| 1. |
- Madru, Renata, et al.
(författare)
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(68)Ga-labeled superparamagnetic iron oxide nanoparticles (SPIONs) for multi-modality PET/MR/Cherenkov luminescence imaging of sentinel lymph nodes.
- 2014
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Ingår i: American journal of nuclear medicine and molecular imaging. - 2160-8407. ; 4:1, s. 60-69
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to develop (68)Ga-SPIONs for use as a single contrast agent for dynamic, quantitative and high resolution PET/MR imaging of Sentinel Lymph Node (SLN). In addition (68)Ga enables Cherenkov light emission which can be used for optical guidance during resection of SLN. SPIONs were labeled with (68)Ga in ammonium acetate buffer, pH 5.5. The labeling yield and stability in human serum were determined using instant thin layer chromatography. An amount of 0.07-0.1 mL (~5-10 MBq, 0.13 mg Fe) of (68)Ga-SPIONs was subcutaneously injected in the hind paw of rats. The animals were imaged at 0-3 h and 25 h post injection with PET/CT, 9.4 T MR and CCDbased Cherenkov optical systems. A biodistribution study was performed by dissecting and measuring the radioactivity in lymph nodes, kidneys, spleen, liver and the injection site. The labeling yield was 97.3 ± 0.05% after 15 min and the (68)Ga-SPIONs were stable in human serum. PET, MR and Cherenkov luminescence imaging clearly visualized the SLN. Biodistribution confirmed a high uptake of the (68)Ga-SPIONs within the SLN. We conclude that generator produced (68)Ga can be labeled to SPIONs. Subcutaneously injected (68)Ga-SPIONs can enhance the identification of the SLNs by combining sensitive PET and high resolution MR imaging. Clinically, hybrid PET/MR cameras are already in use and (68)Ga-SPIONs have a great potential as a single-dose, tri-modality agent for diagnostic imaging and potential Cherenkov luminescent guided resection of SLN.
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| 2. |
- Madru, Renata, et al.
(författare)
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99mTc-Labeled Superparamagnetic Iron Oxide Nanoparticles for Multimodality SPECT/MRI of Sentinel Lymph Nodes.
- 2012
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 53:3, s. 459-463
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to develop multimodality SPECT/MRI contrast agents for sentinel lymph node (SLN) mapping in vivo. METHODS: Nanoparticles with a solid iron oxide core and a polyethylene glycol coating were labeled with (99m)Tc. The labeling efficiency was determined with instant thin-layer chromatography and magnetic separation. The stability of the radiolabeled superparamagnetic iron oxide nanoparticles (SPIONs) was verified in both sterile water and human serum at room temperature 6 and 24 h after labeling. Five Wistar rats were injected subcutaneously in the right hind paw with (99m)Tc-SPIONs (25-50 MBq, ∼0.2 mg of Fe) and sacrificed 4 h after injection. Two animals were imaged with SPECT/MRI. All 5 rats were dissected; the lymph nodes, liver, kidneys, spleen, and hind paw containing the injection site were removed and weighed; and activity in the samples was measured. The microdistribution within the lymph nodes was studied with digital autoradiography. RESULTS: The efficiency of labeling of the SPIONs was 99% 6 h after labeling in both water and human serum. The labeling yield was 98% in water and 97% in human serum 24 h after labeling. The SLN could be identified in vivo with SPECT/MRI. The accumulation of (99m)Tc-SPIONs (as the percentage injected dose/g [%ID/g]) in the SLN was 100 %ID/g, whereas in the liver and spleen it was less than 2 %ID/g. Digital autoradiography images revealed a nonhomogeneous distribution of (99m)Tc-SPIONs within the lymph nodes; nanoparticles were found in the cortical, subcapsular, and medullary sinuses. CONCLUSION: This study revealed the feasibility of labeling SPIONs with (99m)Tc. The accumulation of (99m)Tc-SPIONs in lymph nodes after subcutaneous injection in animals, verified by SPECT/MRI, is encouraging for applications in breast cancer and malignant melanoma.
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| 3. |
- Madru, Renata, et al.
(författare)
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Development of a Hybrid Nanoprobe for Triple-Modality MR/SPECT/Optical Fluorescence Imaging
- 2014
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Ingår i: Diagnostics. - : MDPI AG. - 2075-4418. ; 4:1, s. 13-26
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Tidskriftsartikel (refereegranskat)abstract
- Hybrid clinical imaging is an emerging technology, which improves disease diagnosis by combining already existing technologies. With the combination of high-resolution morphological imaging, i.e., MRI/CT, and high-sensitive molecular detection offered by SPECT/PET/Optical, physicians can detect disease progression at an early stage and design patient-specific treatments. To fully exploit the possibilities of hybrid imaging a hybrid probe compatible with each imaging technology is required. Here, we present a hybrid nanoprobe for triple modality MR/SPECT/Fluorescence imaging. Our imaging agent is comprised of superparamagnetic iron oxide nanoparticles (SPIONs), labeled with 99mTc and an Alexa fluorophore (AF), together forming 99mTc-AF-SPIONs. The agent was stable in human serum, and, after subcutaneous injection in the hind paw of Wistar rats, showed to be highly specific by accumulating in the sentinel lymph node. All three modalities clearly visualized the imaging agent. Our results show that a single imaging agent can be used for hybrid imaging. The use of a single hybrid contrast agent permits simultaneous hybrid imaging and, more conventionally, allow for single modality imaging at different time points. For example, a hybrid contrast agent enables pre-operative planning, intra-operative guidance, and post-operative evaluation with the same contrast agent.Keywords: SPION, SPECT, optical, fluorescence imaging, magnetic resonance imaging, MR, SLN
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| 4. |
- Madru, Renata, et al.
(författare)
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Simultaneous Preclinical Positron Emission Tomography-Magnetic Resonance Imaging Study of Lymphatic Drainage of Chelator-Free Cu-Labeled Nanoparticles
- 2018
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Ingår i: Cancer Biotherapy & Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 33:6, s. 213-220
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hybrid positron emission tomography (PET)-magnetic resonance imaging (MRI) systems have been taken in use as new clinical diagnostic tools including detection and therapy planning of cancer. To reduce the amount of contrast agents injected in patients while fully benefitting both modalities, dual-modality probes are required.MATERIAL AND METHODS: This study was first aimed at developing a hybrid PET-MRI probe by labeling superparamagnetic iron oxide nanoparticles (SPIONs) with 64Cu using a fast and chelator-free conjugation method, and second, to demonstrate the ability of the agent to target sentinel lymph nodes (SLNs) in vivo using simultaneous PET-MRI imaging.RESULTS: High labeling efficiency of 97% produced within 10-15 min was demonstrated at room temperature. 64Cu-SPIONs were chemically stable in mouse serum for 24 h and after intradermal injection in the hind paw of C57BL/6J mice, demonstrated specific accumulation in the SLN. Simultaneous PET-MRI clearly demonstrated visualization of 64Cu-SPIONs, in dynamic and static imaging sequences up to 24 h after administration.CONCLUSION: The use of a single hybrid probe and simultaneous hybrid imaging provides an efficient, complementary integration of quantitation and is expected to improve preoperative planning and intraoperative guidance of cancer treatments.
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| 5. |
- Madru, Renata
(författare)
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Superparamagnetic iron oxide nanoparticles (SPIONs) as a multimodality imaging probe for sentinel nodes : Design and Preclinical Evaluation
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Breast cancer and malignant melanoma disseminate through the lymphatic system and the first metastases arise in one or two regional, sentinel lymph nodes (SLNs) draining the primary tumour site. Therefore, identification and characterization of the SLNs is of major importance for cancer staging and for choice of therapy in patients. The standard clinical procedure relies on lymphoscintigraphy after intradermal injection of radiolabelled colloids (such as 99mTc-Nanocolloid in Europe) and blue dye to identify the SLNs intra-operatively. Resected SLN-biopsies are then sent for histopathological analysis. This technique, however, is limited by the non-specificity of the tracer, lack of anatomical structures as reference in scintigraphic images, and involves a tight schedule between surgery and pathological examination. In Papers I and II, we propose a new generation tracers (probes) based on superparamagnetic iron oxide nanoparticles (SPIONs) radiolabelled with Tc-99m and Cy 5.5 Alexa Fluor. SPIONs have the great advantage to be produced within a narrow size distribution (20-50 nm) optimal for transport via lymphatic vessels and accumulate in SLNs. Owing to their large surface-to-volume ratio and biocompatible coating; a high radiolabelling yield was demonstrated. After subcutaneous injection of the probe in the hind paw of Wistar rats, 99mTc-SPION-Cy 5.5 the SLNs were easily identified SPECT-MRI and optical imaging modalities. In Paper III and V, a fast one-step radiolabelling method was developed to conjugate 68Ga-SPIONs and 64Cu-SPIONs for positron emission tomography (PET), MRI, and Cherenkov luminescence imaging (CLI) of SLNs. After administration of the probes as in the previous papers in rats and mice, quantitative PET and MRI images were acquired simultaneously. The images clearly depicted the SLNs. A benefit of CLI is that they enable intra-operative optical imaging without the use of toxic fluorophores. In Paper IV non-homogeneous activity distribution in SLN was demonstrated by using digital autoradiography images (DARG), and together with data acquired from biodistribution of the agents in rats from Paper I-III and V, the absorbed doses were calculated for the different radionuclides. It has been shown that the common approach of medical intern radiation doses, MIRD, assuming a homogenous activity distribution it may underestimate the absorbed dose in some regions in SLN.
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