Bone Cancer
Medical Tests & Diagnosis
Anamnesis (detailed medical review of past health state)
One of the first steps in establishing a cancer diagnosis is a detailed
and complex medical review of a patient's past health problems and general
health state, family medical history, symptoms, and bone cancer risk factors.
Laboratory Tests
There are four laboratory tests used to diagnose bone cancer:
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Alkaline phosphatase test: Alkaline phosphatase
is an enzyme that can be measured in blood tests. Normally, this enzyme
is present in high levels when bone-forming cells are very active
(usually in young children when their bones grow or when a broken
bone mends). High levels of alkaline phosphatase can also be an indicator
of bone tumors (when the tumor creates abnormal bone tissues). Even
if this test is not always conclusive, it signals the need for further
investigation.
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PTH test: PTH (parathormone) is a protein hormone
produced by the parathyroid gland. This protein is the most important
regulator of body's calcium and phosphorus. Lower-than-normal levels
of parathormone can be an indicator of bone cancer.
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Serum phosphorus: This is a test that measures
the level of phosphorus in the blood. Higher than normal levels of
phosphorus can be an indicator of bone cancer.
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Ionized calcium and serum calcium: These are
two blood tests that measure the amount of calcium in the blood. Ionized
or free calcium is the metabolically-active portion of calcium and
can be measured in blood tests. Calcium is an important element of
the bone structure. Higher than normal levels of calcium can be an
indicator of bone cancer.
Imaging Tests
1. Bone X-Ray: An x-ray test uses high energy electromagnetic
radiation to penetrate the body & bones to create their image on a
film. Dense tissues or structures appear white, the air black, and other
structures in shades of gray.
There are four types of x-rays used to diagnose bone cancer.
- Joints x-ray: This type of x-ray focuses on the knee,
hip, shoulder, wrist, ankle, hip, or other joint bones.
- Hands x-ray: This types of x-ray focuses on the bones
of the hands
- Extremities x-ray: This type of x-ray focuses on the
hands, wrists and feet bones.
- Chest x-ray: This type of x-ray determines if the
bone cancer has spread to the lungs.
The majority of bone tumors show up on x-ray films. When the bone is
affected by cancer, it has a ragged appearance or looks like it has a
hole inside.
2. Computed Tomography (CT scan): This test is similar with an
x-ray procedure, and creates a detailed cross-sectional image of the body.
A CT scan is usually performed in two steps for a better diagnosis outcome:
- First, the targeted area is scanned without a contrast agent
- Second, the targeted area is scanned after a contrast agent was
administrated.
The advantage of a CT scan is that it helps the doctor to locate the
tumor and "see" the tumor's size, shape, and spreading pattern.
3. Magnetic Resonance
Imaging (MRI): This test uses radio waves and strong magnets
to reveal a complete image of a targeted area of the body. The
energy from the radio waves is absorbed by the tissues and then
released into a pattern that allows the cancer to be diagnosed.
The MRI scan is one of the most conclusive tests for bone cancer
because it clearly outlines the bone tumors.
4. Positron Emission Tomography (PET): This is another
test used in diagnosing bone cancer. Positron Emission Tomography
uses radioactive glucose to locate cancer. This glucose contains
a radioactive atom that is absorbed by the cancerous cells and
then detected by a special camera. Usually, this test is performed
when the doctor suspects that the cancer spread to other organs
or structures.
5. Radionuclide Bone Scan: This type of scan uses
a very low radioactive material (diphosphonate) to "see"
whether or not the cancer has spread to other bones and the damage
suffered by the bone. Diseased bone cells from the entire skeleton
absorb this radioactive material and are then detected by the
scanning device. Affected areas appear as dense, gray to black
spots on the scan image. The main disadvantage of this test is
that cancer, arthritis, infection, or other bone diseases display
a similar pattern. Usually, radionuclide bone scan is followed
by other imaging tests or bone biopsy to complete the cancer diagnosis.
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Biopsies
A biopsy is a medical procedure that removes a tissue sample for microscopic
examination. The biopsy is the most conclusive test because it confirms
if the tumor is malignant or benign, the bone cancer type (primary or
secondary bone cancer), and stage.
According to the tumor size and type (malignant or benign) and the biopsy's
purpose (to remove the entire tumor or only a small tissue sample), there
are two types of biopsies used in bone cancer diagnose. These are: needle
biopsy and incisional biopsy.
1. Needle biopsy: During this procedure, the doctor makes a small
hole in the affected bone and removes a tissue sample from the tumor.
There are two types of needle biopsies:
- Fine needle aspiration: During this procedure, the tissue
sample is removed with a thin needle attached to a syringe.
- Core needle aspiration: During this procedure, the doctor
removes a small cylinder of tissue sample from the tumor with a rotating
knife like device.
2. Incisional biopsy: During this procedure, the doctor cuts into
the tumor and removes a tissue sample.
Article by Alina Morrow, MS
Medical Writer
OmniMedicalSearch.com
Page Covers: What are the tests for bone cancer?
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