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

IMPeTUs parameters correlate with clinical features in newly diagnosed multiple myeloma

Objectives

To investigate the correlations between IMPeTUs-based 18 F-FDG PET/CT parameters and clinical features in patients with newly diagnosed multiple myeloma (MM).

Materials and methods

PET/CT were analysed according to the IMPeTUs criteria. We correlated these PET/CT parameters with known clinically relevant features, bone marrow plasma cell (BMPC) infiltration rate and the presence of cytogenetic abnormalities.

Results

A total of 149 patients (86 males, 63 females; mean age, 59.9 ± 9.7 years) were included. Bone marrow metabolic state correlated with the most clinical features including hemoglobin (rho=-0.23, p=0.004), FLC ratio (rho=0.24, p=0.005), β2 M (rho=0.28, p=0.001), CRP (rho=0.25, p=0.003), serum calcium (rho=0.22, p=0.02), serum creatinine (rho=0.24, p=0.004) and BMPC (rho=0.21, p=0.003). Besides, the level of hemoglobin was significant lower (0.043), and the levels of FLC ratio (0.037), β2 M (p=0.024), CRP (p=0.05), and BMPC (p=0.043) were significant higher in patients having hypermetabolism in limbs and ribs. Hottest bone lesion Deauville criteria had a moderate correlation with CRP (rho=0.27, p=0.001) and serum calcium (rho=0.25, p=0.01).

Conclusion

Several IMPeTUs-based PET/CT parameters showed significant correlations with clinical features reflecting disease burden and biology, suggesting that these new criteria can be used in the risk stratification in MM patients.

Functional Imaging in the Evaluation of Treatment Response in Multiple Myeloma: The Role of PET-CT and MRI

Bone disease is among the defining characteristics of symptomatic Multiple Myeloma (MM). Imaging techniques such as fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) and magnetic resonance imaging (MRI) can identify plasma cell proliferation and quantify disease activity. This function renders these imaging tools as suitable not only for diagnosis, but also for the assessment of bone disease after treatment of MM patients. The aim of this article is to review FDG PET/CT and MRI and their applications, with a focus on their role in treatment response evaluation. MRI emerges as the technique with the highest sensitivity in lesions' detection and PET/CT as the technique with a major impact on prognosis. Their comparison yields different results concerning the best tool to evaluate treatment response. The inhomogeneity of the data suggests the need to address limitations related to these tools with the employment of new techniques and the potential for a complementary use of both PET/CT and MRI to refine the sensitivity and achieve the standards for minimal residual disease (MRD) evaluation.

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.

Pretreatment Serum Levels of IL-1 Receptor Antagonist and IL-4 Are Predictors of Overall Survival in Multiple Myeloma Patients Treated with Bortezomib

Multiple myeloma (MM) is characterized by the malignant proliferation of monoclonal plasma cells in the bone marrow with an elevation in monoclonal paraprotein, renal impairment, hypercalcemia, lytic bony lesions, and anemia. Immune cells and associated cytokines play a significant role in MM growth, progression, and dissemination. While some cytokines and their clinical significance are well described in MM biology, others remain relatively unknown. The present study examines the influence on progression-free survival (PFS) and overall survival (OS) by the serum levels of 27 selected cytokines in 61 newly diagnosed MM patients receiving first-line therapy with bortezomib-based regimens. The measurements were performed using a Bio-Rad Bio-Plex Pro Human Cytokine 27-Plex Assay and a MAGPIX Multiplex Reader, based on the Bio-Plex^® 200 System (Bio-Rad). The following levels were determined: IL-1β, IL-1Ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, Eotaxin, FGF, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, MIP-1β, PDGF-BB, RANTES, TNF-α, and VEGF. Most patients received a VCD chemotherapy regimen (bortezomib, cyclophosphamide, and dexamethasone). In the final multivariate model, IL-13 cytokine level (HR 0.1411, 95% CI: 0.0240-0.8291, p = 0.0302) and ASCT (HR 0.3722, 95% CI: 0.1826-0.7585, p = 0.0065) significantly impacted PFS. Furthermore, ASCT (HR 0.142, 95% CI: 0.046-0.438, p = 0.0007), presence of bone disease at diagnosis (HR 3.826, 95% CI: 1.471-9.949, p = 0.0059), and two cytokine levels-IL-1Ra (HR 1.017, 95% CI: 1.004-1.030, p = 0.0091) and IL-4 (HR 0.161, 95% CI: 0.037-0.698, p = 0.0147)-were independent predictors of OS. Three clusters of MM patients were identified with different cytokine profiles. In conclusion, serum pretreatment levels of IL-13 and IL-4 are predictors of better PFS and OS, respectively, whereas IL-1Ra pretreatment levels negatively impact OS in MM patients treated with bortezomib-based chemotherapy. Cytokine signature profile may have a potential influence on the outcome of patients treated with bortezomib.

Utility and Clinical Implications of Appendicular Skeleton Magnetic Resonance Imaging in Multiple Myeloma: A Single-Institutional 15-Year Experience

OBJECTIVE

The aim of this study was to evaluate the utility of appendicular skeleton magnetic resonance imaging (MRI) in the management of multiple myeloma over 15 years.

METHODS

A total of 107 appendicular MRIs were obtained from 67 patients. Variables including age, sex, diagnosis, stage, indication, transplant status, MRI result, and treatment course were analyzed.

RESULTS

The most common indication was pain (76.6%). The most commonly affected bone groups were the proximal lower (54.3%) and upper extremity (47.6%). Most (83%) positive examinations demonstrated focal disease. Advanced Durie-Salmon stage was associated with increase in appendicular disease (P = 0.0056). Increasing age and prior negative positron emission tomography/computed tomography were associated with a decrease in appendicular disease (P = 0.0036 and 0.0011). When neoplasm was seen, 58.5% underwent management alteration. Advanced stage and history of relapse were associated with treatment alterations (P = 0.0096 and 0.0031).

CONCLUSION

Appendicular MRIs comprised 9.6% of MRIs ordered. Appendicular MRI elucidates both neoplastic and nonneoplastic causes of pain. Most examinations with MRI positive for myeloma had subsequent skeletal disease and resulted in altered management.

A proposed index of diffuse bone marrow [18F]-FDG uptake and PET skeletal patterns correlate with myeloma prognostic markers, plasma cell morphology, and response to therapy

PURPOSE

The investigation of a semi-quantitative index in the pelvis to assess for diffuse bone marrow (BM) [18F]-FDG uptake and the investigation of PET skeletal patterns in multiple myeloma (MM) patients, in accordance with prognostic markers, clonal plasma cell (cPC) morphology, and response to therapy.

METHODS

We prospectively analyzed [18F]-FDG PET/CT in 90 MM patients (newly diagnosed, 60; relapsed/refractory, 30). Among other PET/CT parameters, we calculated the ratio SUVmax pelvis/liver and examined for correlations with known MM prognostic parameters, cPC morphology (good vs. low/intermediate differentiation), and response to therapy.

RESULTS

SUVmax pelvis/liver ratio was significantly lower for the group of good differentiation vs. intermediate/low differentiation cPCs (p < 0.001) and showed a positive correlation with BM infiltration rate, β2 microglobulin, serum ferritin, international staging system (ISS), and revised ISS; no significant correlation was found with hemoglobin. A cutoff value of 1.1 showed an excellent specificity (99%) and high sensitivity (76%) for diffuse BM involvement (AUC 0.94; p < 0.001). Mixed pattern and appendicular involvement correlated with poor prognostic features while normal pattern, found in 30% of patients, correlated with good prognostic features. Presence of ≥ 10 focal lesions negatively predicted for overall response (p < 0.05; OR 4.8). The CT component improved the diagnostic performance of PET.

CONCLUSION

This study showed, for the first time, that cPC morphology and markers related with MM biology, correlate with SUVmax pelvis/liver index, which could be used as a surrogate marker for BM assessment and disease prognosis; PET patterns correlate with MM prognostic features and response rates.

Pre-treatment metabolic tumour volume and total lesion glycolysis are superior to conventional positron-emission tomography/computed tomography variables for outcome prediction in patients with newly diagnosed multiple myeloma in clinical practice

Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) are positron-emission tomography/computed tomography (PET/CT) variables for predicting multiple myeloma's (MM) outcome. We retrospectively investigated and compared the predictive value of MTV, TLG and high-risk PET/CT variables in clinical practice in 185 patients with newly diagnosed symptomatic MM. High-risk PET/CT findings were defined as the presence of at least one of the following: more than three focal lesions, maximum standardised uptake value (SUVmax ) >4·2 and extramedullary disease. MTV was defined as the volume of myeloma lesions visualised on PET/CT with SUV ≥ 2·5. TLG was calculated as the sum of the product of the average SUV and MTV of all lesions. The mortality prediction optimal cut-off values for MTV and TLG were 56·4 cm3 and 166·4 g, respectively. High-burden MTV (≥56·4 cm3 ), TLG (≥166·4 g) and high-risk PET/CT findings differed significantly in progression-free survival (PFS) and overall survival (OS). High-burden MTV and TLG findings also predicted survival outcomes in young patients (age <75 years) and patients with high-risk chromosomal abnormalities. High-burden MTV and TLG independently predicted both worse PFS and OS. Pre-treatment MTV and TLG independently predicted survival outcomes in clinical practice and may be more useful than high-risk PET/CT variables.

FDG-PET/CT, a Promising Exam for Detecting High-Risk Myeloma Patients?

Multiple myeloma (MM) is a haematological neoplasm characterized by a clonal proliferation of malignant plasma cells in the bone marrow. MM is associated with high morbidity and mortality and variable survival, which can be very short for some patients but over 10 years for others. These differences in survival are explained by intra- and inter-tumoral heterogeneity and demonstrate the potential benefits of adapting the treatment course for high-risk patients with a poorer prognosis. Indeed, identification of these high-risk patients is necessary and is based on the identification of high-risk biomarkers including clinical variables, genomics and imaging results. Positron emission tomography combined with computed tomography using 18F-deoxyfluoroglucose (FDG-PET/CT) is a reliable technique for the initial staging of patients with symptomatic multiple myeloma (MM), and has been included in the IMWG (International Myeloma Working Group) recommendations in 2019. According to clinical studies, FDG-PET/CT characteristics could be used to define high-risk patients at initial diagnosis of symptomatic MM. The goal of this review is to demonstrate the prognostic value of FDG-PET in symptomatic MM patients, particularly in identifying high-risk patients, and thus, to best adapt therapeutic management in the future.

PET-FDG: Impetus

The International Myeloma Working Group (IMWG)recommends FDG PET/CT (Fluoro-Deoxy-glucose Positron Emission Tomography/Computed Tomography) as the gold standard imaging modality for initial evaluation and response to therapy assessment in multiple myeloma. In fact, FDG PET/CT, provides multiple useful indexes to risk-stratify patients and has significant prognostic value. However, multiple myeloma remains a complex disease to interpret on imaging. The Italian myeloma criteria for PET use (IMPeTUs) were proposed to standardize FDG PET/CT reading in multiple myeloma. In this communication an overview on IMPeTUs is provided as well as some examples of application.