Evaluation On Cardiac Function Effect Of Chest Radiation Therapy By SPECT Perfusion Imaging

Objective1. To evaluate if the myocardial perfusion SPECT is the sensitive,specify,veracious examination method to evaluate the effection of chest tumor radiation therapy on cardiac function or not.2. to evaluate if the myocardial perfusion spect/ct tomography fusion imaging could optimize Radiationtreatment planning,rational design field of radiation,protect the cardiac function.3. to evaluate the influence factor of chest tumor radiation therapy on cardiac function effect.Methods1. fifty caces of chest tumor from October 2009 to the December 2010 were reviewed retrospectively. Have the myocardial perfusion imaging,Myocardial Enzymes,Cardiac troponin I,ultrasonic cardiogram,electrocardiogram(ECG) test before and after radiotherapy. The comparition and study of test results proved that the myocardial perfusion SPECT is a sensitive,specify,veracious examination method to evaluate the effection of chest tumor radiation therapy on cardiac function.2. Choosing 8 cases with coronary heart disease that myocardial perfusion imaging abnormal before radiation therapy.Make the case accept Intensity Modulation Radiated Therapy(IMRT).Thansit the myocardial perfusion image and CT image to Philips Pinnacle3V9.0 planning system. Using the image fusion software to two sets of image registration method respectively different registration experiment and fuseing two sets of image. Standard method uses eye-measurement,two points- measurement,three points- measurement,four points- measurement,five points- measurement,six points- measurement. With six points- measurement as image registration standard data analysis. Analysis of the image difference between ocular estimate measurement,two points- measurement,three points- measurement,four points- measurement,five points- measurement and six points- measurement. Through the fusion image outline target area, reasonable design the method of radiation field to avoid myocardial perfusion imaging sparse and defect areas are ray, thus further protect heart function.3. Choosing 42 patients with chest tumors that myocardial perfusion imaging is normal before radiotherapy, all accept lines three-dimensional conformal or intensity-modulated radio therapy. The radiation dose in 40-70Gy.there are 18 cases that the radiation dose > 60Gy.there are 24 cases that the radiation dose≤60Gy. 28 cases with Cardiac radiation area≤50%.14 cases with Cardiac radiation area>50%.22 cases older than 60.20 cases younger than 60. analyzing the case According to factors such as the age,radiation dose,cardiac radiation area so as to observe the relationship between Chest tumor radioactive heart damage and the factors such as the age,radiation dose and cardiac radiation area.Results1. 50 cases of patients with thoracic oncology accept the myocardial perfusion SPECT test before radiation treatment:8 cases abnormal in myocardial perfusion imaging(16%).4 cases abnormal in Myocardial Enzymes(8%).5 cases abnormal in Cardiac troponin I test(10%). 5 cases abnormal in ultrasonic cardiogram(10%).4 cases abnormal in electrocardiogram test(8%). After radiotherapy of 50 cases of patients with thoracic oncology: 24cases abnormal in myocardial perfusion imaging(48%).14cases abnormal in Myocardial Enzymes(28%).18cases abnormal in Cardiac troponin I test(36%). 17cases abnormal in ultrasonic cardiogram(34%).15cases abnormal in electrocardiogram test(30%). Difference was statistically significant (P=0.00018,<0.05)Through comparing the left ventricular function parameters measured by myocardial perfusion imaging SPECT radiation and echocardiography before and after radiation treatment,found that there are no differences in Left ventricular ejection fraction and Left ventricular volume test between two test methods2. Using the image fusion software to two sets of image registration method respectively different registration experiment. The value is statistically significant difference among of the image registration using eye-measurement, two points, three points and six points methods (P < 0.05).The difference of four points , five points, six points method image registration was not statistically significant (P > 0.05). Using four points, five points, six points for image registration is better than eye-measurement, two points, three points. Through the fusion image outlining target area and reasonable special field of radiation can avoid myocardial perfusion imaging sparse and defect areas from rays, reducing the incidence of radioactive heart damage, further protect the heart function.3. 10 cases with abnormal myocardial perfusion imaging occurred in 18 cases with the radiation dose > 60Gy, accounting for 55.56% (10/18). 6 cases with abnormal myocardial perfusion imaging occurred in 24 cases with the radiation dose≤60Gy, accounting for 25%(6/24). Both are statistically significant difference (P = 0.041, < 0.05). 8 cases with abnormal myocardial perfusion imaging occurred in 28 cases with heart irradiated volume≤50%, accounting for 28.57%(8/28). 8 cases with abnormal myocardial perfusion imaging occurred in14 cases with heart irradiated volume >50%, accounting for 57.14%(8/14). Both are statistically significant difference (P=0.001,<0.05).12 cases with abnormal myocardial perfusion imaging occurred in22 cases after radiotherapy with age>60, accounting for 54.55%(10/22). 4 cases with abnormal myocardial perfusion imaging occurred in 20 cases after radiotherapy with age≤60, accounting for 20%(4/20). Both are statistically significant difference(P=0.021,<0.05). 9 cases with abnormal myocardial perfusion imaging occurred in 24 male patients after radiotherapy, accounting for 37.5% (9/24). 6 cases with abnormal myocardial perfusion imaging occurred in 18 female patients after radiotherapy, accounting for 38.9%(7/18). Both are not statistically significant difference (P=0.605, >0.05).Conclusion1. SPECT myocardial perfusion imaging is a high sensitivity, specificity , accuracy and non-invasive method for evaluating cardiac function after thoracic oncology radiotherapy.2. It was the first time that using SPECT perfusion imaging image and positioning CT sectional anatomy guide optimized radiation plan, design special field of radiation and further protect heart function.3. Chest tumor radioactive heart damage is related to the radiation dose, cardiac radiation area and the age.