Dual-isotope position emitting tomography for disease evaluation
Simultaneous dual-isotope positron emission tomography (PET) is used to improve disease evaluation. Two distinct molecular probes are simultaneously provided to the imaging target. One of the probes is labeled with a radionuclide that emits positrons to provide double coincidence events in PET. The other probe is labeled with a radionuclide that emits positrons+prompt gammas to provide triple coincidence events in PET. One of the probes is a metabolic probe, and the other probe is a selective probe that includes a ligand or antibody that is biologically responsive to receptor/antigen status. A PET system is employed that can provide simultaneous double coincidence and triple coincidence PET images. The resulting images provide simultaneous metabolic imaging and receptor/antigen imaging. Applications include disease evaluation, such as cancer staging (e.g., for breast cancer, prostate cancer, etc.).
1. A method of positron emission tomography (PET) comprising:
labeling a first probe with a first positron emitting radionuclide to provide a first labeled probe, wherein the first probe is a selective probe that includes an antibody or ligand that is biologically responsive to receptor or antigen status;
labeling a second probe with a second positron emitting radionuclide to provide a second labeled probe, wherein the second probe is a metabolic probe;
wherein one of the first and second radionuclides provides double coincidence events in PET by emission of a positron, and the other of the first and second radionuclides provides triple coincidence events in PET by emission of a positron and a gamma ray photon;
introducing the first and second labeled probes into an imaging subject simultaneously;
performing PET on the imaging subject with a PET system capable of simultaneously providing double coincidence and triple coincidence PET images;
wherein the PET system includes a detector that is responsive to the gamma ray photon, and is not responsive to photons generated by positron annihilation.
2. The method of claim 1 , wherein the first probe selectively bonds to an antigen or receptor selected from the group consisting of: human epidermal growth factor receptor 2 (HER2/neu), estrogen receptor alpha (ER-α), estrogen receptor beta (ER-β), and prostate-specific membrane antigen (PSMA).
3. The method of claim 1 , wherein the second probe is selected from the group consisting of: Fludeoxyglucose (FDG), 3′-fluoro-3′-deoxy-L-thymidine (FLT), and F-choline.
4. The method of claim 1 , wherein the first positron emitting radionuclide provides double coincidence events in PET by emission of a positron, and wherein the second positron emitting radionuclide provides triple coincidence events in PET by emission of a positron and a gamma ray photon.
5. The method of claim 1 , wherein the first positron emitting radionuclide provides triple coincidence events in PET by emission of a positron and a gamma ray photon, and wherein the second positron emitting radionuclide provides double coincidence events in PET by emission of a positron.
6. The method of claim 5 , wherein the first positron emitting radionuclide comprises 1-124, In-110, Sc-44, Ga-68, and Na-22.
7. The method of claim 5 , wherein the second positron emitting radionuclide comprises F-18, C-11, or Cu-64.
8. The method of claim 1 ,
wherein the first probe is biologically responsive to an antigen or receptor that relates to a cancer.
9. The method of claim 8 , wherein the cancer is selected from the group consisting of: breast cancer and prostate cancer.