Current radiopharmaceuticals最新文献

Background: Transarterial Radioembolization (TARE) is a widespread radiation therapy for unresectable hepatic lesions, but a clear understanding of the dose-response link is still missing. The aim of this preliminary study is to investigate the role of both dosimetric and clinical parameters as classifiers or predictors of response and survival for TARE in hepatic tumors and to present possible response cut-off.

Methods: 20 patients treated with glass or resin microspheres according to a personalized workflow were included. Dosimetric parameters were extracted from personalized absorbed dose maps obtained from the convolution of 90Y PET images with 90Y voxel S-values.

Results: D₉₅ ≥ 104 Gy and tumor mean absorbed dose MADt ≥ 229 Gy were found to be optimal cut-off values for complete response, while D₃₀ ≥ 180 Gy and MAD_t ≥ 117 Gy were selected as cut-off values for at least partial response and predicted better survival. Clinical parameters Alanine Transaminase (ALT) and Model for End-Stage Liver Disease (MELD) didn't show sufficient classification capability for response or survival.

Concusion: These preliminary results highlight the importance of an accurate dosimetric evaluation and suggest a cautious approach when considering clinical indicators. Dosimetric cut-off values could be a support tool in both planning and post-treatment phases. Larger multi-centric randomized trials, with standardized methods regarding patient selection, response criteria, Regions of Interest definition, dosimetric approach and activity planning are needed to confirm these promising results.

Aims: We aim to reveal an effect of residual activity leftover within the medical materials other than the empty syringe used for injection of the tracer on SUV measurements and consequently effect on possible treatment response assessment.

Background: Staging and follow-up of pediatric lymphoma patients mainly achieved by the help of PET/CT scans. It is crucial to make an optimal imaging technique for interpreting individual images and assessing treatment response.

Objective: Standardized uptake value measurement is an important quantification parameter in PET/CT scanning of childhood lymphomas. Low dose of activity used in pediatric oncology patients makes them vulnerable to small changes of input values for subsequent metabolic parameters.

Methods: Sixty-eight pediatric lymphoma patients below 50 kg were included into the study. SUVmax, SUVpeak values of the most metabolically active lesions, along with liver and mediastinum, were recorded. Metabolic parameters of the lesions/lymph nodes, mediastinum and liver parenchyma were compared before and after counts from medical materials other than empty syringe were taken into account. Wilcoxon signed-rank test was used for non-parametric paired sampled tests for the groups.

Results: There were statistically significant differences between the whole 6 above-mentioned groups confirming the importance of residual counts on metabolic parameters (p < 0.001).

Conclusion: Our study demonstrated residual radioactivity in medical materials such as serum line tubes, i.v. catheters, three-way stopcock and also butterfly needles used during intravenous injection should also be included for optimum quantitative metabolic parameter values and to minimize its the adverse effect on treatment response evaluation, especially in borderline lesions.

Radiation treatment has been advancing ever since the discovery of X-rays in 1895. The goal of radiotherapy is to shape the best isodose on the tumor volume while preserving normal tissues. There are three advantages: patient cure, organ preservation, and cost-effectiveness. Randomized trials in many various forms of cancer (including breast, prostate, and rectum) with a high degree of scientific proof confirmed radiotherapy's effectiveness and tolerance. Such accomplishments, critical to patients' quality of life, have been supported in the past. Radiopharmaceuticals were developed to diagnose and treat various disorders, including hyperthyroidism, bone discomfort, cancer of the thyroid gland, and other conditions like metastases, renal failure, and myocardial infarction and cerebral infarction perfusion. It is also possible to sterilize thermo-labile materials with a radioactive substance. This includes surgical dressings and a wide range of other medical supplies. Nuclear medicine provides various advantages, including tumor localization, safe diagnosis, no radiation buildup, and excellent treatment effectiveness. Nowadays, the field of nuclear pharmacy is focused on developing novel radioactive pharmaceutical substances that will be useful.

Background: Chlorins (dihydroporphyrins) are tetrapyrrole-based compounds that are more effective in photodynamic therapy than porphyrins. The instability of the compounds and their oxidation to porphyrin limits the use of these compounds. However, the design and synthesis of new stable chlorin-based cationic photosensitizers with the potential for use in cancer photodynamic therapy can be interesting.

Methods: In this research, new tetracationic meso substituted chlorins were designed, synthesized, and characterized. After determining the chemical structure and spectroscopic properties of five new photosensitizers, their phototoxicity on breast cancer cell lines (MCF-7) was investigated under optimized conditions in terms of factors such as photosensitizer concentrations and light intensity.

Results: The results of cytotoxicity assayed by the MTT method showed that the synthesized compounds, even up to the concentration of 50 μM had very low toxicity in the absence of light, which indicates their safety under dark conditions. Compounds A1 and A3 with the best physicochemical properties such as solubility, high absorption intensity in the effective range of photodynamic therapy, and the high quantum yield of singlet oxygen, had a good toxic effect (IC₅₀ = 0.5 μM) on the cancer cells (MCF-7) in the presence of laser light.

Conclusion: According to the obtained results, compounds A1 and A3 have the potential to continue research on PDT for confirmation and use in treatment.

Aim: In the current study, we aimed to mitigate radiation-induced small intestinal toxicity using post-irradiation treatment with nano-micelle curcumin.

Background: Small intestine is one of the most radiosensitive organs within the body. Wholebody exposure to an acute dose of ionizing radiation may lead to severe injuries to this tissue and may even cause death after some weeks.

Objective: This study aimed to evaluate histopathological changes in the small intestine following whole-body irradiation and treatment with nanocurcumin.

Materials and methods: Forty male Nordic Medical Research Institute mice were grouped into control, treatment with 100 mg/kg nano-micelle curcumin, whole-body irradiation with cobalt-60 gamma-rays (dose rate of 60 cGy/min and a single dose of 7 Gy), and treatment with 100 mg/kg nano-micelle curcumin 1 day after whole-body irradiation for 4 weeks. Afterward, all mice were sacrificed for histopathological evaluation of their small intestinal tissues.

Results: Irradiation led to severe damage to villi, crypts, glands as well as vessels, leading to bleeding. Administration of nano-micelle curcumin after whole-body irradiation showed a statistically significant improvement in radiation toxicity of the duodenum, jejunum and ileum (including a reduction in infiltration of polymorphonuclear cells, villi length shortening, goblet cells injury, Lieberkühn glands injury and bleeding). Although treatment with nano-micelle curcumin showed increased bleeding in the ileum for non-irradiated mice, its administration after irradiation was able to reduce radiation-induced bleeding in the ileum.

Conclusion: Treatment with nano-micelle curcumin may be useful for mitigation of radiationinduced gastrointestinal system toxicity via suppression of inflammatory cells' infiltration and protection against villi and crypt shortening.

In recent years, there has been an increased interest in ⁴⁴Ti/⁴⁴Sc generators as an onsite source of ⁴⁴Sc for medical applications without needing a proximal cyclotron. The relatively short half-life (3.97 hours) and high positron branching ratio (94.3%) of ⁴⁴Sc make it a viable candidate for positron emission tomography (PET) imaging. This review discusses current ⁴⁴Ti/⁴⁴Sc generator designs, focusing on their chemistry, drawbacks, post-elution processing, and relevant preclinical studies of the ⁴⁴Sc for potential PET radiopharmaceuticals.