What Is Radiopharmacy?

Radiopharmaceuticals must comply with the pharmacopoeia like general drugs, such as sterility, no pyrogen, and low chemical toxicity.

PET

Radiopharmaceutical (radio pharmaceutical) refers to a special class of drugs containing radionuclides for medical diagnosis and treatment. Radionuclide-labeled compounds or biological agents for medical diagnosis or treatment in the body.

Radiopharmaceutical requirements

Radiopharmaceuticals must comply with the pharmacopoeia like general drugs, such as sterility, no pyrogen, and low chemical toxicity.

PET

There should be certain requirements for the type, energy and radioactive half-life of the nuclear radiation it emits according to the needs of diagnosis and treatment.

Radiopharmaceutical Classification

Radiopharmaceuticals

Diagnostic drugs are mainly 99mTc labeled compounds, accounting for more than 80% of nuclear medicine diagnostic drugs, followed by

99Tcm-TRADOT-1

Nucleotide-labeled compounds such as 201Tl, 67Ga, 123I, 75Se, 51Cr, and 113mIn, etc., are recorded in vivo by the in vitro monitoring gamma-ray device. The therapeutic drug is to provide radioactive irradiation to the internal organs of the patient, and there are nuclides labeled compounds such as 131I, 32P, 198Au, 186Re. Today's medical radionuclides are mainly produced by reactors and accelerators, and some can be obtained through radionuclide generators and nuclear fuel reprocessing.

photons (the energy is preferably 100-300keV) in nuclear rays have strong penetrating power, and can be easily detected by nuclear medicine detection instruments after being introduced into the body

99mTc-MIBI myocardial blood flow perfusion imaging

Detected in vitro, so it is suitable for imaging; at the same time, photons have a low ionization density in the tissue, so that the body is less damaged by ionizing radiation. Therefore, diagnostic radioactive drugs mostly use nuclides and their markers that emit photons. .

99Tcm-labeled radiopharmaceutical 99Tcm has excellent nuclear performance, is a pure gamma photon emitter with an energy of 140keV and a T1 / 2 of 6.02h. It is easy to obtain and can be used for morphological and functional imaging of almost all important organs of the human body. 99Tcm is the most commonly used radionuclide in imaging examination. At present, 99Tcm and its labeled compounds account for more than 80% of imaging drugs used worldwide. It is widely used in heart, brain, kidney, bone, lung, thyroid, etc. Examination of various organ diseases, and most of them are already provided with matching kits.

2. 131I, 201Tl, 67Ga, 111In, 123I and other radionuclides and their labeled drugs such as gamma photon nuclides and their labeled drugs also have more applications, and play their own characteristics and roles in clinical.

3 Positron radiopharmaceuticals such as 11C, 13N, 15O, and 18F (Table 1-2) have unique advantages in studying human physiology, biochemistry, metabolism, and receptors. Among them, fluorine [18F] deoxyglucose (18F -FDG) is currently the most widely used positron radioactive drug.

Radiopharmaceutical therapy

Appropriate radiation energy and range in the tissue are the basic guarantees for selective and concentrated irradiation of diseased tissues to avoid damage to normal tissues and to obtain the expected therapeutic effect. The physical and chemical properties of various commonly used therapeutic radiopharmaceuticals are shown in Table 1-3.

Radiotherapy drugs that emit pure beta-rays 32P, 89Sr, 90Y, etc.

Radioactive therapeutic drugs 131I, 153Sm, 188Re, 117mSn, 117Lu, etc. with -rays when emitting -rays

131I is still the most commonly used radiopharmaceutical for the treatment of thyroid diseases; radiopharmaceuticals such as 89SrCl2, 153Sm-EDTMP, 117Snm-DTPA, and 177Lu-EDTMP have also achieved satisfactory results in the pain relief treatment of bone metastases. In recent years by 1

Treatment of radiopharmaceuticals into the body

The 88W-188Re generator received 188Re as a therapeutic radiopharmaceutical, and its -ray energy was 2.12 MeV; its gamma-ray energy was 155keV, and T1 / 2 was 16.9h. The biological effect of ionizing radiation produced by the emission of -rays destroys the diseased tissue, and the -rays emitted by it can be used for imaging, the internal radiation absorbed dose is estimated, and the change of the lesion range before and after treatment is evaluated. At present, 188Re-HEDP has been used to treat bone pain of malignant tumors with bone metastases, 188ReO4- to treat or prevent restenosis after angioplasty, and 188Re-lipiodol interventional treatment of liver cancer.

Development status of radiopharmaceuticals

Radiopharmaceutical single photon

Development status of single photon radiopharmaceuticals:

Since 1985, the development and synthesis of 99mTc-labeled radiopharmaceuticals, such as 99mTc-sestamibi, 99mTc-ECD, 99mTc-DTPA, etc. have become common imaging of myocardial perfusion imaging, cerebral blood flow perfusion imaging and renal dynamic imaging. In addition, a batch of new radiopharmaceuticals such as 99mTc-N (NOEt) 2, 99mTc-HL91, 99mTc-TRADOT-1 are also about to be used in the clinic.

Radiopharmaceutical positron

Development status of positron radiopharmaceuticals:

In the 1980s, the Institute of Isotope of the Chinese Academy of Atomic Energy produced 18F using a reactor and artificially synthesized 18F-FDG.

FDG

Due to insufficient production volume and no corresponding clinical imaging device in China, the drug has not been used in the clinic. At the end of the 1980s, the institute introduced a proton accelerator from the Belgian IBA company, but did not introduce a PET scanner, so it has not been able to produce positron medicines. The clinical application of 18F-FDG did not begin until the China-Japan Friendship Hospital adopted a domestic second-ring PET. . In the early 1990s, several hospitals in Beijing had applied for the establishment of PET centers, but failed. In 1995, Shandong Zibo Wanjie Hospital introduced a complete set of equipment from GE and began the production and application of positron medicines in the true sense of China. However, the equipment only produced two positron medicines, 18F-FDG and 13N-NH + 4. The Shanghai Institute of Applied Physics, Chinese Academy of Sciences also introduced IBA accelerators and synthesizers to provide 18F-FDG drugs for PET introduced by the hospital. In the late 1990s, Beijing, Shanghai, and Guangzhou successively introduced small proton accelerators to produce 18F-FDG for clinical use. At the first high-energy positron conference held in Beijing in 2000, only 18F-FDG and 13N-NH + 4 were reported; until the second high-energy positron conference held in Shanghai in 2002, 11C-Raclopride and 11C-choline and other drugs are reported. Since then, domestic research and clinical applications of positron drugs have continued to increase, and their types have exceeded 20