Role of 18F-FDG PET/CT in the assessment of bone involvement in newly diagnosed multiple myeloma: preliminary results

Ga-68 Pentixafor PET/CT in multiple myeloma and its correlation with clinical parameters: institutional pilot study

OBJECTIVE

This study evaluates the role of Ga-68 Pentixafor PET/CT in staging and follow-up of multiple myeloma (MM) and its correlation with clinical parameters.

METHODS

Thirteen participants (9 males, 4 females; median age: 65 years) with MM were recruited in this prospective observational study. Six participants were included for staging evaluation, seven were included for follow-up evaluation, and underwent Ga-68 Pentixafor PET/CT. Focal PET-positive bone marrow lesions or diffuse bone marrow uptake (uptake more than liver) was considered a positive scan. The quantitative variables like SUVmax, SUVmean, total bone marrow volume and uptake (TBMV & TBMU) and tumor to background ratio (TBRmax) were obtained. Durie Salmon Plus Staging (DSPS) was used for MM staging by PET/CT and was compared with the International Staging System (ISS). Statistical comparison was performed between PET/CT quantitative variables and laboratory parameters.

RESULTS

Twelve participants (12/13) had positive Ga-68 Pentixafor PET/CT, among which one was diagnosed to have anemia of chronic disease. One participant (1/13) who was clinically negative on follow-up had negative Ga-68 Pentixafor PET/CT. The sensitivity, specificity, PPV and NPV of Ga-68 Pentixafor PET/CT in MM (95% CI) were observed to be 100%, 50%, 91.6% and 100%, respectively. The correlation between DSPS and ISS in the patients who came for staging scans was found to be statistically significant (p-value 0.02). In quantitative analysis, either of the quantitative variables in Ga-68 Pentixafor PET/CT was positively correlated with clinical parameters related to tumor burden like CRAB score, serum protein electrophoresis M-protein, beta 2 microglobulin, LDH, percentage of plasma cells infiltrates in bone marrow aspiration, ISS, serum free light chain and negatively correlated with hemoglobin, albumin (p < 0.5).

CONCLUSION

Ga-68 Pentixafor PET/CT is a promising tracer and the only available non-invasive tool to assess the whole-body disease burden of CXCR4 receptors in staging and follow-up of MM. In addition, it has a vital role in the development of CXCR4-targeted theranostics. Dual tracer imaging using F-18 FDG and Ga-68 Pentixafor PET/CT may help in evaluating tumor heterogeneity in MM and add prognostic value at diagnosis and follow-up.

The added diagnostic value of 18 F-FDG PET/CT radiomic analysis in multiple myeloma patients with negative visual analysis

PURPOSE

A small number of patients diagnosed with multiple myeloma (MM) by bone marrow aspiration reported as being disease-free on 18 F-FDG PET/CT. We aim to evaluate the diagnostic value of radiomics approach in patients with MM who were negative by visual analysis.

MATERIALS AND METHODS

Thirty-three patients judged negative by visual analysis were assigned to the MM group. Contemporaneous 31 disease-free patients served as the control group. 70% of the whole data set was used as training set (23 from MM group and 22 from control group) and 30% as testing set (10 from MM group and 9 from control group). Axial skeleton volumes were automatically segmented and high-dimensional imaging features were extracted from PET and CT. The unsupervised machine learning method was used to filter and reduce the dimensions of the extracted features. Random forest was used to construct the prediction model and then validated with 10-fold cross-validation and evaluated on the independent testing set.

RESULTS

One thousand seven hundred two quantitative features were extracted from PET and CT. Of those, three first-order and one high-order imaging features were uncorrelated. With the cross-validation on the training group, the sensitivity, specificity, accuracy and area under the curve of random forest were 0.850, 0.792, 0.818 and 0.894, respectively. On the independent testing set, the accuracy of the model was 0.850 and the area under the curve was 0.909.

CONCLUSION

Radiomic analysis based on 18 F-FDG PET/CT using machine learning model provides a quantitative, objective and efficient mechanism for diagnosing patients with MM who were negative by visual analysis.

Prognostic significance of extramedullary disease (EMD) detected on pre-transplant 18F-FDG PET/CT in patients with multiple myeloma: Results of PIPET-M trial

Background

It is difficult to prognosticate the post-Autologous Stem Cell Transplant (ASCT) responses in multiple myeloma (MM) with the currently available prognostication models. 18F-FDGPET/CT has numerous advantages to prognosticate the post-transplant responses by assessing extramedullary disease (EMD) in addition to the extent of active disease. We aimed at identifying the prognostic value of EMD in predicting progression-free survival (PFS) and overall survival (OS).

Methods

This is a single centre prospective study from western India during a study period of 2014-2022 (with a median follow-up of patients of 6 years). All ASCT patients underwent 18F-FDG-PET/CT as part of pre-transplant workup. The conditioning and treatment protocols were not modified based on PET/CT findings. EMD on PET/CT was correlated with pre-transplant biochemical markers and post-ASCT survival/ progression (as defined by revised IMWG criteria). Statistical analysis was done using SPSS ver. 20.

Results

Patients with pre-ASCT EMD had a hazard-ratio for post-transplant all-cause mortality of 5.46 (p-0.045). Pre-transplant β2M and LDH were significantly higher in patients with EMD (p-0.036). The 6-year median OS in patients with and without EMD were 57.1%, and 80.6% respectively. Kaplan-Meier analysis showed poorer OS in patients with EMD χ2 (1-0.496, p-0.481). There was no significant difference in clinical or biochemical EFS among patients with EMD.

Conclusion

EMD detected on 18F-FDG-PET/CT has a higher hazard for mortality and is significantly correlated with pre-transplant higher β2M and LDH levels. Thus, EMD by pre-transplant 18F-FDG-PET/CT has a significant prognostic role.

Head-to-head comparison of [68Ga]Ga-PSMA-11 and [18F]FDG PET/CT in multiple myeloma

PURPOSE

The aim of this study was to compare [18F]FDG and [68Ga]Ga-PSMA-11 PET/CT image findings in patients with multiple myeloma (MM).

METHODS

Twenty consecutive patients with symptomatic biopsy-proven MM were submitted to whole body [18F]FDG and [68Ga]Ga-PSMA-11 PET/CT with a time interval of 1-8 days between procedures. All lesions were counted and had their maximum SUV (SUVmax) measured. Intra-class correlation (ICC) was used to assess the agreement between [18F]FDG and [68Ga]Ga-PSMA-11 PET/CT findings.

RESULTS

A total of 266 lesions were detected in 19/20 patients. [18F]FDG detected 223/266 (84%) lesions in 17 patients and [68Ga]Ga-PSMA-11 190/266 (71%) lesions in 19 patients. Both procedures did not identify any active lesion in 1 patient. Forty-three (16%) lesions were detected only by [68Ga]Ga-PSMA-11 and 76 (29%) only by [18F]FDG. Both tracers identified 147 (55%) lesions. Intralesional mismatch of FDG-PSMA uptake was identified in 25 of these 147 lesions, found in 8 different patients. Different lesions with uptake of only [18F]FDG or [68Ga]Ga-PSMA-11 in the same patient were found in 4 patients. The highest SUVmax of [18F]FDG and [68Ga]Ga-PSMA-11 had a median (min-max) SUVmax of 6.5 (2.0-37.8) and 5.5 (1.7-51.3), respectively. [18F]FDG and [68Ga]Ga-PSMA-11 respectively identified 18 and 19 soft tissue lesions. False-positive [18F]FDG findings had minimal or no uptake of [68Ga]Ga-PSMA-11. Good reliability (ICC ≥ 0.75) was found for number of lesions, number of soft tissue lesions and highest SUVmax in each patient.

CONCLUSION

[18F]FDG or [68Ga]Ga-PSMA-11 alone can detect most MM lesions. Almost half of the lesions take up only one of the tracers, reflecting increased glycolysis or angiogenesis in specific lesions, and suggesting their possible complementary role in MM. The marked [68Ga]Ga-PSMA-11 uptake in some cases raises the possibility of a theranostic approach in selected patients.

Cluster analysis of autoencoder-extracted FDG PET/CT features identifies multiple myeloma patients with poor prognosis

F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a robust imaging modality used for staging multiple myeloma (MM) and assessing treatment responses. Herein, we extracted features from the FDG PET/CT images of MM patients using an artificial intelligence autoencoder algorithm that constructs a compressed representation of input data. We then evaluated the prognostic value of the image-feature clusters thus extracted. Conventional image parameters including metabolic tumor volume (MTV) were measured on volumes-of-interests (VOIs) covering only the bones. Features were extracted with the autoencoder algorithm on bone-covering VOIs. Supervised and unsupervised clustering were performed on image features. Survival analyses for progression-free survival (PFS) were performed for conventional parameters and clusters. In result, supervised and unsupervised clustering of the image features grouped the subjects into three clusters (A, B, and C). In multivariable Cox regression analysis, unsupervised cluster C, supervised cluster C, and high MTV were significant independent predictors of worse PFS. Supervised and unsupervised cluster analyses of image features extracted from FDG PET/CT scans of MM patients by an autoencoder allowed significant and independent prediction of worse PFS. Therefore, artificial intelligence algorithm-based cluster analyses of FDG PET/CT images could be useful for MM risk stratification.

Prognostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography at diagnosis in untreated multiple myeloma patients: a systematic review and meta-analysis

Multiple myeloma is a clonal B-lymphocyte tumor of terminally differentiated plasma cells. ¹⁸F-FDG PET/CT can provide valuable data for the diagnosis, restaging, and evaluate prognosis of multiple myeloma (MM). This meta-analysis aimed to evaluate the prognostic value of pre-treatment ¹⁸F-FDG PET/CT at diagnosis in MM patients. Related researches came from Embase, PubMed, and Cochrane Library databases through a systematic search, and the last one was updated on April 26, 2021. Cochran Q test and I-squared statistics were used to test for heterogeneity among the studies analyzed. The fixed model and random model were used to combine results when appropriate. Stata 12.0 was used to perform statistical analysis, and p < 0.05 was considered statistically significant. A total of 16 articles with 2589 patients were included in this study. Our results indicated PET/CT has an excellent prognostic role in MM, that higher SUV_max, more FL and EMD were associated with poor OS and PFS. SUVmax: OS (HR 1.89, 95% CI 1.47-2.44), PFS (HR 1.34, 95% CI 1.18-1.51); Fl: OS (HR 2.65, 95% CI 1.83-3.79), PFS (HR 1.61, 95% CI 1.40-1.86); EMD: OS (HR 2.11, 95% CI 1.41-3.16), PFS (HR 2.18, 95% CI 1.69-2.81). Furthermore, similar results were observed in most subgroup analyzes. Conclusion Pre-treatment ¹⁸F-FDG PET/CT examination has prognostic value for myeloma patients and has guiding significance for clinical treatment.

18F-FDG Versus Non-FDG PET Tracers in Multiple Myeloma

Multiple myeloma (MM) accounts for 0.9% of cancer diagnoses, and incidence and mortality rate have increased in previous years. 18F-fluorodeoxyglucose (FDG) PET-computed tomography (CT) is an established modality for MM evaluation. MR imaging is helpful where 18F-FDG PET-CT is lacking. To standardize PET reporting, methods like Italian Myeloma Criteria for PET Use and Deauville criteria have been studied. Tracers like 11C-acetate and 11C-choline/18F-fluoromethylcholine (FCH) have shown higher sensitivity and detected more focal lesions and diffuse involvement than 18F-FDG PET-CT. 18F-FCH showed higher maximum standardized uptake value than 18FDG. 11C-methionine appears to be the best radiopharmaceutical, apart from 18F-FDG, for evaluating MM.

18 F-FDG PET/CT and MRI in the Management of Multiple Myeloma: A Comparative Review

During the last two decades, the imaging landscape of multiple myeloma (MM) has evolved with whole-body imaging techniques such as fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) and MRI replacing X-ray skeletal survey. Both imaging modalities have high diagnostic performance at the initial diagnosis of MM and are key players in the identification of patients needing treatment. Diffusion-weighted MRI has a high sensitivity for bone involvement, while 18F-FDG PET/CT baseline parameters carry a strong prognostic value. The advent of more efficient therapeutics, such as immunomodulatory drugs and proteasome inhibitors, has called for the use of sensitive imaging techniques for monitoring response to treatment. Diffusion-weighted MRI could improve the specificity of MRI for tumor response evaluation, but questions remain regarding its role as a prognostic factor. Performed at key time points of treatment in newly diagnosed MM patients, 18F-FDG PET/CT showed a strong association with relapse risk and survival. The deployment of minimal residual disease detection at the cellular or the molecular level may raise questions on the role of these imaging techniques, which will be addressed. This review summarizes and outlines the specificities and respective roles of MRI and 18F-FDG PET/CT in the management of MM.

Role of FDG PET in the staging of multiple myeloma

¹⁸F-Fluorodeoxyglucose (FDG) PET has been used for staging of hematologic malignancies for years. In multiple myeloma, this imaging modality can be used in many different scenarios, including initial staging, evaluation of treatment response, and investigation of residual disease or early relapse. FDG PET-CT has excellent diagnostic performance, similar to other advanced imaging modalities such as whole-body CT and MRI, and it is particularly helpful for the assessment of extramedullary disease. It also offers important prognostic information on survival and risk of relapse, both at baseline and after therapy. This review will cover the main applications, advantages, and limitations of FDG PET-CT in multiple myeloma and related clonal plasma cell proliferative disorders, such as smoldering multiple myeloma and plasmacytoma.

Oncologist perspective: role of imaging in myeloma

With major advancements in treatments for multiple myeloma (MM), it is critical that we evaluate our methods for both diagnosing MM and monitoring its progression over time. Imaging methods, such as conventional skeletal x-ray, low-dose whole-body CT, MRI, and PET-CT, provide valuable information that influences our clinical decision-making. In this review, we will evaluate the role of these imaging techniques throughout the MM disease course, from diagnosis to follow-up after therapy, and also provide appropriate recommendations.

Metabolic Volume Measurements in Multiple Myeloma

Multiple myeloma (MM) accounts for 10-15% of all hematologic malignancies, as well as 20% of deaths related to hematologic malignant tumors, predominantly affecting bone and bone marrow. Positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (FDG-PET/CT) is an important method to assess the tumor burden of these patients. It is often challenging to classify the extent of disease involvement in the PET scans for many of these patients because both focal and diffuse bone lesions may coexist, with varying degrees of FDG uptake. Different metrics involving volumetric parameters and texture features have been proposed to objectively assess these images. Here, we review some metabolic parameters that can be extracted from FDG-PET/CT images of MM patients, including technical aspects and predicting MM outcome impact. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are volumetric parameters known to be independent predictors of MM outcome. However, they have not been adopted in clinical practice due to the lack of measuring standards. CT-based segmentation allows automated, and therefore reproducible, calculation of bone metabolic metrics in patients with MM, such as maximum, mean and standard deviation of the standardized uptake values (SUV) for the entire skeleton. Intensity of bone involvement (IBI) is a new parameter that also takes advantage of this approach with promising results. Other indirect parameters obtained from FDG-PET/CT images, such as visceral adipose tissue glucose uptake and subcutaneous adipose tissue radiodensity, may also be useful to evaluate the prognosis of MM patients. Furthermore, the use and quantification of new radiotracers can address different metabolic aspects of MM and may have important prognostic implications.

Intensity of bone involvement: a quantitative 18F-FDG PET/CT evaluation for monitoring outcome of multiple myeloma

PURPOSE

The parameter intensity of bone involvement (IBI) was recently proposed to quantitatively assess patients with multiple myeloma using 18F-fluorodeoxyglucose-PET combined with computed tomography (18F-FDG PET/CT) images. Here, we aimed to calculate IBI variation (ΔIBI) between two consecutive PET/CT of the same patient and verified its relationship with a subjective visual analysis of the images and with clinical outcome.

METHODS

Consecutive whole-body 18F-FDG PET/CT performed to assess the outcomes of 29 patients diagnosed with multiple myeloma were retrospectively evaluated. ΔIBI was calculated after bone segmentation, using liver standardized uptake value as a threshold to determine metabolically active volumes in the skeleton. For each pair of consecutive PET/CTs, two nuclear medicine physicians classified visually the most recent image as PET-remission, PET-progression or PET-stable when compared to the previous examination.

RESULTS

The lowest ΔIBI was -1.27 and the highest was 0.29. PET-remission was related to ΔIBI <0 (median = -0.10; -1.27 to +0.03), while PET-progression was related to ΔIBI >0 (median = 0.02; -0.07 to +0.29). ΔIBI around zero was found in images classified as PET-stable (median = 0.00; -0.08 to +0.06). Significant difference in ΔIBI was found between the three groups. Multivariate stepwise analysis showed that IBI value at diagnostic PET/CT, serum calcium and percentage of plasma cells in the bone marrow are independent prognostic factors.

CONCLUSION

Delta IBI provides quantitative data for variations of 18F-FDG uptake in the bone marrow during the follow-up of the patients. In addition, higher IBI values at diagnosis are associated with a higher risk of patient's death.

Bone marrow tracer uptake pattern of PET-CT in multiple myeloma: image interpretation and prognostic value

PURPOSE

To evaluate the prognostic value of bone marrow (BM) imaging pattern and other imaging findings assessed by ¹⁸F-FDG PET-CT in multiple myeloma(MM) and to find out the image interpretation cut-off to define different BM tracer uptake pattern.

MATERIALS AND METHODS

We retrospectively studied PET-CT examinations and clinical data of 100 healthy individuals and 172 newly diagnosed MM patients. A BM uptake > liver SUVmean was selected as the positivity cut-off of pathological uptake in BM after comparing BM uptake in normal control and MM patients. With this interpretation cut-off, we defined the BM FDG uptake pattern as four types: normal, focal, diffuse, and mixed. The clinical correlation and prognostic value of BM uptake pattern were evaluated. The findings were validated in an independent prospective cohort with 72 MM patients.

RESULTS

In MM cohort, 34.9% patients had focal BM uptake pattern, 3.5% had diffuse pattern, 38.4% had mixed pattern, and 23.3% had normal BM uptake. Diffuse/mixed pattern was correlated with clinical and imaging parameters indicating high tumor burden, and inferior progression free survival (PFS; 3-year-PFS 26.8%) and overall survival (OS; 3-year-OS 50.6%). BM uptake pattern was an independent prognostic factor and diffuse/mixed pattern was associated with inferior OS (P = 0.037, HR 7.16) and PFS (P = 0.015, HR 7.77). The prognostic value of BM uptake pattern was also confirmed in validation set.

CONCLUSION

We propose an FDG uptake higher than liver as the positivity cut-off to discriminate between physiological and pathological uptake in BM and defined four BM FDG uptake pattern. BM FDG uptake pattern is a reliable prognostic predictor of MM.

Comparison of [18F]FDG PET/CT and MRI for Treatment Response Assessment in Multiple Myeloma: A Meta-Analysis

The present study was designed to assess the additional value of 2-deoxy-2[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) to magnetic resonance imaging (MRI) in the treatment response assessment of multiple myeloma (MM). We performed a meta-analysis of all available studies to compare the detectability of treatment response of [¹⁸F]FDG PET/CT and MRI in treated MM. We defined detecting a good therapeutic effect as positive, and residual disease as negative. We determined the sensitivities and specificities across studies, calculated the positive and negative likelihood ratios (LR), and made summary receiver operating characteristic curves (SROC) using hierarchical regression models. The pooled analysis included six studies that comprised 278 patients. The respective performance characteristics (95% confidence interval (CI)) of [¹⁸F]FDG PET/CT and MRI were as follows: sensitivity of 80% (56% to 94%) and 25% (19% to 31%); specificity of 58% (44% to 71%) and 83% (71% to 91%); diagnostic odds ratio (DOR) of 6.0 (3.0-12.0) and 1.7 (0.7-2.7); positive LR of 1.8 (1.3-2.4) and 1.4 (0.7-2.7); and negative LR of 0.33 (0.21-0.53) and 0.81 (0.62-1.1). In the respective SROC curves, the area under the curve was 0.77 (SE, 0.038) and 0.59 (SE, 0.079) and the Q* index was 0.71 and 0.57. Compared with MRI, [¹⁸F]FDG PET/CT had higher sensitivity and better DOR and SROC curves. Compared with MRI, [¹⁸F]FDG PET/CT had greater ability to detect the treatment assessment of MM.

Multiple Myeloma, Version 3.2021, NCCN Clinical Practice Guidelines in Oncology

Multiple myeloma is a malignant neoplasm of plasma cells that accumulate in bone marrow, leading to bone destruction and marrow failure. This manuscript discusses the management of patients with solitary plasmacytoma, smoldering multiple myeloma, and newly diagnosed multiple myeloma.

MRI versus 18F-FDG-PET/CT for detecting bone marrow involvement in multiple myeloma: diagnostic performance and clinical relevance

PURPOSE

To compare the diagnostic performance of MRI and ¹⁸F-FDG-PET/CT in detecting bone marrow involvement (BMI) in patients with multiple myeloma (MM).

MATERIALS AND METHODS

This retrospective study was approved by our Institutional Review Board. Two radiologists and two nuclear medicine specialists independently and blindly reviewed 84 pairs of MRI and PET/CT scans obtained in 73 MM patients. Readers assessed the presence and patterns of BMI. The best valuable comparator (BVC) for BMI was established by a panel review of all baseline and follow-up imaging, and biological and pathological information. Intra- and inter-reader agreement and correlation between MRI and PET/CT were assessed using the prevalence-adjusted bias-adjusted kappa (k) coefficient. Diagnostic performance of MRI and PET/CT in detecting BMI was evaluated from ROC characteristics. Association between imaging and biological, pathological, and clinical findings was assessed using Wilcoxon rank-sum and chi-square tests.

RESULTS

Intra- and inter-reader agreement was very good for MRI (k = 0.90 [0.81; 1.00] and 0.88 [0.78; 0.98]). Intra- and inter-reader agreement was good for PET/CT (k = 0.80 [0.69; 0.91] and 0.71 [0.56; 0.86]). The sensitivity of MRI to detect BMI (97% [90%; 100%]) was significantly superior to that of PET/CT (76% [64%; 85%]) (p < 0.001). The specificity of MRI (86% [57%; 98%]) was lower than that of PET/CT (93% [66%; 100%]), without reaching statistical significance (p = 0.32). There was a strong correlation between decisions regarding patient management and PET/CT findings (p < 0.001).

CONCLUSION

MRI is significantly more sensitive than PET/CT to detect BMI in MM. Patient management is more strongly correlated with PET/CT findings.

KEY POINTS

• MRI and PET/CT have very close diagnostic value for the detection of bone marrow involvement in multiple myeloma. • MRI has a significantly higher sensitivity and better reproducibility. • PET/CT findings appear to have a higher impact on clinical decisions.

Chemokine receptor-4 targeted PET/CT with 68Ga-Pentixafor in assessment of newly diagnosed multiple myeloma: comparison to 18F-FDG PET/CT

PURPOSE

¹⁸F-FDG PET/CT has some limitations in the evaluation of multiple myeloma (MM). Since chemokine receptor-4 is overexpressed in MM, we perform a prospective cohort study to compare the performance of ⁶⁸Ga-Pentixafor and ¹⁸F-FDG PET/CT in newly diagnosed MM.

METHODS

Thirty patients with newly diagnosed MM were recruited. All patients underwent ⁶⁸Ga-Pentixafor and¹⁸F-FDG PET/CT within 1 week after enrollment. A positive PET/CT was defined as the presence of focal PET-positive lesions in bone marrow or diffuse bone marrow patterns (uptake > liver). Bone marrow uptake values in ⁶⁸Ga-Pentixafor and¹⁸F-FDG PET/CT (total bone marrow glycolysis [TBmG_FDG], total bone marrow uptake with ⁶⁸Ga-Pentixafor [TBmU_CXCR4], total bone marrow volume [TBmV], SUVmean, and SUVmax) were obtained by drawing total bone marrow volume of interest on PET/CT. The positive rates of the PET/CT scans were statistically compared, and the correlation between quantitative bone marrow uptake values and clinical characteristics, laboratory findings, and staging was analyzed.

RESULTS

⁶⁸Ga-Pentixafor PET/CT had a higher positive rate than ¹⁸F-FDG PET/CT in recruited patients (93.3 vs. 53.3%, p = 0.0005). In quantitative analysis, bone marrow uptake values in ⁶⁸Ga-Pentixafor (TBmU_CXCR4, SUVmax, and SUVmean) were positively correlated with end organ damage, staging, and laboratory biomarkers related to tumor burden including serum β2-microglobulin, serum free light chain, and 24-h urine light chain (p < 0.05). In ¹⁸F-FDG PET/CT, only the SUVmean of total bone marrow was positively correlated with serum free light chain and 24-h urine light chain (p < 0.05).

CONCLUSIONS

⁶⁸Ga-Pentixafor PET/CT is promising in assessment of newly diagnosed MM.

TRIAL REGISTRATION NUMBER

NCT03436342.

Medullary Abnormalities in Appendicular Skeletons Detected With 18F-FDG PET/CT Predict an Unfavorable Prognosis in Newly Diagnosed Multiple Myeloma Patients With High-Risk Factors

OBJECTIVE. The prognostic value of medullary abnormalities in the appendicular skeleton (AS) of patients with multiple myeloma (MM) has recently been suggested. However, functional evaluation of these abnormalities using PET/CT has not been investigated to date. This study aimed to explore the prevalence and prognostic relevance of AS medullary abnormalities depicted by PET/CT in patients with MM. MATERIALS AND METHODS. This retrospective study included 228 consecutive patients with newly diagnosed, symptomatic MM who were treated with novel agents. All patients underwent pretreatment ¹⁸F-FDG PET/CT. RESULTS. There were 157 (68.9%) patients with zero AS focal lesions, 33 (14.5%) with one to three AS focal lesions, and 38 (16.7%) with more than three AS focal lesions on pre-treatment PET/CT. Patients with more than three AS focal lesions showed significantly shorter progression-free survival (PFS) and overall survival (OS) than did those with fewer lesions (both, p < 0.001). In multivariate analysis, the presence of more than three AS focal lesions remained prognostic for both PFS and OS (both, p < 0.001). Furthermore, the presence of more than three AS focal lesions discriminated patients with both significantly shorter PFS and significantly shorter OS even among patients with established high-risk parameters, including high-risk cytogenetic abnormalities, advanced disease stage, and established high-risk PET/CT findings. CONCLUSION. The presence of more than three focal lesions in the AS on pretreatment PET/CT was an independent predictor of poor survival in patients with newly diagnosed MM. Remarkably, this finding discriminated patients with shorter survival from among those with established high-risk factors. Evaluation of findings in the AS may complement and improve the prognostic performance of known stratification systems as well as PET/CT.

Fluorodeoxyglucose-PET/Computed Tomography as a Predictor of Prognosis in Multiple Myeloma

Fluorodeoxyglucose-PET/CT is a valuable tool for the work-up of patients with newly diagnosed and relapsed/refractory multiple myeloma, because it assesses bone damage with high sensitivity and specificity and detects extramedullary sites of proliferating clonal plasma cells (extramedullary diseases). PET/CT provides valuable prognostic data at diagnosis and at restaging during the course of the disease. Consistencies between independent studies confirm the negative prognostic value of extramedullary disease and greater than 3 focal lesions, whereas the role of standardized uptake value is more conflicting. Standardization of the technique is ongoing.

Fludeoxyglucose F 18 PET/Computed Tomography Evaluation of Therapeutic Response in Multiple Myeloma

Multiple myeloma is a malignancy of terminally differentiated plasma cells representing the second most common hematological malignancy. The recognition that disease outside the marrow can significantly influence the outcome of patients has highlighted the importance of imaging to define presence of tumor. Recent studies have demonstrated an added value of using imaging to assess presence of disease both inside and outside the marrow. To this end, the response criteria have been revised to include PET/computed tomography to be used in conjunction with bone marrow assessment to determine minimal residual disease status.

PET with Fluorodeoxyglucose F 18/Computed Tomography as a Staging Tool in Multiple Myeloma

In the past decade novel treatment options have dramatically prolonged the survival of patients with multiple myeloma. PET combined with computed tomography (CT) is a sensitive and reliable functional imaging tool that enables diagnosis and assessment of response to chemotherapy/radiotherapy, and combines high sensitivity in identifying both lytic lesions and extramedullary soft-tissue masses with the ability to provide reliable prognostic information in the management of patients with myeloma. This review comprises a comprehensive overview of PET with fluorodeoxyglucose F 18/CT imaging in combination with other convenient imaging procedures, and attempts at standardization with emphasis on post-therapy findings in patients with myeloma.

Pretreatment 18F-FDG PET/CT combined with quantification of clonal circulating plasma cells as a potential risk model in patients with newly diagnosed multiple myeloma

PURPOSE

Both ¹⁸F-FDG PET/CT and clonal circulating plasma cell (CPC) quantification are emerging tools for multiple myeloma (MM) prognostication that have been validated in recent studies. This study investigated the value of PET/CT coupled with CPC quantification for MM prognostication that may contribute to future risk-adapted treatment.

METHODS

We retrospectively analysed the prognostic relevance of a combination of pretreatment PET/CT findings and CPC levels in 163 consecutive patients with newly diagnosed, symptomatic MM receiving novel agents during induction therapies.

RESULTS

High-risk PET/CT findings and elevated CPC levels were defined by the presence of >3 focal lesions with or without extramedullary disease and CPCs ≥0.10% of the total mononuclear cells evaluated, respectively. Subsequently, patients were divided into three groups: PET-CPC stage I included patients with no high-risk PET/CT findings and low CPC levels; stage III included patients with high-risk PET/CT findings and high CPC levels; and stage II included the remaining patients. The three groups of patients differed significantly in terms of both progression-free survival (PFS) and overall survival (OS) (median PFS: not reached [NR] and 36.4 and 15.9 months, and median OS: NR, NR, and 40.4 months for stages I, II, and III, respectively; P < 0.001 for both PFS and OS). This system discriminated both PFS and OS even among younger (age < 75 years) or older (≥ 75 years) patients, patients with Revised International Staging System stage II or III, and patients with or without high-risk cytogenetic characteristics. In the multivariate analysis, the PET-CPC staging system remained prognostic for both PFS and OS.

CONCLUSIONS

The PET-CPC staging system predicted survival outcomes independently of established risk factors in patients with newly diagnosed MM. Pretreatment ¹⁸F-FDG PET/CT assessment combined with CPC quantification may improve the prognostication of MM and facilitate the development of novel risk-adapted approaches for MM.

How We Manage Patients with Plasmacytomas

PURPOSE OF REVIEW

To discuss the diagnostic approach, treatment options, and future considerations in the management of plasmacytomas, either solitary or in the context of overt multiple myeloma (MM).

RECENT FINDINGS

Advanced imaging techniques such as whole-body magnetic resonance imaging and positron emission tomography/computerized tomography are essential for the diagnostic workup of solitary plasmacytomas (SP) to rule out the presence of other disease foci. The role of flow cytometry and clonal plasma cell detection is currently under study together with other prognostic factors for the identification of patients with SP at high risk of progression to overt MM. Solitary plasmacytomas are treated effectively with local radiotherapy whereas systemic therapy is required at relapse. Clonal plasma cells that accumulate at extramedullary sites have distinct biological characteristics. Patients with MM and soft tissue involvement have poor outcomes and should be treated as ultra-high risk. A revised definition of SP that distinguishes between true solitary clonal PC accumulations and SP with minimal bone marrow involvement should be considered to guide an appropriate therapeutic and follow-up approach. Future studies should be conducted to determine optimum treatment approaches for patients with MM and paraskeletal or extramedullary disease.

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.

Predictive value of 18 F-FDG PET/CT scanning in combination with clinical parameters in patients with newly diagnosed multiple myeloma

OBJECTIVE

To evaluate the association of ¹⁸ F-2'-deoxy 2'-fluorodeoxyglucose (¹⁸ F-FDG) PET/CT with clinical parameters in predicting patients with newly diagnosed multiple myeloma (MM).

METHODS

A total of 120 MM patients undergoing ¹⁸ F-FDG PET/CT scanning were analyzed in a retrospective cohort study.

RESULTS

Based on multivariate analysis, β2M, LDH, number of focal lesions (FLs), and SUVmax were significantly correlated with OS. These 4 variables were used to construct a new staging system (NSS) based on the number of risk factors. NSS provided a better discrimination of risk between stages III and II than International staging system (ISS) (P < .001 vs P = .086). For OS, there was no significant difference among risk groups in Durie-Salmon (DS) stage (P > .05). Based on Spearman correlation analysis, the presence of lesions in appendicular skeleton, number of FLs, and SUVmax appeared to indicate advanced stage of MM. ROC curves which showed the combination of β2M with calcium got a specificity of 96.3% for lesions in appendicular skeleton, and LDH alone had 100% specificity in predicting the number of FLs, although the sensitivity was only 50%.

CONCLUSIONS

¹⁸ F-FDG PET/CT in combination with clinical parameters provided an accurate and simple method for risk stratification of patients with newly diagnosed MM.

A prospective study comparing whole-body skeletal X-ray survey with 18F-FDG-PET/CT, 18F-NaF-PET/CT and whole-body MRI in the detection of bone lesions in multiple myeloma patients

Background

For decades, the most widely used imaging technique for myeloma bone lesions has been a whole-body skeletal X-ray survey (WBXR), but newer promising imaging techniques are evolving.

Purpose

To compare WBXR with the advanced imaging techniques 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), 18F-sodium fluoride (NaF) PET/CT and whole-body magnetic resonance imaging (WB-MRI) in the detection of myeloma bone lesions.

Material and Methods

Fourteen patients with newly diagnosed multiple myeloma were prospectively enrolled. In addition to WBXR, all patients underwent FDG-PET/CT, NaF-PET/CT, and WB-MRI. Experienced specialists performed blinded readings based on predefined anatomical regions and diagnostic criteria.

Results

In a region-based analysis, a two-sided ANOVA test showed that the extent of detected skeletal disease depends on the scanning technique (P < 0.0001). Tukey’s multiple comparison test revealed that WB-MRI on average detects significantly more affected regions than WBXR (P < 0.005), FDG-PET/CT (P < 0.0001), and NaF-PET/CT (P < 0.05). In a patient-based analysis, a Cochran’s Q test showed that there are no significant differences in the proportion of patients with bone disease detected by the different scanning techniques (P = 0.23). Determination of intrareader variability resulted in Kappa coefficients corresponding to moderate (FDG-PET/CT) and substantial agreement (WB-MRI, WBXR, NaF-PET/CT).

Conclusion

WB-MRI detects on average significantly more body regions indicative of myeloma bone disease compared to WBXR, FDG-PET/CT, and NaF-PET/CT. The lack of significance in the patient-based analysis is most likely due to the small number of study participants.

Diagnostic Advances in Multiple Myeloma

There have been several advances in the diagnosis of multiple myeloma (MM) in recent years. Serum free light chains have improved the ability to diagnose light chain MM; however, there are still difficulties in the serologic diagnosis of MM in some cases, particularly IgA MM. A novel heavy/light chain assay is able to improve the accuracy of diagnosis in these cases. Free light chains may also improve the diagnosis of extramedullary disease in difficult cases such as disease involving the central nervous system, pleura, or ascites. Advances in imaging such as whole body low-dose computed tomography (CT) whole body magnetic resonance imaging (MRI), and positron emission tomography/computed tomography (PET/CT) have improved sensitivity in identifying lytic bone lesions, which would enable earlier treatment, and monitoring of osseous disease particularly in non- or oligosecretory disease. New techniques such as fused PET/MRI may further enhance the diagnosis of both bone lesions and extramedullary disease.

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.

Role of 18F-FDG PET/CT in the diagnosis and management of multiple myeloma and other plasma cell disorders: a consensus statement by the International Myeloma Working Group

The International Myeloma Working Group consensus aimed to provide recommendations for the optimal use of ¹⁸fluorodeoxyglucose (¹⁸F-FDG) PET/CT in patients with multiple myeloma and other plasma cell disorders, including smouldering multiple myeloma and solitary plasmacytoma. ¹⁸F-FDG PET/CT can be considered a valuable tool for the work-up of patients with both newly diagnosed and relapsed or refractory multiple myeloma because it assesses bone damage with relatively high sensitivity and specificity, and detects extramedullary sites of proliferating clonal plasma cells while providing important prognostic information. The use of ¹⁸F-FDG PET/CT is mandatory to confirm a suspected diagnosis of solitary plasmacytoma, provided that whole-body MRI is unable to be performed, and to distinguish between smouldering and active multiple myeloma, if whole-body X-ray (WBXR) is negative and whole-body MRI is unavailable. Based on the ability of ¹⁸F-FDG PET/CT to distinguish between metabolically active and inactive disease, this technique is now the preferred functional imaging modality to evaluate and to monitor the effect of therapy on myeloma-cell metabolism. Changes in FDG avidity can provide an earlier evaluation of response to therapy compared to MRI scans, and can predict outcomes, particularly for patients who are eligible to receive autologous stem-cell transplantation. ¹⁸F-FDG PET/CT can be coupled with sensitive bone marrow-based techniques to detect minimal residual disease (MRD) inside and outside the bone marrow, helping to identify those patients who are defined as having imaging MRD negativity.

Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET/CT) Findings in an Unusual Case of Multiple Myeloma Presenting with a Large Extra-Axial Intracranial Mass

Background

We aimed to present unusual cranial FDG PET/CT findings of a 56-year-old female with multiple myeloma (MM).

Case Report

Plain CT images revealed a lytic lesion in the right parietal bone, filled with an oval-shaped, large, extra-axial, extradural, intracranial mass which measured 75×75×40 mm and had smooth borders. The right parietal lobe was compressed by the mass. The maximum standardized uptake value (SUV_max) of the mass lesion was 8.94 on FDG PET/CT images. Multiple lytic lesions with an increased uptake were also detected in other calvarial bones, in several vertebras and in the proximal left femur. After seven months, a control FDG PET/CT following radiotherapy and chemotherapy revealed almost complete regression of the right parietal extra-axial mass lesion. The number, size and metabolism of lytic lesions in other bones also decreased.

Conclusions

FDG PET/CT was useful for an initial evaluation of MM lesions and was effective in monitoring the response of these lesions to therapy.

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

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

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.

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.

Improvement of diagnostic confidence for detection of multiple myeloma involvement of the ribs by a new CT software generating rib unfolded images: Comparison with 5- and 1-mm axial images

OBJECTIVE

To investigate the performance of a new CT software generating rib unfolded images for improved detection of rib osteolyses in patients with multiple myeloma.

MATERIALS AND METHODS

One hundred sixteen patients who underwent whole-body reduced-dose multidetector computed tomography (WBRD-MDCT) for multiple myeloma diagnosis and during follow-up were retrospectively evaluated. Nonenhanced CT scans with 5- and 1-mm slice thickness were interpreted by two readers with focus on detection of rib involvement (location, number, fracture). Image analysis of "unfolded," 1-mm-based CT rib images was subsequently undertaken. We classified the number of lytic bone lesions into 0, 1, 2, <5, <10 and ≥10. For all three data sets the reading time was registered.

RESULTS

An approximated sum of 6,727 myeloma-related rib lesions was found. On a patient-based analysis, CT (5 mm), CT (1 mm) and CT (1 mm "unfolded rib") yielded a sensitivity, specificity and accuracy of 79.7/94.7/87.1, 88.1/93/90.5 and 98.3/96.5/97.4, respectively. In a lesion-based analysis, the sensitivity, specificity and accuracy of the three evaluations were 69.7/87.2/70.5, 79.8/55.9/78 and 96.5/89.7/96.1. Mean reading time for 5 mm/1 mm axial images and unfolded images was 178.7/215.1/90.8 s, respectively.

CONCLUSION

The generation of "unfolded rib" images improves detection of rib involvement in patients with multiple myeloma and significantly reduces reading time.

Pomalidomide and Low-Dose Dexamethasone Improves Health-Related Quality of Life and Prolongs Time to Worsening in Relapsed/Refractory Patients With Multiple Myeloma Enrolled in the MM-003 Randomized Phase III Trial

BACKGROUND

Health-related quality of life (HRQoL) is an important element for consideration in treatment decisions in patients with relapsed/refractory multiple myeloma (RRMM). The pivotal MM-003 (A Phase 3, Multicenter, Randomized, Open-Label Study to Compare the Efficacy and Safety of Pomalidomide in Combination With Low-Dose Dexamethasone vs. High-Dose Dexamethasone in Patients With Refractory Multiple Myeloma or Relapsed and Refractory Multiple Myeloma and Companion Study [NIMBUS]) randomized, open-label, multicenter, phase III trial demonstrated improved progression-free survival (PFS) and prolonged overall survival (OS) with pomalidomide (POM) plus low-dose dexamethasone (POM + LoDEX) versus high-dose dexamethasone (HiDEX) in patients with RRMM in whom lenalidomide (LEN) and bortezomib (BORT) had failed. MM-003 also investigated HRQoL as a predefined secondary end point.

PATIENTS AND METHODS

Recruited patients (n = 455) were refractory to their last treatment and had failed LEN and BORT after ≥ 2 consecutive cycles of each (alone or in combination). Eight clinically relevant and validated HRQoL domains from the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30, EORTC QLQ-MY20, and EQ-5D questionnaires were selected for analysis. Time to symptom worsening based on minimally important differences (MIDs) was calculated.

RESULTS

Clinically meaningful improvements in HRQoL as determined by MIDs, regression analyses, and best response analyses were observed more frequently in patients receiving POM + LoDEX than in those receiving HiDEX. POM + LoDEX significantly extended median time to clinically meaningful worsening in HRQoL versus HiDEX in 4 HRQoL domains and demonstrated a trend in an additional 3 domains. Patients in the HiDEX arm experienced earlier HRQoL deterioration compared with those in the POM + LoDEX arm in each domain analyzed.

CONCLUSION

POM + LoDEX offer good clinical outcomes that lead to improved and prolonged HRQoL compared with HiDEX in patients with RRMM and end-stage disease.

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.

State of the art imaging of multiple myeloma: comparative review of FDG PET/CT imaging in various clinical settings

18-Flurodeoxyglucose Positron Emission Tomography with computed tomography (FDG PET/CT) and Magnetic Resonance Imaging (MRI) have higher sensitivity and specificity than whole-body X-ray (WBXR) survey in evaluating disease extent in patients with multiple myeloma (MM). Both modalities are now recommended by the Durie-Salmon Plus classification although the emphasis is more on MRI than PET/CT. The presence of extra-medullary disease (EMD) as evaluated by PET/CT imaging, initial SUVmax and number of focal lesions (FL) are deemed to be strong prognostic parameters at staging. MRI remains the most sensitive technique for the detection of diffuse bone marrow involvement in both the pre and post-therapy setting. Compression fractures are best characterized with MRI signal changes, for determining vertebroplasty candidates. While PET/CT allows for earlier and more specific evaluation of therapeutic efficacy compared to MRI, when signal abnormalities persist years after treatment. PET/CT interpretation, however, can be challenging in the vertebral column and pelvis as well as in cases with post-therapy changes. Hence, a reading approach combining the high sensitivity of MRI and superior specificity of FDG PET/CT would be preferred to increase the diagnostic accuracy. In summary, the established management methods in MM, mainly relying on biological tumor parameters should be complemented with functional imaging data, both at staging and restaging for optimal management of MM.

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

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