Assessment of doxorubicin cardiac toxicity using gated ⁹⁹mTc-hexakis-2-methoxyisobutylisonitrile myocardial single photon emission computed tomography: wall thickening and motion abnormalities can be an early sign of cardiac involvement.

BACKGROUND: Advancement in chemotherapy has significantly improved the prognosis of cancer patients. However, many anticancer drugs have serious cardiovascular side effects. We assessed doxorubicin-induced cardiac toxicity (DCT) during and after preoperative chemotherapy using gated (99m)Tc-hexakis-2-methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) in patients with malignant bone and soft tissue tumors.

METHODS AND RESULTS: Gated (99m)Tc-MIBI SPECT was performed before, and after the middle and final courses of preoperative chemotherapy. Gated (99m)Tc-MIBI SPECT was quantitatively analyzed with QGS/QPS software. We also assessed the reproducibility of measurements of global and regional functions from gated SPECT images. Twenty-eight patients (19 males and 9 females), eligible for preoperative chemotherapy, were included. All patients had normal myocardial perfusion images based on QPS during preoperative chemotherapy. Wall thickening (WT) and motion (WM) decreased after the middle course of preoperative chemotherapy compared to baseline. After the final course of preoperative chemotherapy, significant decreases of ejection fraction, WT and WM, and one-third mean filling rate were observed compared to baseline. By regression analysis, correlation coefficients of inter- and intra-observer reproducibility of global and regional functions were excellent (r ≥ 0.95).

CONCLUSIONS: Gated (99m)Tc-MIBI SPECT can monitor the deterioration of cardiac function in asymptomatic patients with possible DCT. WT and WM might be useful as early markers of ventricular dysfunction due to DCT.