[68Ga]Pentixafor PET/CT for staging and prognostic assessment of newly diagnosed multiple myeloma: comparison to [18F]FDG PET/CT.

PURPOSE: To evaluate the prognostic performance of [68Ga]Pentixafor PET/CT at baseline for staging of patients with newly diagnosed multiple myeloma (MM) and to compare it with [18F]FDG PET/CT and the Revised-International Staging System (R-ISS). METHODS: Patients who underwent [68Ga]Pentixafor and [18F]FDG PET/CT imaging were retrospectively included. Patient staging was performed according to the Durie-Salmon PLUS staging system based on [68Ga]Pentixafor PET/CT and [18F]FDG PET/CT images, and the R-ISS. Progression-free survival (PFS) at patient follow-up was estimated using the Kaplan-Meier estimator and compared using the log-rank test. Area under the receiver operating characteristic curve (AUC) was calculated to assess predictive performance. RESULTS: Fifty-five MM patients were evaluated. Compared with [18F]FDG PET, [68Ga]Pentixafor PET detected 25 patients as the same stage, while 26 patients were upstaged and 4 patients were downstaged (P = 0.001). After considering the low-dose CT data, there was no statistically significant difference in the number of patients classified in each stage using [68Ga]Pentixafor PET/CT and [18F]FDG PET/CT (P = 0.091). [68Ga]Pentixafor PET/CT-based staging discriminated PFS outcomes in patients with different disease stages (stage I vs. stage II, stage I vs. stage III, and stage II vs. stage III; all P < 0.05), whereas for [18F]FDG PET/CT, there was only a difference in median PFS between stage I and III (P = 0.021). When staged by R-ISS, the median PFS for stage III was significantly lower than that for stage I and II (P = 0.008 and 0.035, respectively). When predicting 2-year PFS based on staging, the AUC of [68Ga]Pentixafor PET/CT was significantly higher than that of [68Ga]Pentixafor PET (0.923 vs. 0.821, P = 0.002), [18F]FDG PET (0.923 vs. 0.752 P = 0.002), and R-ISS (0.923 vs. 0.776, P = 0.005). CONCLUSIONS: [68Ga]Pentixafor PET/CT-based staging possesses substantial potential to predict disease progression in newly diagnosed MM patients.

Learning curves in radiological reporting of whole-body MRI in plasma cell disease: a retrospective study.

BACKGROUND: The plasma cell disease is been studying by the whole-body MRI technology. However, the time requested to learn this radiological technique is unknown. PURPOSE: To esteem, quantitatively and qualitatively, the essential time to learn the whole-body MRI diffusion-weighted imaging with background body signal suppression in patients with plasma cell disease. MATERIALS AND METHODS: Between January 2015 and February 2017, three readers in-training with different levels of experience examined the anonymised and randomised whole-body MRI images of 52 patients with a diagnosis of plasma cell disease and analysed their morphological (T1w, T2w with and without fat suppression) and functional sequences. Reports of an expert radiologist were considered the standard of reference. Images were analysed in two sessions, during which each reader was timed. Readers reported the number of segments with lesions and staged the disease using the Durie-Salmon PLUS staging system. Weighted Cohen's ĸ and Z-test were used to compare the trainees' reports with those of the expert radiologist, and learning curves were drawn up to show changes between the two sessions. RESULTS: Weighted Cohen's ĸ of number of lesioned segments increased from 0.536 ± 0.123 to 0.831 ± 0.129 (Prob > Z under 0.005), thus approaching the goal of ĸ > 0.8. Trainees reached the level of experienced radiologist in terms of time by the 33rd patient. Agreement concerning the Durie-Salmon PLUS increased from 0.536 ± 0.123 to 0.831 ± 0.129 (Prob > Z under 0.005). CONCLUSIONS: The findings of this study demonstrate that whole-body MRI with DWIBS can be learned in about 80 reports and leads to a high level of inter-observer concordance when using the Durie-Salmon PLUS staging system.

A Comparison of Different Staging Systems for Multiple Myeloma: Can the MRI Pattern Play a Prognostic Role?

OBJECTIVE: The objective of this study is to compare the most recent systems for the staging of multiple myeloma (MM), the Durie-Salmon PLUS system and the International Staging System, according to patients' survival rates and response to therapy. Another objective is to verify whether patterns of bone marrow alteration on MRI (i.e., focal, diffuse, or variegated patterns) can provide prognostic information for patients with MM. MATERIALS AND METHODS: We retrospectively enrolled 85 patients with MM who were monitored for a minimum of 6 years and who underwent contrast-enhanced spinal and pelvic MRI at 1.5 T and whole-body FDG PET/CT at the time of diagnosis. Patients underwent MM staging performed using both staging systems and were divided into groups on the basis of their MRI patterns. These patient groups were then compared in terms of survival, response to therapy, and duration of response. RESULTS: Both staging systems showed great capability in differentiating patients with a worse prognosis from patients with a better outcome, with the capability of both systems found to be statistically significant, albeit less statistically significant for the Durie-Salmon PLUS system (p = 0.010 vs p = 0.046, respectively). Patients with a focal pattern on MRI had a worse survival rate than did the patients with other MRI patterns (p = 0.032). CONCLUSION: These data indicate that both the International Staging System and the Durie-Salmon PLUS system have great potential for characterizing and stratifying MM to determine the survival outcome and therapy response of patients. Observation of a focal pattern on MRI seems to be associated with poorer survival.

The role of CT in PET/CT for assessing diffuse infiltration of bone marrow in multiple myeloma using the Durie-Salmon PLUS staging system.

PET/CT has been identified as one of the routine methods for the assessment of multiple myeloma (MM) bone marrow infiltration. In the routine method of performing PET/CT, the 18F-Fludeoxyglucose (18F-FDG) uptake in this disease is often used in the assessment of this condition, however CT diagnosis is not currently commonly used. The aim of the present study was to investigate the importance of CT in PET/CT for assessing diffuse infiltration (DI) of bone marrow in MM. MRI was used as a control in the present study, which is the gold standard for assessing DI of bone marrow and is divided into 3 levels: Mild, moderate and severe DI. Subsequently, a total of four combinations of PET and CT results were listed using the enumeration method for the evaluation of DI in the bone marrow. These combinations were respectively compared with the three levels of MR imaging to screen the most consistent method. The concordances of the new method and routine 18F-FDG PET/CT for the assessment of DI with MR imaging were compared using the McNemar test, respectively. The results of the DI assessment from the two methods were verified by performing Durie-Salmon (D-S) PLUS staging. Compared with MR imaging, the results were as follows: PET and CT exhibited negative results, suggesting mild DI; one of them was positive, suggesting moderate DI; and two were positive, suggesting severe DI. The results of concordance between two methods (new and routine) and MR imaging are indicated as follows: For the new method, McNemar test, P=0.513 and Kappa=0.745; for the routine 18F-FDG PET/CT method, McNemar test, P=0.03 and Kappa=0.547. Re-performance of D-S PLUS staging presented the following results: New method, McNemar test, P=0.317 and Kappa=0.93; for the routine method, McNemar test, P=0.223 and Kappa=0.811. These findings indicated that the CT component of PET/CT could improve the concordance with MRI results in the assessment of DI, and the same results were obtained when D-S PLUS staging was performed. The CT in PET/CT can enhance diagnostic accuracy in the assessment of DI by reducing the false negatives when compared with the routine 18F-FDG method.