Study Of Radionuclide Therapy Dose Monitoring And Improvement Methods Based On Cerenkov Luminescence Imaging

Radionuclide therapy is firmly established as an effective treatment modality,short-rang particles produced by radionuclides was used to kill malignant cells in the target area.However,the normal tissues and organs are safe during the process of therapy.In view of the lack of an effective dose monitoring method for radionuclide therapy,a method of using Cerenkov luminescence imaging to monitor the radiation dose in radionuclide therapy was proposed.The Geant4 simulation kit was used to construct virtual water phantom and thyroid phantom to study the relationship between the Cerenkov photon emission and dose in radionuclide therapy.Moreover,a chest voxel model was used to study Cerenkov luminescence imaging in the breast cancer radionuclide therapy.Quantum dot was used to enhance the optical signal intensity.The major research contents are as follows:(1)The Geant4 was used to construct virtual water phantom and thyroid phantom to study the relationship between the Cerenkov emission and dose.The results show that the number of Cerenkov photons produced under different distributions has the same distribution with the dose,and there was a quantitative relationship between the Cerenkov emission and dose.Moreover,the Cerenkov emission and dose has the same distribution pattern in the thyroid phantom.(2)A chest voxel phantom was constructed to simulate the Cerenkov luminescence imaging in the breast cancer radionuclide therapy.The results show that with the increase of tumor depth the quality of the Cerenkov luminescence imaging decreases significantly,and the detection efficiency of photon was exponential decline.In the case of two tumors Cerenkov luminescence imaging indicates that the ratio of the radionuclide activity within the tumor and the intensity of Cerenkov luminescence have a certain relationship.And the Cerenkov luminescence imaging has a well resolution for irregular shape of tumor.(3)Two types of core/shell quantum dots(QDs)were used to improve the sensitivity and accuracy of Cerenkov luminescence imaging.The results show that the different kinds and emission peaks of QDs have different optimal concentrations to enhance the signal intensity of the Na131 I solution.For emission peak at 580 nm and 660 nm of Cd Se/Zn S quantum dots the optimal concentration value were 0.1 mg/ml and 0.25 mg/ml,respectively.For emission peak at 580 nm and 620 nm of Cd Te/Cd S quantum dots the optimal concentration value were 0.1 mg/ml and 0.75 mg/ml,respectively.For the same type of QDs,the fluorescence emission peaks of long QDs were more suitable than those of short QDs for the improvement of optical signal intensity...