Natural
gallium (
31Ga) consists of a mixture of two stable
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...
s: gallium-69 and gallium-71. The most commercially important
radioisotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
s are gallium-67 and gallium-68.
Gallium-67 (half-life 3.3 days) is a gamma-emitting isotope (the gamma ray emitted immediately after electron capture) used in standard nuclear medical imaging, in procedures usually referred to as
gallium scan
A gallium scan is a type of nuclear medicine test that uses either a gallium-67 (67Ga) or gallium-68 (68Ga) radiopharmaceutical to obtain images of a specific type of tissue, or disease state of tissue. Gallium salts like gallium citrate and gal ...
s. It is usually used as the free ion, Ga
3+. It is the longest-lived radioisotope of gallium.
The shorter-lived gallium-68 (half-life 68 minutes) is a
positron-emitting isotope generated in very small quantities from germanium-68 in
gallium-68 generator
A germanium-68/gallium-68 generator is a device used to extract the positron-emitting isotope 68Ga of gallium from a source of decaying germanium-68. The parent isotope 68Ge has a half-life of 271 days and can be easily utilized for in-hospital ...
s or in much greater quantities by proton bombardment of
68Zn in low-energy medical
cyclotron
A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. Lawrence, Ernest O. ''Method and apparatus for the acceleration of ions'', filed: Jan ...
s,
for use in a small minority of diagnostic
PET scan
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, ...
s. For this use, it is usually attached as a tracer to a carrier molecule (for example the somatostatin analogue
DOTATOC
Edotreotide (USAN, also known as (DOTA0- Phe1- Tyr3) octreotide, DOTA-TOC, DOTATOC) is a substance which, when bound to various radionuclides, is used in the treatment and diagnosis of certain types of cancer. When used therapeutically it is an ...
), which gives the resulting
radiopharmaceutical
Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which ...
a different tissue-uptake specificity from the ionic
67Ga radioisotope normally used in standard gallium scans.
List of isotopes
, -
,
56Ga
, style="text-align:right" , 31
, style="text-align:right" , 25
, 55.99491(28)#
,
,
p
,
55Zn
, 3+#
,
,
, -
,
57Ga
, style="text-align:right" , 31
, style="text-align:right" , 26
, 56.98293(28)#
,
, p
,
56Zn
, 1/2−#
,
,
, -
,
58Ga
, style="text-align:right" , 31
, style="text-align:right" , 27
, 57.97425(23)#
,
, p
,
57Zn
, 2+#
,
,
, -
,
59Ga
, style="text-align:right" , 31
, style="text-align:right" , 28
, 58.96337(18)#
,
, p
,
58Zn
, 3/2−#
,
,
, -
,
60Ga
, style="text-align:right" , 31
, style="text-align:right" , 29
, 59.95706(12)#
, 70(10) ms
,
β+
,
60Zn
, (2+)
,
,
, -
,
61Ga
, style="text-align:right" , 31
, style="text-align:right" , 30
, 60.94945(6)
, 168(3) ms
, β
+
,
61Zn
, 3/2−
,
,
, -
,
62Ga
, style="text-align:right" , 31
, style="text-align:right" , 31
, 61.944175(30)
, 116.18(4) ms
, β
+
,
62Zn
, 0+
,
,
, -
,
63Ga
, style="text-align:right" , 31
, style="text-align:right" , 32
, 62.9392942(14)
, 32.4(5) s
, β
+
,
63Zn
, (3/2−)
,
,
, -
,
64Ga
, style="text-align:right" , 31
, style="text-align:right" , 33
, 63.9368387(22)
, 2.627(12) min
, β
+
,
64Zn
, 0(+#)
,
,
, -
, style="text-indent:1em" ,
64mGa
, colspan="3" style="text-indent:2em" , 42.85(8) keV
, 21.9(7) μs
,
,
, 2+
,
,
, -
,
65Ga
, style="text-align:right" , 31
, style="text-align:right" , 34
, 64.9327348(9)
, 15.2(2) min
, β
+
,
65Zn
, 3/2−
,
,
, -
,
66Ga
, style="text-align:right" , 31
, style="text-align:right" , 35
, 65.931589(3)
, 9.49(7) h
, β
+
,
66Zn
, 0+
,
,
, -
,
67Ga
[Deexcitation gamma used in medical imaging]
, style="text-align:right" , 31
, style="text-align:right" , 36
, 66.9282017(14)
, 3.2612(6) d
,
EC
,
67Zn
, 3/2−
,
,
, -
,
68Ga
[ Medically useful ]radioisotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
, style="text-align:right" , 31
, style="text-align:right" , 37
, 67.9279801(16)
, 67.71(9) min
, β
+
,
68Zn
, 1+
,
,
, -
,
69Ga
, style="text-align:right" , 31
, style="text-align:right" , 38
, 68.9255736(13)
, colspan=3 align=center, Stable
, 3/2−
, 0.60108(9)
,
, -
, rowspan=2,
70Ga
, rowspan=2 style="text-align:right" , 31
, rowspan=2 style="text-align:right" , 39
, rowspan=2, 69.9260220(13)
, rowspan=2, 21.14(3) min
, β
− (99.59%)
,
70Ge
, rowspan=2, 1+
, rowspan=2,
, rowspan=2,
, -
,
EC (0.41%)
,
70Zn
, -
,
71Ga
, style="text-align:right" , 31
, style="text-align:right" , 40
, 70.9247013(11)
, colspan=3 align=center, Stable
, 3/2−
, 0.39892(9)
,
, -
,
72Ga
, style="text-align:right" , 31
, style="text-align:right" , 41
, 71.9263663(11)
, 14.095(3) h
, β
−
,
72Ge
, 3-
,
,
, -
, style="text-indent:1em" ,
72mGa
, colspan="3" style="text-indent:2em" , 119.66(5) keV
, 39.68(13) ms
,
IT
,
72Ga
, (0+)
,
,
, -
,
73Ga
, style="text-align:right" , 31
, style="text-align:right" , 42
, 72.9251747(18)
, 4.86(3) h
, β
−
,
73Ge
, 3/2−
,
,
, -
,
74Ga
, style="text-align:right" , 31
, style="text-align:right" , 43
, 73.926946(4)
, 8.12(12) min
, β
−
,
74Ge
, (3-)
,
,
, -
, style="text-indent:1em" ,
74mGa
, colspan="3" style="text-indent:2em" , 59.571(14) keV
, 9.5(10) s
,
,
, (0)
,
,
, -
,
75Ga
, style="text-align:right" , 31
, style="text-align:right" , 44
, 74.9265002(26)
, 126(2) s
, β
−
,
75Ge
, (3/2)−
,
,
, -
,
76Ga
, style="text-align:right" , 31
, style="text-align:right" , 45
, 75.9288276(21)
, 32.6(6) s
, β
−
, ''
76Ge''
, (2+,3+)
,
,
, -
,
77Ga
, style="text-align:right" , 31
, style="text-align:right" , 46
, 76.9291543(26)
, 13.2(2) s
, β
−
,
77Ge
, (3/2−)
,
,
, -
,
78Ga
, style="text-align:right" , 31
, style="text-align:right" , 47
, 77.9316082(26)
, 5.09(5) s
, β
−
,
78Ge
, (3+)
,
,
, -
, rowspan=2,
79Ga
, rowspan=2 style="text-align:right" , 31
, rowspan=2 style="text-align:right" , 48
, rowspan=2, 78.93289(11)
, rowspan=2, 2.847(3) s
, β
− (99.911%)
,
79mGe
, rowspan=2, (3/2−)#
, rowspan=2,
, rowspan=2,
, -
, β
−,
n (.089%)
,
78Ge
, -
, rowspan=2,
80Ga
, rowspan=2 style="text-align:right" , 31
, rowspan=2 style="text-align:right" , 49
, rowspan=2, 79.93652(13)
, rowspan=2, 1.697(11) s
, β
− (99.11%)
,
80Ge
, rowspan=2, (3)
, rowspan=2,
, rowspan=2,
, -
, β
−, n (.89%)
,
79Ge
, -
, rowspan=2,
81Ga
, rowspan=2 style="text-align:right" , 31
, rowspan=2 style="text-align:right" , 50
, rowspan=2, 80.93775(21)
, rowspan=2, 1.217(5) s
, β
− (88.11%)
,
81mGe
, rowspan=2, (5/2−)
, rowspan=2,
, rowspan=2,
, -
, β
−, n (11.89%)
,
80Ge
, -
, rowspan=2,
82Ga
, rowspan=2 style="text-align:right" , 31
, rowspan=2 style="text-align:right" , 51
, rowspan=2, 81.94299(32)#
, rowspan=2, 0.599(2) s
, β
− (78.5%)
,
82Ge
, rowspan=2, (1,2,3)
, rowspan=2,
, rowspan=2,
, -
, β
−, n (21.5%)
,
81Ge
, -
, rowspan=2,
83Ga
, rowspan=2 style="text-align:right" , 31
, rowspan=2 style="text-align:right" , 52
, rowspan=2, 82.94698(32)#
, rowspan=2, 308(1) ms
, β
− (60%)
,
83Ge
, rowspan=2, 3/2−#
, rowspan=2,
, rowspan=2,
, -
, β
−, n (40%)
,
82Ge
, -
, rowspan=2,
84Ga
, rowspan=2 style="text-align:right" , 31
, rowspan=2 style="text-align:right" , 53
, rowspan=2, 83.95265(43)#
, rowspan=2, 0.085(10) s
, β
−, n (70%)
,
83Ge
, rowspan=2,
, rowspan=2,
, rowspan=2,
, -
, β
− (30%)
,
84Ge
, -
,
85Ga
, style="text-align:right" , 31
, style="text-align:right" , 54
, 84.95700(54)#
, 50# ms
300 ns,
,
, 3/2−#
,
,
, -
,
86Ga
, style="text-align:right" , 31
, style="text-align:right" , 55
, 85.96312(86)#
, 30# ms
300 ns,
,
,
,
,
* Commercially available materials may have been subjected to an undisclosed or inadvertent isotopic fractionation. Substantial deviations from the given mass and composition can occur.
Gallium-67
Gallium-67 () has a half-life of 3.26 days and decays by
electron capture
Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Thi ...
and
gamma emission (in de-
excitation) to stable zinc-67. It is a
radiopharmaceutical
Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which ...
used in
gallium scan
A gallium scan is a type of nuclear medicine test that uses either a gallium-67 (67Ga) or gallium-68 (68Ga) radiopharmaceutical to obtain images of a specific type of tissue, or disease state of tissue. Gallium salts like gallium citrate and gal ...
s (alternatively, the shorter-lived gallium-68 may be used). This gamma-emitting isotope is imaged by gamma camera.
Gallium-68
Gallium-68 () is a
positron emitter with a half-life of 68 minutes, decaying to stable zinc-68. It is a
radiopharmaceutical
Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which ...
,
generated ''in situ'' from the
electron capture
Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Thi ...
of germanium-68 (half-life 271 days) owing to its short half-life. This positron-emitting isotope can be imaged efficiently by PET scan (see
gallium scan
A gallium scan is a type of nuclear medicine test that uses either a gallium-67 (67Ga) or gallium-68 (68Ga) radiopharmaceutical to obtain images of a specific type of tissue, or disease state of tissue. Gallium salts like gallium citrate and gal ...
); alternatively, the longer-lived gallium-67 may be used. Gallium-68 is only used as a positron emitting tag for a ligand which binds to certain tissues, such as
DOTATOC
Edotreotide (USAN, also known as (DOTA0- Phe1- Tyr3) octreotide, DOTA-TOC, DOTATOC) is a substance which, when bound to various radionuclides, is used in the treatment and diagnosis of certain types of cancer. When used therapeutically it is an ...
, which is a
somatostatin analogue useful for imaging
neuroendocrine tumors
Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly occur in the intestine, where they are often called carcinoid tumors, but they are also found in the pancreas, lun ...
. Gallium-68 DOTA scans are increasingly replacing octreotide scans (a type of
indium-111 scan using octreotide as a somatostatin receptor ligand). The is bound to a chemical such as
DOTATOC
Edotreotide (USAN, also known as (DOTA0- Phe1- Tyr3) octreotide, DOTA-TOC, DOTATOC) is a substance which, when bound to various radionuclides, is used in the treatment and diagnosis of certain types of cancer. When used therapeutically it is an ...
and the positrons it emits are imaged by
PET-CT
Positron emission tomography–computed tomography (better known as PET-CT or PET/CT) is a nuclear medicine technique which combines, in a single gantry, a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scan ...
scan. Such scans are useful in locating
neuroendocrine tumors
Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly occur in the intestine, where they are often called carcinoid tumors, but they are also found in the pancreas, lun ...
and
pancreatic cancer.
Thus, octreotide scanning for NET tumors is being increasingly replaced by
gallium-68 DOTATOC scan.
References
* Isotope masses from:
**
* Isotopic compositions and standard atomic masses from:
**
**
* Half-life, spin, and isomer data selected from the following sources.
**
**
**
{{Navbox element isotopes
Gallium
Gallium