Miho Ishikawa

Hiroshima University, Hirosima, Hiroshima, Japan

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Publications (6)10.88 Total impact

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    ABSTRACT: PURPOSE Lenalidomide and bortezomib have been successfully used in the treatment of multiple myeloma (MM), of which bone disease is a key feature. Bortezomib has been linked to increased bone formation and osteoblastic activity; however, the effect of lenalidomide on bones remains unknown. Therefore, in this study, trabecular microstructural analysis and biomechanics assessed by a clinical CT-based finite element model (CT/FEM) were used to investigate whether lenalidomide affects the microarchitecture of bones. METHOD AND MATERIALS Sixty-seven MM patients (male, n=37; mean age, 67.1±10 years; female, n=30; mean age, 68.6±10 years) were examined by 64-detector CT after a mean period of six months of either therapy with bortezomib- (n=33) or lenalidomide (n=19), or follow-up without treatment (n=15). Using a bone mineral calibration phantom and a 3D image analysis system, bone mineral content per tissue volume (BMC/TV), trabecular parameters, and mechanical properties of the third lumbar vertebrae were calculated. The statistical significance of the change with respect to baseline over time was assessed using a two-way analysis of variance with repeated measures. To investigate whether baseline geometric or biomechanical indices predict the subsequent response to treatment, the Spearman rank correlation test was performed for each baseline index with respect to post-treatment changes. RESULTS At the second CT examination, trabecular number, failure load and stiffness increased in the lenalidomide group (P<0.01) and decreased in the bortezomib group (P<0.01), whereas the follow-up group remained unchanged. BMC/TV was increased in the lenalidomide- and bortezomib groups (P<0.01, P<0.05, respectively). Trabecular thickness decreased in the lenalidomide group (P<0.01). In the lenalidomide group, the changes in BMC/TV and trabecular spacing negatively correlated with baseline values (ρ=-0.60 and -0.63, respectively). CONCLUSION Lenalidomide treatment resulted in significant increases in BMC/TV, trabecular number and CT/FEM-derived estimates of bone strength, while failure load and stiffness decreased in the bortezomib group. Baseline BMC/TV and trabecular spacing predicted lenalidomide-induced bone changes. CLINICAL RELEVANCE/APPLICATION Lenalidomide treatment promoted significant increases in bone strength. Mechanical properties, assessed by a CT/FEM, provided useful information about treatment response in multiple myeloma.
    No preview · Conference Paper · Dec 2013
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    ABSTRACT: PURPOSE Asymptomatic multiple myeloma is an asymptomatic plasma-cell proliferative disorder associated with a high risk of progression to symptomatic multiple myeloma. Predictive factors for the progression of this disease are unclear. This study was performed to evaluate the effectiveness of the iterative decomposition of water and fat with echo asymmetric and least-squares estimation (IDEAL) MRI to predict symptomatic myeloma in patients without visible focal lesions. METHOD AND MATERIALS The lumbar spine was examined with 3T-MRI in 47 patients with multiple myeloma (asymptomatic myeloma, 23; symptomatic myeloma, 24). The fat-signal fraction (FSF) obtained by IDEAL sequence was calculated as the mean value from three vertebral bodies. We evaluated factors predictive of symptomatic myeloma. They included sex, age, FSF, MR signal intensity pattern (MR pattern), bone marrow plasma cell percentage (BMPC%) obtained from a biopsy specimens, presence of IgA monoclonal protein, serum monoclonal protein level (M protein), serum albumin level, serum β2-microglobulin (β2m) level, the β2m/albumin ratio, reductions in levels of uninvolved immunoglobulins, and the kappa/lambda ratio. For data analysis, univariate and multivariate logistic regression analyses, as well as receiver operating characteristic curves, were used. A difference with P < .05 was considered significant. RESULTS Univariate analysis demonstrated that MR pattern, FSF, BMPC%, M protein, the reduction in uninvolved immunoglobulins, β2m, and the β2m/albumin ratio were significantly associated with symptomatic myeloma. Results of multivariate analysis demonstrated that β2m, FSF, and the reduction in uninvolved immunoglobulins had significant effects in differentiation between asymptomatic and symptomatic myeloma. The area under the curve was 0.805 for FSF, 0.844 for β2m, and 0.793 for BMPC%. CONCLUSION Fat quantification results using the IDEAL sequence in MRI were significantly different in patients with symptomatic- and asymptomatic myeloma. The FSF and β2m facilitated the discrimination of symptomatic- from asymptomatic myeloma. CLINICAL RELEVANCE/APPLICATION Predictive factors for the progression to symptomatic myeloma included FSF and β2m. The discriminative performance of FSF is comparable to that of BMPC% obtained from biopsy specimen.
    No preview · Conference Paper · Dec 2013
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    ABSTRACT: To evaluate the effectiveness of the iterative decomposition of water and fat with echo asymmetric and least-squares estimation (IDEAL) MRI to quantify tumour infiltration into the lumbar vertebrae in myeloma patients without visible focal lesions. The lumbar spine was examined with 3 T MRI in 24 patients with multiple myeloma and in 26 controls. The fat-signal fraction was calculated as the mean value from three vertebral bodies. A post hoc test was used to compare the fat-signal fraction in controls and patients with monoclonal gammopathy of undetermined significance (MGUS), asymptomatic myeloma or symptomatic myeloma. Differences were considered significant at P < 0.05. The fat-signal fraction and β(2)-microglobulin-to-albumin ratio were entered into the discriminant analysis. Fat-signal fractions were significantly lower in patients with symptomatic myelomas (43.9 ±19.7%, P < 0.01) than in the other three groups. Discriminant analysis showed that 22 of the 24 patients (92%) were correctly classified into symptomatic or non-symptomatic myeloma groups. Fat quantification using the IDEAL sequence in MRI was significantly different when comparing patients with symptomatic myeloma and those with asymptomatic myeloma. The fat-signal fraction and β(2)-microglobulin-to-albumin ratio facilitated discrimination of symptomatic myeloma from non-symptomatic myeloma in patients without focal bone lesions. KEY POINTS : • A new magnetic resonance technique (IDEAL) offers new insights in multiple myeloma. • Fat-signal fractions were lower in patients with symptomatic myelomas than in those with asymptomatic myelomas. • The β2-microglobulin-to-albumin ratio also aided discrimination of symptomatic myeloma. • The fat-signal fraction may provide information about the myeloma cell mass.
    No preview · Article · Dec 2011 · European Radiology
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    ABSTRACT: PURPOSE Computed tomography (CT) is used for the diagnosis and management of multiple myeloma patients to better clarify the extent of bone destruction and to evaluate the osteopenia. However, no previous reports have assessed changes in trabecular bones during the course of the disease. The purpose of this study was to evaluate differences in spinal microarchitecture among patients with different clinical stages of multiple myeloma. METHOD AND MATERIALS We examined the spinal microarchitecture in patients with asymptomatic myeloma (n=35), symptomatic myeloma (n=29), and in 155 sex- and age-matched normal controls by using a 64-detector CT (GE). The patients were 27 men and 37 women (mean age 71.1 and 69.2 years, respectively). Using 64-detector CT data and a 3D image analysis system (TRI/3D-BON; RATOC, Japan), we calculated trabecular parameters of the third lumbar vertebrae including the trabecular bone volume fraction, -thickness (TbT), -number, -separation, and -width, the fractal dimension, Euler’s number, degree of anisotropy (DA), and the structure model index. We compared the trabecular parameters in the three study groups by one-way analysis of variance using the Scheffe post hoc test. Differences were considered significant at p<0.05. RESULTS Among the three groups, TbT (737.4 ± 100 μm, p<0.01) was significantly elevated in asymptomatic myeloma (Fig. 1) compared to controls in males, while no significant difference was detected between controls and symptomatic myeloma. DA (male, 1.56 ± 0.25; female, 1.59 ± 0.25, p<0.01) was significantly elevated in asymptomatic myeloma compared to controls in both genders. Among male patients, DA in symptomatic myeloma (1.36 ± 0.16, p<0.01) was lower than in asymptomatic myeloma, while among female patients, DA in symptomatic myeloma (1.58 ± 0.25) was similar to that in asymptomatic myeloma. CONCLUSION In multiple myeloma, trabecular bones were thickened and oriented along one direction in the asymptomatic stage; their thickness and directionality were reduced during the progression to symptomatic myeloma in male patients. In females, no trabecular parameters could differentiate asymptomatic- from symptomatic myeloma. CLINICAL RELEVANCE/APPLICATION Analysis of the trabecular microstructure of the lumbar spine is useful to elucidate changes in the course of myeloma and may help to predict vertebral fractures in the disease.
    No preview · Conference Paper · Nov 2011
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    ABSTRACT: To evaluate the accuracy of trabecular analysis of the lumbar spine by using multidetector computed tomography (CT) in differentiating multiple myeloma patients without spinal fractures from control subjects. This retrospective single-institution study was approved by the institutional review board, with a waiver of informed consent. Spinal microarchitecture was examined by using 64-detector row CT in 29 patients with multiple myeloma and 51 control subjects. The patients were 13 men and 16 women (mean ages, 71.1 and 69.2 years, respectively). By using multidetector CT data, eight parameters were calculated for the L3 vertebral trabeculae with a three-dimensional image analysis system. The χ(2) test was used to select a preliminary set of predictors for multiple myeloma. A multivariable generalized linear model was constructed to identify parameters that could be used to differentiate between patients and controls. Parameters with findings of P < .05 were included in the multivariable model. Generalized linear models showed that mean trabecular thickness (TbTh) (patients, 703.7 μm ± 46.7 [standard deviation]; controls, 661.1 μm ± 35.7) and fractal dimension (FD) (patients, 2.23 ± 0.24; controls, 2.41 ± 0.15) in men (P = .05 and .03, respectively) and degree of anisotropy (DA) (patients, 1.63 ± 0.23; controls, 1.38 ± 0.10) in women (P = .02) had significant effects in differentiation between patients and controls. Significant differences were observed in spinal microarchitecture between control subjects and multiple myeloma patients without pathologic fractures. Independent predictors of multiple myeloma included TbTh and FD in male patients and DA in female patients.
    Preview · Article · Apr 2011 · Radiology
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    ABSTRACT: PURPOSE/AIM 1. To review CT images of malignant pleural mesothelioma (MPM) to facilitate early detection 2. To demonstrate imaging spectra of pleural diseases to differentiate them from MPM CONTENT ORGANIZATION 1. Anatomy of the pleura using thin-section CT 2. Imaging spectrum of asbestos-related pleural diseases a. MPM b. Pleural plaques and round atelectasis c. Asbestos-related pleural effusion d. Pleural calcification 3. Imaging spectrum of pleural diseases without asbestos exposure a. Inflammatory pleuritis b. Pleuritis carcinomatosis 4. Tips for the early diagnosis of MPM SUMMARY As the incidence of life-threatening MPM is increasing, early identification is critical to improve its prognosis. However, the differentiation of MPM from other diffuse pleural abnormalities is difficult because there are a number of pleural diseases and most of their findings are non-specific. A precise analysis of the relationship between a disease and the pleural structure is important because MPM primarily involves the parietal pleura. Checking for asbestos exposure is also crucial.
    No preview · Conference Paper ·