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Quantitative, high resolution radionuclide imaging versatility is key to success in the development of theranostic agents. In general, there are three types of isotope radiation that can be used for radionuclide therapy applications: α-particles, β-particles and Auger electrons. Each radionuclide is characterized by its own decay properties, tissue range, half-life and chemistry, proposing the opportunity to adapt the features of the radionuclide and carrier to a particular type of cancer and in the long run to the needs of an individual patient. Several isotopes are combined γ and particle emitters enabling personalized high precision therapy guided by Single Photon Emission Tomography (SPECT) that allows forprovion of 3D and 4D images of the isotope distribution.
Most targeted radioactive pharmaceuticals will have off-target effects and cytotoxic profiles that need to be qualified and quantified. In addition, there is a crucial role of imaging and dosimetry in the selection, planning and response monitoring of the treatment. Since most of the research is done in mouse models, ultra-high resolution and high molecular sensitivity requirements as well as extremely high γ -energies of combined emitters often complicate the successful development of new theranostic agents and tracers to ready out therapeutic- and side-effects.
Comprehensive theranostics data from one versatile platform
Until today, there was not a single preclinical imaging system able to handle all these challenges. Now, MILabs’ VECTor system is a platform that combines nuclear PET and SPECT imaging with X-ray CT and Optical imaging in a single, easy-to-use system. Recent publications from users of this innovative platform underline the enabling theranostic versatility of the MILabs VECTor platform:
– van der Have et al. reported in the May 2016 issue of Nuclear Medicine & Biology, how accurate quantitative imaging of the therapeutic isotope 131I in mice at < 0.6 mm resolution can be performed despite very high g-energies. 131I is commonly used in the clinic for image guided treatment of e.g. thyroid cancer, through utilizing combined β and γ emission. It now can be imaged quantitatively in mouse models without the need for using imaging substitutes such as 99mTc -pertechnetate or 123I/124I. Read entire article here
– In the Theranostics 2016/Vol. 6/Issue 6, Chatalic et al. report on the use of 111In (combined therapy-imaging through Auger electrons and γ emission) and 177Lu (combined therapy-imaging through β and γ emission) for the personalized treatment of prostate cancer (PCa). They demonstrate through targeted and biodistribution imaging of mice plus quantitative dosimetry, that PSMA I&T is a promising theranostic tool for PCa. PSMA-specific uptake in kidneys can be successfully tackled using blocking agents such as 2-PMPA. Read entire article here
– While the combined emission of α-particles and γ photons make 213Bi a very promising radionuclide for theranostic applications, its research use in mouse models has remained largely elusive due to the high energy of its emitted photons (440keV). In the JNM 2016, de Swart et al. demonstrate that despite its high energy, the VECTor system can quantitative image 213Bi agents with sub-mm resolution in mice. Read entire article here
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