Markers of Cardiotoxicity in Early Breast Cancer Patients Treated With a Hypofractionated Schedule: A Prospective Study.

PURPOSE: To evaluate, in a series of early breast cancer (BC) patients treated with hypofractionated adjuvant radiotherapy (RT), whether N-terminal-pro hormone B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin I assay measurements can predict acute clinical or preclinical cardiotoxicity. PATIENTS AND METHODS: The study comprised 44 consecutive patients, who underwent conservative surgery with or without (neo)adjuvant chemotherapy and hypofractionated adjuvant RT. The RT schedule consisted in a total dose of 42.4 Gy in 16 fractions administered 5 days per week. Twenty-one patients received a subsequent boost to the tumor bed consisting of a total dose of 10 Gy in 4 fractions delivered via a direct electron field. All patients underwent 12-lead electrocardiogram, echocardiogram, and cardiac clinical examinations before RT to assess cardiovascular risk factors; these examinations were repeated yearly for 5 consecutive years. High-sensitivity cardiac troponin I and NT-proBNP were analyzed from serum samples at baseline, after delivery of the fourth and 16th RT fractions, and 12 months after treatment completion. RESULTS: No increase in cardiac troponin I and B-type natriuretic peptide levels related to left breast irradiation was observed. No statistical difference in NT-proBNP and high-sensitivity troponin I levels between left- and right-sided BC was found. An increase was observed of B-type natriuretic peptide levels at baseline, during treatment, and until 12 months after RT related to hypertension, with the P value near to the .05 threshold for age and chemotherapy. CONCLUSION: Conformational hypofractionated RT in left-sided BC may not cause acute myocardial damage. Early cardiac screening may be used to identify patients with cardiologic risk factors, patients who are older than 60 years, and patients who received chemotherapy that could result in clinically relevant cardiac pathologies.

Improvement of the performances of a commercial hand-held laser-induced breakdown spectroscopy instrument for steel analysis using multiple artificial neural networks.

In this article, we present a study on the optimization of the analytical performance of a commercial hand-held laser-induced breakdown spectroscopy instrument for steel analysis. We show how the performances of the instrument can be substantially improved using a non-linear calibration approach based on a set of Artificial Neural Networks (ANNs), one optimized for the determination of the major elements of the alloy, and the others specialized for the analysis of minor components. Tests of the instrument on steel samples used for instrument internal calibration demonstrate a comparable accuracy with the results of the ANNs, while the latter are considerably more accurate when unknown samples, not used for calibration/training, are tested.