Myeloma
Fast Facts:
- Most common primary bone malignancy in adults.
- Lifetime risk is 1:143
- 5-year survival: 45%
Indications for PET/CT:
PET/CT has become a valuable diagnostic and management tool for myeloma patients (including solitary and multiple myeloma, non-secretory myeloma, relapsing disease, and extramedullary myeloma). It has been used successfully in many aspects of the disease process, including:
- Diagnosis
- Initial Staging
- Assessing Response to Therapy & Prognosis
- Recurrence, Restaging & Management
PET/CT Presentations/Manifestations:
- Most commonly, active myeloma presents with multiple, well-defined FDG-avid lytic lesions (typically involving the axial and proximal appendicular skeleton).
- Myeloma can present with diffuse skeletal increased FDG-uptake without well-defined lesions on the CT portion of the exam (the bones may appear osteopenic, without evidence of cortical destruction).
- If multiple foci of FDG uptake are noted without associated CT abnormalities, this likely represents early active disease (it is estimated that 30-50% of bone loss is required before lesions become visible on radiographs).
- Scattered non-avid lytic lesions are presumed to represent treated lesions.
- Extramedullary lesions most frequently involve the liver, spleen, lymph nodes and subcutaneous soft tissues.
Case 1
Case 2
Case 2 (Image 2)
Large FDG-avid lytic lesions involving the bilateral iliac bones, consistent with active myeloma.
Case 2 (Image 3)
FDG-avid lytic lesion within the manubrium, consistent with active myeloma.
Case 2 (Image 4)
Small FDG-avid lytic lesion of the T4 spinous process, consistent with active myeloma (an active right rib lesion is also noted, incompletely seen on this image).
Case 2 (Image 5)
Bilateral FDG-avid rib fractures, highly suspicious for pathologic fractures in this patient with multiple FDG-avid bone lesions.
Case 3
Case 3 (Image 2)
FDG-avid lytic lesion of the sacrum, consistent with active myeloma. A 3-mm left iliac bone lesion (arrow) is non-avid, presumably due to its small size, which is beneath the resolution of PET.
Case 3 (Image 3)
FDG-avid lytic lesion of the left iliac bone, consistent with active myeloma.
Case 3 (Image 4)
Tiny FDG-avid lytic lesion of the left medial acetabulum, consistent with active myeloma (would you have noticed this lesion if this study was only a CT scan?).
Case 4
Case 4 (Image 2)
Multiple (too numerous to count) lucent bone lesions are scattered throughout the spine of this patient (same patient as Image 1). All are non-avid, consistent with successfully treated disease.
Case 4 (Image 3)
Lucent lesions involving the spine and adjacent rib, non-avid, consistent with treated disease.
Case 4 (Image 4)
Multiple non-avid lucent lesions involving the spine and iliac bones, consistent with treated disease.