The Lawrence Livermore Realistic Phantom was developed under
the direction of the U.S Department of Energy, primarily as a
reference standard for the in-vivo counting of emissions from
low-energy transuranic nuclides.
The organs of interest are the lungs, liver and lymph nodes.
Each of these may be radioactive or inert. These organs are
accommodated in a male thorax generally similar to average
adult males.
The Livermore phantom contains a synthetic bone skeleton
molded within a soft-tissue-equivalent material. The organs
are located in an internal cavity with a separate torso cover
that closes the phantom. Anterior sections of ribs and the
sternum are molded into this cover.
Soft-tissue-equivalent blocks are used to position the organs
and fill significant air spaces, providing continuity of the
soft tissues throughout the phantom. The phantom is shipped
assembled with inert organs. Any or all of these organs can be
replaced with radioactive organs, which are shipped in
separate packages.
All organs are made of soft-tissue equivalent materials. Lungs
are available with nuclides uniformly dispersed throughout the
lung molding material. Optional organs (developed by RSD and
not part of
 the original DOE specifications) are inert, but
have holes in 2 cm2 grids. These either can be filled with
inert plugs or with active capsules to establish any desired
distribution within the lungs.
The liver as the same loading flexibility, but another option
is available, designed for use with solutions having
relatively short half-lives. This liver is a hollow shell with
a fill/drain port.
If the liver is not required, it may be replaced with the
Abdominal Contents, which are also available with a hole
matrix, or active.
Lymph nodes are available as hollow shells or as active
packets. Two are 8 mm in diameter by 17 mm long. A third is 13
mm in diameter by 25 mm long. They are positioned in recesses
molded in a lymph node block.
 Transuranic emissions from individuals with varying amounts of
muscle and/or adipose tissue may be so attenuated as to be
undetectable. Chest overlay plates were developed to ensure
the validity of in-vivo counting of such individuals.
There are three sets of plates, each in four graded
thicknesses. One set
is equivalent to 87% adipose and 13%
muscle, another is equivalent to 50% adipose and 50% muscle,
and the third is equivalent to 100% muscle. Plates of each
material and/or each thickness are available separately.
Three sets of concentric circles are drawn in permanent black
ink over the torso cover and over each chest overlay plate.
They range in 1 in. increments from 1 in. to 5 in. in
diameter, with a 5.5 in. diameter outer circle. One set of
circles is placed over each lung region, with the outer circle
tangent to the inferior aspect of the clavicle and protruding
over the sternum. The third set is placed over the liver.
A 2cm2 grid is projected in red ink over most of
the chest surface by the same technique that is used for the
circles. All targets are consistent among all phantoms.
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Radiation Therapy
The Lawrence Livermore