Download New Positron-Emission Tomography/Computed Tomography

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Novel Approaches
Susan Doyle-Lindrud, DNP, AOCNP®, DCC—Associate Editor
New Positron-Emission Tomography/Computed Tomography
Imaging for Bone Metastases
Susan Doyle-Lindrud, DNP, AOCNP®, DCC
With the increase in new therapies to treat cancer, improved diagnostic tools are
needed to help determine best treatment options. Many radiopharmaceuticals used
with positron-emission tomography/computed tomography have been tested to
evaluate solid cancers. Two of the newer radiopharmaceuticals are 18F sodium fluoride and radiolabeled choline. This article reviews these new technologies, providing
background and potential clinical use.
At a Glance
• Several new radiotracers have been developed and are being evaluated in clinical
oncology practice.
• These new radiopharmaceuticals are being used with positron-emission tomography/
computed tomography imaging.
• This new type of imaging may allow for earlier detection of metastases than traditional methods.
Susan Doyle-Lindrud, DNP, AOCNP®, DCC, is an assistant dean of Academic Affairs in the School of Nursing
at Columbia University in New York, NY. The author takes full responsibility for the content of the article.
The author did not receive honoraria for this work. No financial relationships relevant to the content of
the article have been disclosed by the author or editorial staff. Doyle-Lindrud can be reached at smd9@
columbia.edu, with copy to editor at [email protected].
Key words: computed tomography; positron-emission tomography; diagnostic tools; radiopharmaceuticals
Digital Object Identifier: 10.1188/16.CJON.135-136
B
one is one of the most common
sites for distant metastases from
cancer. Metastatic disease is a more
frequent cause of cancer in the bone
than primary bone tumors, and bone
is the third most common organ affected by cancer after the lung and liver
(O’Sullivan, Carty, & Cronin, 2015). Of
the primary tumors that metastasize to
the bone, the most common are breast,
prostate, thyroid, renal, and lung cancers
(Bastawrous, Bhargava, Behnia, Djang,
& Haseley, 2014). Metastatic lesions may
initially cause little to no symptoms and
may be diagnosed incidentally during
the staging evaluation. Bony metastatic
disease mainly involves the vertebral
column, sacrum, pelvis, and proximal
femurs. Within the vertebral column, the
most common site is the lumbar spine,
followed by the thoracic and cervical
spine (Choi & Raghavan, 2012).
Detecting bone metastases through imaging is important for staging purposes.
Imaging helps to identify the lesion and
directs further care, such as a biopsy
for diagnostic purposes and staging, or
further imaging to identify oncologic
emergencies, such as a spinal cord compression. The choice of imaging is determined based on clinical presentation and
pathologic diagnosis.
Characteristics of Bone
Metastases
Bone metastases are characterized as
osteolytic, osteoblastic, or mixed. Osteo-
Clinical Journal of Oncology Nursing • Volume 20, Number 2 • Novel Approaches
lytic means that the tumor causes bone
breakdown. On x-ray, this looks like a hole
or lucency within the bone. Osteolytic
disease is seen in multiple myeloma, melanoma, renal cell carcinoma, and thyroid
cancers. Osteoblastic disease is characterized by the deposition of new bone formation because of activation of osteoblasts.
Although these areas are harder because
of the deposition of additional bony tissue, they are actually weaker than normal
bone tissue. Examples of tumors that
have predominantly osteoblastic bony
metastases are prostate cancer, Hodgkin
lymphoma, and small cell carcinoma of
the lung (Fang & Xu, 2015).
Imaging
For decades, the imaging of osseous
metastatic disease has been obtained by
a bone scan with the most commonly
used tracer, technetium 99m methylene
diphosphonate. This tracer accumulates
in areas of increased osteoblastic activity, providing information on the entire
skeleton. The bone scan has been shown
to be an effective, low-cost, and widely
available test (Cuccurullo, Cascini, Tamburrini, Rotondo, & Mansi, 2013). The
bone scan is useful for evaluating osteoblastic lesions found in lung and prostate
cancers but is less useful for osteolytic
tumors, such as multiple myeloma. The
addition of single photon emission computed tomography (SPECT) to bone scans
has improved diagnostic accuracy. However, SPECT does not improve the sensitivity for lytic lesions (Yang, Liu, Wang,
Xu, & Deng, 2011).
Another diagnostic test, the 18F fluorodeoxyglucose positron-emission tomography (18F-FDG-PET), is useful for
diagnosing metastatic disease, including
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