Endocrine Abstracts

The 68Ge/68Ga generator has the potential to greatly expand positron emission tomography (PET) imaging to benefit more patients, by allowing many PET applications in hospitals without immediate access to cyclotrons and costly radiochemistry facilities. It is often suggested that ‘68Ga is the new 99mTc,’ drawing parallels with conventional radiopharmacy practice where radiopharmaceuticals are prepared with little more complex equipment than a syr...

Metastatic bone lesion is a common syndrome of many cancer diseases in an advanced state. The major symptom is severe pain, spinal cord compression and pathological fracture, associated with an obvious morbidity. Common treatments including systemic application of bisphosphonate drugs aim on pain reduction and on improving the quality of life of the patient. Particularly patients with multiple metastatic lesions benefit from bone-targeting therapeutic radiopharmaceuticals....

Radioactive isotopes of copper are of interest in the development of imaging agents for positron emission tomography (PET) and companion therapeutics. The synthesis of a ligand, 5-(8-methyl-3,6,10,13,16,19-hexaaza-bicyclo[6.6.6]icosan-1-ylamino)-5-oxopentanoic acid (MeCOSar), designed to form stable complexes with radioactive copper isotopes that can be tethered to tumour targeting peptides and antibodies will be presented.The MeCOSar ligand has been con...

Outpatient theranostics began 30 years ago in Western Australia with world-first phase 1/11 clinical trials of Samarium-153-EDTMP for pain palliation of skeletal metastases prospective individualised dosimetry in each patient, based upon a calculated maximum radiation absorbed dose of 2Gy to haemopoietic marrow was performed by quantitative whole-body gamma imaging, to prescribe the safe effective administered therapeutic activity, which was then given on the same day as an ou...

Two anti-CD-20 radioantibody therapies: Y-90 ibritumomab tiuxetan (Zevalin) and I-131 tositutumomab (Bexxar) were approved in the USA in the early 2000s. The safety and efficacy of both Bexxar and Zevalin were proven relative to rituximab. While Zevalin remains on the market, sales are reportedly low. Bexxar exited the market in 2014 after low sales. Bexxar cost $26K USD, ‘very expensive’ by early 21st century standards, but low compared to cancer therapies in 2016. ...

The prostate specific membrane antigen (PSMA) has been reported to be selectively overexpressed in the tumor-associated neovasculature of a wide variety of solid tumors including breast carcinoma, and growth and progression of breast cancers are accompanied by increased neovascularization (angiogenesis). In this context, the robust expression of PSMA by breast cancer lesions as evidenced using PSMA-PET/CT makes PSMA an interesting potential target for antiangiogenic therapy of...

Abstract unavailable at time of publishing....

The intrinsic selectivity and flexibility of bioorthogonal click chemistries make them an almost ideal synthetic methodology for the creation of radiolabeled PET imaging agents. One type of bioorthogonal reaction, the inverse electron demand Diels-Alder reaction between tetrazine and TCO, has particularly appealing characteristics for in vivo pretargeting applications. Simply put, the thrust of pretargeted imaging is to harness the exquisite tumor-targeting properties...

Background: The current focus of personalized medicine is towards the use of the theranostic approach – the development of an interdependent, collaborative targeted therapeutic and a companion diagnostic test. [DOTA0,D-Phe1,Tyr3]-octreotate (DOTA-TATE) and ligands targeting prostate-specific membrane antigen (PSMA) have been introduced recently as 177Lu-labeled theranostics for neuroendocrine tumors and prostate cancer respectiv...

Determination of radiochemical purity (RCP) of radiopharmaceuticals based on 68Ga-BCA-peptides (68Ga-DOTA-TOC/-TATE, 68Ga-NODAGA-RGD2, 68Ga-PSMA-HBED-CC, etc.) is an extremely important part of QC in routine clinical practice. Nature of gallium leads to formation of two major radiochemical impurities in the radiopharmaceutical: hydrolyzed 68Ga (colloid) and unbounded ionic forms of 68Ga. The amounts o...

Gliomas are a highly heterogeneous group of brain tumours that are refractory to treatment, and highly invasive. The treatment and prognosis depend upon the tumor grade. Treatment of Grade II/III gliomas typically consists of maximal safe resection, followed by external beam radiation therapy. Although less aggressive than GBM, mortality is high with a 5-year survival rate of only 25.9%. Glioma tumors has been demonstrated NK-1 receptor system and substance P can be used as a ...

Aim: Auger electron (AE)-emitting radionuclides are well suited as molecularly targeted radionuclide therapeutics (MRT) due to the high energy deposition density in the immediate vicinity of the decay site which avoids to a large extent non-specific radiotoxicity. However, due to the short range of the low-energy Auger (and Coster-Kronig) electrons, it is imperative that the AE emitting agent is closely associated with the cell nucleus. In this study we evaluate the dose depos...

Multiple myeloma (MM) is a B-cell tumor of monoclonal plasma cells in the bone marrow and is the second most common age-related hematologic malignancy reported in the United States. Very late antigen-4 (VLA-4, α4β1 integrin, CD49d/CD29) is overexpressed on MM. LLP2A is a highly specific peptidomimetic ligand that targets activated VLA-4 with high affinity. In this study, we evaluated 68Ga radiolabeled-DOTA-PEG4-LLP2A tracer...

The currently best known example of a commercialized theranostics is the combination of HercepTest and Herceptin wherein the former is used for HER2 expression assessment and selection of patients that might benefit from the treatment with the latter. However, HercepTest requires biopsy which is an invasive procedure, not sufficiently accurate, and very difficult to perform on several lesions and repeatedly in order to monitor the treatment response. While positron emission to...

The use of gallium-68 (68Ga) is rapidly expanding with new applications arising almost every week. Therefore, the global availability of this nuclide is a critical issue. 68Ga is currently sourced from commercial 68Ge/68Ga generators but their production is limited by the availability of the parent nuclide 68Ge. Alternatively, the use of a 68Zn salt solution in a liquid target has been proposed [1] [2]. With thi...

We developed an improved process for producing high quality 67Cu using an electron accelerator instead of a high energy proton accelerator. The beta/gamma emitting radioisotope 67Cu was created using the (g,p) reaction on isotopically enriched 68Zn target (nominally 40 g, 98% enrichment). The high energy photons were produced by bremsstrahlung conversion of electrons from a 45 MeV electron LINAC. A specially designed water cooled converter, end...

Application of Ga-68 for clinical and non-clinical studies are rapidly growing in Asia. In this study, China, India, Japan, and Korea were selected to follow up the current status. In case of clinical trial, India was the most active among the four countries. Most of clinical trials in India were imaging studies of neuroendocrine tumor patients by using somatostatin derivatives such as 68Ga-DOTA-TOC, 68Ga-DOTA-NOC and 68Ga-DOTA-TATE. Prostate c...