Neovascularization of bone marrow in patients with diffuse multiple myeloma

Whole-body magnetic resonance imaging (WBMRI) versus whole-body computed tomography (WBCT) for myeloma imaging and staging

Myeloma-associated bone disease (MBD) develops in about 80-90% of patients and severely affects their quality of life, as it accounts for the majority of mortality and morbidity. Imaging in multiple myeloma (MM) and MBD is of utmost importance in order to detect bone and bone marrow lesions as well as extraosseous soft-tissue masses and complications before the initiation of treatment. It is required for determination of the stage of disease and aids in the assessment of treatment response. Whole-body low-dose computed tomography (WBLDCT) is the key modality to establish the initial diagnosis of MM and is now recommended as reference standard procedure for the detection of lytic destruction in MBD. In contrast, whole-body magnetic resonance imaging (WBMRI) has higher sensitivity for the detection of focal and diffuse plasma cell infiltration patterns of the bone marrow and identifies them prior to osteolytic destruction. It is recommended for the evaluation of spinal and vertebral lesions, while functional, diffusion-weighted MRI (DWI-MRI) is a promising tool for the assessment of treatment response. This review addresses the current improvements and limitations of WBCT and WBMRI for diagnosis and staging in MM, underlining the fact that both modalities offer complementary information. It further summarizes the corresponding radiological findings and novel technological aspects of both modalities.

Quantitative whole-body MR imaging for assessment of tumor burden in patients with multiple myeloma: correlation with prognostic biomarkers

Background

To assess the quantification of tumor burden in multiple myeloma (MM) patients using whole-body magnetic resonance imaging (MRI) and to identify the correlation between MRI parameters and prognostic biomarkers.

Methods

We retrospectively analyzed 95 newly diagnosed MM patients treated at our hospital from June 2018 to March 2020. All patients underwent whole-body MRI examination, including diffusion-weighted whole-body imaging with background body signal suppression (DWIBS), modified Dixon chemical-shift imaging (mDIXON), and short TI inversion recovery (STIR) sequences. The MRI presentation was used to determine MM infiltration patterns and calculate apparent diffusion coefficient (ADC) and a fat fraction (FF). The one-way ANOVA and Kruskal-Wallis test were used to compare the differences of these values between DS, ISS, and R-ISS stages in different MM infiltration patterns. Spearman correlation test was used for correlation analysis of ADC and FF against prognostic biomarkers, and two independent sample t-test was used to evaluate the differences of ADC and FF in different free light-chain ratio groups.

Results

The MRI presentation was classified into normal pattern (36 patients; 37.9%), diffuse (27 patients; 28.4%), and focal (32 patients; 33.7%) infiltration patterns. Statistically significant ADC and FF differences between different DS, ISS, and R-ISS stages were observed in normal/diffuse infiltration patterns but not in focal infiltration patterns. The ADC and FF of the normal/diffuse infiltration pattern showed correlations with hemoglobin, β2-microglobulin, bone marrow plasma cells, flow cytometry of bone marrow cells, and serum monoclonal protein. In contrast, ADC in focal infiltration patterns was negatively correlated with β2-microglobulin and C-reactive protein. The FF of patients with a normal/diffuse infiltration pattern was higher in the low free light-chain ratio group than that in the high free light-chain ratio group (P=0.023).

Conclusions

Our observations indicate that quantitative whole-body functional MRI examination may serve as an effective complement to imaging diagnosis based on morphology and provide further information on the tumor burden of patients with MM.

Osteocyte Vegf-a contributes to myeloma-associated angiogenesis and is regulated by Fgf23

Multiple Myeloma (MM) induces bone destruction, decreases bone formation, and increases marrow angiogenesis in patients. We reported that osteocytes (Ocys) directly interact with MM cells to increase tumor growth and expression of Ocy-derived factors that promote bone resorption and suppress bone formation. However, the contribution of Ocys to enhanced marrow vascularization in MM is unclear. Since the MM microenvironment is hypoxic, we assessed if hypoxia and/or interactions with MM cells increases pro-angiogenic signaling in Ocys. Hypoxia and/or co-culture with MM cells significantly increased Vegf-a expression in MLOA5-Ocys, and conditioned media (CM) from MLOA5s or MM-MLOA5 co-cultured in hypoxia, significantly increased endothelial tube length compared to normoxic CM. Further, Vegf-a knockdown in MLOA5s or primary Ocys co-cultured with MM cells or neutralizing Vegf-a in MM-Ocy co-culture CM completely blocked the increased endothelial activity. Importantly, Vegf-a-expressing Ocy numbers were significantly increased in MM-injected mouse bones, positively correlating with tumor vessel area. Finally, we demonstrate that direct contact with MM cells increases Ocy Fgf23, which enhanced Vegf-a expression in Ocys. Fgf23 deletion in Ocys blocked these changes. These results suggest hypoxia and MM cells induce a pro-angiogenic phenotype in Ocys via Fgf23 and Vegf-a signaling, which can promote MM-induced marrow vascularization.

Comparison of whole body magnetic resonance imaging (WBMRI) to whole body computed tomography (WBCT) or 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) in patients with myeloma: Systematic review of diagnostic performance

OBJECTIVES

To undertake a systematic review to determine the diagnostic performance of whole body MRI (WBMRI) including diffusion weighted sequences (DWI) compared to whole body computed tomography (WBCT) or 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) in patients with myeloma.

METHODS

Two researchers searched the primary literature independently for WBMRI studies of myeloma. Data were extracted focusing on the diagnostic ability of WBMRI versus WBCT and 18F-FDG PET/CT. Meta-analysis was intended.

RESULTS

6 of 2857 articles were eligible that included 147 patients, published from 2008 to 2016. Studies were heterogeneous including both newly diagnosed & relapsed patients. All were single centre studies. Four of the six studies (66.7%) accrued prospectively and 5/6 (83.3%, 3 prospective) included WBMRI and 18F-FDG PET/CT. Three of seven (42.9%) included DWI. The lack of an independent reference standard for individual lesions was noted in 5/6 (83.3%) studies. Studies reported that WBMRI detected more lesions than 18F-FDG PET/CT (sensitivity 68-100% versus 47-100%) but was less specific (specificity 37-83% versus 62-85.7%). No paper assessed impact on management.

CONCLUSIONS

Studies were heterogeneous, the majority lacking an independent reference standard. Future prospective trials should address these limitations and assess the impact of WBMRI on management.

Whole-body MRI, dynamic contrast-enhanced MRI, and diffusion-weighted imaging for the staging of multiple myeloma

Magnetic resonance imaging (MRI) is the most sensitive imaging technique for the detection of bone marrow infiltration, and has therefore recently been included in the new diagnostic myeloma criteria, as proposed by the International Myeloma Working Group. Nevertheless, conventional MRI only provides anatomical information and is therefore only of limited use in the response assessment of patients with multiple myeloma. The additional information from functional MRI techniques, such as diffusion-weighted imaging and dynamic contrast-enhanced MRI, can improve the detection rate of bone marrow infiltration and the assessment of response. This can further enhance the sensitivity and specificity of MRI in the staging of multiple myeloma patients. This article provides an overview of the technical aspects of conventional and functional MRI techniques with practical recommendations. It reviews the diagnostic performance, prognostic value, and role in therapy assessment in multiple myeloma and its precursor stages.

Imaging of Spinal Manifestations of Hematological Disorders

Imaging manifestations of hematological diseases and their potential complications are broad, and there may be significant overlap in features of various disease processes. Knowledge of appropriate choice of imaging test, pertinent imaging patterns, and pathophysiology of disease can help the reader increase specificity in the diagnosis and treatment of the patient. Most importantly, we encourage readers of this review to engage their radiologists during the diagnostic, treatment, and management phases of care delivery.

MRI in multiple myeloma: a pictorial review of diagnostic and post-treatment findings

Magnetic resonance imaging (MRI) is increasingly being used in the diagnostic work-up of patients with multiple myeloma. Since 2014, MRI findings are included in the new diagnostic criteria proposed by the International Myeloma Working Group. Patients with smouldering myeloma presenting with more than one unequivocal focal lesion in the bone marrow on MRI are considered having symptomatic myeloma requiring treatment, regardless of the presence of lytic bone lesions. However, bone marrow evaluation with MRI offers more than only morphological information regarding the detection of focal lesions in patients with MM. The overall performance of MRI is enhanced by applying dynamic contrast-enhanced MRI and diffusion weighted imaging sequences, providing additional functional information on bone marrow vascularization and cellularity.

This pictorial review provides an overview of the most important imaging findings in patients with monoclonal gammopathy of undetermined significance, smouldering myeloma and multiple myeloma, by performing a ‘total’ MRI investigation with implications for the diagnosis, staging and response assessment.

Main message

• Conventional MRI diagnoses multiple myeloma by assessing the infiltration pattern.

• Dynamic contrast-enhanced MRI diagnoses multiple myeloma by assessing vascularization and perfusion.

• Diffusion weighted imaging evaluates bone marrow composition and cellularity in multiple myeloma.

• Combined morphological and functional MRI provides optimal bone marrow assessment for staging.

• Combined morphological and functional MRI is of considerable value in treatment follow-up.

Intravoxel Incoherent Motion Diffusion-weighted Imaging of Multiple Myeloma Lesions: Correlation with Whole-Body Dynamic Contrast Agent-enhanced MR Imaging

PURPOSE

To correlate intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters with the enhancement patterns of bone marrow and focal lesion obtained on whole-body (WB) dynamic contrast agent-enhanced (DCE) magnetic resonance (MR) images in patients with stage-III multiple myeloma (MM) before and after systemic therapy.

MATERIALS AND METHODS

Twenty-seven patients with MM were retrospectively included in this institutional review board-approved study. Requirement for written informed consent was waived. All patients underwent WB DCE MR imaging before treatment and 18 patients underwent repeat MR imaging 3 months after treatment. A transverse IVIM DWI sequence with 10 b values (0, 10, 20, 30, 50, 80, 100, 200, 400, and 800 sec/mm(2)) was acquired within bone marrow and focal lesions. The IVIM parameters (perfusion fraction [f], molecular diffusion coefficient [D], and perfusion-related D [D*]) and apparent diffusion coefficient (ADC) were extracted for both focal lesions and bone marrow and correlated with focal lesions and maximal bone marrow enhancement (BMEmax) (Spearman correlation coefficient) at baseline and at follow-up (Wilcoxon signed-rank test).

RESULTS

D and ADC values positively correlated with BMEmax (r = 0.7, P < .001; and r = 0.455, P = .0435, respectively). Patients with increased BMEmax showed significantly increased ADC and D within bone marrow versus patients who did not have increased BMEmax (ADC, 0.67 × 10(-3) mm(2)/sec vs 0.54 × 10(-3) mm(2)/sec, P = .03; D, 0.58 × 10(-3) mm(2)/sec vs 0.42 × 10(-3) mm(2)/sec, P < .001). Within focal lesions, f was the maximum in lesions that showed enhancement followed by washout. After treatment in good responders, the significant decrease in maximal enhancement value of focal lesions (baseline vs after treatment, 213.9% ± 78.7 [standard deviation] vs 131% ± 53.6, respectively; P < .001) was accompanied by a significant decrease in f (baseline vs after treatment, 11% ± 3.8 vs 5.8% ± 4.7, respectively; P < .001).

CONCLUSION

Diffuse bone marrow involvement is associated with increased D. Hypervascular focal lesions with high maximal enhancement value of focal lesions also show high f value. Likewise, the decreased maximal enhancement value of focal lesions after treatment is accompanied by decreased f.

Pre-treatment staging of multiple myeloma patients: comparison of whole-body diffusion weighted imaging with whole-body T1-weighted contrast-enhanced imaging

BACKGROUND

Multiple myeloma (MM) is a hematologic malignancy characterized by the clonal proliferation of plasma cells. Accurate staging is of pivotal importance in the management of MM. Advanced imaging techniques, such as magnetic resonance imaging (MRI), are increasingly used for the initial diagnosis and staging of MM.

PURPOSE

To compare whole-body (WB) MR diffusion-weighted imaging with background body signal suppression (DWIBS) with (WB) MR fat-suppressed T1-weighted contrast-enhanced imaging (T1-CE) in the pre-treatment staging evaluation of multiple myeloma (MM) patients.

MATERIAL AND METHODS

Thirty-six patients with MM were included in the study. T1-CE and DWIBS were performed using a 3 T scanner. The Durie-Salmon plus staging system was used. Kappa statistics was used to assess agreement.

RESULTS

For all MM stages good to very good agreement was found for both T1-CE and DWIBS. The unweighted kappa statistic indicated a moderate, good and very good agreement between T1-CE and DWIBS for stages I, II, and III, respectively. In particular, in 67% of patients the MM staging according to T1-CE was not different from DWIBS. In the remaining 33% of patients, the MM stage obtained with T1-CE was lower than that provided by DWIBS.

CONCLUSION

DWIBS and T1-CE were concordant in the majority of patients. In a minority of cases DWIBS evidenced areas of water restriction that did not correspond to contrast enhancement areas. Studies monitoring therapeutic response in relation to tumour burden and aggressiveness should be performed to assess the clinical relevance of DWIBS findings.

Tumor load in patients with multiple myeloma: β2-microglobulin levels versus whole-body MRI

OBJECTIVE

Beta-2-microglobulin is a serum maker of tumor burden in hematologic malignancies. We aimed to correlate serum β2-microglobulin levels in patients with multiple myeloma (MM) to tumor mass determined by whole-body MRI.

MATERIALS AND METHODS

We retrospectively included patients with newly diagnosed, untreated MM who underwent whole-body MRI at our institution between 2003 and 2011. Patients with a glomerular filtration rate of less than 60 mL/min were excluded from analysis because β2-microglobulin levels are increased in renal failure. Thirty patients could be included. Whole-body MRI examinations (T1-weighted turbo spin-echo and STIR sequences) were assessed by two musculoskeletal radiologists in consensus for focal lesions and the presence of diffuse myeloma infiltration. The presence of diffuse infiltration was confirmed by histology as the reference standard. MM was staged according to the Durie and Salmon PLUS staging system.

RESULTS

According to whole-body MRI findings, MM was classified as Durie and Salmon PLUS stage I (low grade) in 13 patients, stage II (intermediate grade) in six patients, and stage III (high grade) in 11 patients. As we expected, most patients with stage I disease (12/13) had normal β2-microglobulin levels (≤ 3 mg/L). Higher β2-microglobulin values were associated with a higher stage of disease (p < 0.05). However, five of six patients with stage II MM and five of 11 patients with stage III MM showed normal β2-microglobulin levels. Thus, 10 of 17 patients (58.8%) with substantial infiltration in the bone marrow showed false-negative β2-microglobulin levels.

CONCLUSION

Serum β2-microglobulin levels correlate with tumor stage in MM. However, it may be misleading as a marker of tumor load in a subset of patients with substantial myeloma infiltration in the bone marrow. Whole-body MRI may display the full tumor load and correctly show the extension of myeloma infiltrates.

Differentiation of myeloma and metastatic cancer in the spine using dynamic contrast-enhanced MRI

Spinal myeloma and metastatic cancer cause similar symptoms and show similar imaging presentations, thus making them difficult to differentiate. In this study, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed to differentiate between 9 myelomas and 22 metastatic cancers that present as focal lesions in the spine. The characteristic DCE parameters, including the peak signal enhancement percentage (SE%), the steepest wash-in SE% during the ascending phase and the wash-out SE%, were calculated by normalizing to the precontrast signal intensity. The two-compartmental pharmacokinetic model was used to obtain K(trans) and kep. All nine myelomas showed the wash-out DCE pattern. Of the 22 metastatic cancers, 12 showed wash-out, 7 showed plateau, and 3 showed persistent enhancing patterns. The fraction of cases that showed the wash-out pattern was significantly higher in the myeloma group than the metastatic cancer group (9/9=100% vs. 12/22=55%, P=.03). Compared to the metastatic cancer group, the myeloma group had a higher peak SE% (226%±72% vs. 165%±60%, P=.044), a higher steepest wash-in SE% (169%±51% vs. 111%±41%, P=.01), a higher K(trans) (0.114±0.036 vs. 0.077±0.0281/min, P=.016) and a higher kep (0.88±0.26 vs. 0.49±0.23 1/min, P=.002). The receiver operating characteristic analysis to differentiate between these two groups showed that the area under the curve was 0.798 for K(trans), 0.864 for kep and 0.919 for combined K(trans) and kep. These results show that DCE-MRI may provide additional information for making differential diagnosis to aid in choosing the optimal subsequent procedures or treatments for spinal lesions.

Tumor endothelial markers as a target in cancer

INTRODUCTION

Several anti-angiogenic agents have been developed and some of them have been clinically applied in the tumor therapy. Anti-angiogenic therapy faces some hurdles: inherent or acquired resistance, increased invasiveness, and lack of biomarkers. Characterization of tumor endothelial markers may help to target endothelium and to identify potential predictive factors of response to anti-angiogenic therapies. Numerous surrogates, angiogenic and endothelium markers have emerged from recent pre-clinical studies, including physiological and soluble molecules in plasma and from platelets, circulating cells, tumor tissue factors and imaging markers. However, no wholly validated biomarkers currently exist to predict the success or the failure of the anti-angiogenic therapy of cancer. Therefore, the research of suitable and validate biomarkers is currently ongoing.

AREAS COVERED

This review provides an overview of the status of our knowledge concerning tumor endothelial markers, therapeutics targeting, possible resistance mechanisms and predictive value of these biomarkers and discuss future strategies to use and identify them in the anti-angiogenic therapy.

EXPERT OPINION

Anti-angiogenesis is a milestone to improve the treatment of several types of cancer and predictive biomarkers for a response to anti-endothelium therapy are one of the most important challenges for anti-angiogenesis research.

Imaging in multiple myeloma

In multiple myeloma, imaging is required to determine the stage of disease and to anticipate impending bone fractures. Whereas the traditionally used Durie and Salmon staging system includes lytic bone lesions in plain films as criteria, modern systems include MRI findings. MRI is most sensitive to both diffuse bone marrow involvement as well as solid plasma cell tumors. Whole-body low-dose CT (WBCT) may replace plain films in the near future, since it is quicker, more sensitive, and is better tolerated by patients. Intramedullary lesions are well seen as long as they are located in long bones where they are surrounded by fat. Diffuse bone marrow infiltration as well as intravertebral lesions, however, are difficult to detect with WBCT in the absence of frank destruction of cancellous bone. PET or PET-CT with 18-fluoro-deoxyglucose (FDG) are insensitive to diffuse bone marrow infiltration, but may help to assess treatment response in solitary or multiple solid plasma cell tumors which have a high FDG uptake before treatment.

Response assessment in patients with multiple myeloma during antiangiogenic therapy using arterial spin labeling and diffusion-weighted imaging: a feasibility study

RATIONALE AND OBJECTIVES

To determine whether response to anti-angiogenic therapy in patients with multiple myeloma can be assessed by noncontrast perfusion magnetic resonance imaging (MRI) (ie, arterial-spin-labeling [ASL]), and diffusion-weighted [DWI] MRI.

MATERIALS AND METHODS

The study protocol was approved by the local institutional ethic board. Ten consecutive patients (eight men, two women; mean age 60.5 ± 8.5 years) with Stage III multiple myeloma were prospectively included. MRI was performed at baseline, as well as 3 and 8 weeks after onset of antiangiogenic therapy. Functional MRI data were compared with clinical outcome and conventional lesion size and signal-intensity measurements. Differences between baseline and follow-up values for ASL-MRI and DWI-MRI were assessed using a paired Student t-test.

RESULTS

Nine patients responded well to therapy, whereas one patient was classified a nonresponder. Temporary changes in signal intensity between baseline and follow-up examinations were inconsistent on T1-weighted (w) and T2w images. Likewise, determination of lesion size at follow-up proved unreliable. ASL showed a marked decrease in perfusion from baseline (251 ± 159 mL/(min*100g)) to follow-up at 3 weeks (115 ± 85 mL/(min*100g), P = .01) and 8 weeks (101 ± 90 mL/(min*100g, P = .01), respectively. Relative to the baseline examination, mean diffusion increased from 0.68 ± 0.19 × 10(-3) s/mm(2) at baseline to 0.94 ± 0.24 × 10(-3) s/mm(2) after 3 weeks (P = .04), and 0.96 ± 0.40 × 10(-3) s/mm(2) after 8 weeks (P = .049). Both methods were able to correctly classify 9/10 patients as responder or nonresponder.

CONCLUSION

ASL perfusion as well as DWI-MRI provide accurate, clinically relevant information regarding tumor viability and can predict response already early after therapy onset, as opposed to classical lesion size and MRI signal-intensity measurements.

[Whole body functional MR imaging: hemato-oncologic applications]

Hemato-oncologic imaging combines anatomical and functional imaging data for optimal staging and follow-up of patients. It is currently possible to achieve high spatial resolution and functional evaluation at whole body MR imaging. Functional imaging may be achieved with two techniques: dynamic imaging following intravenous contrast injection and diffusion-weighted imaging. The purpose of this article is to demonstrate how both functional imaging techniques can be combined with whole body MR imaging for the evaluation of multiple myeloma and lymphomas.

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.

Dynamic contrast enhanced magnetic resonance imaging of diffuse spinal bone marrow infiltration in patients with hematological malignancies

Objective

To investigate the significance of the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) parameters of diffuse spinal bone marrow infiltration in patients with hematological malignancies.

Materials and Methods

Dynamic gadolinium-enhanced MR imaging of the lumbar spine was performed in 26 patients with histologically proven diffuse bone marrow infiltration, including multiple myeloma (n = 6), acute lymphoblastic leukemia (n = 6), acute myeloid leukemia (n = 5), chronic myeloid leukemia (n = 7), and non-Hodgkin lymphoma (n = 2). Twenty subjects whose spinal MRI was normal, made up the control group. Peak enhancement percentage (E_max), enhancement slope (ES), and time to peak (TTP) were determined from a time-intensity curve (TIC) of lumbar vertebral bone marrow. A comparison between baseline and follow-up MR images and its histological correlation were evaluated in 10 patients. The infiltration grade of hematopoietic marrow with plasma cells was evaluated by a histological assessment of bone marrow.

Results

Differences in E_max, ES, and TTP values between the control group and the patients with diffuse bone marrow infiltration were significant (t = -11.51, -9.81 and 3.91, respectively, p < 0.01). E_max, ES, and TTP values were significantly different between bone marrow infiltration groups Grade 1 and Grade 2 (Z = -2.72, -2.24 and -2.89 respectively, p < 0.05). E_max, ES and TTP values were not significantly different between bone marrow infiltration groups Grade 2 and Grade 3 (Z = -1.57, -1.82 and -1.58 respectively, p > 0.05). A positive correlation was found between E_max, ES values and the histological grade of bone marrow infiltration (r = 0.86 and 0.84 respectively, p < 0.01). A negative correlation was found between the TTP values and bone marrow infiltration histological grade (r = -0.54, p < 0.01). A decrease in the E_max and ES values was observed with increased TTP values after treatment in all of the 10 patients who responded to treatment (t = -7.92, -4.55, and 5.12, respectively, p < 0.01).

Conclusion

DCE-MRI of spine can be a useful tool in detecting diffuse marrow infiltration of hematological malignancies, while its parameters including E_max, ES, and TTP can reflect the malignancies' histological grade.

Role of radiography, MRI and FDG-PET/CT in diagnosing, staging and therapeutical evaluation of patients with multiple myeloma

Multiple myeloma is a malignant B-cell neoplasm that involves the skeleton in approximately 80% of the patients. With an average age of 60 years and a 5-years survival of nearly 45% Brenner et al. (Blood 111:2516–2520, 35) the onset is to be classified as occurring still early in life while the disease can be very aggressive and debilitating. In the last decades, several new imaging techniques were introduced. The aim of this review is to compare the different techniques such as radiographic survey, multidetector computed tomography (MDCT), whole-body magnetic resonance imaging (WB-MRI), fluorodeoxyglucose positron emission tomography- (FDG-PET) with or without computed tomography (CT), and ^99mTc-methoxyisobutylisonitrile (^99mTc-MIBI) scintigraphy. We conclude that both FDG-PET in combination with low-dose CT and whole-body MRI are more sensitive than skeleton X-ray in screening and diagnosing multiple myeloma. WB-MRI allows assessment of bone marrow involvement but cannot detect bone destruction, which might result in overstaging. Moreover, WB-MRI is less suitable in assessing response to therapy than FDG-PET. The combination of PET with low-dose CT can replace the golden standard, conventional skeletal survey. In the clinical practise, this will result in upstaging, due to the higher sensitivity.

Patients with plasma cell disorders examined at whole-body dynamic contrast-enhanced MR imaging: initial experience

This study was approved by the institutional review board, and informed consent was obtained from all subjects. The authors prospectively evaluated the feasibility of multistation whole-body dynamic contrast material-enhanced magnetic resonance (MR) imaging performed in patients with plasma cell disorders to assess disease extension and the time-signal intensity curves of diffuse and focal bone marrow infiltration. Three healthy adult male volunteers (age range, 29-31 years) and 21 patients (12 men, nine women; age range, 34-79 years) underwent whole-body dynamic unenhanced (volunteers) and contrast-enhanced MR imaging, which was performed by using an 18-channel 1.5-T MR system. A five-station (three sagittal and two coronal planes) fat-saturated three-dimensional gradient-echo sequence (3.3-3.6/1.3 [repetition time msec/echo time msec], 20 degrees flip angle, voxel size of 2 x 2.6 x [3-5] mm) was performed seven times. The temporal resolution of the five-station dynamic contrast-enhanced examination was 60 seconds with use of parallel imaging. Time-signal intensity curves for the bone marrow and the focal lesions were successfully obtained in all patients.

SUPPLEMENTAL MATERIAL

http://radiology.rsnajnls.org/cgi/content/full/250/3/905/DC1http://radiology.rsnajnls.org/cgi/content/full/250/3/905/DC2http://radiology.rsnajnls.org/cgi/content/full/250/3/905/DC3.

Imaging in multiple myeloma

In multiple myeloma, imaging is required to determine the stage of disease and to anticipate impending bone fractures. Whereas the traditionally used Durie and Salmon staging system includes lytic bone lesions in plain films as criteria, modern systems include MRI findings. MRI is most sensitive to both diffuse bone marrow involvement as well as solid plasma cell tumors. Whole-body low-dose CT (WBCT) may replace plain films in the near future, since it is quicker, more sensitive and is better tolerated by patients. Intramedullary lesions are well seen as long as they are located in long bones where they are surrounded by fat. Diffuse bone marrow infiltration as well as intravertebral lesions, however, are difficult to detect with WBCT in the absence of frank destruction of cancellous bone. PET or PET-CT with 18-fluoro-deoxyglucose (FDG) are insensitive to diffuse bone marrow infiltration, but may help to assess treatment response in solitary or multiple solid plasma cell tumors which have a high FDG uptake before treatment.

Oncohaematologic disorders affecting the skeleton in the elderly

Multiple myeloma is a hemato-oncologic disease in the elderly population, with a peak incidence in the eighth decade, and represents a malignant bone marrow neoplasia in which a monoclonal strain of atypical plasma cells proliferates and may result in bone destruction. Skeletal metastases represent the most common malignant bone tumor and are the third most common location for distant metastases. They occur predominantly in adults, especially in the elderly population. Chronic lymphatic leukemia is a typical malignancy of the elderly patient and aplastic anemia is a hematologic disorder characterized by pancytopenia, bone marrow hypoplasia, and lack of extramedullary hematopoiesis. Osteomyelofibrosis and sclerosis are chronic myeloproliferative diseases of the elderly, with a peak incidence in the sixth and seventh decade of life. This article addresses these oncohaematologic disorders affecting the skeleton in the elderly, examining the radiographic scanning methods, staging, and prognosis for each.

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.

Whole body MRI and PET/CT in haematological malignancies

The usefulness of whole body magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT) in haematological malignancies is reviewed. PET/CT combining functional and anatomical information is currently a valuable tool in the management of patients with lymphoma, especially in the assessment of early treatment response. MRI is advantageous in evaluating bone marrow involvement and therefore plays an important role in clinical decision making for patients with myeloma. The development of whole body functional MR studies is underway and can potentially complement the PET/CT for better patient care.

The evolving role of MRI in oncohaematological disorders

Magnetic resonance imaging (MRI) has opened new possibilities to current diagnostic radiology in the evaluation of bone marrow. Compared with other imaging modalities, MRI is the only technique able to directly visualise bone marrow with its different components of red and yellow marrow. Other advantages of MRI are high-contrast resolution and multiplanar view, as well as extensive coverage of the skeleton with whole-body MRI (WBMRI). However, specificity of signal alterations of bone marrow is low. Therefore, MRI findings need to be integrated with clinical and laboratory findings as well as with haematological and oncological evaluation. MRI provides information that effectively aids diagnosis, staging and follow-up of various bone marrow disorders. There is increasing interest in the capabilities of MRI in the evaluation of bone marrow, in particular of haematological malignancies. According to some authors much work remains to be done to improve sensitivity and specificity of MRI in order to define the real clinical value of this imaging modality in the multidisciplinary management of patients with a haematological malignancy. This article presents recent developments and perspectives in the use of MRI in oncohaematological diseases.

Targeting the vascular endothelial growth factor pathway in the treatment of multiple myeloma

Multiple myeloma is a clonal plasma cell malignancy within the bone marrow associated with bone loss, renal disease and immunodeficiency. Despite new insights into the pathogenesis of multiple myeloma and novel targeted therapies, the median survival remains 3-5 years. It is now well established that the intimate relation between the tumor cells and components of the microenvironment plays a key role in multiple myeloma pathogenesis. Specifically, tumor cells impact the bone marrow and thereby cause immune suppression and lytic bone lesions; conversely, components of the bone marrow provide signals that influence the behavior of multiple myeloma cells, including tumor cell growth, survival, migration and drug resistance. Important contributing effectors are tumor cell-stroma cell and cell-extracellular matrix contacts, the bone marrow vasculature, and a variety of cytokines and growth factors in the bone marrow milieu.

MR Imaging Evaluation of the Bone Marrow and Marrow Infiltrative Disorders of the Lumbar Spine

The use of MR imaging in assessing lumbar bone marrow first requires an understanding of the bone marrow's normal composition and the various imaging sequences available for use. One of the most useful sequences is the T1-weighted spin-echo sequence. This sequence may be combined with other sequences such as T2-weighted or diffusion-weighted sequences; techniques such as fat suppression, chemical shift imaging, and contrast-enhanced imaging are discussed. The varying features of normal lumbar marrow related to the normal physiologic changes that occur with aging and with changes in hematopoietic demand are important to understand and are described. The appearances of infiltrative marrow disease are explained on the basis of marrow composition and whether disease causes proliferation, replacement, or depletion of normal marrow components.

Preoperative imaging of superficially located glioma resection using short inversion-time inversion recovery images in high-field magnetic resonance imaging

OBJECTIVES

Short inversion-time inversion recovery (STIR) is the only magnetic resonance imaging (MRI) sequence able to produce high contrast images of both brain-CSF and gray matter-white matter in the central nervous system. The aim of the present study is to evaluate the effectiveness of STIR in imaging tumor involvement of the cortical surface and intra-axial structures, its usefulness in the resection of superficially located gliomas.

PATIENTS AND METHODS

In this study, we perform conventional MRI (1.5 T) and STIR (3.0 T) before surgery in 10 patients with superficially located glioma. We estimate the spatial relationship between the tumor bulk, the adjacent cortical surface and intra-axial structures on T2WI (1.5 T) and STIR (3.0 T). STIR findings are applied to resection of the tumor in each case.

RESULTS

For all patients, STIR provided more satisfactory images than T2WI of both the cortical surface structures and intra-axial structures surrounding the tumor. During surgery, the clear demonstration of cortical surface structures on preoperative STIR images assisted in determining tumor location and the sulci to be split for the trans-sulcal approach for patients whose cortex was normal in colour. Clear contrast on STIR between the tumor margin and peritumoral edema was useful for tumor resection.

CONCLUSION

STIR is able to demonstrate anatomical details of the cortical surface and intra-axial structures of the brain and is therefore suitable for the preoperative evaluation of superficially located gliomas.

Total-body MR-imaging in oncology

Although MRI is an effective modality in oncology, state-of-the-art total-body MRI (TB-MRI) in the past was infeasible in the diagnostic work-up, due to the need for repeated examinations with repositioning and separate surface coils to cover all body parts. To overcome this limitation, either a moving table platform in combination with the body-coil or a special designed rolling table platform with one body phased-array coil have been implemented with promising results for both tumor staging and metastases screening. Since 2004, state-of-the-art TB-MR imaging with high spatial resolution has become feasible using a newly developed 1.5 Tesla TB-MRI system with multiple receiver channels. This review gives an overview based on the recent literature as well as our own experience concerning the possibilities, challenges, and limitations of TB-MRI in oncology, emphasizing both oncological staging and early tumor detection in asymptomatic subjects.

Overexpression of cyclooxygenase-2 in multiple myeloma: association with reduced survival

Cyclooxygenases (COX) are key enzymes in the conversion of arachidonic acid to prostaglandins. Several studies have shown a relation between angiogenesis and COX-2 expression. Elevated expression of cyclooxygenase-2 (COX-2), however, has not been reported in multiple myeloma (MM) in the literature. The aim of this study is to investigate COX-2 expression in MM as well as its correlation with prognostic factors and estimated survival rates. Immunohistochemical staining of the paraffin-embedded bone marrow biopsy tissues (n = 51) was performed using isoform-specific COX-2 polyclonal antisera (Santa Cruz Biotechnology, Santa Cruz, CA). Results were correlated with recognized clinical parameters, which were retrospectively obtained from patients' files. There were 15, 19, and 17 bone marrow biopsy specimens with negative, weak-moderate, and strong COX-2 immunostaining, respectively. According to univariate analysis, beta2-microglobulin, age, stage, COX-2 expression, and serum lactate dehydrogenase levels were significant prognostic factors for survival in patients with multiple myeloma. COX-2 expression, age, and serum lactate dehydrogenase levels (greater than 1x normal level) were significant prognostic factors by multivariate analysis. Kaplan-Meier overall survival estimate of those patients with negative or weak-moderate COX-2 immunoreactivity in myeloma cells was significantly better than that of patients with strong COX-2 immunoreactivity (log-rank chi(2) = 21,43, P < 0.001). COX-2 overexpression was associated with reduced estimated survival. Poor prognostic factors such as LDH, age, and beta2-microglobulin were also correlated with COX-2 expression. Potent, specific COX-2 inhibitors showing evident antiangiogenic and antitumor effects on cancers could provide new therapeutic strategies in the treatment of MM.

Prognostic significance of magnetic resonance imaging of bone marrow in previously untreated patients with multiple myeloma

BACKGROUND

Magnetic resonance imaging (MRI) has been a useful technique for the assessment of patients with multiple myeloma (MM). We evaluated the prognostic significance of different MRI patterns in symptomatic patients with MM.

PATIENTS AND METHODS

A total of 142 symptomatic MM patients underwent MRI before treatment. MRI patterns of involvement were correlated with known prognostic variables, including the International Staging System (ISS), response to treatment and survival.

RESULTS

Focal marrow lesions were identified in 50% of patients, diffuse marrow replacement in 28%, a variegated pattern in 14% and normal pattern in 8%. When patients with the diffuse pattern were compared with patients with the other MRI patterns, they had features of more advanced disease such as higher ISS, anemia, hypercalcemia, elevated lactate dehydrogenase and extensive marrow plasmacytosis. Response rate was similar among patients with different MRI patterns. Median survival was 24 months for patients with the diffuse pattern, 51 months for those with the focal pattern, 52 months for those with the variegated pattern and 56 months for patients with the normal pattern (P = 0.001). The presence or absence of a diffuse MRI pattern separated patients with ISS stages I and II into two subgroups with significantly different survival times of 28 months and 61 months, respectively (P = 0.01). Furthermore, a diffuse MRI pattern predicted inferior outcome regardless of whether or not patients had received high-dose therapy with autologous stem cell transplantation.

CONCLUSION

Diffuse marrow replacement on MRI adds to the evaluation of patients with multiple myeloma and their management.