Er-165 is a radiolanthanide, usually in trivalent state. The ionic radius of Er3+ is 89 pm, i.e. just 3% larger than Lu3+, which explains that chelators suitable for Lu-177 can be directly employed for Er-165 too, in particular DOTA.
Er-165 decays by electron capture decay with a half-life of 10.36 hours to stable Ho-165.
Er-165 emits no γ-rays, but X-rays, notably Kα at ≈47 keV (59.4(9) %) and Kβ at ≈54 keV (14.3(19) %). These energies make Er-165 suitable for SPECT-imaging.
The mean photon energy per decay is 37 keV and the mean electron energy emitted per decay is 5 keV . Most electrons are short-range Auger electrons with <1 µm and <26 µm respectively. Er-165 has therefore been proposed as therapeutic Auger electron emitter .
Er-165 is produced by proton irradiation of natural Ho carbonate targets at Hevesy Laboratory at DTU. A Ho/Er separation is performed by ion exchange chromatography.
Activity will be shipped from the Hevesy Laboratory (DTU, Risø, Denmark) to the users in form of Er3+ solution.
Parameter | Specifications |
---|---|
Production route | Ho-165(p,n)Er-165 |
Daughter | Decays to stable Ho-165: 100% EC |
Half-life | 10.36 h |
Processing | Multi-step ion exchange |
Primary Container | 2.5 mL borosilicate glass V-vial with silicon rubber screw cap |
Product Grade | n.c.a. |
Physical Form | Liquid |
Chemical Form | Er3+ ion in 0.1 M HCl solution (1-2 ml) |
Radioactive Concentration (gamma spectrometry) | Up to 1 GBq/ml |
Appearance | Clear colourless solution |
Radionuclide identification (gamma spectrometry) | Metal impurities determined by ICP-OES for each batch |
Radionuclidic Purity (gamma spectrometry) | t.b.d. |
Chemical purity (ICP-OES) | t.b.d. |
Molar activity (ICP-OES) | t.b.d. |
Apparent Molar Activity | t.b.d. |
Microbiological quality | Bioburden and endotoxin burden can be analysed post release, upon request |
Bacterial endotoxin | Bioburden and endotoxin burden can be analysed post release, upon request |
pH (pH strips) | t.b.d. |
Additional information | |
Activity available | 1 GBq (more to be discussed) upon request |
Activity limit for UN2910 (excepted package) shipment | 20 MBq in dry state or 2 MBq in liquid form |
Other information |