Current radiopharmaceuticals最新文献

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.

Introduction: Pulmonary embolism (PE) can be diagnosed by perfusion lung scintigraphy using human albumin macroaggregates labelled ^99mTc (^99mTc-MAA). When PE is suspected, subcutaneous Low Molecular Weight Heparin (LMWH) should be administered even before the results of the PE diagnostic flowchart. In our study, we aimed to evaluate a possible interaction (in vitro interference) between ^99mTc-MAA and LMWH.

Methods: The reconstitution of MAA kit was performed according to the manufacturer's instruction. After labelling, we carried out the following preparations: a standard dose of ^99mTc-MAA alone, as control; ^99mTc-MAA and enoxaparin at different ratios. According to the manufacturer's instruction, the radiochemical purity was performed and evaluated immediately (T₀), after 15 and 30 minutes after incubation (T₁₅ and T₃₀).

Results: We compared the radiochemical purity of ^99mTc-MAA with: (i) radiochemical purity of ^99mTc-MAA and enoxaparin (11 ratio), (ii) radiochemical purity of ^99mTc-MAA and enoxaparin (0.5 ratio), and (iii) radiochemical purity of ^99mTc-MAA and enoxaparin (ratio 2). No significant differences were found between all the measured parameters at each time point for each ratio. We also tested the stability of ^99mTc-MAA in physiological conditions (at 37°C in PBS): the initial radiochemical purity of ^99mTc-MAA was 99.78%. The values of 99mTc-MAA radiochemical purity were high in all conditions of possible interaction with LMWH, with values ranging from 98.00% at T0 to 95% at T₃₀.

Conclusion: We found no statistically significant change in the in vitro stability of ^99mTc-MAA in the presence of enoxaparin, excluding a possible direct interference. Future studies will be needed to check the ^99mTc-MAA stability under physiological conditions.

Aims: The aim of this retrospective study was to investigate SUVs variability with respect to lesion size, administered dose, and reconstruction algorithm.

Background: SUV_max and SUV_peak are influenced by technical factors as count statistics and reconstruction algorithms.

Objective: To fulfill the aim, we evaluated the SUVs variability with respect to lesion size, administered dose, and reconstruction algorithm (ordered - subset expectation _maximization plus point spread function option - OSEM+PSF, regularized Bayesian Penalized Likelihood - BPL) in a 5 - rings BGO PET/CT scanner.

Methods: Discovery IQ scanner (GE Healthcare, Milwaukee, Wisconsin, US) was used for list mode acquisition of 25 FDG patients, 12 injected with 3.7 MBq/kg (Standard Dose protocol - SD) and 13 injected with 1.8 MBq/kg (Low Dose protocol - LD). Each acquisition was reconstructed at different time/FOV with both OSEM+PSF algorithm and BPL using seven different beta factors. SUVs were calculated in 70 lesions and analysed in function of time/FOV and Beta. Image quality was evaluated as a coefficient of variation of the liver (CV - liver).

Results: SUVs were not considerably affected by time/FOV. However, SUVs were influenced by beta: differences were higher in small lesions (37% for SUV_max, 15% for SUV_peak) compared to larger ones (14% and 6%). CV - liver ranged from 6% with Beta-500 (LD and SD) to 13% with Beta- 200 (LD). CV - liver of BPL with Beta-350 (optimized for clinical practice in our institution) in LD was lower than CV - liver of OSEM+PSF in SD.

Conclusion: When a high sensitivity 5 - rings BGO PET/CT scanner is used with the same reconstruction algorithm, quantification by means of SUV_max and SUV_peak is a robust standard compared to the activity and scan duration. However, both SUVs and image quality are influenced by reconstruction algorithms and the related parameters should be considered to obtain the best compromise between detectability, quantification, and noise.