MR Assessment And Preliminary Study On Significance Of MMP-9 Expression In Different Part Of Giant Cell Tumor Of Bone

Deep Analysis of local recurrence of giant cell tumor of bone with soft tissue extension after intralesional curettageObjective: Our purpose was to assess local recurrent rate of giant cell tumor of bone(GCTB) with soft tissue extension to spot new clues for the prediction of which characteristic features of the soft tissue extension best indicated the recurrence of GCTB after intralesional curettage.Materials and methods: 48 cases of GCTB with soft tissue extension after intralesional curettage were recruited. Patients were divided into two groups based on various objective features of the soft tissue extension, such as size, number, margin, adjacent tissues evolvement, signal intensity characteristics, static enhancement and Jaffe’s grade. Difference of local recurrence rate in each group was compared by chi-square test and χ2 value correction for continuity. Risk factors were assessed by multivariate logistic regression analysis.Results: Local recurrence rate had significant difference in groups of extended soft tissue’s size, number and margin(p <0.05). There was no significant statistical difference in groups of adjacent tissues evolvement and Jaffe’s grade(p >0.05). Soft tissue’s size, number and margin were independent risk factors of local recurrence of GCTB with soft tissue extension after intralesional curettage(p<0.05).Conclusions: The local recurrence rate of GCTB with soft tissue extension treated by intralesional curettage would be higher if the extended soft tissue is large, multiple and without integrated bone-envelope around. When meeting such conditions, we advocate the higher recurrence rate should be taken into full consideration for the choice of appropriate surgical procedures.Triple-Phase Dynamic MRI: A New Clue to Predict Malignant Transformation of Giant Cell Tumor of BoneObjective: Our purpose was to compare characteristics of time-intensity curve on triple-phase dynamic contrast-enhanced MRI among groups of giant cell tumor of bone(GCTB), recurrent benign giant cell tumor of bone(RBGCTB), and secondary malignant giant cell tumor of bone(SMGCTB) to find clues to predict the malignant transformation of GCTB.Subjects and methods: 9 cases of SMGCTB, 12 cases of RBGCTB were involved in our study. Cases were divided into four groups: group A, GCTB(n=9); group B, SMGCTB(n=9); group C, GCTB(n=12); group D, RBGCTB(n=12). Enhancement index(EI) of lesion on DCEMRI was calculated using formula: EI(t)=[S(t)-S(0)]/S(0), where S(0) was signal intensity of lesion on non-contrast-enhanced T1-weighted images and S(t) was signal intensity of lesion on DCEMRI(t=30,60,180 sec).Enhancement index of each group in each phase was compared using One-Way ANOVA analysis. Slope values of time-intensity curve were compared by the same way.Results: Time-intensity curve of SMGCTB was characterized by a steep upward slope followed by an early and rapid washout phase. Time-intensity curve of GCTB and RBGCTB was characterized by a steep slope followed by a relatively slow washout phase. No significant difference of enhancement index was found in the first phase(p>0.05). There was significant difference in the second and the third phase(p<0.05). Enhancement index of group B(SMGCTB) was smaller. There was difference of descending slope value(p<0.05) and no difference of rise slope value(p>0.05).Conclusions: Dynamic contrast-enhanced MRI appears a helpful method to find new clue to predict the malignant transformation of GCTB. We suggest patients of GCTB should take DCEMRI examination before and after operation and DCEMRI should be important data of clinical followed-up.Expression and MRI Significance of Matrix Metalloproteinase-9 in Peripheral tissue and Central tissue of GCTBObjective: Our purpose was to compare MMP-9 expression in peripheral tissue, central tissue in giant cell tumor of bone(GCTB) and MMP-9 protein expression with MRI parameters to find evidences of multiple therapeutic targets of GCTB.Subjects and methods: 17 cases of GCTB were involved in our study. 4 specimens in peripheral tissue, central tissue and normal tissue in each GCTB case were chosen respectively. 4 cases were examined by RT-PCR and Western-blot to test MMP-9 m RNA and protein expression. All cases were examined by immunohistochemical staining and HE staining. The correlations of MMP-9 immunohistochemical staining grade and MRI parameters were also evaluated. Data were expressed as mean ± standard error. Student’s t-tests were used to compare two sets of data. The relative expression of MMP-9 m RNA and protein were compared using One-Way ANOVA analysis with Dunnett’s posttest for comparisons of more than two data sets. Non-parametric statistics(chi-square test or χ2 value correction for continuity) were applied to data with abnormal distribution and p values of <0.05 were considered statistically significant.Results: MMP-9 immunohistochemical staining grade which were over 2 grade(++) in peripheral tissue(77.94%) was higher than that in central tissue(29.41%), p<0.05. MMP-9 m RNA relative expression levels in peripheral tissue, central tissue and normal tissue were 0.88±0.07, 0.35±0.04 and0.12±0.03 respectively. MMP-9 protein relative expression levels in peripheral tissue, central tissue and normal tissue were 0.92±0.04, 0.42±0.06 and 0.13±0.02 respectively. Higher MMP-9m RNA and protein expression levels were detected in peripheral tissue. p<0.05. On MRI which showed local bone destruction with soft tissue extension, the numbers of MMP-9 immunohistochemical staining grade shown as 2-3 grade in peripheral tissue were more than that shown as 1-2 grade. No significant difference between cases which showed as local bone destruction with soft tissue extension on MRI and MMP-9 immunohistochemical staining grade in central tissue was found. There was no significant difference was found between MMP-9 immunohistochemical staining grade in peripheral tissue, central tissue of GCTB and other MRI characteristics.Conclusions: The MMP-9 relative expression in peripheral tissue was higher than that in central tissue of GCTB. The over expression of MMP-9 in peripheral tissue of GCTB was correlated to local bone destruction with soft tissue extension on MRI. If we took MMP-9 as a biomarker or potential therapeutic target of GCTB, the different expression level in different part of GCTB should be taken into full consideration.