Current radiopharmaceuticals最新文献

Angiogenesis phenomenon, as a highly affecting factor on the growth and spread of cancer cells, depends on specific molecular interactions between components of the extracellular matrix and vascular cells. αv integrin acts as a cell adhesive molecule involved in tumor invasion and angiogenesis. Among the various combinations of integrin subunits expressed on the surface of cells, α_vβ₃ integrin has a particularly interesting expression pattern during angiogenesis. The α_vβ₃ integrin is a vital receptor affecting tumor growth, tumor invasiveness, metastasis, and angiogenesis overexpressed on various human tumors, leading to the development of different theranostics probes and radiopharmaceuticals. The α_vβ₃ integrin can recognize several extracellular matrix molecules in the base of the RGD adhesive sequence. This review provides an overview of the status, trends and future of the most studied α_vβ₃ integrin-binding ligand, RGD tripeptides, labeled with various radioisotopes. An overview of the pre-clinical models for radiolabeled RGD peptides and clinical aspects of the RGD- based radiopharmaceuticals is provided with some new considerations and ways forward.

Background: Despite substantial research, the mechanisms behind stress Tako-tsubo cardiomyopathy (TTC) remain rather elusive.

Objective: The purpose of this paper was to provide a detailed review of the mainstream factors underlying the pathophysiology of TTC, highlighting the novel contributions of molecular pathology and in-vivo molecular imaging.

Methods: A careful literature review selected all papers discussing TTC, specifically those providing novel insights from myocardial pathology and cardiac molecular imaging.

Results: Results concerning myocardial pathology, defect extension, sites and relationships between functional parameters underline the existence of a causal relationship between a determinant (e.g., the release of catecholamines induced by stress) and an outcome for TTC, which is not limited to a reversible contractile cardiomyopathy, but it includes reversible changes in myocardial perfusion and a long-lasting residual deficit in sympathetic function. Besides, they reinforce the hypothesis that sympathetic nerves may exert a complex control on cardiac contractile function, which is likely to be direct or indirect through metabolism and microvascular perfusion changes during anaerobic and aerobic conditions.

Conclusion: TTC is characterized by acute transient left ventricular systolic dysfunction, which can be challenging to distinguish from myocardial infarction at presentation. Catecholamineinduced myocardial injury is the most established theory, but other factors, including myocardial metabolism and perfusion, should be considered of utmost importance. Each effort to clarify the numerous pathways and emerging abnormalities may provide novel approaches to treat the acute episode, avoid recurrences, and prevent major adverse cardiovascular events.

Introduction: This study aimed to determine the critical organ doses in ²²³Ra, ⁸⁹Sr, ¹⁵³Sm, and ³²P treatments via dosimetry using the phantoms.

Material and methods: The OpenDose was used to calculate S values (mGy MBq^-1s^-1) for bone surface, red bone marrow, urinary bladder wall, testes, ovaries, uterus, and kidneys using male (ICRP110AM) and female (ICRP110AF) phantoms. The cortical thoracic spine was modeled as metastasis. Moreover, the absorbed doses were computed via MIRD formalism according to the activities of 3.3, 148, 2220, and 370 MBq for ICRP110AM and 4.015, 148, 2701, and 370 MBq for ICRP110AF in ²²³Ra, ⁸⁹Sr, ¹⁵³Sm, and ³²P treatments, respectively.

Results: Whilst the maximum bone surface doses were found as 1.22E+02 and 8.51E+01 mGy at ³²P treatment, the minimum bone surface doses were calculated as 8.42E-02 and 8.26E-02 mGy at ²²³Ra. In terms of the comparison of red bone marrow, urinary bladder wall, and kidney doses, ¹⁵³Sm and ⁸⁹Sr treatments showed maximum doses of 2.45E-03, 1.50E-03, 3.23E-07, 5.45E-06, 1.20E-01, 1.49E-01 mGy and the minimum doses with 3.46E-05, 1.99E-05, 6.33E-09, 8.77E-09, 1.19E-04, 1.15E-04 mGy, respectively. The maximum testes and ovaries-uterus doses were found as 6.17E-08, 7.40E-06, 3.46E-07 mGy in ¹⁵³Sm treatment, and minimum testes and ovaries doses as 1.70E-09, 1.34E-07 mGy in ²²³Ra. The minimum uterus dose with 7.03E-09 mGy was determined in ⁸⁹Sr treatment.

Conclusion: It is observed that ²²³Ra produces low critical organ doses in the treatment of painful bone metastasis. Among the beta-emitting radionuclides, ⁸⁹Sr stands out by showing optimal dosimetric results.

Nuclear medicine specialty involves the administration of unsealed radioactive substances to patients to allow specific diagnostics and treatments using radiopharmaceuticals, radiotracers, and materials. Developing a radiopharmaceutical must involve considering and addressing some limitations such as its retention by unintended organs, which can influence patient and worker safety, imaging findings, and diagnostic and therapeutic accuracy. This paper presents data on the changing biodistribution, localization, stability, and accuracy patterns of radiopharmaceuticals by liposome encapsulation.

Methods: Data are presented for 5 male New Zealand white rabbits. They were injected intravenously with the ^99mTc-liposomes encapsulated MIBI through a marginal ear vein, and whole-body images were acquired using a dual-head gamma camera. Cationic PEGylated liposomes were prepared using the conventional thin-film-hydration method. The liposomes were tested for particle size, zeta potential, high-performance-liquid-chromatography (HPLC), and toxicity.

Results: The liver activity was slightly greater than or equivalent to heart uptake, using ^99mTcsestamibi, MIBI, without liposome as a reference. The absorbed doses in myocardium cells after injecting rabbits with ^99mTc-MIBI labeled with free positive lower pH liposomes was greater than in the liver, whereas ^99mTc labeled with encapsulated MIBI within positive liposomes showed a significantly higher heart-to-liver ratio. The heart-to-spleen activity uptake ratio in ^99mTc-MIBI was higher than or equal to one but increased in ^99mTc labeled with MIBI and free positive liposomes. Injecting rabbits with ^99mTc labeled with encapsulated MIBI raised myocardium uptake to 2-4 times more than the spleen. Heart-to-bowel activity began to rise with 99m Tc-labeld-MIBI and liposomes.

Conclusion: This study provides findings in radiopharmaceutical biodistribution using liposomal agents. Adding free liposomes using a pH gradient technique enhanced the uptake and localization of the radiotracer. However, tracer encapsulation during the formation of the liposomes showed even better specificity.

Background: During the development of novel Re-188 radiopharmaceuticals, it was discovered that no calibration settings were published to calibrate Re-188 on the Capintec CRC-25PET dose calibrator.

Methods: Sodium [¹⁸⁸Re]perrhenate was eluted from an OncoBeta ¹⁸⁸W/¹⁸⁸Re generator to measure activity on a Capintec CRC-25R dose calibrator using established dose calibrator settings provided by the manufacturer. The eluent was then used to tune the calibra on settings on a Capintec CRC-25PET dose calibrator, accounting for geometry. Radionuclidic purity of the [¹⁸⁸Re]perrhenate source was verified via gamma spectroscopy.

Results: The calibrator number for Re-188 was determined to be 469 x 10 for the Capintec CRC-25PET dose calibrator, which differed from the manufacturer provided calibra on number of 496 x 10 for the Capintec CRC-25R dose calibra on model. W-188 breakthrough was characterised as < 0.01%.

Conclusion: This previously unreported calibration number can be used to determine the activity of Re- 188 labelled radiopharmaceuticals using the Capintec CRC-25PET dose calibrator model.

Background: Myelosuppression is common and threatening during tumor treatment. However, the effect of radiation on bone marrow activity, especially leukocyte count, has been underestimated in cervical cancer. The aim of this study was to evaluate the severity of radiotherapy- induced acute leukopenia and its relationship with intestinal toxicity.

Methods: The clinical data of 59 patients who underwent conventional radiation alone for cervical cancer were retrospectively analyzed. The patients had normal leukocyte count on admission, and the blood cell count, gross tumor volume (GTV) dose, and intestinal toxicity were evaluated.

Results: During radiotherapy (RT), 47 patients (79.7%) developed into leukopenia, with 38.3% mild and 61.7% moderate. The mean time for leukopenia was 9 days. Compared with leukopenianegative patients, leukopenia-positive ones had lower baseline leukocyte count, while neutrophil/ lymphocyte (NLR) and monocyte/lymphocyte (MLR) showed no significance. Logistic regression analysis indicated that excluding the factors for age, body mass index (BMI), TNM stage, surgery and GTV dose, baseline leukocyte count was an important independent predictor of leukopenia (OR=0.383). During RT, a significant reduction was found in leukocyte, neutrophil and lymphocyte count at week 2 while monocyte count after 2 weeks. Furthermore, NLR and MLR showed a significant and sustained upward trend. About 54.2% of patients had gastrointestinal symptoms. However, no significant relevance was noted between leukocyte count as well as NLR/MLR and intestinal toxicity, indicating leukopenia may not be the main factor causing and aggravating gastrointestinal reaction in cervical cancer.

Conclusion: Our results suggest the underrated high prevalence and severity of leukopenia in cervical cancer patients receiving RT, and those with low baseline leukocyte count are more likely for leukopenia, for whom early prevention of infection may be needed during RT.

Introduction: F18 and Ga68 radioisotopes are used in PET imaging for prostate cancer. It was aimed to calculate the prostate, testicle and bladder effective doses (ED) caused by F18 and Ga68 used in prostate cancer imaging with PET/CT via simulation with the GATE toolkit and evaluate the ED in terms of fertility.

Methods: The prostate, testicle and bladder were defined together with their geometric properties and densities in GATE simulation. F18 and Ga68 with activity of 277.5 MBq and 151.7 MBq were identified in the prostate as a source organ. The ED, uncertainties, and S values were taken as an output file in the TXT format with the DoseActors command. S values were used for validation of the simulation.

Results: The ED of the prostate, total testicle and bladder for F18 were found to be 6.627E-04 ± 1.799E-06, 12.74E-07 ± 4.11E-08 and 1.617E-05 ± 4.317E-09 (Gy/s), respectively. The ED of the prostate, total testicle, and bladder for Ga68 were found to be 9.195E-04 ± 2.660E-06, 6.54E-07 ± 2.93E-08 and 4.290E-05 ± 6.936E-09 (Gy/s), respectively.

Conclusion: It was found that Ga68 produced high prostate and bladder ED, and F18 produced high testicular ED. In terms of male fertility, Ga68 seems to be a good alternative because it produces low testicular doses. The ED of the testicle both F18 and Ga68 were below the reported spermatogonia and azoospermia dose.

Background: HYNIC-Bombesin (BBN) is a potential peptide for targeted radionuclide therapy in gastrin-releasing peptide receptor (GRPr)-positive malignancies. The ¹⁸⁸Re-HYNICBBN is a promising radiopharmaceutical for use in prostate cancer therapy.

Objective: The aim of this study was to estimate the absorbed dose due to ¹⁸⁸Re-HYNIC-BBN radio-complex in human organs based on bio-distribution data of rats.

Methods: In this research, using bio-distribution data of ¹⁸⁸Re-HYNIC-BBN in rats, its radiation absorbed dose of the adult human was calculated for different organs based on the MIRD dose calculation method.

Results: A considerable equivalent dose amount of ¹⁸⁸Re-Hynic-BBN (0.093 mGy/MBq) was accumulated in the prostate. Moreover, all other tissues except for the kidneys and pancreas approximately received insignificant absorbed doses.

Conclusion: Since the acceptable absorbed dose for the complex was observed in the prostate, ¹⁸⁸Re-Hynic-Bombesin can be regarded as a new potential agent for prostate cancer therapy.

Background: In recent years, there has been a significant increase in studies investigating the potential use of plant-origin products in the treatment and diagnosis of different types of cancer.

Methods: In this study, Estragole (EST) was isolated from basil leaves via ethanolic extraction using an 80% ethanol concentration. The isolation process was performed using the High Performance Liquid Chromatography (HPLC) method. The EST isolated from the basil plant was radiolabeled with ¹³¹I using the iodogen method. Quality control studies of the radiolabeled EST (¹³¹IEST) were carried out by using Thin Layer Radio Chromatography (TLRC). Next, in vitro cell, culture studies were done to investigate the bio-affinity of plant-originated EST labeled with ¹³¹I on human medulloblastoma (DAOY) and human glioblastoma-astrocytoma (U-87 MG) cell lines. Finally, the cytotoxicity of EST was determined, and cell uptake of ¹³¹I-EST was investigated on cancer cell lines by incorporation studies.

Results: As a result of these studies, it has been shown that ¹³¹I-EST has a significant uptake on the brain cells.

Conclusion: This result is very satisfying, and it has encouraged us to do in vivo studies for the molecule in the future.

The use of the one-of-a-kind qualities possessed by substances at the nanoscale is the core concept of nanotechnology. Nanotechnology has become increasingly popular in various business sectors because it enables better construction and more advanced product design. Nanomedicine is the name given to the application of nanotechnology in the medical and healthcare fields. It has been used to fight against some of the most prevalent diseases, such as cancer and cardiovascular diseases. This current manuscript provides an overview of the recent advancements in nanotechnology in drug delivery and imaging.