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WHOLE-BODY-LOW-DOSE MDCT
IN THE INVESTIGATION OF
MULTIPLE MYELOMA (MM) –
A NEW APPROCH AND OUR EXPERIENCE
Kamenetsky Natalya (1), Rachmilewitz Eliezer (2),
Katz Rama (1),
(1)Department of Diagnostic Imaging
(2) Department of Heamatology
E. Wolfson Medical Center, Holon, Israel.
• The idea of our study came from lately
published literature, especially the article:
“Whole-body low dose multidetector row-CT
in the diagnosis of MM:
an alternative to conventional radiography”
EJR,2005.
MM – Definition and diagnosis
Uncontrolled proliferation of neoplastic
plasma cell clone in the bone marrow.
Diagnosis based on laboratory and radiographic findings:
• Bone marrow containing more then 15% plasma cells
(normally no more then 4%).
• Blood serum or urine containing an abnormal protein
(M protein, Bence-Jones protein).
• Bone lesions found on skeletal survey as
generalized osteopenia or lytic bone deposits.
MM – Demographics:
• Most common primary bone tumor in adult.
• Multifocal lesions more common
• Solitary (Plasmacytoma) less common:
may be Intra/Extraosseous.
• Age: 40 years or older.
• M:F = 2:1
• More common in Afro-Americans then in
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Caucasians. Less common in Asians.
Median survival: 3-4 years.
MM – Skeletal involvement:
Osteolytic lesion
(80%) - found
particularly with nodular marrow infiltration.
small discrete lytic areas of bone destruction
with no reactive bone formation.
Arises within the medulla, may progress to
infiltrate the cortex and periosteum and be
accompanied with extraosseous soft tissue
masses.
MM-Skeletal involvment:
• Diffuse osteopenia (85%) is associated
with a packed pattern of marrow infiltration
– thinning of all trabeculae, vertebral body
collapse.
• Osteosclerosis –
or diffuse.
rare (1-3%), may be focal
• Normal survey (10%).
Skeletal involvement in MM:
Frequency in different bones correlates with
normal sites of red marrow distribution :
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Vertebra (66%).
Ribs (45%).
Skull (40%).
Shoulder (40%).
Pelvis (30%).
Long bones (25%).
CT versus plain film:
• Bone lesions of the axial skeleton, are
significantly better recognized by CT
by reducing the effects of overlying
soft tissue and bony structures.
• Bone lesions of the appendicular
skeleton are mostly well recognized in
both modalities.
Roll of imaging in MM patients:
• Diagnosis and staging.
• Diagnosis of extramedullary or solitary
plasmacytoma and directing a biopsy if
needed.
• Monitoring treatment response.
• Detection of relapse.
• Assessing fracture risk and directing
prophylactic treatment.
Staging by Durie and Saimon:
Stage 1:
(All)
Hemoglobin
>10g/100ml
Serum calcium
<12mg/100ml
M component IgG: <5g/100ml
IgA: <3g/100ml
Urine light chain
<4 g/24hr
Bone Lesion
none /solitary
Stage 2: Between Stage 1 and 3.
Stage 3:
(1 or more)
<8.5 g/100ml
>12mg/100ml
>7g/100ml
>5g/100ml
>12g/24hr
multiple
MM – Staging:
Patients with more then two unequivocal
lytic lesions are classified as stage 3,
indicating immediate treatment.
Different imaging modalities
in MM:
X-ray – Conventional plain film survey, CT.
MRI
Radionuclid imaging – Tc(99m)- MIBI,
F-18 FDG-PET.
Plain film skeletal survey:
Multiple lytic lesions (80%).
Solitary (Plasmacytoma) expansible lytic lesion.
Osteopenia (85%).
Vertebral body collapse and pathological fractures.
Normal survey (10%).
Shrinking or sclerosing deposits indicate a response.
Residual osteolysis may persist in inactive phase of disease.
No detection of extraosseous involvement.
CT Imaging:
• Detect disease in bone, bone marrow and
extramedullary sites.
• Focal pattern – sharp, lytic lesions with no sclerotic
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rim.
Diffuse faint osteolysis.
High (soft tissue) attenuation value of bone marrow.
• Positive response to treatment – Shrinking or
sclerosing deposit, disappearance of soft tissue
masses, reappearance of cortical contour and fatty
marrow content.
Our experience:
• On April - November 2006 we performed
41 CT skeletal surveys:
• 30 patients with known diagnosis of MM.
• 5 to exclude MM lesion in MGUS patients.
• 6 in other patients.
CT survey study protocol:
• Patient laying supine, cranio-caudal position,
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arms on abdomen.
Scan length from top of the skull down to the
end of the knees.
With suspended respiration when possible.
No oral or IV contrast material.
CT survey study protocol:
* Low dose CT parameters are based on the article from EJR 2005.
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MDCT 16 slices.
Surview 1536 mm.
120 KV, 70 mAs (300 mAs in spine CT)
Overall radiation dose of 5 mSv.
16*0.75mm collimation with 0.5 sec
rotation time.
• Table speed – 18mm/sec.
• Slice thickness – 3mm.
• Mean acquisition time – 38 sec.
CT survey study protocol:
• Reconstruction was done from raw data.
• bone filter with B60f kernel.
• F.O.V = 500mm max.
• multiplanar reformatted (MPR) whole body images
were reconstructed in sagital and coronal planes.
Divided into 3 different body parts:
• Head and neck, including cervical spine
• Chest and abdomen including the relevant spinal
column and arms
• pelvis and thighs.
Plain film skeletal survey protocol:
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Skull – AP and lateral.
Vertebral column – AP and lateral for each level.
Ribs – AP and oblique.
Pelvis – AP.
Upper and lower extremities – AP and lateral.
• Overall - 20 different plain films per patient.
• Radiation dose of 2.4 mSv.
Our experience – results:
• The majority had IgG gammopathy and
suffered from both osteopenia and lytic
lesions.
• 12 (29%) patients had vertebral collapse.
• 5 (12%) patients had large vertebral
lytic lesion at high risk for collapse.
Results:
In 7 (17%) patients we detected
significant extramedullary finding:
• 2 (4%) as part of the MM dieses itself.
• 5 (12%) not directly relevant to MM but
demand forwarder investigation.
CT versus plain film survey:
• 16 MM patients had a conventional plain film
survey done no more than two weeks before
the CT.
Comparing the two imaging modalities we found:
• In 5 (31%) patients lytic lesion that where not
found on the conventional survey.
• In 2 (12.5%) patients vertebral lytic lesion in
risk of collapse that were not found on the
plain film survey.
CT versus plain film survey:
Advantage:
• More sensitive and accurate in identifying and
characterizing lytic lesions.
• Especially important in the evaluation of
vertebral collapse and their possible
complications.
• Most beneficial in the diagnosis of large
lytic lesions in risk of phatological fracture.
CT versus plain film survey:
Advantage:
• Identify extramedullary involvement of the
dieses itself or incidental finding that may be
important.
• Guide biopsies.
Disadvantage:
• Higher radiation dose.
Radiation dose of X-ray Imaging:
Exam
type
Plain
film
survey
CT low
dose
70 mAs
CT high
dose
250 mAs
Radiation
dose
2.4
mSv
5
mSv
25.5
mSv
Summary:
• Accurate detection of skeletal lesions is
essential for the diagnosis, staging and
treatment in MM.
• The number, size and anatomic location of the
lesions are important to evaluate the patient’s
prognosis and quality of life.
• Whole body low dose CT is much more
sensitive and accurate than the classic plain
film survey.
Summary:
• In low dose CT the radiation dose is about
twice that of a plain film survey but much
lower than conventional skeletal CT.
• As in the literature, we propose this study as
an efficient and relatively available in
compare to other imaging modalities, for MM
patients.
MERCI! THANK YOU!
!!‫תודה‬
MERCI! THANK YOU!
!!‫תודה‬