Prognostic Significance of the Number of Focal Lesions in Whole Body Magnetic
Resonance Imaging before and after Autologous Stem Cell Transplantation
Hil engass J1,2, Ayyaz S1, Kilk K3, Weber MA3, Listl K3 Hielscher T4, Egerer G1, Kauczor HU3, Delorme S2, Ho AD1, Goldschmidt H1, Neben K1
1 Department of Hematology, Oncology and Rheumatology, University of Heidelberg, Germany; 2 Department of Radiology, German Cancer Research Center Heidelberg, Germany; 3 Department of
Interventional and Diagnostic Radiology, University of Heidelberg, Germany; 4 Department of Biostatistics, German Cancer Research Center Heidelberg, Germany
Figure 1: Examples of focal and
Figure 2: Overal survival probability for patient groups
Introduction
diffuse infiltration by multiple myeloma
according to the number of focal lesions at first MRI
as seen in MRI (arrow heads)
Magnetic resonance imaging (MRI) has been demonstrated to be the most sensitive imaging
technique to detect both diffuse and focal infiltration of multiple myeloma cel s in bone marrow. Whole
body magnetic resonance imaging (WB-MRI) can be applied using affordable extensions to standard
MRI scanners. Recent studies have shown that the presence and number of focal lesions (FL) in MRI
are of prognostic significance in symptomatic as wel as smoldering multiple myeloma. The aim of the
present study was to investigate the significance of persisting FL after autologous stem cel
p = 0.17
transplantation. Examples of FL before and after therapy are shown in figure 1.
Patients
WB-MRI of 100 patients with symptomatic myeloma treated with high dose chemotherapy were
evaluated retrospectively before the start of systemic treatment and after single or tandem
autologous stem cel transplantation. Number of FL was assessed by two investigators in consensus
for each time point separately. The analysis was approved by the institutional ethics committee.
Methods
Figure 3: Overal survival probability for patient groups
MRI protocol included T1 and T2 weighted sequences in coronal orientation of the whole body
according to the number of focal lesions at second MRI
(excluding T2 of the lower legs to maintain acceptable examination time) as wel as T1 and T2
weighted sequences of the whole spine in sagittal orientation. MRI-remission was assessed by two
experienced radiologists in consensus for focal and diffuse infiltration separately and in combination.
Overal survival was defined as time from second MRI until death of any cause.
Results
p = 0.02
Response in MRI was assessed as shown in table 1. At second MRI an fCR was found in 25; an fPR
in 22; an fSD in 26 and an fPD in 27 patients (table 1). Patients in different groups of numbers of FL
at first and second MRI are shown in table 2. For evaluation of prognostic significance of the number
of FL for overal survival a log rank test resulted in a p-value of 0.17 for the first and 0.02 for the
second WB-MRI. Kaplan-Meier plots for overal survival according to the number of FL at first and
second MRI are shown in Figure 2 and 3 respectively. The number of FL was not of prognostic
significance for progression free survival (p = 0.6 and p = 0.8 at first and second MRI respectively).
Serological and MRI-defined response concerning FL were significantly associated (p = 0.003;
Conclusion
Kendal ´s Tau 0.26) with a trend to an underestimation of response in FL compared to serological
response.
The fact that the number of FL after high dose chemotherapy but not at first diagnosis of symptomatic
myeloma had a significant impact on survival in our study, confirms the importance of the
Table 1: Focal MRI-response at time of second MRI
measurement of residual disease after systemic treatment as it has been demonstrated for methods
Table 2: Focal at first and second MRI
as flow cytometry and others. Thereby WB-MRI al ows the evaluation of nearly the whole bone
f-CR total disappearance of focal lesions
25
first MRI
second MRI
marrow compartment non-invasively and without the need of irradiation exposure. A limitation of MRI
0
24
25
is the fact that it is not capable of differentiating between FL containing vital tumor cel s and those
f-PR reduction of the number of FL of 50% or more 22
representing osteolyses without active myeloma cel s. New functional MRI sequences like dynamic
1-10
36
51
f-SD unchanged number
26
contrast-enhanced MRI and diffusion weighted imaging may overcome this disadvantage. Further
11-20
13
13
studies wil show which imaging technique is most useful in myeloma or if different clinical and
f-PD increase in number of focal lesions
27
>20
27
11
scientific questions necessitate different methods.
There are no relevant conflicts of interest to disclose

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