Radiation doses from 161Tb and 177Lu in single tumour cells and micrometastases
EJNMMI Phys. 2020-05-19; 7(1):
DOI: 10.1186/s40658-020-00301-2
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1. EJNMMI Phys. 2020 May 19;7(1):33. doi: 10.1186/s40658-020-00301-2.
Radiation doses from 161Tb and 177Lu in single tumour cells and micrometastases.
Alcocer-Ávila ME(1), Ferreira A(2), Quinto MA(3), Morgat C(4), Hindié E(5),
Champion C(6).
Author information:
(1)Centre Lasers Intenses et Applications, Université de Bordeaux – CNRS – CEA,
Talence, F-33400, France.
(2)CERVO Brain Research Center, Department of Biochemistry, Microbiology and
Bioinformatics, Université Laval, Quebec City, G1J 2G3, Quebec, Canada.
(3)Instituto de Física Rosario, CONICET – Universidad Nacional de Rosario,
Rosario, S2000 EKF, Argentina.
(4)Service de Médecine Nucléaire, Hôpital Haut-Lévêque, CHU de Bordeaux, Pessac,
33604, France.
(5)Service de Médecine Nucléaire, Hôpital Haut-Lévêque, CHU de Bordeaux, Pessac,
33604, France. .
(6)Centre Lasers Intenses et Applications, Université de Bordeaux – CNRS – CEA,
Talence, F-33400, France. .
BACKGROUND: Targeted radionuclide therapy (TRT) is gaining importance. For TRT to
be also used as adjuvant therapy or for treating minimal residual disease, there
is a need to increase the radiation dose to small tumours. The aim of this in
silico study was to compare the performances of 161Tb (a medium-energy β- emitter
with additional Auger and conversion electron emissions) and 177Lu for
irradiating single tumour cells and micrometastases, with various distributions
of the radionuclide.
METHODS: We used the Monte Carlo track-structure (MCTS) code CELLDOSE to compute
the radiation doses delivered by 161Tb and 177Lu to single cells (14 μm cell
diameter with 10 μm nucleus diameter) and to a tumour cluster consisting of a
central cell surrounded by two layers of cells (18 neighbours). We focused the
analysis on the absorbed dose to the nucleus of the single tumoral cell and to
the nuclei of the cells in the cluster. For both radionuclides, the simulations
were run assuming that 1 MeV was released per μm3 (1436 MeV/cell). We considered
various distributions of the radionuclides: either at the cell surface,
intracytoplasmic or intranuclear.
RESULTS: For the single cell, the dose to the nucleus was substantially higher
with 161Tb compared to 177Lu, regardless of the radionuclide distribution: 5.0 Gy
vs. 1.9 Gy in the case of cell surface distribution; 8.3 Gy vs. 3.0 Gy for
intracytoplasmic distribution; and 38.6 Gy vs. 10.7 Gy for intranuclear location.
With the addition of the neighbouring cells, the radiation doses increased, but
remained consistently higher for 161Tb compared to 177Lu. For example, the dose
to the nucleus of the central cell of the cluster was 15.1 Gy for 161Tb and 7.2
Gy for 177Lu in the case of cell surface distribution of the radionuclide, 17.9
Gy for 161Tb and 8.3 Gy for 177Lu for intracytoplasmic distribution and 47.8 Gy
for 161Tb and 15.7 Gy for 177Lu in the case of intranuclear location.
CONCLUSION: 161Tb should be a better candidate than 177Lu for irradiating single
tumour cells and micrometastases, regardless of the radionuclide distribution.
DOI: 10.1186/s40658-020-00301-2
PMCID: PMC7237560
PMID: 32430671