The role of anatomic and functional staging in myeloma: description of Durie/Salmon plus staging system

Late-stage myeloma invades kidney without significant effect on renal function: findings from 53 autopsies in a single institute

Renal manifestations of multiple myeloma (MM) including cast nephropathy, amyloidosis, and renal calcification have been widely recognized. However, the severity of histopathological findings has not been addressed so far, and the clinical significance of these pathological findings is unclear. We sought to clarify the relationship between the severity of renal pathology and clinical characteristics. We analyzed 53 autopsies performed on patients who died from MM. The kidneys were evaluated using light microscopy, and the severity of pathological findings was recorded. The most common renal lesion was cast nephropathy (n = 27). Other findings included amyloidosis (n = 10), renal calcification (n = 5), microbial infection (n = 4), and MM infiltration (n = 17). The incidence of MM infiltration was substantially higher than previously reported. Renal MM infiltration was detected even when bone marrow plasmacytosis was limited. However, a significantly higher degree of renal MM infiltration was observed when MM cells invaded the liver. No correlation was observed between serum creatinine levels and degree of MM infiltration, but these tended to be elevated when cast nephropathy was severe. These findings may provide clues to understand both renal injury and extramedullary diseases in patients with MM.

The Role of 18F-FDG PET/CT in Multiple Myeloma Staging according to IMPeTUs: Comparison of the Durie-Salmon Plus and Other Staging Systems

We aimed at comparing the Durie–Salmon Plus (DS Plus) staging system based on Italian Myeloma criteria for PET USe (IMPeTUs) with other two staging systems in predicting prognosis of patients with all stages of newly diagnosed multiple myeloma (MM). A total of 33 MM patients were enrolled in this retrospective study. The variation between the DS Plus classification and Durie–Salmon staging system (DSS) or Revised International Staging System (RISS) classification was assessed. When staged by the DSS, patients in stage I and stage II did not reach the median overall survival (OS), and the median OS was 33 months for stage III (p=0.3621). When staged by the DS Plus, patients in stage I did not reach the median OS of stage I, and the median OS for stages II and III was 38 and nine months, respectively (p=0.0064). When staged by the RISS, patients in stage I did not reach the median OS, and the median OS was 33 and 16 months for stage II and stage III, respectively (p=0.0319). The concordances between two staging systems were 0.07 (DS Plus versus DSS) and 0.37 (DS Plus versus RISS), respectively. Multivariate analysis revealed that DS Plus stage III (HR: 11.539, p=0.021) and the Deauville score of bone marrow ≥4 (HR: 3.487, p=0.031) were independent prognostic factors associated with OS. Both the DS Plus based on IMPeTUs and RISS possessed a better potential in characterizing and stratifying MM patients compared with the DSS. Moreover, DS Plus stage III and the Deauville score of bone marrow ≥4 were reliable prognostic factors in newly diagnosed MM patients.

Diagnostic performance of 18F-FDG PET/CT and whole-body MRI before and early after treatment of multiple myeloma: a prospective comparative study

OBJECTIVE

To determine the diagnostic accuracy of WB-MRI and ¹⁸F-FDG PET/CT in detecting infiltration pattern, disease activity, and response to treatment in patients with multiple myeloma (MM).

MATERIALS AND METHODS

Fifty-six patients with confirmed MM were included in the present study for pre-treatment evaluation. Among these individuals, 22 patients were available for the post-treatment evaluation of response to therapy. All patients were imaged with both WB-MRI and ¹⁸F-FDG PET/CT. All radiographic findings of infiltration pattern, disease activity, and response to therapy were compared. The diagnostic performance of both modalities was estimated using bone marrow aspirate and biopsy as the reference test.

RESULTS

For detection of active myelomatous tissue at diagnosis, WB-MRI achieved higher sensitivity (94%) than ¹⁸F-FDG PET/CT (75%) (p = 0.0039), whereas both modalities achieved the same specificity (80%). For detection of residual myelomatous tissue after treatment, ¹⁸F-FDG PET/CT achieved higher specificity (86%) than WB-MRI (43%) (p = 0.0081), whereas both modalities achieved the same sensitivity (75%).

CONCLUSION

WB-MRI is more sensitive than ¹⁸F-FDG PET/CT in the diagnosis of MM before treatment; however, ¹⁸F-FDG PET/CT is more specific than WB-MRI in detecting residual involvement in treated patients.

Established and Novel Prognostic Biomarkers in Multiple Myeloma

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by notable interpatient heterogeneity. There have been important advances in therapy and overall survival, but some patients with high-risk features still have poor survival rates. Therefore, accurate identification of this subset of patients has been integral to improvement of patient outcome. During the last few years, cytogenetics, gene expression profiling, MRI and PET/CT, as well as serum free light chain assays have been used as accurate biomarkers to better characterize the diverse course and outcome of the disease. With the recent advances of massive parallel sequencing techniques, the development of new models that better stratify high-risk groups are beginning to be developed. The use of multiparameter flow cytometry and next-generation sequencing have paved the way for assessment of minimal residual disease and better prognostication of post-therapeutic outcomes. Circulating tumor cells and circulating tumor DNA are promising potential biomarkers that demonstrate the spatial and temporal heterogeneity of MM. Finally, more prognostic markers are being developed that are specific to immunotherapeutic agents. In this review, we discuss these traditional and novel biomarkers that have been developed for MM and also those that can predict disease progression from precursor stages. Together, these biomarkers will help improve our understanding of the intrapatient and interpatient variabilities and help develop precision medicine for patients with high-risk MM.

The Critical Role of Imaging in the Management of Multiple Myeloma

Multiple myeloma (MM) is characterized by abnormal proliferation of plasma cells in the bone marrow leading to symptoms of anemia, renal failure, hypercalcemia, and bone lesions. Bone imaging is critical for the diagnosis, staging, assessment for the presence and extent of bone lesions, and initial treatment of MM. Skeletal survey is the preferred initial imaging modality due to its availability and low cost. However, it has poor sensitivity and patients with occult myeloma may escape detection, delaying their diagnosis and treatment. New cross-sectional imaging modalities such as low-dose whole body CT, MRI, and PET-CT have high sensitivity and specificity for detecting lytic lesions and extramedullary relapse in MM. The combined use of cross-sectional imaging may provide complimentary information for staging, prognosis, and disease monitoring. In this review, we will discuss commonly used imaging modalities and their advantages and disadvantages in the management of MM.

Guidelines for the use of imaging in the management of patients with myeloma

The role of imaging in myeloma has gained increasing importance over the past few years. The recently revised definition of myeloma from the International Myeloma Working Group (IMWG) includes cross sectional imaging as a method to define bone disease and also incorporates its use in the disease definition for patients with suspected smouldering myeloma. The National Institute for Health and Care Excellence myeloma guidelines also recommend cross sectional imaging for patients with suspected myeloma. There is also increasing use of imaging in disease assessments and the International Myeloma Working Group has recently incorporated imaging in defining new response categories of minimal residual disease negativity, with or without imaging-based evidence of disease. Plain X-rays have previously been the standard imaging modality included in a myeloma work up at presentation but evidence is mounting for use of cross-sectional modalities such as computed tomography (CT), magnetic resonance imaging (MRI) and 18 fluoro-deoxyglucose (18 F-FDG) positron emission tomography (PET)/CT. Funding and therefore availability of newer imaging techniques remains a barrier. Here, we propose an evidence-based approach to the use and technical application of the latest imaging modalities at diagnosis and in the follow-up of patients with myeloma and plasmacytoma.

11C-Methionine-PET in Multiple Myeloma: A Combined Study from Two Different Institutions

¹¹C-methionine (MET) has recently emerged as an accurate marker of tumor burden and disease activity in patients with multiple myeloma (MM). This dual-center study aimed at further corroboration of the superiority of MET as positron emission tomography (PET) tracer for staging and re-staging MM, as compared to ¹⁸F-2`-deoxy-2`-fluoro-D-glucose (FDG).

78 patients with a history of solitary plasmacytoma (n=4), smoldering MM (SMM, n=5), and symptomatic MM (n=69) underwent both MET- and FDG-PET/computed tomography (CT) at the University Centers of Würzburg, Germany and Navarra, Spain. Scans were compared on a patient and on a lesion basis. Inter-reader agreement was also evaluated. In 2 patients, tumor biopsies for verification of discordant imaging results were available.

MET-PET detected focal lesions (FL) in 59/78 subjects (75.6%), whereas FDG-PET/CT showed lesions in only 47 patients (60.3%; p<0.01), accordingly disease activity would have been missed in 12 patients. Directed biopsies of discordant results confirmed MET-PET/CT results in both cases.

MET depicted more FL in 44 patients (56.4%; p<0.01), whereas in two patients (2/78), FDG proved superior. In the remainder (41.0%, 32/78), both tracers yielded comparable results. Inter-reader agreement for MET was higher than for FDG (κ = 0.82 vs κ = 0.72).

This study demonstrates higher sensitivity of MET in comparison to standard FDG to detect intra- and extramedullary MM including histologic evidence of FDG-negative, viable disease exclusively detectable by MET-PET/CT. MET holds the potential to replace FDG as functional imaging standard for staging and re-staging of MM.

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 Multiple Myeloma

Multiple myeloma is the most common bone malignancy. Imaging plays an important role in identifying the extent of the disease, disease process, guiding biopsies, and diagnosing associated spinal and intracranial complications. Multiple myeloma and related plasma cell proliferative disorders have a diverse set of clinicopathologic findings and on neuroimaging present unique and diverse findings from the disease and from complications of the disease and treatment, which are valuable for clinicians and radiologists.

Application of PET/CT in treatment response evaluation and recurrence prediction in patients with newly-diagnosed multiple myeloma

Multiple myeloma (MM) causes osteolytic lesions which can be detected by 18F-fluorodeoxyglucose positron emission tomography/Computed tomography (18F-FDG PET/CT). We prospectively involve 96 Newly diagnosed MM to take PET/CT scan at scheduled treatment time (figure 1), and 18F-FDG uptake of lesion was measured by SUVmax and T/Mmax. All MM patients took bortezomib based chemotherapy as induction and received ASCT and maintenance. All clinical features were analyzed with the PET/CT image changes, and some relationships between treatment response and FDG uptakes changes were found: Osteolytic lesions of MM uptakes higher FDG than healthy volunteers, and this trend is more obvious in extramedullary lesions. Compared to X-ray, PET/CT was more sensitive both in discoering bone as well as extramedullary lesions. In newly diagnosed MM, several adverse clinical factors were related to high FDG uptakes of bone lesions. Bone lesion FDG uptakes of MM with P53 mutation or with hypodiploidy and complex karyotype were also higher than those without such changes. In treatment response, PET/CT showed higher sensitivity in detecting tumor residual disease than immunofixation electrophoresis. But in relapse prediction, it might show false positive disease recurrences and the imaging changes might be influenced by infections and hemoglobulin levels. Conclusion: PET/CT is sensitive in discovering meduallary and extrameduallary lesions of MM, and the 18F-FDG uptake of lesions are related with clinical indictors and biological features of plasma cells. In evaluating treatment response and survival, PET/CT showed its superiority. But in predicting relapse or refractory, it may show false positive results.

Musculoskeletal Imaging Findings of Hematologic Malignancies

Hematologic malignancies comprise a set of prevalent yet clinically diverse diseases that can affect every organ system. Because blood components originate in bone marrow, it is no surprise that bone marrow is a common location for both primary and metastatic hematologic neoplasms. Findings of hematologic malignancy can be seen with most imaging modalities including radiography, computed tomography (CT), technetium 99m (^99mTc) methylene diphosphonate (MDP) bone scanning, fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT, and magnetic resonance (MR) imaging. Because of the diversity of imaging appearances and clinical behavior of this spectrum of disease, diagnosis can be challenging, and profound understanding of the underlying pathophysiologic changes and current treatment modalities can be daunting. The appearance of normal bone marrow at MR imaging and FDG PET/CT is also varied due to dynamic compositional changes with normal aging and in response to hematologic demand or treatment, which can lead to false-positive interpretation of imaging studies. In this article, the authors review the normal maturation and imaging appearance of bone marrow. Focusing on lymphoma, leukemia, and multiple myeloma, they present the spectrum of imaging findings of hematologic malignancy affecting the musculoskeletal system and the current imaging tools available to the radiologist. They discuss the imaging findings of posttreatment bone marrow and review commonly used staging systems and consensus recommendations for appropriate imaging for staging, management, and assessment of clinical remission. ^©RSNA, 2017.

PET/MR Imaging of Multiple Myeloma

PET-magnetic resonance (MR) is a hybrid imaging modality that combines PET and MR. Evidence for this new modality is in the process of being developed, but both component modalities are well tested in the diagnosis and management of multiple myeloma. It allows advanced bimodality imaging of the whole body with an adaptable field of view and it can be used for monitoring plasma cell dyscrasias for progression to multiple myeloma, for assessing disease burden in patients with known multiple myeloma, for assessing response to therapy and relapse after remission, and for radiation therapy treatment planning.

The effect of microenvironmental factors on the development of myeloma cells

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by the accumulation of monoclonal plasma cells (PCs) in the bone marrow and other tissues. Although there are several new therapies, MM remains fatal. The interaction between MM cells and the bone marrow microenvironment promotes drug resistance and cancer cells survival. In our present work, we compared the antigen expression pattern of normal and pathological PCs and investigated the possible connections between various surface receptors, adhesion molecules, and recurrent genetic aberrations. We showed that the expression of CD29, CD27, and CD81 is lower in MM cells than in normal PCs. We found correlation of chromosome 11 hyperdiploidity and the decrease of CD27 expression. We demonstrated that MM cells with CD20 positivity also have CD28 expression. Multiple myeloma patients with active CD29 showed better response to treatment. Our results suggest that these changes may result in an alteration of the interaction between stromal cell and MM cell facilitating cell survival and the development of a more aggressive and resistant phenotype.

Simplified response monitoring criteria for multiple myeloma in patients undergoing therapy with novel agents using computed tomography

INTRODUCTION

Multiple myeloma is a malignant hematological disorder of the mature B-cell lymphocytes originating in the bone marrow. While therapy monitoring is still mainly based on laboratory biomarkers, the additional use of imaging has been advocated due to inaccuracies of serological biomarkers or in a-secretory myelomas. Non-enhanced CT and MRI have similar sensitivities for lesions in yellow marrow-rich bone marrow cavities with a favourable risk and cost-effectiveness profile of CT. Nevertheless, these methods are still limited by frequently high numbers of medullary lesions and its time consumption for proper evaluation.

OBJECTIVE

To establish simplified response criteria by correlating size and CT attenuation changes of medullary multiple myeloma lesions in the appendicular skeleton with the course of lytic bone lesions in the entire skeleton. Furthermore to evaluate these criteria with respect to established hematological myeloma-specific parameters for the prediction of treatment response to bortezomib or lenalidomide.

MATERIALS AND METHODS

Non-enhanced reduced-dose whole-body CT examinations of 78 consecutive patients (43 male, 35 female, mean age 63.69±9.2years) with stage III multiple myeloma were retrospectively re-evaluated. On per patient basis, size and mean CT attenuation of 2-4 representative lesions in the limbs were measured at baseline and at a follow-up after a mean of 8 months. Results were compared with the course of lytical bone lesions as well with that of specific hematological biomarkers. Myeloma response was assessed according to the International Myeloma Working Group (IMWG) uniform response criteria. Testing for correlation between response of medullary lesions (Resp_med) and response of all myeloma manifestations including osteolyses (Resp_total) was performed using the corrected contingency coefficient (C_corr).

RESULTS

The correlation between Resp_med based on length diameter and transverse diameter and Resp_total was perfect (C_corr=1.0; p<0.0001) whereas the correlation based on density was moderate (C_corr=0.54; p<0.0001). The evaluation of simplified response criteria with a measurement of only 2 medullary lesions yielded the best sensitivity and specificity valued for treatment-induced changes for the length diameter evaluation with 94.4%/95.7% for prediction of progressive disease and 78.6%/93.3% for prediction of therapy response. There were no significant differences between patients treated with bortezomib and lenalidomide (p>0.05).

CONCLUSION

Measurements of size of a minimum of two medullary lesions is sufficient for response assessment and correlates very well with the course of lytic bone lesions and that of hematologic parameters.

FDG-PET imaging in hematological malignancies

The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques.

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.

Liver involvement by multiple myeloma presenting as hypervascular focal lesions in a patient with chronic hepatitis B infection

Extramedullary myeloma refers to the infiltration of neoplastic monoclonal plasma cells in either organs or soft tissues. The disease is clinically and radiologically underestimated compared with the autopsy findings and is usually associated with a more aggressive clinical course and poorer outcome. A minority of patients with extramedullary myeloma show hepatic involvement, usually in the form of diffuse parenchymal infiltration. When focal infiltration is present, variable imaging findings have been described both on CT scan and MRI. We report the case of a 63-year-old male with hepatitis B virus-related liver disease and biopsy-proven multiple myeloma involving the liver, manifesting as hypervascular focal liver lesions on MRI. A brief review of the literature is also proposed.

Multi-technique hybrid imaging in PET/CT and PET/MR: what does the future hold?

Integrated positron-emission tomography and computed tomography (PET/CT) is one of the most important imaging techniques to have emerged in oncological practice in the last decade. Hybrid imaging, in general, remains a rapidly growing field, not only in developing countries, but also in western industrialised healthcare systems. A great deal of technological development and research is focused on improving hybrid imaging technology further and introducing new techniques, e.g., integrated PET and magnetic resonance imaging (PET/MRI). Additionally, there are several new PET tracers on the horizon, which have the potential to broaden clinical applications in hybrid imaging for diagnosis as well as therapy. This article aims to highlight some of the major technical and clinical advances that are currently taking place in PET/CT and PET/MRI that will potentially maintain the position of hybrid techniques at the forefront of medical imaging technologies.

Multimodality imaging of osseous involvement In haematological malignancies

The purpose of this article is to provide a comprehensive review of the imaging features of osseous involvement in haematological malignancies. Osseous involvement can be seen in various haematological malignancies including lymphomas, plasma cell neoplasms, leukaemias and myeloproliferative neoplasms. Imaging plays a crucial role in initial diagnosis, staging and in the assessment of treatment response in these patients.

11C-Methionine-PET in Multiple Myeloma: Correlation with Clinical Parameters and Bone Marrow Involvement

Multiple myeloma (MM) remains an essentially incurable hematologic malignancy originating from clonal plasma cells. This study evaluated the usefulness of the radiotracers ¹¹C-methionine (MET) and ¹⁸F-2`-deoxy-2`-fluorodeoxyglucose (FDG) for staging and re-staging in MM.

43 patients with MM underwent both MET- and FDG-PET/CT for staging or re-staging within 3±2 days. Scans were compared on a patient and on a lesion basis. Tracer uptake was correlated with the degree of bone marrow (BM) involvement and standard clinical parameters of disease activity. Additionally, BM samples were stained for L-type amino acid transporter 1 (LAT1) expression in 15 patients. MET-PET detected focal lesions (FL) in 39/43 subjects (90.7%), whereas 10 patients were missed in FDG-PET/CT (detection rate, 33/43; 76.7%; p<0.05). MET depicted more FL in 28/43 patients (65.1%; p<0.001), whereas in the remainder (34.9%, n=15) both tracers yielded comparable results. LAT1 was highly expressed on the cell surface of myeloma cells. Both FDG and MET uptake correlated significantly with biopsy-proven BM involvement (p<0.001), with MET demonstrating a stronger correlation (SUV_mean, r=0.9 vs r=0.6; SUV_max, r=0.88 vs r=0.58). Abnormal beta-2-microglobulin and free light chain levels correlated with the presence of focal intramedullary lesions detected in MET- or FDG-PET/CT (MET, p=0.006 and p=0.01, respectively; FDG, p=0.02 and p=0.01). MET appears to be superior to FDG for staging and re-staging of both intra- and extramedullary MM lesions. Tracer uptake correlates with BM involvement, β2m and FLC levels and appears to be a more accurate marker of tumor burden and disease activity.

18F-FDG PET/CT, 99mTc-MIBI, and MRI in the prediction of outcome of patients with multiple myeloma: a comparative study

PURPOSE

The aim of this study was to compare the relative contribution of 18F-FDG PET/CT, 99mTc-MIBI, and MRI in predicting progression-free survival (PFS) and overall survival (OS) in multiple myeloma (MM) patients.

PATIENTS AND METHODS

Thirty-three newly diagnosed MM patients had been evaluated in a previous study by 18F-FDG PET/CT, 99mTc-MIBI, and spine and pelvis MRI reporting focal lesions and diffuse bone marrow involvement. Twenty-seven patients were then subjected to a mean follow-up period of 58 months, whereas 6 patients were lost.

RESULTS

18F-FDG PET/CT, 99mTc-MIBI, and MRI were positive in 26, 24, and 22 patients, respectively, showing diffuse bone marrow involvement in 12, 21, and 17 patients and a total of 185, 56, and 39 focal lesions, respectively. At follow-up, 18 patients showed complete or partial remission, whereas 9 patients developed progressive disease, 7 of which died of myeloma. Univariate and subsequent multivariate analysis showed that F-FDG PET/CT focal uptake and Tc-MIBI focal and diffuse uptake predicted PFS (P = 0.0006), whereas 18F-FDG PET/CT focal uptake and 99mTc-MIBI focal uptake predicted OS (P = 0.0010). Although MRI diffuse pattern predicted PFS at univariate analysis (P = 0.0376), it was not retained in the model at multivariate analysis. Receiver operating characteristic curve analysis showed that the number of focal lesions best discriminating for PFS and OS prediction was 4 and 11 for 18F-FDG PET/CT and 2 in both cases for 99mTc-MIBI, respectively. By Kaplan-Meier analysis and log-rank testing, PFS and OS at follow-up were significantly better in patients showing a number of focal lesions at F-FDG PET/CT or Tc-MIBI lower than the respective cutoff (P = 0.03, P = 0.004, and P < 0.0001, respectively). Finally, PFS was significantly better in patients showing absent/faint diffuse Tc-MIBI uptake than in those having moderate/intense diffuse uptake (P = 0.0012).

CONCLUSIONS

18F-FDG PET/CT and 99mTc-MIBI may be useful in predicting PFS and OS in myeloma patients.

Apparent diffusion coefficient maps integrated in whole-body MRI examination for the evaluation of tumor response to chemotherapy in patients with multiple myeloma

RATIONALE AND OBJECTIVES

To determine the diagnostic value of apparent diffusion coefficient (ADC) maps in the assessment of response to chemotherapy in patients with multiple myeloma (MM).

MATERIALS AND METHODS

Fourteen patients (seven women) with MM underwent whole-body magnetic resonance imaging (WB-MRI) study on a 1.5T scanner, before and after chemotherapy. DWI with background body signal suppression (DWIBS) sequences (b values: 0, 500, and 1000 mm(2)/sec) were qualitatively analyzed, along with T1 turbo spine echo and short tau inversion recovery T2-weighted images, to evaluate bone lesions. On ADC maps, regions of interest were manually drawn along contours of lesions. The ADC values percentage variation (ΔADC) before (MR1) and after (MR2) chemotherapy were calculated and compared between responders (11 of 14) and nonresponders (3 of 14). The percentage of plasma cells by the means of the bone marrow aspirate was evaluated as parameter for response to chemotherapy.

RESULTS

Twenty-four lesions, hyperintense on DWIBS as compared to normal bone marrow, were evaluated. In responder group, the mean ADC values were 0.63 ± 0.24 × 10(-3) mm(2)/s on MR1 and 1.04 ± 0.46 × 10(-3) mm(2)/s on MR2; partial or complete signal intensity decrease during follow-up on DWIBS was found along with a reduction of plasma cells infiltration in the bone marrow. The mean ADC values for nonresponders were 0.61 ± 0.05 × 10(-3) mm(2)/s on MR1 and 0.69 ± 0.09 × 10(-3) mm(2)/s on MR2. The mean variation of ΔADC in responders (Δ = 66%) was significantly different (P < .05) than in nonresponders (Δ = 15%).

CONCLUSIONS

WB-MRI with DWIBS sequences, by evaluating posttreatment changes of ADC values, might represent a complementary diagnostic tool in the assessment of response to chemotherapy in MM patients.

18 FDG-PET/CT for prognostic stratification of patients with multiple myeloma relapse after stem cell transplantation

The aim of this study was to investigate the prognostic value of 18F-fluorodeoxyglucose positron emission tomography–computed tomography (18F-FDG-PET/CT) in 37 patients with a history of multiple myeloma (MM) and suspected or confirmed recurrence after stem cell transplantation (SCT). All patients had been heavily pretreated. Time to progression (TTP) and overall survival (OS) were correlated to a number of different PET-derived as well as clinical parameters. Impact on patient management was assessed.

Absence of FDG-avid MM foci was a positive prognostic factor for both TTP and OS (p<0.01). Presence of >10 focal lesions correlated with both TTP (p<0.01) and OS (p<0.05). Interestingly, presence of >10 lesions in the appendicular skeleton proved to have the strongest association with disease progression. Intensity of glucose uptake and presence of extramedullary disease were associated with shorter TTP (p=0.037 and p=0.049, respectively). Manifestations in soft tissue structures turned out to be a strong negative predictor for both, TTP and OS (p<0.01, respectively). PET resulted in a change of management in 30% of patients.

Our data underline the prognostic value of 18F-FDG-PET/CT in MM patients also in the setting of post-SCT relapse. PET/CT has a significant impact on patient management.

Quantitative Analysis of MR Imaging to Assess Treatment Response for Patients with Multiple Myeloma by Using Dynamic Intensity Entropy Transformation: A Preliminary Study

PURPOSE

To develop a quantitative measure of bone marrow changes in magnetic resonance (MR) images and investigate its capability for assessment of treatment response for patients with multiple myeloma (MM).

MATERIALS AND METHODS

This study was retrospective, institutional review board approved, and HIPAA compliant. Informed consent was waived. Patients (n = 64; mean age, 58.8 years [age range, 27-75 years]) who were diagnosed with MM and underwent autologous bone marrow stem cell transplantation (BMT) were evaluated. A pair of spinal MR examinations performed before and after BMT was collected from each patient's records. A three-dimensional dynamic intensity entropy transformation (DIET) method was developed to transform MR T1-weighted signal voxel by voxel to a quantitative entropy enhancement value (qEEV), from which predictor variables were derived to train a linear discriminant analysis classifier by using a leave-one-out method. The output of the linear discriminant analysis provided a qEEV-based response index for quantitative assessment of treatment response. The performance of quantitative response index for the discrimination of responder and nonresponder patients was evaluated by receiver operating characteristic curve analysis.

RESULTS

Among the 46 and 18 clinically diagnosed responder and nonresponder patients, the quantitative response index at a chosen decision threshold correctly identified 42 responder and 17 nonresponder patients. The agreement between the DIET method and the clinical outcome reached 0.922 (59 of 64; κ = 0.816; area under the receiver operating characteristic curve, 0.886 ± 0.042).

CONCLUSION

This study demonstrated the feasibility of quantitative response index to differentiate responder and nonresponder patients and had substantial agreement with clinical outcomes, which indicated that this quantitative measure has the potential to be an image biomarker to assess MM treatment response.

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.

Effects of Radiotherapy in the treatment of multiple myeloma: a retrospective analysis of a Single Institution

Background

Palliative irradiation of osteolytic lesions is a considerable component in the treatment for patients with multiple myeloma. In this study, we analyzed the efficacy of irradiation in these patients.

Patients and methods

We retrospectively analyzed 153 patients with multiple myeloma who were admitted to our department between 1989 and 2013. According to the staging system of Durie & Salmon 116 patients were classified as stage III. 107/153 patients were treated with radiotherapy of at least one and up to 6 bony lesions at different times. In order to evaluate the effect of local radiotherapy on pain relief and bone recalcification a uni- and multivariate analysis was performed using a binary logistic regression model to correct for multiple measurements. Complete information on dose, fractionation and volume of radiotherapy was available from 81 patients treated in 136 target volumes for pain relief, and from 69 patients treated in 108 target volumes for recalcification. Total radiation doses varied between 8 Gy to 50 Gy (median dose 25 Gy in 2.5 Gy fractions, 5 times a week).

Results

Radiotherapy resulted in complete local pain relief in 31% and partial local pain relief in 54% of the patients. In the univariate analysis, higher total radiation doses (p = 0.023) and higher age (p = 0.014) at the time of radiotherapy were significantly associated with a higher likelihood of pain relief, whereas no significant association was detected for concurrent systemic treatment, type and stage of myeloma and location of bone lesions. The same variables were independent predictors for pain relief in the multivariate analysis. Recalcification was observed in 48% of irradiated bone lesions. In the uni- and multivariate analysis higher radiation doses were significantly associated (p = 0.048) with an increased likelihood of recalcification. Side effects of radiotherapy were generally mild.

Conclusions

Higher total biological radiation doses were associated with better pain relief and recalcification in this retrospective evaluation of multiple myeloma patients. In addition, in the elderly the therapeutic measures appear to develop a better analgesic effect.

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.

[PET-CT for nuclear medicine diagnostics of multiple myeloma]

BACKGROUND

Functional or morphofunctional imaging modalities are used in myeloma patients for the diagnosis and therapy management within research protocols. Despite new staging criteria, which take into account the viability of a myeloma lesion, positron emission tomography (PET) is not used routinely.

OBJECTIVES

The impact of PET is therefore open. The role of PET and PET computed tomography (PET-CT) for the diagnosis and therapy management is discussed.

RESULTS

The use of PET with 18F-fluorodeoxyglucose (FDG) allows the measurement of viable myeloma lesions and correlates with the stage of disease. A negative FDG examination correlates with a better prognosis. Furthermore, the number of focal lesions as well as the whole functional volume of myeloma lesions in FDG have a prognostic impact. Several studies have demonstrated the impact of FDG for the assessment of therapy monitoring and show that FDG is an earlier indicator for therapy response as compared to magnetic resonance imaging (MRI). The CT component of the new hybrid systems allows the assessment of osteolytic lesions in CT and their viability in FDG. The combination of PET with an MRT scanner allows the simultaneous measurement of bone marrow infiltration, focal lesions and their viability.

CONCLUSION

The use of modern hybrid scanners, such as PET-CT and PET-MRT facilitates the simultaneous measurement of viable myeloma lesions, osteolytic lesions and bone marrow infiltration in the whole body; therefore, it is expected that these imaging modalities will play a greater role both in diagnosis and therapy management.

Multiple myeloma

This article presents a review of multiple myeloma, precursor states, and related plasma cell disorders. The clinical roles of fluorodeoxyglucose PET/computed tomography (CT) and the potential to improve the management of patients with multiple myeloma are discussed. The clinical and research data supporting the utility of PET/CT use in evaluating myeloma and other plasma cell dyscrasias continues to grow.

Solitary extramedullary plasmacytoma of the parotid gland imaged with 18F-FDG PET/CT

A 75-year-old woman presented with a 1-year history of an enlarging mass in the left parotid gland. Biopsy revealed a parotid plasmacytoma, and the patient was referred for a staging F-FDG PET/CT to evaluate the presence of multiple myeloma bone involvement. The PET/CT scan showed intense FDG uptake in the neck mass but no FDG-avid lymphadenopathy or distant metastases. Plasmacytoma involving the parotid gland is extremely rare. We present the F-FDG PET/CT imaging of solitary parotid plasmacytoma.

Comparison of (11)C-4'-thiothymidine, (11)C-methionine, and (18)F-FDG PET/CT for the detection of active lesions of multiple myeloma

Purpose

The aims of this study were to evaluate the possibility of using ¹¹C-methionine (¹¹C-MET) and ¹¹C-4′-thiothymidine (¹¹C-4DST) whole-body PET/CT for the imaging of amino acid metabolism and DNA synthesis, respectively, when searching for bone marrow involvement in patients with multiple myeloma (MM) and to compare these findings with those for ¹⁸F-FDG PET/CT and aspiration cytology.

Methods

A total of 64 patients with MM, solitary plasmacytoma, monoclonal gammopathy of undetermined significance, or an unspecified diagnosis were prospectively enrolled. All the patients underwent three whole-body PET/CT examinations within a period of 1 week. First, the tracer accumulation was visually evaluated as positive, equivocal, or negative for 55 focal lytic lesions visualized using CT in 24 patients. Second, the percentages of marrow plasma cells as calculated using a bone marrow aspiration smear and tracer accumulation were evaluated in the posterior iliac crests of 36 patients.

Results

Among the 55 lytic lesions, the ¹¹C-MET and ¹¹C-4DST findings tended to reveal more positive findings than the ¹⁸F-FDG findings. Based on the standard criteria for the diagnosis of active myeloma using the percentage of marrow plasma cells, significant differences were found between the ¹⁸F-FDG and ¹¹C-MET findings and between the ¹⁸F-FDG and ¹¹C-4DST findings, but no significant difference was observed between the ¹¹C-MET and ¹¹C-4DST findings.

Conclusion

The addition of ¹¹C-MET and ¹¹C-4DST to ¹⁸F-FDG when performing PET/CT enabled clearer evaluations of equivocal lesions. Based on cytological diagnostic criteria, ¹¹C-MET and ¹¹C-4DST were more sensitive than ¹⁸F-FDG for the detection of active lesions. ¹¹C-MET and ¹¹C-4DST were more useful than ¹⁸F-FDG for the detection of active lesions, especially during the early stage of disease.

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.

Reconstruction of multiple myeloma lesions around the pelvis and acetabulum

Multiple myeloma is a malignancy of monoclonal plasma cells (plasma cells are of B-lymphocyte lineage of the hematopoietic system). It is the second most prevalent blood malignancy after non-Hodgkin's lymphoma. It accounts for approximately 1 % of all malignancies and 2 % of all cancer deaths. Bony involvement is very common; the incidence of pelvic and periacetabular involvement in MM is reported to be around 6 %. Lytic lesions comprise a hallmark of multiple myeloma, which may be complicated with pathologic fractures in a substantial percentage of patients. Pelvic and periacetabular bony involvement of multiple myeloma is associated with some unique characteristics regarding the biomechanics of this specific anatomical region, the morbidity, the overall survival, and prognosis, which all reflect to impairment of quality of life. In this paper, we review the special features of multiple myeloma lesions around the pelvis and acetabulum and present an algorithm of management with the use of current surgical techniques.