18F－MyoZone的标记工艺影响因素及在正常猪的心肌

Factors for the synthesis of 18F-MyoZone and myocardial tomography in normal swine

的研究18F－MyoZone标记工艺的影响因素，并以中华小型猪为对象，评价其用于心肌灌注显像的性能。方法采用18F－F－取代OTs前体的方法制备18F－MyoZone，通过改变K2CO3或标记前体用量、反应时间、反应温度等条件，研究影响标记的因素，并在正常中华小型猪中行5、30、60和120 min心肌断层显像。结果K2CO3用量、前体用量、反应温度及反应时间均能影响18F－MyoZone的标记率，以K2CO3影响最为显著。最优条件为1.0 mg K2CO3、2.0 mg mpp2－OTs、90 ℃反应20 min。此条件下18F－MyoZone的总制备时间为60 min，未校正的放射化学产率为（24.0±5.1）%，放化纯〉98%。PET显像结果显示，18F－MyoZone在心肌中有很高的初始摄取（注射后5 min SUV为8.17±1.83）和较好的滞留（注射后120 min SUV为5.78±0.99）。18F－MyoZone在肝中清除很快，注射后5、30、60和120 min的心/肝比值分别为3.32、5.31、6.09和5.76。从注射后5～120 min，心肌轮廓始终清晰可见，周围器官组织几乎无干扰，图像质量佳。结论18F－MyoZone具有良好的心肌灌注显像性能，其制备过程中应特别注意K2CO3的用量。

ObjectiveTo study the factors affecting the synthesis of 18F-MyoZone, and to evaluate its potential as a myocardial perfusion imaging （MPI） agent in normal Chinese mini-swine.Methods18F-MyoZone was prepared by substituting the leaving group toluenesulfonyloxy （OTs） from the precursor compound with 18F-fluoride （18F-F-）. The conditions affecting the labeling yield were studied by varying the amount of K2CO3 and precursor compound, 18F-fluorination reaction time and temperature. PET was performed at 5, 30, 60 and 120 min post-injection on normal Chinese mini-swine.ResultsThe doses of K2CO3 and precursor, the reaction time and the reaction temperature could affect the labeling yield of 18F-MyoZone, especially K2CO3. The optimized synthetic condition was 1.0 mg K2CO3,2.0 mg mpp2-OTs, 20 min reaction time at 90 ℃. The total radio-synthesis time in this condition was 60 min. The uncorrected radiochemical yield was （24.0±5.1）%. The radiochemical purity was 〉98%. PET imaging showed that 18F-MyoZone had high initial uptake （SUV=8.17±1.83 at 5 min post-injection） and good retention （SUV=5.78±0.99 at 120 min post-injection） in the heart. The clearance of 18F-MyoZone from liver was very fast. The heart/liver ratios were 3.32, 5.31, 6.09 and 5.76 at 5, 30, 60 and 120 min post-injection, respectively. From 5 to 120 min post-injection, the outline of heart was clear and intact. There was almost no interference from the adjacent organs. The quality of PET images was highly satisfactory.Conclusions18F-MyoZone has the potential to be a good myocardial perfusion agent. The amount of K2CO3 used could significantly affect the labeling yield of 18F-MyoZone.