguanidine ((123)I-mIBG) scintigraphy and its interrelationship with conventional echocardiography, 2D strain imaging and several biomarkers.
Methods: We performed (123)I-mIBG scintigraphy, conventional and strain echocardiography and biomarker (NT-proBNP, TNF-α, galectin-3, IL-6, troponin I, ST-2 and sFlt-1) assessment in 59 breast cancer survivors 1 year after anthracycline treatment. Interobserver and intermethod variability was calculated on planar and SPECT (123)I-mIBG scintigraphy, using the heart/mediastinum (H/M) ratio and washout (WO). Pearson's r and multivariate analyses were performed to identify correlations and independent predictors of (123)I-mIBG scintigraphy results.
Results: Delayed planar anterior whole-heart ROI (WH) H/M ratios and WO were the most robust (123)I-mIBG parameters. Significant correlations were observed between (123)I-mIBG parameters and several conventional echo parameters, global longitudinal and radial strain (GLS and GRS) and galectin-3. The highest Pearson's r was observed between delayed H/M ratio and GRS (Pearson's r 0.36, p = 0.01). Multivariate analysis showed that GRS was the only independent predictor of the delayed WH H/M ratio (p = 0.023).
Conclusion: The delayed planar H/M ratio is the most robust (123)I-mIBG parameter. It correlates with several conventional echocardiographic parameters, GLS, GRS and galectin-3. Of these, only GRS predicts the H/M ratio.
Keywords: 123I-mIBG scintigraphy; 2D strain imaging; Anthracyclines; Biomarkers; Breast cancer; Cardiotoxicity.