Dose Deposits from 90Y, 177Lu, 111In, and 161Tb in Micrometastases of Various Sizes: Implications for Radiopharmaceutical Therapy
Journal of Nuclear Medicine. 2016-02-09; 57(5): 759-764
DOI: 10.2967/jnumed.115.170423
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1. J Nucl Med. 2016 May;57(5):759-64. doi: 10.2967/jnumed.115.170423. Epub 2016 Feb
9.
Dose Deposits from 90Y, 177Lu, 111In, and 161Tb in Micrometastases of Various
Sizes: Implications for Radiopharmaceutical Therapy.
Hindié E(1), Zanotti-Fregonara P(2), Quinto MA(3), Morgat C(2), Champion C(4).
Author information:
(1)CHU de Bordeaux, Service de Médecine Nucléaire, CNRS-UMR 5287, LabEx TRAIL,
Université de Bordeaux, Pessac, France; and
.
(2)CHU de Bordeaux, Service de Médecine Nucléaire, CNRS-UMR 5287, LabEx TRAIL,
Université de Bordeaux, Pessac, France; and.
(3)Université de Bordeaux, CNRS/IN2P3, Centre d’Etudes Nucléaires de Bordeaux
Gradignan (CENBG), Gradignan, France.
(4)Université de Bordeaux, CNRS/IN2P3, Centre d’Etudes Nucléaires de Bordeaux
Gradignan (CENBG), Gradignan, France
.
Radiopharmaceutical therapy, traditionally limited to refractory metastatic
cancer, is being increasingly used at earlier stages, such as for treating
minimal residual disease. The aim of this study was to compare the effectiveness
of (90)Y, (177)Lu, (111)In, and (161)Tb at irradiating micrometastases. (90)Y and
(177)Lu are widely used β(-)-emitting radionuclides. (161)Tb is a medium-energy
β(-) radionuclide that is similar to (177)Lu but emits a higher percentage of
conversion and Auger electrons. (111)In emits γ-photons and conversion and Auger
electrons.METHODS: We used the Monte Carlo code CELLDOSE to assess electron doses
from a uniform distribution of (90)Y, (177)Lu, (111)In, or (161)Tb in spheres
with diameters ranging from 10 mm to 10 μm. Because these isotopes differ in
electron energy per decay, the doses were compared assuming that 1 MeV was
released per μm(3), which would result in 160 Gy if totally absorbed.
RESULTS: In a 10-mm sphere, the doses delivered by (90)Y, (177)Lu, (111)In, and
(161)Tb were 96.5, 152, 153, and 152 Gy, respectively. The doses decreased along
with the decrease in sphere size, and more abruptly so for (90)Y. In a 100-μm
metastasis, the dose delivered by (90)Y was only 1.36 Gy, compared with 24.5 Gy
for (177)Lu, 38.9 Gy for (111)In, and 44.5 Gy for (161)Tb. In cell-sized spheres,
the dose delivered by (111)In and (161)Tb was higher than that of (177)Lu. For
instance, in a 10-μm cell, (177)Lu delivered 3.92 Gy, compared with 22.8 Gy for
(111)In and 14.1 Gy for (161)Tb.
CONCLUSION: (177)Lu, (111)In, and (161)Tb might be more appropriate than (90)Y
for treating minimal residual disease. (161)Tb is a promising radionuclide
because it combines the advantages of a medium-energy β(-) emission with those of
Auger electrons and emits fewer photons than (111)In.
© 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.
DOI: 10.2967/jnumed.115.170423
PMID: 26912441 [Indexed for MEDLINE]