Search results for "dota"
showing 10 items of 98 documents
Bone targeting compounds for radiotherapy and imaging: *Me(III)-DOTA conjugates of bisphosphonic acid, pamidronic acid and zoledronic acid
2016
Background Bisphosphonates have a high adsorption on calcified tissues and are commonly used in the treatment of bone disorder diseases. Conjugates of bisphosphonates with macrocyclic chelators open new possibilities in bone targeted radionuclide imaging and therapy. Subsequent to positron emission tomography (PET) examinations utilizing 68Ga-labelled analogues, endoradiotheraphy with 177Lu-labelled macrocyclic bisphosphonates may have a great potential in the treatment of painful skeletal metastases. Methods Based on the established pharmaceuticals pamidronate and zoledronate two new DOTA-α-OH-bisphosphonates, DOTAPAM and DOTAZOL(MM1.MZ) were successfully synthesized. The ligands were labe…
Evaluation of the inverse electron demand Diels-Alder reaction in rats using a scandium-44-labelled tetrazine for pretargeted PET imaging
2019
Background Pretargeted imaging allows the use of short-lived radionuclides when imaging the accumulation of slow clearing targeting agents such as antibodies. The biotin-(strept)avidin and the bispecific antibody-hapten interactions have been applied in clinical pretargeting studies; unfortunately, these systems led to immunogenic responses in patients. The inverse electron demand Diels-Alder (IEDDA) reaction between a radiolabelled tetrazine (Tz) and a trans-cyclooctene (TCO)-functionalized targeting vector is a promising alternative for clinical pretargeted imaging due to its fast reaction kinetics. This strategy was first applied in nuclear medicine using an 111In-labelled Tz to image TC…
Instant kit preparation of 68Ga-radiopharmaceuticals via the hybrid chelator DATA: clinical translation of [68Ga]Ga-DATA-TOC
2019
Purpose The widespread use of 68Ga for positron emission tomography (PET) relies on the development of radiopharmaceutical precursors that can be radiolabelled and dispensed in a simple, quick, and convenient manner. The DATA (6-amino-1,4-diazapine-triacetate) scaffold represents a novel hybrid chelator architecture possessing both cyclic and acyclic character that may allow for facile access to 68Ga-labelled tracers in the clinic. We report the first bifunctional DATA chelator conjugated to [Tyr3]octreotide (TOC), a somatostatin subtype 2 receptor (SST2)-targeting vector for imaging and functional characterisation of SSTR2 expressing tumours. Methods The radiopharmaceutical precursor, DATA…
Biodistribution and post-therapy dosimetric analysis of [177Lu]Lu-DOTAZOL in patients with osteoblastic metastases: first results
2019
Abstract Background Preclinical biodistribution and dosimetric analysis of [177Lu]Lu-DOTAZOL suggest the bisphosphonate zoledronate as a promising new radiopharmaceutical for therapy of bone metastases. We evaluated biodistribution and normal organ absorbed doses resulting from therapeutic doses of [177Lu]Lu-DOTAZOL in patients with metastatic skeletal disease. Method Four patients with metastatic skeletal disease (age range, 64–83 years) secondary to metastatic castration-resistant prostate carcinoma or bronchial carcinoma were treated with a mean dose of 5968 ± 64 MBq (161.3 mCi) of [177Lu]Lu-DOTAZOL. Biodistribution was assessed with serial planar whole body scintigraphy at 20 min and 3,…
Labeling of DOTA-conjugated HPMA-based polymers with trivalent metallic radionuclides for molecular imaging.
2017
Background In this work, the in vitro and in vivo stabilities and the pharmacology of HPMA-made homopolymers were studied by means of radiometal-labeled derivatives. Aiming to identify the fewer amount and the optimal DOTA-linker structure that provides quantitative labeling yields, diverse DOTA-linker systems were conjugated in different amounts to HPMA homopolymers to coordinate trivalent radiometals Me(III)* = gallium-68, scandium-44, and lutetium-177. Results Short linkers and as low as 1.6% DOTA were enough to obtain labeling yields > 90%. Alkoxy linkers generally exhibited lower labeling yields than alkane analogues despite of similar chain length and DOTA incorporation rate. High sta…
New Insights into the complexation of lead(II) by 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane (DOTAM): structural, thermodynami…
2007
The lead(II) coordination properties of the tetrapodal ligand DOTAM [1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraaza-cyclododecane] have been investigated both in the solid state and in solution in order to ascertain the stereoactivity of the lone pair and to rationalize the structural effects of a cyclen-based scaffold on the metal uptake kinetics. The crystal structure of the free base shows that the pendant acetamide groups are not equivalent: two are folded over the macrocycle and maintained by an intramolecular hydrogen bond involving an amide hydrogen atom and a neighboring tertiary amine of the cyclen ring, while the other two are extended and point away from the macrocyclic cav…
Squaric Acid-Based Radiopharmaceuticals for Tumor Imaging and Therapy.
2021
Targeting vectors bound to a chelator represent a significant fraction of radiopharmaceuticals used nowadays for diagnostic and therapeutic purposes in nuclear medicine. The use of squaramides as coupling units for chelator and targeting vector helps to circumvent the disadvantages of several common coupling methods. This review gives an overview of the use of squaric acid diesters (SADE) as linking agents. It focuses on the conjugation of cyclic chelators, e.g., DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), as well as hybrid chelators like AAZTA5 (6-pentanoic acid-6-amino-1,4-diazepine tetracetic acid) or DATA5m (6-pentanoic acid-6-amino-1,4-diazapine-triacetate) to diff…
Surgical management of retinal detachment because of macular hole in highly myopic eyes
2012
PURPOSE: The purpose of this study was to review the current management of macular hole retinal detachment in highly myopic eyes. METHODS: We searched English MEDLINE databases from January 1997 to January 2011 for surgical management of macular hole retinal detachment in highly myopic eyes. The main outcomes reported include retinal reattachment and visual acuity after primary surgery. RESULTS: Surgical procedures including pneumoretinopexy, pars plana vitrectomy with gas or silicone oil tamponade with or without laser therapy around the macular hole, and macular buckling have been the primary treatment choices. New techniques, including internal limiting membrane or epiretinal membrane pe…
68 ga-dotatoc pet/ct follow up after single or hypofractionated gamma knife icon radiosurgery for meningioma patients
2021
68Ga-DOTATOC represents a useful tool in tumor contouring for radiosurgery planning. We present a case series of patients affected by meningiomas on who we performed 68Ga-DOTATOC positron emission tomography (PET)/CT pre-operatively, a subgroup of which also underwent a post-operative 68Ga-DOTATOC PET/CT to evaluate the standardized uptake value (SUV) modification after Gamma Knife ICON treatment in single or hypofractionated fractions. Twenty patients were enrolled/included in this study: ten females and ten males. The median age was 52 years (range 33–80). The median tumor diameter was 3.68 cm (range 0.12–22.26 cm), and the median pre-radiotherapy maximum SUV value was 11 (range 2.3–92). …
Pedagogu gatavība pārmaiņām vispārējā izglītībā kompetenču pieejas ieviešanas kontekstā
2019
Ineses Irmejas maģistra darbs “Pedagogu gatavība pārmaiņām vispārējā izglītībā kompetenču pieejas ieviešanas kontekstā”. Maģistra darba mērķis ir izpētīt pārmaiņu būtību izglītībā un faktorus, kas ietekmē pedagogu gatavību kompetenču pieejas ieviešanai mācību saturā vispārējā izglītībā astoņās Latvijas skolās, kuras darbojas kā mācību saturu aprobējošās izglītības iestādes jeb pilotskolas. Darba teorētiskajā daļā anlizēta pārmaiņu nepieciešamības aktualitāte mūsdienu kontekstā, raksturoti pedagogu gatavību veicinoši faktori pārmaiņu ieviešanas kontekstā, kā arī faktori, kas gatavību var mazināt. Izstrādātas gatavības fāzes un pazīmes. Praktiskajā daļā veikts pētījums par pedagogu gatavību p…