Early Detection Of Cardiac Damage Using ^99mTc-MIBI SPECT Gated Myocardial Perfusion Imaging In Patients With Esophageal Cancer During Chemoradiotherapy

Objective:The primary aim of this prospective study was to investigate the value of 99mTc-methoxyisobutylisonitrile (MTBI) single photon emission computed tomography (SPECT) gated myocardial perfusion imaging (MPI) in the detection of cardiac damage as early as during concurrent chemoradiotherapy (CCRT) for esophageal cancer (EC). The second aim was to analyse the correlation between cardiac damage and the dose-volume factors.Materials and Methods:Eighteen patients with EC who received cisplatin and 5-fluorouracile based CCRT were enrolled in the study (three 3D-CRT and fifteen IMRT). The 99mTc-MIBI SPECT GMPI was performed pre-CCRT and during CCRT (40 Gray) respectively. The results of the SPECT were quantitatively analysed with QGS/QPS software and read by two experienced nuclear medicine physicians. The correlation between the changes in the SPECT parameters and the RT dosimetric data was analysed.Results:Compared with the baseline, the imaging during CCRT showed not only significant decreases in the wall motion (WM) (1/20 segments), wall thickening (WT) (2/20 segments), end-diastolic perfusion (EDP) (5/20 segments) and end-systolic perfusion (ESP) (8/20 segments) (p<0.05) but also a significant increase in the heart rate (74.63±7.79 vs 81.49±9.90, p=0.036). New myocardial perfusion defects were observed in 8 of the 18 patients. The V37-V40 was significantly higher (p<0.05) in the patients with the new perfusion defects during RT than in the patients who did not exhibit these defects.Conclusions:Concurrent chemoradiotherapy for EC induces cardiac damage from an early stage.99mTc-MIBI SPECT GMPI can detect the occurrence of cardiac impairment during CCRT. The WM, WT, EDP and ESP may be valuable as early indicators of cardiac damage. The percentage of the heart volume that receives a high dose is an important factor that is correlated with RIHD.