Magnetic resonance imaging of the spine in multiple myeloma

New diagnostic strategy for multiple myeloma: A review

Multiple myeloma (MM) is the second most prevalent hematological malignancy and is distinguished by the aberrant proliferation of monoclonal plasma cells inside the bone marrow and production of M-protein. This condition frequently results in bone deterioration, acute kidney damage, anemia, and hypercalcemia. However, the clinical manifestations and accompanying symptoms of MM vary and may change as the condition evolves. Therefore, diagnosis of MM is difficult. At present, the confirmation of MM diagnosis necessitates the use of bone marrow biopsy, a procedure that is both invasive and challenging for assessing dynamic alterations in the disease. The integration of laboratory testing technologies with imaging technology has the potential to enhance the diagnostic effectiveness and provide a thorough evaluation of disease progression and prognosis in patients with MM. All the examination methods have advantages and disadvantages. Therefore, diagnosis is determined by the application of clinical characteristics, serological tests, and imaging investigations.

(Smoldering) multiple myeloma: mismatch between tumor load estimated from bone marrow biopsy at iliac crest and tumor load shown by MRI

In multiple myeloma and its precursor stages, precise quantification of tumor load is of high importance for diagnosis, risk assessment, and therapy response evaluation. Both whole-body MRI, which allows to investigate the complete bone marrow of a patient, and bone marrow biopsy, which is commonly used to assess the histologic and genetic status, are relevant methods for tumor load assessment in multiple myeloma. We report on a series of striking mismatches between the plasma cell infiltration estimating the tumor load from unguided biopsies of the bone marrow at the posterior iliac crest and the tumor load assessment from whole-body MRI.

Vertebral multiple myeloma with pathological fracture: the most common etiology for emergency spine surgery in patients with no cancer diagnosis on admission

OBJECTIVE

Vertebral compression fractures are common in multiple myeloma (MM). Modern treatment paradigms place emphasis on treatment with radiation, with surgery reserved for cases involving frank instability or severe neural compression. However, experience at the authors' institution has led them to suspect a more prominent role for surgical intervention in some settings. The authors undertook the present study to better understand the incidence of MM in undiagnosed patients who require urgent surgery for pathological vertebral fracture.

METHODS

The authors reviewed a prospectively collected database of all patients who underwent surgery with the senior author at their main hospital between June 1, 1998, and June 30, 2020. Patients admitted from the emergency room or after transfer from another hospital who then underwent surgery for pathological fracture during the same admission were included in the final analysis. Patients scheduled for elective surgery and those with previous cancer diagnoses were excluded.

RESULTS

Forty-three patients were identified as having undergone urgent surgical decompression and/or stabilization for pathological fracture. Histopathology confirmed diagnosis of MM in 22 (51%) patients, lung metastasis in 5 (12%) patients, and breast metastasis in 4 (9%) patients. Twelve (28%) patients were diagnosed with other types of metastatic carcinoma or undifferentiated disease. Sixteen of 29 (55%) men and 6 of 14 (42%) women were diagnosed with MM (p = 0.02). Seventeen of 34 (50%) patients who underwent surgery for neurological deficit, 5 of 6 (83%) patients who underwent surgery for spinal instability, and 0 (0%) patients who underwent surgery for pain with impending spinal cord injury were diagnosed with MM (p = 0.12).

CONCLUSIONS

A majority of patients presenting to the authors' hospital with no history of malignancy who required urgent surgery for pathological compression fracture were found to have MM or plasmacytoma. This disease process may affect a significant portion of patients requiring decompressive or stabilizing surgery for compression fracture in academic medical centers.

Multiple myeloma with intractable lumbar pain and diagnostic challenge with MRI: A case report

We present a 63-year-old male patient with intractable bone pain and rapidly progressive osteoporosis, who was diagnosed with multiple myeloma (MM) by CT despite normal magnetic resonance imaging (MRI) findings. The gold standard diagnostic modality for MM is MRI as it can be used to sensitively evaluate bone marrow, however, the current case highlights that MRI is not always accurate in evaluating MM. CT in combination with MRI could be used for secondary osteoporosis with intractable bone pain in order to determine the diagnosis, treatment, and prognosis.

Minimal residual disease in multiple myeloma: use of magnetic resonance imaging

The increasing percentage of patients achieving deep responses in multiple myeloma has led to the need for more sophisticated instruments to measure residual disease as a potential source of relapse. As minimal residual disease assessment is mostly performed on a bone marrow specimen from a certain area of the body, such samples have the limitation that they might not really represent the actual tumor burden, because focal accumulations of malignant cells might be either hit or missed. Magnetic resonance imaging is a highly sensitive technique for the assessment of tumor burden and can be performed as whole-body protocol, overcoming the problem of sampling error for minimal residual disease assessment. Despite its high sensitivity, however, magnetic resonance imaging cannot differentiate between vital and necrotic lesions after therapy. Therefore, new fusion and functional techniques are currently under investigation, and image-guided biopsies are performed to combine the strengths of all available methods.

MR Imaging of Multiple Myeloma in Tumour Mass Measurement at Diagnosis and during Treatment

The bone marrow of the spine, pelvis and proximal femora was examined with MR imaging at diagnosis in 30 cases of multiple myeloma (MM), and during treatment on 69 occasions. The MR pattern was normal, focal or diffuse and correlated to stage. A tumour mass index (TMI) was calculated by estimating the total myeloma mass visualised at MR imaging. The TMI correlated significantly with stage, lytic bone lesions, serum calcium, serum β-2-microglobulin and survival. No abnormalities were seen at MR investigation in 4 of 6 patients classified as stage II because of osteoporosis only. Therapy efficacy evaluation with MR imaging corresponded to clinical evaluation on 54 of the 69 occasions. MR examination of bone marrow in MM patients can be used for tumour mass assessment, both at diagnosis and during follow-up. Valuable information can be obtained when the tumour mass is difficult to estimate using clinical criteria, e.g. in non-secretory MM or when osteoporosis is the only variable indicating an increase in the tumour mass.

State-of-the-Art Imaging and Staging of Plasma Cell Dyscrasias

Monoclonal gammopathy of unknown significance (MGUS) is a clinically asymptomatic premalignant clonal plasma cell or lymphoplasmacytic proliferative disorder. Smoldering multiple myeloma, also called asymptomatic multiple myeloma, is an intermediate stage between MGUS and symptomatic multiple myeloma. As the name implies, extraosseous or extramedullary myeloma refers to the presence of myeloma deposits outside the skeletal system. Waldenström macroglobulinemia is a distinct subtype of plasma cell dyscrasia characterized by lymphoplasmacytic lymphoma in the bone marrow with an associated IgM monoclonal gammopathy. Amyloidosis is a condition characterized by extracellular deposition of fibrils composed of a variety of normal serum proteins.

MR imaging and PET/CT in diagnosis and management of multiple myeloma

Multiple myeloma is a common hematologic malignancy among the elderly population. Although there have been many advances in treatment over the past few decades, the overall prognosis for the disease remains poor. Conventional radiography has long been the standard of reference for the imaging of multiple myeloma. However, 10%-20% of patients with multiple myeloma do not have evidence of disease at conventional radiography. There is a growing body of evidence supporting use of magnetic resonance (MR) imaging and 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) in diagnosis and management of multiple myeloma. MR imaging is useful in detection of bone marrow infiltration, a finding often missed at conventional radiography. FDG PET/CT is especially sensitive for the detection of extramedullary disease and can help detect the metabolically active lesions that often precede evidence of osseous destruction at conventional radiography. MR imaging and FDG PET/CT are useful tools that can provide essential information for diagnosis and management of patients with multiple myeloma. Both modalities allow accurate localization of disease after chemotherapy or autologous stem cell transplantation and can provide important prognostic information that can influence further clinical decision making regarding therapy, particularly when tumor serum markers may be a less reliable indicator of disease burden after repeated treatments.

A magnetic resonance imaging-based prognostic scoring system to predict outcome in transplant-eligible patients with multiple myeloma

Diffuse and focal bone marrow infiltration patterns detected by magnetic resonance imaging have been shown to be of prognostic significance in all stages of monoclonal plasma cell disorders and have, therefore, been incorporated into the definition of the disease. The aim of this retrospective analysis was to develop a rapidly evaluable prognostic scoring system, incorporating the most significant information acquired from magnetic resonance imaging. Therefore, the impact of bone marrow infiltration patterns on progression-free and overall survival in 161 transplant-eligible myeloma patients was evaluated. Compared to salt and pepper/minimal diffuse infiltration, moderate/severe diffuse infiltration had a negative prognostic impact on both progression-free survival (P<0.001) and overall survival (P=0.003). More than 25 focal lesions on whole-body magnetic resonance imaging or more than seven on axial magnetic resonance imaging were associated with an adverse prognosis (progression-free survival: P=0.001/0.003 and overall survival: P=0.04/0.02). A magnetic resonance imaging-based prognostic scoring system, combining grouped diffuse and focal infiltration patterns, was formulated and is applicable to whole-body as well as axial magnetic resonance imaging. The score identified high-risk patients with median progression-free and overall survival of 23.4 and 55.9 months, respectively (whole-body-based). Multivariate analyses demonstrated that the magnetic resonance imaging-based prognostic score stage III (high-risk) and adverse cytogenetics are independent prognostic factors for both progression-free and overall survival (whole-body-based, progression-free survival: hazard ratio=3.65, P<0.001; overall survival: hazard ratio=5.19, P=0.005). In conclusion, we suggest a magnetic resonance imaging-based prognostic scoring system which is a robust, easy to assess and interpret parameter summarizing significant magnetic resonance imaging findings in transplant-eligible patients with multiple myeloma.

Role of Magnetic Resonance Imaging in the Management of Patients With Multiple Myeloma: A Consensus Statement

Purpose

The aim of International Myeloma Working Group was to develop practical recommendations for the use of magnetic resonance imaging (MRI) in multiple myeloma (MM).

Methods

An interdisciplinary panel of clinical experts on MM and myeloma bone disease developed recommendations for the value of MRI based on data published through March 2014.

Recommendations

MRI has high sensitivity for the early detection of marrow infiltration by myeloma cells compared with other radiographic methods. Thus, MRI detects bone involvement in patients with myeloma much earlier than the myeloma-related bone destruction, with no radiation exposure. It is the gold standard for the imaging of axial skeleton, for the evaluation of painful lesions, and for distinguishing benign versus malignant osteoporotic vertebral fractures. MRI has the ability to detect spinal cord or nerve compression and presence of soft tissue masses, and it is recommended for the workup of solitary bone plasmacytoma. Regarding smoldering or asymptomatic myeloma, all patients should undergo whole-body MRI (WB-MRI; or spine and pelvic MRI if WB-MRI is not available), and if they have > one focal lesion of a diameter > 5 mm, they should be considered to have symptomatic disease that requires therapy. In cases of equivocal small lesions, a second MRI should be performed after 3 to 6 months, and if there is progression on MRI, the patient should be treated as having symptomatic myeloma. MRI at diagnosis of symptomatic patients and after treatment (mainly after autologous stem-cell transplantation) provides prognostic information; however, to date, this does not change treatment selection.

[Radiological diagnostics of multiple myeloma]

CLINICAL/METHODICAL ISSUE

Robust and reliable imaging methods are required to estimate the skeletal tumor load in multiple myeloma, as well as for the diagnosis of extraskeletal manifestations. Imaging also plays an essential role in the assessment of fracture risk and of vertebral fractures.

STANDARD RADIOLOGICAL METHODS

The conventional skeletal survey has been the gold standard in the imaging of multiple myeloma for many years.

METHODICAL INNOVATIONS

Other modalities which have been investigated and are in use are whole-body computed tomography (WBCT), 18F-fluorodeoxyglucose positron emission tomography computed tomography (FDG PET-CT) and whole-body magnetic resonance imaging (WBMRI). These techniques are able to depict both mineralized bone and the bone marrow with a high sensitivity for myeloma lesions.

PERFORMANCE

Several studies have shown that cross-sectional imaging is superior to the skeletal survey in the detection of myeloma lesions and WBMRI has been shown to be significantly more sensitive than WBCT for the detection of focal myeloma lesions as well as for diffuse infiltration. The FDG PET-CT technique has a sensitivity comparable to WBMRI.

ACHIEVEMENTS

Due to the higher sensitivity in the detection of myeloma lesions WBCT and WBMRI should replace the skeletal survey.

PRACTICAL RECOMMENDATIONS

A WBCT should be performed if there is suspicion of multiple myeloma. If no focal lesions are found WBMRI or at least MRI of the spine and pelvis should be additionally performed if available. If WBMRI has been initially performed and focal lesions are present, an additional WBCT may be performed to assess the extent of bone destruction and fracture risk. In cases of monoclonal gammopathy of undetermined significance (MGUS), solitary and smoldering myeloma, a WBMRI, if available, should be performed in addition to WBCT.

Imaging of multiple myeloma: usefulness of MRI and PET/CT

Multiple myeloma is a heterogeneous hematologic disorder of plasma cells with varied bone marrow imaging appearances. With advancements in both treatment and use of advanced imaging over the last several decades, it is important for radiologists to recognize the imaging presentation of the disease and the staging implications of imaging. This paper reviews the staging as it relates to imaging, consensus recommendations for imaging, expected imaging appearances of myeloma, pitfalls, and complications associated with treatment that are demonstrable on imaging.

Evolving role of FDG PET/CT in multiple myeloma imaging and management

OBJECTIVE

Multiple myeloma is the most common cause of primary malignancy in bones. Radiography has been the imaging reference standard for decades. However, the growing use of CT, MRI, and PET technology has led to earlier diagnosis of multiple myeloma, more accurate therapy assessment, and better prediction of patient outcome. This article is focused on the evolving role of (18)F-FDG PET/CT in multiple myeloma diagnosis, therapy assessment, and prognosis.

CONCLUSION

FDG PET/CT is a valuable imaging modality in diagnosis, therapy assessment, and prognosis of multiple myeloma.

Comparison of modern and conventional imaging techniques in establishing multiple myeloma-related bone disease: a systematic review

This systematic review of studies compared magnetic resonance imaging (MRI), (18) F-fluorodeoxyglucose positron emission tomography (FDG-PET), FDG-PET with computerized tomography (PET-CT) and CT with whole body X-Ray (WBXR) or (whole body) CT in order to provide evidence-based diagnostic guidelines in multiple myeloma bone disease. A comprehensive search of 3 bibliographic databases was performed; methodological quality was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria (score 1-14). Data from 32 directly comparative studies were extracted. The mean QUADAS score was 7·1 (3-11), with quality hampered mainly by a poor description of selection and execution criteria. All index tests had a higher detection rate when compared to WBXR, with up to 80% more lesions detected by the newer imaging techniques; MRI (1·12-1·82) CT (1·04-1·33), PET (1·00-1·58) and PET-CT (1·27-1·45). However, the modern imaging techniques detected fewer lesions in the skull and ribs. In a direct comparison CT and MRI performed equally with respect to detection rate and sensitivity. This systematic review supports the International Myeloma Working Group guidelines, which recommend that WBCT can replace WBXR. In our opinion, the equal performance of MRI also indicates that it is a valuable alternative. As lesions of the skull and ribs are underdiagnosed by modern imaging techniques we advise additional X-rays of these regions. The consequences of this approach are discussed.

Diffusion-weighted imaging for non-invasive and quantitative monitoring of bone marrow infiltration in patients with monoclonal plasma cell disease: a comparative study with histology

Bone marrow plasma cell infiltration is a crucial parameter of disease activity in monoclonal plasma cell disorders. Until now, the only way to quantify such infiltration was bone marrow biopsy or aspiration. Diffusion-weighted imaging (DWI) is a magnetic resonance imaging-technique that may mirror tissue cellularity by measuring random movements of water molecules. To investigate if DWI is capable of assessing bone marrow cellularity in monoclonal plasma cell disease, we investigated 56 patients with multiple myeloma or monoclonal gammopathy of undetermined significance, and 30 healthy controls using DWI of the pelvis and/or the lumbar spine. In 25 of 30 patients who underwent biopsy, bone marrow trephine and DWI could be compared. Of the patients with symptomatic disease 15 could be evaluated after systemic treatment. There was a positive correlation between the DWI-parameter apparent diffusion coefficient (ADC) and bone marrow cellularity as well as micro-vessel density (P<0·001 respectively). ADC was significantly different between patients and controls (P<0·01) and before and after systemic therapy (P<0·001). In conclusion, DWI enabled bone marrow infiltration to be monitored in a non-invasive, quantitative way, suggesting that after further investigations on larger patient groups this might become an useful tool in the clinical work-up to assess tumour burden.

Prognostic significance of focal lesions in whole-body magnetic resonance imaging in patients with asymptomatic multiple myeloma

PURPOSE

With whole-body magnetic resonance imaging (wb-MRI), almost the whole bone marrow compartment can be examined in patients with monoclonal plasma cell disease. Focal lesions (FLs) detected by spinal MRI have been of prognostic significance in symptomatic multiple myeloma (sMM). In this study, we investigated the prognostic significance of FLs in wb-MRI in patients with asymptomatic multiple myeloma (aMM).

PATIENTS AND METHODS

Wb-MRI was performed in 149 patients with aMM. The prognostic significance of the presence and absence, as well as the number, of FLs for progression into sMM was analyzed.

RESULTS

FLs were present in 28% of patients. The presence per se of FLs and a number of greater than one FL were the strongest adverse prognostic factors for progression into sMM (P < .001) in multivariate analysis. A diffuse infiltration pattern in MRI, a monoclonal protein of 40 g/L or greater, and a plasma cell infiltration in bone marrow of 20% or greater were other adverse prognostic factors for progression-free survival in univariate analysis.

CONCLUSION

We recommend use of wb-MRI for risk stratification of patients with asymptomatic multiple myeloma.

International myeloma working group consensus statement and guidelines regarding the current role of imaging techniques in the diagnosis and monitoring of multiple Myeloma

Several imaging technologies are used for the diagnosis and management of patients with multiple myeloma (MM). Conventional radiography, computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine imaging are all used in an attempt to better clarify the extent of bone disease and soft tissue disease in MM. This review summarizes all available data in the literature and provides recommendations for the use of each of the technologies. Conventional radiography still remains the 'gold standard' of the staging procedure of newly diagnosed and relapsed myeloma patients. MRI gives information complementary to skeletal survey and is recommended in MM patients with normal conventional radiography and in all patients with an apparently solitary plasmacytoma of bone. Urgent MRI or CT (if MRI is not available) is the diagnostic procedure of choice to assess suspected cord compression. Bone scintigraphy has no place in the routine staging of myeloma, whereas sequential dual-energy X-ray absorptiometry scans are not recommended. Positron emission tomography/CT or MIBI imaging are also not recommended for routine use in the management of myeloma patients, although both techniques may be useful in selected cases that warrant clarification of previous imaging findings, but such an approach should ideally be made within the context of a clinical trial.

Therapeutic implications of myeloma staging

Clinical staging, such as with the Durie-Salmon clinical staging method, remains the most easily usable available method to classify patients with untreated multiple myeloma. However, for the development of new treatment strategies and comparison with prior results, new and powerful prognostic factors are now available. Serum beta 2 microglobulin alone represents the most reliable prognostic factor in multiple myeloma. Beta 2 microglobulin alone allows simple and reproducible classification of patients into low grade myeloma with low serum beta 2 microglobulin versus high grade myeloma with high serum beta 2 microglobulin. Plasma cell labelling index is an additional factor which allows identification of patients with MGUS as well as subclassification of patients with low serum beta 2 microglobulin into those with relatively better or worse prognosis. For each grade of myeloma young (less than 63 years of age) patients have a slightly better survival. Independently of serum beta 2 microglobulin and labelling index, DNA content values allow the identification of a subset of patients with biclonal or hypodiploid tumors and high grade disease. New or more sophisticated methods for evaluating myeloma cells such as by immunophenotyping or assessment of multi drug resistance enable the development of specific approaches to treatment in individual cases. It should also prove possible to identify patients especially suitable for newer biologic agents such as alfa interferon, G or G-MCSF and the various interleukins.

Whole-body MRI versus whole-body MDCT for staging of multiple myeloma

OBJECTIVE

The purpose of our study was to compare the detection rate of bone manifestations of multiple myeloma in whole-body MRI compared with MDCT and to assess accuracy in staging.

SUBJECTS AND METHODS

Forty-one patients with histologically confirmed myeloma were prospectively examined with a whole-body MDCT protocol and whole-body MRI on a 1.5-T system. The MRI protocol consisted of T1-weighted spin-echo and STIR sequences. For data analysis, the entire skeleton was divided into 61 regions per patient. Image evaluation was performed in a consensus reading by two radiologists blinded to the patients' history, with separate evaluation of each technique. The patients were staged by MRI and MDCT data separately according to the Durie and Salmon PLUS staging system.

RESULTS

On MRI, 15 patients showed no involvement. In 26 patients, 975 regions were affected: 21 patients were stage I, two were stage II, and 18 were stage III. On MDCT, 19 patients showed no involvement. In 22 patients, 462 regions were affected. For the detection rate, MRI was statistically superior to MDCT (p < 0.001, Wilcoxon's signed rank test). According to MDCT, 25 patients were stage I, seven were stage II, and nine were stage III. In 21 patients with involvement detected on both methods, MRI showed more extensive disease than MDCT. Eleven patients were understaged with MDCT compared with MRI, which was statistically significant (p < 0.001, chi-square test).

CONCLUSION

Whole-body MDCT leads to a significantly lower detection rate and staging in patients with multiple myeloma.

Guidelines for the use of imaging in the management of myeloma

In 2001, reference to the use of imaging in the British Committee for Standards in Haematology guidelines for the diagnosis and management of myeloma was confined to the standard use of plain X-rays in the diagnostic skeletal survey and emergency use of computed tomography (CT) and magnetic resonance (MR) imaging in the setting of cord compression. Since then, there has been a steady rise in interest in the use of various imaging techniques in the management of myeloma. The purpose of imaging in the management of myeloma includes the assessment of the extent and severity of the disease at presentation, the identification and characterisation of complications, and the assessment of response to therapy. Plain radiography, CT, and MR imaging are generally established examination techniques in myeloma whilst positron emission tomography (PET) and (99)Technetium sestamibi (MIBI) imaging are promising newer scanning techniques under current evaluation. These stand-alone imaging guidelines discuss recommendations for the use of each modality of imaging at diagnosis and in the follow up of patients with myeloma.

Role of MRI for the diagnosis and prognosis of multiple myeloma

For the correct staging of patients with multiple myeloma sensitive detection is mandatory in order to estimate prognosis and to decide for adequate therapy. Magnetic resonance imaging (MRI) is superior to radiography for both, focal and diffuse involvement. Five different infiltration patterns can be differentiated: (1) normal appearance of bone marrow despite minor microscopic plasma cell infiltration, (2) focal involvement, (3) homogeneous diffuse infiltration, (4) combined diffuse and focal infiltration, (5) "salt-and-pepper"-pattern with inhomogeneous bone marrow with interposition of fat islands. For the fast and complete assessment of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique should be employed. The focal involvement is clearly demonstrated as areas of high signal intensity on, e.g. STIR images. Diffuse involvement is best detected on unenhanced T1-weighted SE sequences and it manifests as homogeneous signal reduction. It can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. With parallel imaging and special coil devices, such as total imaging matrix (Siemens systems, Avanto) a "screening" of the whole red bone marrow as for myeloma infiltration is possible within a reasonable time. Patients without bone marrow infiltration have a significantly longer survival than patients with bone marrow infiltration in MRI at the time of diagnosis. However, even in stage I disease (Durie and Salmon) and negative X-ray films bone marrow infiltration in MRI may be detected in 29-50% of patients. Those patients typically show an earlier disease progression. Recently, MRI has been implemented in the clinical staging of patients with multiple myeloma. MRI may also monitor response to therapy. Signs of good response in cases with focal involvement are: reduction of signal intensity on T2-weighted spin echo images, lack or rim-like enhancement after contrast material injection or even a normalisation of bone marrow signal. In case of diffuse involvement a partly patchy reconversion to fatty marrow can be seen.

[Staging of multiple myeloma with MRI: comparison to MSCT and conventional radiography]

The staging of patients with multiple myeloma demands sensitive imaging methods for the assessment of the skeletal system. MRI allows for direct visualization of the bone marrow which exhibits five different infiltration patterns in multiple myeloma: 1. normal appearance of the bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. "salt and pepper" pattern with inhomogeneous bone marrow signals due to multiple fat islands. The combination of T1w-SE and STIR sequences is best suited for detecting all infiltration patterns and for the differential diagnoses e. g. hemangiomas. With parallel imaging in MRI, acquisition times can be markedly reduced and whole-body screening of the bone marrow can be achieved within 30 min. MRI is superior to radiography for the detection of focal as well as diffuse infiltration. Multidetector computed tomography and especially 16- and 64-detector row scanners allow fast imaging with thin slice collimation and multiplanar reconstructions. With low-dose protocols, effective dose reduction can be achieved, so that radiation exposure is only slightly higher than that of a whole-body skeletal x-ray exam. Sensitivity of MSCT is markedly superior to conventional radiography. Due to the direct visualization of the bone marrow with MRI, MRI is superior in detecting early infiltrations with myeloma cells without osteolyses. In advanced multiple myeloma, CT on the other hand, enables for more precise assessment of bony destructions and fracture risk.

Recent developments in hematopoietic stem cell transplantation for multiple myeloma

Multiple myeloma (MM) is often successfully controlled with conventional chemotherapy; however, complete remissions are uncommon, and cure is rare. High-dose therapy followed by administration of autologous or allogeneic stem cells, used for the treatment of MM in the past 15 years, is promising as a means of increasing remission rates and improving survival. Autologous transplantation has not always demonstrated survival benefits in randomized studies because most of the patients receiving transplants have relapses, whereas patients given conventional therapy can receive salvage transplants when relapse occurs. Efforts to improve the results of autologous transplantation include targeted radiation, tandem transplantation, and posttransplantation immunotherapy. Only allogeneic hematopoietic stem cell transplantation is potentially curative, owing to a graft-versus-myeloma effect. Although patients who receive either allogeneic or autologous stem cell transplants for MM have similar 3- to 5-year survival rates, only allograft recipients appear to enjoy long-term disease-free survival. High transplantation-related mortality associated with allogeneic stem cell transplantation is currently the major limitation to wider use of this potentially curative modality. Strategies designed to improve the therapeutic index of allografts include the use of nonablative conditioning regimens, peripheral blood cells rather than bone marrow, graft engineering, and targeted conditioning therapies, such as bone-seeking radioisotopes.

Magnetic resonance imaging as a supplement for the clinical staging system of Durie and Salmon?

BACKGROUND

This study evaluated the prognostic value of a three-grade staging system of spinal involvement using magnetic resonance imaging (MRI) in patients with multiple myeloma and determined its usefulness as an independent parameter in the staging system of Durie and Salmon.

METHODS

Seventy-seven previously untreated patients with multiple myeloma underwent MRI of the thoracic and lumbar spine with unenhanced T1-weighted spin echo and short-tau inversion time inversion recovery sequences. The patients were evaluated according to their infiltration patterns and the extent of bone marrow involvement was staged using a three-grade scale: Stage I, no focal or diffuse infiltration; Stage II, 1-10 foci or mild diffuse infiltration; Stage III, more than 10 foci or strong diffuse infiltration.

RESULTS

The infiltration patterns had no significant effect on survival. Of 77 patients, 25 would have been understaged using the standard staging system of Durie and Salmon without the findings of MRI and 8 patients would have been understaged if the staging was based only on MRI. The combination of the staging system of Durie and Salmon and MRI was highly significant with respect to survival (P < 0.0001, log rank analysis). MRI staging I-III was independent of the staging system of Durie and Salmon (Cox regression model).

CONCLUSIONS

A three-grade staging of spinal MRI provides a significant prognostic tool for patients with multiple myeloma. The authors propose including it in the staging system of Durie and Salmon.

Allogeneic hematopoietic cell transplantation for multiple myeloma

At the present time, allogeneic hematopoetic stem cell transplantation (AHSCT) is the only proven treatment for multiple myeloma (MM) that is potentially curative. This conclusion is based on observations of patients who have undergone AHSCT and are living disease-free for 5-15 years. While patients who receive either allogeneic or autologous stem cell transplants for MM have similar 3-5 year survival, only allograft recipients appear to enjoy long-term disease free survival. This is most likely due to an allogeneic graft-versus-myeloma effect, demonstrated most dramatically by complete responses observed after the simple infusion of donor lymphocytes for patients who have relapsed after a prior allograft. The very high transplant related mortality associated with standard allogeneic stem cell transplantation is currently the major limitation to wider use of this potentially curative treatment modality. Complications are age-related and thus standard AHSCT is offered only to patients under age 55; further limiting the utility of this treatment. The challenge for clinical investigators will be to reduce the incidence of post-transplant complications for patients receiving AHSCT for MM. These strategies include the use of non-ablative conditioning regimens, the use of peripheral blood stem cells rather than bone marrow, graft engineering and targeted conditioning therapies such as bone-seeking radioisotopes. In one such approach, tandem autologous/non-ablative allogeneic transplants have been shown to result in relatively low mortality, high complete response rates and 1-year survivals of 81%. Further follow-up and randomized trials will help to define the utility of this strategy.

Allogeneic hematopoietic cell transplantation for multiple myeloma

Some patients with multiple myeloma (MM) who have undergone allogeneic hematopoietic stem cell transplants remain free of disease 5 to 13 years later-a major accomplishment for a malignancy that had been resistant to all investigational therapies. Although it will require longer follow-up to determine how many are truly cured, results for patients with MM transplanted from identical twins suggest that long-term progression-free survival is possible. While 3- to 5-year survival is similar after allogeneic or autologous stem cell transplant for MM, only allograft recipients appear to enjoy long-term disease-free survival, most likely due to an allogeneic graft-versus-myeloma (GVM) effect. The very high transplant-related mortality associated with standard allogeneic stem cell transplantation is currently the major limitation to wider use of this potentially curative treatment. The challenge for clinical investigators will be to reduce the incidence of posttransplant complications. Strategies include the use of nonablative conditioning for allografts, the administration of peripheral blood stem cells (PBSC) rather than bone marrow, and the application of more focused, targeted conditioning therapies such as bone-seeking radioisotopes.

Skeletal survey in advanced multiple myeloma: radiographic versus MR imaging survey

In an attempt to compare the sensitivity of bone radiographs and bone marrow magnetic resonance (MR) imaging for bone lesion detection in patients with stage III multiple myeloma (MM) and to evaluate the possible consequences of the replacement of the conventional radiographic skeletal survey (RSS) by an MR survey of the spinal and pelvic bone marrow in these patients, we obtained MR studies of the thoracic and lumbar spine, pelvis and proximal femurs in addition to the conventional RSS (including radiographs of the skull, entire spine, pelvis, ribs, humerus and femurs) in 80 consecutive patients with newly diagnosed stage III MM according to the Durie and Salmon staging system (based on blood tests and on the RSS). The performance of MR and radiographic studies to detect bone lesions in given anatomic areas and in given patients were compared. The consequences on MM staging following the substitution of the RSS by the MR survey were assessed. MR imaging was superior to radiographs for lesion detection in the spine (76% v 42% of patients) and pelvis (75% v 46% of patients). The RSS was superior to the limited MR imaging survey for the detection of bone involvement in the patient population (87.5% v 79% of patients). If the RSS had been replaced by the MR imaging survey for patient staging, 7/80 patients would have been categorized as stage I and one as stage II MM on the basis of normal MR findings and biological findings consistent with these stages. Substitution of the RSS by a limited spinal and pelvic marrow MR survey would lead to 'understaging' of 10% of patients with otherwise stage III MM on the basis of blood tests and the conventional RSS.

Prognostic value of vertebral lesions detected by magnetic resonance imaging in patients with stage I multiple myeloma

We assessed the role of spinal magnetic resonance imaging (MRI) and bone densitometry as prognostic factors in patients with asymptomatic stage I multiple myeloma (MM) and negative skeletal survey. 55 consecutive patients underwent spinal MRI and 41 of them underwent bone densitometry by dual-energy X-ray absorptiometry (DEXA). Spinal MRI studies showed evidence of bone marrow involvement in 17/55 patients (31%). A diffuse pattern was present in three patients and a focal pattern in 14 patients, nine of them with only one nodular lesion. During a median follow-up of 25 months, 10 patients had disease progression, 8/17 patients with abnormal MRI and 2/38 patients with normal MRI. Median time to disease progression was not reached in both groups but was significantly different for patients with normal and those with abnormal patterns on MRI (P < 0.0001). Lumbar BMD was only slightly decreased compared with normal people (median lumbar Z score -0.43) and was not of prognostic value. Using a multivariate analysis the only two independent significant prognostic parameters were abnormal MRI (P<0.001, HR 30.4, 95% CI 4.3-213) and bone marrow plasmacytosis >20% (P=0.004, HR 16.4, 95% Cl 2.6-104). Thus, spinal MRI but not bone densitometry, appeared to be justified in patients with stage I asymptomatic MM and negative skeletal survey.

Spinal involvement of hematopoietic malignancies and metastasis: differentiation using MR imaging

The purpose of this study was to determine the usefulness of magnetic resonance imaging (MRI) for distinguishing spinal involvement of hematopoietic malignancies (lymphoma, leukemia, and multiple myeloma) from metastasis. 62 spinal MRIs were obtained in 60 patients with hematopoietic malignancies (n = 24) and metastasis (n = 36) in clinically and pathologically proven cases. MRI findings were evaluated in each group of patients for the pattern of involvement, signal change of vertebral body, location of paraspinal mass formation, location of epidural mass formation, cortical destruction, contour change, and compression fracture. Diffuse involvements were more commonly seen in hematopoietic malignancies than in metastasis (p < 0.05). Signal change confined to anterior element was seen in 9 metastasis but was not seen in hematopoietic malignancies. Cortical destructions were more commonly seen in metastasis than in hematopoietic malignancies (p < 0.05). Other findings did not show any statistical significance in both groups. MRI findings such as diffuse involvement, posterior epidural mass formation, and cortical destruction were useful to distinguish spinal involvement of hematopoietic malignancies and metastasis.

Solitary plasmacytoma in the thoracic spine. Two case reports

Plasmacytoma of the spine is rather common, but solitary occurrence is not. We report two cases of solitary plasmacytomas in the thoracic spine. A 72 year old male and a 77 year old male presented with progressive paraparesis. In both cases, magnetic resonance images revealed tumors in the thoracic spine which predominantly occupied the posterior elements of the spine with compression of the spinal cord. Abnormal proteinuria and proteinemia were not detected. The tumors were removed and patients' symptoms improved, the tumors were diagnosed by histopathology to be plasmacytomas. Further neuroradiological studies suggested them to be single lesions, so that the final diagnosis was solitary plasmacytomas. Solitary plasmacytoma should be considered for diagnosis of single spinal lesion even without abnormal proteinemia or proteinuria.

Hematopoietic Cell Transplantation for Multiple Myeloma

BACKGROUND: Multiple myeloma (MM) is a malignant plasma cell disorder with a median survival of three years. Despite the development of numerous conventional chemotherapy regimens and interferons, there has been little progress in improving the survival of patients with MM. Very high-dose chemoradiotherapy and autologous or allogeneic hematopoietic stem cell transplantation (HSCT) can result in high complete remission rates, even in patients with advanced disease. METHODS: A prospective, randomized study has shown that autologous HSCT results in superior response rates, progression-free survival, and disease-free survival compared with conventional chemotherapy. This is the first real advance in the treatment of this disease in 30 years. Unfortunately, few, if any, patients with MM who receive autologous HSCT are cured. RESULTS: Allogeneic HSCT can be curative for a fraction of patients with MM. However, very high transplant-related morbidity and mortality limit the application of allografts to younger patients with compatible donors. CONCLUSIONS: Challenges for the future include the development of less intensive or more disease-specific chemotherapy regimens that preserve the antitumor activity but are less toxic, improvement in the control of graft-vs-host disease in the case of allografts and, for autologous graft recipients, the development of vaccines and cytotoxic lymphocytes to augment a graft vs myeloma effect.

Development of vertebral fractures in patients with multiple myeloma: does MRI enable recognition of vertebrae that will collapse?

PURPOSE

We assessed the relationship between the presence and size of focal marrow abnormalities detected with MRI in vertebral bodies and the subsequent occurrence of vertebral fractures at follow-up in patients with multiple myeloma (MM).

METHOD

We reviewed 179 follow-up MR examinations of the thoracic and lumbar spine prospectively obtained in 37 patients with Stage 3 MM. For each of 131 vertebral bodies that fractured during follow-up, the status of the vertebral bone marrow was assessed on the last MR study obtained at a mean time interval of 4 months prior to fracture occurrence. When focal lesions were observed before fracture in vertebral bodies that later collapsed, their size was compared with that of the contemporary lesions observed in vertebrae that did not collapse.

RESULTS

Of 131 fractures, 82 (63%) appeared in vertebrae previously free of focal bone marrow abnormality at MRI and 49 (37%) appeared in vertebrae in which focal lesions were present on the previous MR study. The size of the lesions that preceded fractures (median 15 mm; range 6-50 mm) was not statistically different from the size of the contemporary lesions (median 15 mm; range 5-60 mm) that did not lead to fracture (p > 0.30).

CONCLUSION

This study in patients with MM suggests a lack of correlation between the preexistence of focal vertebral marrow lesions detected with MRI and the subsequent development of vertebral fractures.

Imaging of the spine. Techniques of MR imaging

Recently, magnetic resonance (MR) imaging has become the preferred method of evaluation for spinal disorders. The vertebrae, intervertebral disks, ligaments, spinal canal, and neural foramen may all be evaluated using current MR imaging techniques. MR imaging with paramagnetic contrast has developed into a valuable technique for diagnosing a tumor, an infection, or a degenerative disease. Computed tomography remains the procedure of choice for examining fine cortical bone detail including evaluation of spine fractures and assessing neural foraminal size, but it is not sensitive for detecting marrow-infiltrating disorders.

Development of plasma cell tumors during treatment of multiple myeloma

Plasma cell tumors (plasmacytomas-PCT) of the bone, or extramedullary PCT, may be diagnosed in patients with or without the diagnostic criteria for systemic multiple myeloma (MM). The reason for the local development of these tumors is not clear. Recent reports emphasize the contribution of CT and MRI in the detection of bone lesions and their expansion into the soft tissues. We report the development of PCT in nine patients with MM under maintenance treatment with alpha-IFN, of whom six had no evidence of systemic relapse and three had indications of early relapse. The PCT were located in the pelvis (4), thoracic (3), cervical (1), and lumbar (2) spine and in 8/9 cases were not demonstrable on plain X-rays. These observations suggest that frequent screening with advanced imaging techniques may detect local disease expansion in asymptomatic patients. Early application of radiochemotherapy may improve prognosis.

The value of magnetic resonance imaging in screening myeloma lesions of the lumbar spine

Screening of the skeleton by plain radiography was compared to magnetic resonance imaging (MRI) of the lumbar spine in 41 patients with multiple myeloma. In the lumbar spine, myeloma lesions were detected in 15 patients with radiography and in 28 patients with MRI. Radiography of the lumbar spine was not positive in any of the 13 cases with negative MRI, but in two of them radiography was positive elsewhere in the skeleton. We suggest that plain radiography is the most suitable method for screening all bone areas in multiple myeloma, but MRI of the lumbar spine is needed to study patients with normal radiographs.

Bone densitometry in patients with multiple myeloma

PURPOSE, PATIENTS, AND METHODS

We performed dual-energy x-ray absorptiometry in 10 selected patients with aggressive multiple myeloma in whom substantial tumor mass reduction was achieved after high-dose chemoradiotherapy followed by autologous blood stem cell transplantation.

RESULTS

In most cases, bone mineral density (BMD) of the spine was initially low (Mean Z score: -2.69, SEM 0.76) and dramatically increased after treatment (mean increase 16.4%; 7.7% with 95% confidence interval 2.2 to 12.2, excluding one patient whose spine BMD increased by 94.8%). In contrast, skeletal roentgenograms, computed tomographic scans, and magnetic resonance imaging did not reveal any significant improvement of patients' bone lesions.

CONCLUSIONS

In patients with multiple myeloma, bone densitometry could be a useful way to assess the efficacy of treatment on bone status.

Detection of bone marrow infiltration by non-Hodgkin's lymphoma--comparison of histological findings, analysis of gene rearrangements, and examination by magnetic resonance imaging

The histological examination of bone marrow specimens is one of the standard procedures in staging non-Hodgkin's lymphoma. To investigate the validity of a conventional unilateral iliac crest biopsy, we performed a prospective study comparing histological findings with analysis of gene rearrangements in bone marrow samples and magnetic resonance imaging of bone marrow. Twenty-seven consecutive patients with non-Hodgkin's lymphoma (ten with high grade, seventeen with low grade) were studied. In twelve patients, histological examination revealed bone marrow infiltration. Results of histology and magnetic resonance imaging were discordant in three of the twenty-seven patients. With magnetic resonance imaging, suspected infiltration was found in two patients without histological evidence for bone marrow involvement in the disease. In one patient, an infiltration was described by histology but MRI revealed no pathological findings. In this case, DNA analysis confirmed bone marrow infiltration by detection of a clonal rearrangement of the immunoglobulin heavy chain gene. Analysis of gene rearrangements was performed in ten patients. As examined by histology, five of them had bone marrow involvement in the disease and five had not. In all these cases, analysis of gene rearrangements confirmed the histological findings. Our data show that, despite the small volume of bone marrow specimens, the sensitivity of an iliac crest biopsy seems to be high in staging non-Hodgkin's lymphoma.