• Proceedings of the PSK Conference
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• 2003.04a
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• pp.156.2-157
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• 2003

166Ho-chitosan complex (HC) is a new radiopharmaceutical approved in Korea for liver cancer. In these studies, therapeutic effect against prostate cancer and biodistribution of HC were evaluated in animal models using the technique of intraprostatic administration. For evaluation of the therapeutic effect, noble rats with AIT orthotopic or subcutaneous prostate cancer were used. (omitted)

• Journal of Radiation Industry
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• v.17 no.4
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• pp.417-425
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• 2023

Lutetium(¹⁷⁷Lu), with its theranostic properties, is one of the most widely used radioisotopes and has a large share of the radiopharmaceutical market due to its many applications and targeted therapeutic research using lutetium-based radiopharmaceuticals. However, lutetium-based radiopharmaceuticals currently approved by the US Food and Drug Administration (FDA) are limited to the indications of gastrointestinal cancer, pancreatic neuroendocrine cancer and metastatic castration-resistant prostate cancer. To overcome these limitations, we aimed to demonstrate the feasibility of expanding the use of lutetium-based radiopharmaceuticals by verifying the availability and therapeutic efficacy of lutetium produced in a research reactor(HANARO). In this study, we confirmed the therapeutic efficacy of lutetium by using cancer cells from different types of cancer. In addition, we selected cancer biomarkers based on characteristics common to various cancer cells and compared and evaluated the therapeutic efficacy of lutetium by regulating the expression of target genes. The results showed that modulation of cancer biomarker gene expression resulted in higher therapeutic efficacy compared to lutetium alone. In conclusion, this study verified the potential use and therapeutic efficacy of lutetium based on the production of a research reactor (HANARO), providing fundamental evidence for the development of lutetium-based radiopharmaceuticals and the expansion of their indications.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.120-128
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• 2019

Radiopharmaceuticals include therapeutic radiopharmaceuticals and diagnostic radiopharmaceuticals. Therapeutic radiopharmaceuticals are administered to the body and ingested at specific organs to detect radiation emitted from the site and to construct an image to diagnose the disease. Diagnostic radiopharmaceuticals are used to treat diseases by killing cells with radiation emitted from radiopharmaceuticals, such as cancer cells, vascular endothelial cells, arthritis, and Alzheimer's disease. The application possibilities of terahertz imaging technology for the combination of radiopharmaceuticals and molecular imaging medicine are discussed and experimental methods are presented. Terahertz imaging is expected to be a powerful technique because of the effective piercing feasibility, which enables to perform safe and high resolutive imaging. To investigate the response of cell to the terahertz wave, both the pulsed and CW THz wave systems are employed. THz imaging of a rat's paraffin-embedded epithelial cell with tumor is studied in advance.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.8 no.2
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• pp.157-166
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• 2022

Targeted alpha therapy began to be applied to the treatment of late-stage cancer patients because of its dramatic therapeutic efficacy in patients who have no responses with beta-emitting radiopharmaceuticals. However, its strong cytotoxicity may cause side effects due to undesirable uptake in non-target tissues. In order to use alpha-emitting radiopharmaceuticals for early-stage patients as well as late-stage cancer patients, therefore, modifications on their chemical structures are required. In this review, the recent progress in the development of alpha-emitting radiopharmaceuticals is discussed.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.9 no.1
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• pp.17-21
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• 2023

In this study, we evaluated the targeting of prostate cancer (PCa) using [¹⁸F]Florastamin in non-clinical study, for the purpose of therapeutic monitoring of [¹⁷⁷Lu]Ludotadipep, a therapeutic radiopharmaceutical for PCa, [¹⁸F]Florastamin/[¹⁷⁷Lu]Ludotadipep was co-administered to a single-individual prostate tumor bearing mouse model, mimicking clinical condition. Considering the difference in half-life of the two isotopes (¹⁸F or ¹⁷⁷Lu), image scan of whole-body autoradiography was performed at 24 or 48 h after preparation of frozen section, respectively. Then, it was confirmed whether they showed the same targeting efficiency for the area of tumor. A tumor xenograft model was prepared using PSMA-overexpressing PC3-PIP prostate cancer cells. [¹⁸F]Florastamin [111 MBq (3 mCi) in 100 µL]/¹⁷⁷Lu]Ludotadipep [3.7 MBq (100 µCi) in 100 µL] was co-administered through the tail vein, and 2 hours after administration, the mice were frozen, and after freezing for 24 hours, whole-body cryosection was performed at 24 h after freezing. Image scanning using cryosection was performed after 24 or 48 hours after freezing, respectively. In the scan image after 24 hours, tumor uptake of [¹⁸F] Florastamin/[¹⁷⁷Lu]Ludotadipep were simultaneously observed specific uptake in the tumor. In the scan image after 48 hours in the same section, signal of ¹⁸F was lost by decay of radioisotope, and specific uptake image for [¹⁷⁷Lu]Ludotadipep was observed in the tumor. Uptake of [¹⁷⁷Lu]Ludotadipep was specific to the same tumor region where [¹⁸F]Florastamin/[¹⁷⁷Lu]Ludotadipep was uptake. These results suggested that [¹⁸F]Florastamin showed the same tumor uptake efficiency to PCa as [¹⁷⁷Lu]Ludotadipep, and effective therapeutic monitoring is expected to be enable using [¹⁸F]Florastamin during [¹⁷⁷Lu]Ludotadipep therapy for PCa.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.1
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• pp.23-30
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• 2015

Radioisotopes emitting low-range highly ionizing radiation such as ${\beta}$-particles are of increasing significance in internal radiotherapy. Among the ${\beta}$-particle emitting radioisotopes, $^{67}Cu$ is an attractive radioisotope for various nuclear medicine applications due to its medium energy ${\beta}$-particle, gamma emissions, and 61.83-hour half-life, which can also be used with $^{64}Cu$ for PET imaging. The production and application of the ${\beta}$-emitting radioisotope $^{67}Cu$ for therapeutic radiopharmaceutical are outlined, and different production routes are discussed. A survey of copper chelators used for antibody labeling is provided. It has been produced via proton, alpha, neutron, and gamma irradiations followed by solvent extraction, ion exchange, electrodeposition. Clinical studies using $^{67}Cu$-labelled antibodies in lymphoma, colon carcinoma and bladder cancer patients are reviewed. Widespread use of this isotope for clinical studies and preliminary treatments has been limited by unreliable supplies, cost, and difficulty in obtaining therapeutic quantities.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.11-27
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• 1999

Peptide imaging is a new diagnostic modality in nuclear medicine. $^{111}In$-pentetreotide ($Octreoscan^R$) is the first commercially available peptide radiopharmaceutical. This review article presents the results of previous studies using $^{111}In$-pentetreotide for several disease states, including neuroendocrine tumors, breast cancer and malignant lymphoma. The use of hand-held probe during surgery and the preliminary results of radiotherapy using radiolabeled somatostatin analogues are also reviewed. It can be concluded that somatostatin receptor scintigraphy is a promising diagnostic tool for localizing primary tumors that express receptors for somatostatin, staging secondary spread of tumor tissue, following up after therapy and identifying patients who may benefit from therapy with unlabelled or radiolabeled octreotide. The somatostatin receptor imaging will stimulate the development of new radiopharmaceuticals for other receptors and enhance the therapeutic use of radiolabeled peptides.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.81-88
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• 1998

The purpose of this study was to examine the radiolabeling and biodistribution of $^{188}Re(V)$-DMSA as a therapeutic cancer radiopharmaceutical. We made a DMSA kit($NaHCO_3$ 1.5 mg, meso-2,3-dimercaptosuccinic acid 1.0 mg, L(+)-ascorbic acid 0.7 mg, $SnCl_2{\cdot}2H_2O$ 0.34 mg, pH 2.9) for labeling with $^{188}Re$. In this kit, $^{188}ReO_4{^-}$ 5 mCi/2 ml added and boiled at $100^{\circ}C$ for 3 hr in water bath. The final pH adjusted to 7.5 with 7% $NaHCO_3$ solution. We checked the labelling efficacy with TLC-SG(n-butanol : acetic acid : $H_2O$ = 3 : 2 : 3) and examined the stability both in room temperature and in serum at $37^{\circ}C$. Biodistribution(1, 3, 13, 24, 48 hr) of $^{188}Re(V)$-DMSA compound was evaluated in Sarcoma 180 tumor-bearing mice. Each labeling efficiency and stability at room temperature for 48 hours was over 98% and 95%, respectively. The stability in serum were 82%(6 hr) and 85%(48 hr). Tumor uptake of $^{188}Re(V)$-DMSA in Sarcoma 180-bearing mice were $0.66{\pm}0.15%$(1 hr), $0.51{\pm}0.10%$(3 hr), $0.19{\pm}0.05%$(24 hr) and $0.13{\pm}0.02%$(48 hr). These result are consistent with those of $^{99m}Tc(V)$-DMSA which were reported previously. In conclusion, $^{188}Re(V)$-DMSA may be a useful therapeutic radiopharmaceutical for treating some cancers and metastatic bone lesion.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1999.04a
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• pp.53-61
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• 1999

Radiation therapy has been used for the cancer treatment and radiation synovectomy$\^$1-3)/. There are two kinds of radiation therapy; the external radiation therapy and the internal radiation therapy. Hitherto, the external radiation therapy has been widely used, but for the lack of its selectivity it requires strong radiation dose and causes the irritation and damage of the normal tissue or organ. Therefore many researchers give their interests to the internal radiation therapy in which the radioactive materials are injected directly into the target organ or tissue. Many ${\beta}$-emitting radionuclides have been studied for the application of the internal radiation theraily. Among them, Holmium-166 has the many beneficial physical characteristics for the internal radiation therapy such as appropriate half life (26.8hr), high ${\beta}$ energy (max. 1.85 MeV(51%), 1.77 MeV (48%), mean 0.67MeV), and low ${\gamma}$ energy (0.081MeV) easily detected by ${\gamma}$-camera. In the internal radiation therapy, the administered radioactive materials should be retained in the target long enough to increase the therapeutic effects and avoid the damage in the normal tissue or organ. For this purpose, radionuclides are used as complex form with carriers. Carriers should have a high affinity with radionuclides in vivo and in vitro, so the complex can be evenly distributed in the lesion but can not be leaked out from the lesion.

• Korean Journal of Radiology
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• v.25 no.2
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• pp.179-188
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• 2024

Objective: ¹⁷⁷Lutetium [Lu] Ludotadipep is a novel prostate-specific membrane antigen targeting therapeutic agent with an albumin motif added to increase uptake in the tumors. We assessed the biodistribution and dosimetry of [¹⁷⁷Lu]Ludotadipep in patients with metastatic castration-resistant prostate cancer (mCRPC). Materials and Methods: Data from 25 patients (median age, 73 years; range, 60-90) with mCRPC from a phase I study with activity escalation design of single administration of [¹⁷⁷Lu]Ludotadipep (1.85, 2.78, 3.70, 4.63, and 5.55 GBq) were assessed. Activity in the salivary glands, lungs, liver, kidneys, and spleen was estimated from whole-body scan and abdominal SPECT/CT images acquired at 2, 24, 48, 72, and 168 h after administration of [¹⁷⁷Lu]Ludotadipep. Red marrow activity was calculated from blood samples obtained at 3, 10, 30, 60, and 180 min, and at 24, 48, and 72 h after administration. Organand tumor-based absorbed dose calculations were performed using IDAC-Dose 2.1. Results: Absorbed dose coefficient (mean ± standard deviation) of normal organs was 1.17 ± 0.81 Gy/GBq for salivary glands, 0.05 ± 0.02 Gy/GBq for lungs, 0.14 ± 0.06 Gy/GBq for liver, 0.77 ± 0.28 Gy/GBq for kidneys, 0.12 ± 0.06 Gy/GBq for spleen, and 0.07 ± 0.02 Gy/GBq for red marrow. The absorbed dose coefficient of the tumors was 10.43 ± 7.77 Gy/GBq. Conclusion: [¹⁷⁷Lu]Ludotadipep is expected to be safe at the dose of 3.7 GBq times 6 cycles planned for a phase II clinical trial with kidneys and bone marrow being the critical organs, and shows a high tumor absorbed dose.