Positive association between heart dosimetry parameters and a novel cardiac biomarker, solubleST‐2, in thoracic cancer chest radiation

BACKGROUND: Early screening and diagnosis of radiation‐induced heart disease (RIHD) is difficult in patients with chest radiation exposure. sST‐2 is involved in myocardial stress or injury. We evaluated the relationship between heart dose parameters and sST‐2 changes in chest malignant tumor patients who received chest radiation. METHODS: We prospectively collected thoracic malignancy cancer patients who had received chest radiotherapy. Heart dosimetry parameters were extracted from the treatment planning system. sST‐2 was measured at baseline, the middle stage, and after radiotherapy (recorded as pre‐ST‐2, mid‐ST‐2, and post‐ST‐2). sST‐2 change rate was calculated. Scatter plots showed the relationship between cardiac dose parameters and ST‐2 change rate. Multiple regression was used to analyze the relationship between cardiac dose parameters and ST‐2 change rate. RESULTS: Totally, 60 patients were enrolled. The mean V(5), V(10), V(20), V(30), V(40), and MHD was 60.93 ± 27.79%, 51.43 ± 25.44%, 39.17 ± 21.75%, 28.07 ± 17.15%,18.66 ± 12.18%, and 18.60 ± 8.63 Gy, respectively. The median M‐LAD was 11.31 (IQR 3.33‐18.76) Gy. The mean pre‐ST‐2, mid‐ST‐2, and post‐ST‐2 was 5.1 ± 3.8, 6.4 ± 3.9, and 7.6 ± 4.4, respectively. sST‐2 was elevated with thoracic irradiation (P < .001). Multivariate linear regression analyses showed that V(5), V(10), V(20), and MHD were independently and positively associated with ST‐2 change rate (β = .04, .04, .04, and .10, respectively, all P < .05). CONCLUSION: Serum sST‐2 levels were elevated over time during radiotherapy. V(5), V(10), V(20) and MHD were independently and positively associated with the elevated ST‐2 change rate.