Pharmacokinetics is an important part of pharmacology, which is guide for drug using rationally, preventing adverse reactions, studying the mechanism of action and drug-drug interaction. PET molecular imaging technology is able to dynamically monitor physiological, biochemical and biological processes in vivo, and it can be applied to the study of pharmacokinetics, tissues distribution and drug-drug interaction. All of these will promote new drug development. This paper summarizes the applications of PET molecular imaging technology to pharmacokinetics in recent years.
Programmed cell death-1 (PD-1) and its ligand (PD-L1) inhibitors can inhibit the PD-1 and PD-L1 combination to block negative control signals. This condition leadings to the activity of T lymphocytes and the enhancement of immune responses. Clinical studies have shown that PD-1/PD-L1 inhibitors have a definite effect on a broad set of malignancies, but a substantial number of patients do not respond. Predicting the immunotherapy response by evaluating the expression of PD-1 and PD-L1 is urgently needed. Molecular imaging modalities, such as PET, SPECT, optical imaging, and MRI, can noninvasively and dynamically detect the overall expression of PD-1/PD-L1 in patients. They can help in selecting patients who are suitable for immunotherapy and monitor the tumor response. This review describes the current status and progress of molecular imaging targeting PD-1/PD-L1 in tumors.
Glioma is the most common intracranial tumor, accounting for 40%–55% of brain tumor cases. The time of diagnosis affects the prognosis of patients. The application of PET imaging agents, which is a noninvasive method of diagnosis, to glioma has increased rapidly in recent years. 18F fluorothymidine (18F-FLT) is a common PET imaging agent, which is a radioactive thymidine analog and is used to evaluate cell proliferation. This imaging agent can provide more information than that from other imaging examinations and agents during and after the treatment of glioma. In this review, we mainly discuss the present research status of glioma imaging agents in the brain, including the 18F-FLT imaging mechanism; the diagnosis, classification, and identification of recurrence and necrosis; the curative effect evaluation and prognosis of glioma from 18F-FLT; and the relationship between 18F-FLT and Ki-67.
Thyroid cancer is an endocrine tumor with a rapid increase in prevalence in recent years. Human malignant tumors are closely related to environmental factors. Environmental changes can induce changes in certain pathogenic genes in the body, thus promoting the occurrence of diseases. A class of non-coding RNAs over 200 nucleotides in length, known as long non-coding RNAs(LncRNAs), has been found in human transcriptomes. LncRNAs are non-coding RNAs over 200 nucleotides in length that are involved in tumorigenesis, cell proliferation, proliferation, apoptosis, migration, and invasion by regulating gene expression. More and more studies have found that LncRNAs are closely related to thyroid cancer. Many LncRNAs have carcinogenic or tumor suppressive effects on the thyroid gland, but its function and mechanism are still unclear. This article reviews the recent research progress of LncRNAs in thyroid cancer, and provides a basis for exploring the mechanism of LncRNAs in thyroid cancer and its clinical application.
Prostate cancer is one of the most common malignancies worldwide. Many advances have been made over the past years, but the treatment of metastatic prostate cancer remains challenging. In many cases, existing therapies have become ineffective for controlling tumor progression. Thus, new approaches are urgently needed. Radioligand therapy with 177Lu-Prostate specific membrane antigen (PSMA) is an innovative and effective therapy for patients with castration-resistant metastatic prostate cancer. PSMA is expected to be a standard regimen for prostate cancer as it is well tolerated by patients and has high potential for improving overall survival.
The author reported one case of 18F-FDG imaging combined with 18F fluorothymidine（18F-FLT） in the diagnosis of primary highly differentiated hepatocellular carcinoma. The characteristics of the disease were analyzed according to clinical symptoms, laboratory examinations, and radiology. The advantages of PET/CT in the diagnosis of liver diseases were expounded, and the deficiency of 18F-FDG in the diagnosis of liver cancer was indicated. The literature on the application of 18F-FLT 11C-acetate to hepatocellular carcinoma was reviewed. This study concluded that the combined use of different imaging agents is of great value in the diagnosis of liver-occupying lesions.
Intestinal duplication is a rare congenital disease. Its clinical manifestations are nonspecific, and preoperative diagnosis is difficult. Gastrointestinal angiography, ultrasound, and CT are often used to detect this disease. A case of small intestinal duplication can be diagnosed through 99TcmO4− imaging. The advantages of this radionuclide imaging have been emphasized in literature. It can be used to diagnose intestinal duplication and help identify causes of lower gastrointestinal bleeding in children.
The author reports two cases of unilateral absent pulmonary perfusion imaging. On the basis of clinical symptoms, laboratory tests, imaging examinations, and pulmonary angiography, the patients were diagnosed with pulmonary arteritis. Pulmonary perfusion imaging can be used as a good testing tool for pulmonary arteritis and has important significance in assessing disease severity and directing further management. This tool plays an irreplaceable role in follow-up and curative effect evaluation.