155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications?

EJNMMI Physics

Table 1 Main decay data of ^xxxTb radionuclides.

Radionuclide	Decay mode (%)	T_1/2	Emitted energy (MeV/nt)
Radionuclide	Decay mode (%)	T_1/2	Electron	Photon	Total
^154gTb	EC, β⁺ (100%)	21.5 h	0.0681	2.2831	2.3512
^154m1Tb	EC (78.20%), IT (21.80%), β⁻(< 0.10%)	9.4 h	–	–	–
^154m2Tb	EC (98.20%), IT (1.80%)	22.7 h	–	–	–
¹⁵⁵ Tb	EC (100%)	5.32 d	0.0434	0.1777	0.2211
^156gTb	EC (100%)	5.35 d	0.0835	1.9371	2.0206
^156m1Tb	IT (100%)	24.4 h	0.0171	0.0370	0.0540
^156m2Tb	IT (100%)	5.3 h	0.0874	0.0048	0.0922

Decay mode, half-life, emitted energy per nuclear transformation (nt) in the form of electron, photon, and the total one of ^xxxTb radionuclides were obtained by the ICRP 107 publication [23] and NUDAT3 database [24] (emitted energy data not available for ^154m1Tb and ^154m2Tb).