Relationship Between CT Perfusion Imaging And Tumor Angiogenesis In Osteosarcoma

Part one CT perfusion imaging for primary bone tumorObjective1. To use CTPI to assess the tumor vascularity in primary bone tumor.2.To investigate the hemodynamic features of the primary bone tumor using CTPI.3. To explore the clinical feasibility of CTPI in differentiating primary bone tumor.Material and methods1.PatientsFrom September 2007 to May2009,We prospectively attempted CTPI in 47 consecutive patients with primary bone tumors confirmed by pathology in in-patient clinic of Nanjing General Hospital of Nanjing Military Command PLA as part of a pilot feasibility study.Inclusion criteria for this study were as followspatients with primary bone tumors confirmed by cytologic and histologic techniques.with measurable tumor lesions by CT,chest CT scan with no evidence of pulmonary metastasis or distant metastasis.exclusion criteria for this study were as followspatients with a global deterioration of health status.with a history of prior radiation,chemotherapy or surgery,positive pregnancy test.second primary,hypersensitiveness to iodine.With renal disease and liver disease.All patients were informed of the investigational nature of the study and signed a written consent for participation.grouping osteosarcoma group (n=28).16 men and 12 women. ages ranged from 9 to 56 years (median age,21 years).The primary sites. extremities limbs(n=27). pelvis (n=1).chondrosarcoma group (n=11).7 men and 4 women. ages ranged from 21 to 54 years (median age,40 years).The primary sites. extremities limbs(n=2).pelvis (n=8), thoracic vertebre (n=1).giant cell tumor of bone group (n=8).4 men and 4 women. ages ranged from 18 to 73 years (median age,28 years).The primary sites. extremities limbs(n=3). pelvis (n=5).2.Imaging StudiesSiemens 64-slice Spiral CT (Somatom,Senation, Germnay).Omnipaque(350 mg/ml,100ml,350 mg/ml,50ml, Manufacturer:GE Healthcare(Shanghai) Co Ltd. Approval Number:350 mg/ml*50ml:H20000597.350 mg/ml*100ml:H20000599).Power injector(OptivantageTM DH, pattern number:MALLINCKRODT)Commercial Perfusion software(Syngo Body PCT Perfusion software, Siemens, Germnay)Software for 3D reconstruction (Space Software, Siemens, Germnay).All the patients were fasting 4 hours before the CT scans on a multidetector scanner (siemens 64-slice Spiral CT).A noncontrast CT was performed to determine the tumor position, which provided the maximal horizontal tumor area.For the CTP study, patients received a power injection of nonionic iodinated contrast agent Omnipaque 1.5ml/kg(350 mg/ml*50ml) 50ml at 6 ml/s via median antecubital vein using a Power injector.At 5 seconds into the injection, a cine (continuous) acquisition was initiated by using the following parameters:100 kV,80 mA,4 x 7.2 mm sections,5 seconds rotation for duration of 25seconds:For the CT reconstruction study, patients received a power injection of nonionic iodinated contrast agent Omnipaque 1.5ml/kg(350 mg/ml*1000ml) 80ml and normal saline in turn via median antecubital vein. at 6 ml/s.At 5 minutes into the injection, a volume acquisition was initiated by using the following parameters:100 kV,80 mA,0.6 mm sections,.Region of Interest (ROI) of arterial phase was placed in the aorta descendens.the scan was triggered when the net bonus of CT value in aorta descendens reached 100Hu(dose care).Data was done by the Space software for the 3D reconstruction of tumors and vessels.The perfusion data were postprocessed by using a commercial software package(syngo Body PCT, Siemens, Germany) based on a deconvolution-based technique.ROI A user-defined ROI was drawn freehand by an experienced radiologist major in bone and soft tissue. incorporating as much of the solid portions of the tumor identified on the noncontrast localizing images as possible and omitting the necrotic regions, blood vessels, calcification,air and subcutaneous fat. Care was also taken to avoid encroaching on tumor boundaries to exclude peritumoral hyperemia.The data were processed into maps or perfusion paramemeters as followsblood flow (BF, in ml·min-1·100g-1.the volume flow rate of blood through the vasculature in a tissue.),blood volume(BV, in ml·100g-1,the volume of blood within the vasculature of a tissue that was flowing and not stagnant.)time to peak (TTP, in seconds,the time taken by the blood elements to achieve the peak of the TDC.)capillary permeability surface product (PS, in ml·min-1·100g-1,the product of permeability and the total surface area of capillary endothelium in a unit mass of tissue representing the total diffusional flux across all capillaries.)time-density curve (TDC). The X-axis was the time of perfusion,the Y-axis was the bonus of the value of CT,demonstrating the changement of perfusion of the tissue.3D reconstruction of tumor vessels3.Data and StatisticalAll the data were processed by Spss16.0 for windows.All the data were noted in mean±standard deviation (mean±SD);To determine the statistically significant difference in CTPI parameters (BF,BV,TTP and PS) among in the three groups, the one-way ANOVA test was employed, and the LSD was used in multiple comparison.Statistical significance was set at P<0.05ResultsCTPI of the tumors were feasible in all of the 47 patients(100%).No adverse reactions to the contrast agent were encountered.The TDC was different among the three groups:The TDC of the osteosarcoma group achieved the peaking fast and showed a high peaking values.It performed as tachy-ascensus model. the curve stayed unchanged for a time or descended slowly;The TDC of the chondrosarcoma group achieved the peaking more slowly and showed a low peaking values;The TDC of the bone giant cell tumor group achieved the peaking fast and showed a high peaking values. However.The curve of ran smoothly and softly, and descended quickly.The perfusion parameters of the osteosarcoma group were noted in mean±SD as follows:BF57.26±29.48ml·min-1·100g-1; BV70.39±28.75ml·100g-1;TTP 119.27±25.66s; PS 47.23±15.01 ml·min-1·100g-.The perfusion parameters of the chondrosarcoma group were noted in mean±SD as follows:BF 19.02±16.13ml·min-1·100g-1; BV 31.78±25.84ml·100g-1; TTP 140.27±24.96s; PS 23.07±11.15ml·min-1·100g-1The perfusion parameters of the giant cell tumor of bone group were noted in mean±SD as follows:BF 74.96±48.65ml·min-1·100g-1; BV 90.78±44.28ml·100g-1; TTP 102.37±19.05s; PS 89.35±32.96ml·min-1·100g-1BF, BV, TTP and PS among the three groups were significantly different (P＜0.05), osteosarcoma and the giant cell tumor of bone showed significantly higher BF,BV and PS than that of chondrosarcoma (all P<0.05),but TTP is significant lower (P＜0.05). BF, BV and TTP value of osteosarcoma and the giant cell tumor of bone were notstatistically significant (all P> 0.05). PS of osteosarcoma was significantly lower than that of the giant cell tumor.Conclusion1.Perfusion CT offers potential for noninvasive and quantatitive monitoring of hemodynamic features in patients with primary bone tumors.and overcomes the incapability of general CT to reflex anatomic and morphological alteration.2.TDC,BF, BV and PS tend to be useful for differentiating benign and malignant primary bone tumors.3. As a non-invasive and convenient method, CTPI provides more detailed vascular information of primary bone tumors.Part two Relationship between CT perfusion imaging and tumor angiogenesis in osteosarcomaObjective1.To investigate the hemodynamic features of osteosarcoma using CTPI2.To use CTPI to assess the tumor vascularity in osteosarcoma3. To establish the relationships between 64-slice spiral computed tomography perfusion imaging (CTPI) parameters and immunohistologic markers of angiogenesis in human osteosarcomaMaterial and methods1.PatientsFrom September 2007 to Jun 2009,We prospectively attempted CTPI in 26 consecutive patients with osteosarcoma confirmed by pathology in in-patient clinic of Nanjing General Hospital of Nanjing Military Command PLA as part of a pilot feasibility study, and immunohistochemical findings of microvessel density (MVD) measurement were evaluated.18 men and 8 women, and 15.Inclusion criteriaThe same as part one.exclusion criteriaThe same as part one. All patients were informed of the investigational nature of the study and signed a written consent for participation.2.1maging StudiesThe same as part one..The data were processed into maps or perfusion paramemeters as followsblood flow (BF, in ml·min-1·100g-1),blood volume(BV, in ml·100g-1)time to peak (TTP, in seconds)capillary permeability surface product (PS, in ml·min-1·100g-1)time-density curve (TDC).3D reconstruction of tumor vessels3.PathologyWe used the paraffins of osteosarcoma which were untreated for immunohistochemical study. and consecutive 4-μm sections were cut and mounted on glass slides. Then the tumor was stained with CD34 immunohistochemical stains(Dako company,Denmark), and MVD was measured by anti-CD34.MVD was evaluated according to the method described by Weidner. The stained sections were screened at low power (x40) and three areas with the most intense neovascularization (hot spots) were selected. Microvessel counts of these areas were performed at high power (x400) Any brown-stained endothelial cell or endothelial cell cluster clearly separated from adjacent microvessels, tumor cells, and other connective-tissue elements was counted as one microvessel stained by CD34 antibody, irrespective of the presence of a vessel lumen. The mean microvessel count of the three richest vascular areas was taken as the MVD.4.Data and StatisticalAll the data were processed by Spss16.0 for windows.All the data were noted in mean±SD;To determine the statistically significant difference in CTPI parameters (BF,BV,TTP and PS) between osteosarcoma group and normal adjacent muscle tissue, the paired t-test was employed, and The correlations of MVD with CTPI parameters were analyzed using Pearson's correlationcient.Statistical significance was set at P<0.05ResultsCTPI of the tumors were feasible in all of the 26 patients(100%).No adverse reactions to the contrast agent were encountered.The TDC of the osteosarcoma achieved the peaking fast and showed a high peaking values.It performed as tachy-ascensus model. the curve stayed unchanged for a time or descended slowly.Mean BF, BV, TTP, and PS values of osteosarcoma group were 46:6 ml·min-1·100g-1 of tissue±25.1 (standard deviation),61.8 ml·100g-1 of tissue±29.5, 122.9 seconds±26.2, and 44.5 ml·min-1·100g-1 of tissue±14.6, respectively, and normal muscle group were 5.2±6.6 ml·min-1·100g-1,9.6±7.3ml·100g-1,115.5±33.1 and 17.0±29.3ml·min-1·100g-1. Osteosarcoma group showed higher BF, BV and PS compared with those of the normal muscle group significantly. however.the TTP between osteosarcoma tissue and normal adjacent muscle tissue was not statistically significant.The mean of the MVD is 43 in our study(rang 13 to 95). BF,BV and PS correlated positively with MVD, but TTP did not.CTPI not only demonstrated the site, size, and 3D contour of the tumors, but also clearly displayed the 3D spatial relationship of the tumors, the deviation of vessels by the tumors as well as bone destruction and enlargement of the periosteum.conclusion1.These preliminary results show that CTPI can be used in ostesarcoma and is worthy of clinical generalization.2. CTPI can be useful for assessing tumor vascularity of osteosarcoma and closely correlated with tumor angiogenesis and reflected MVD measurement.3. CTPI provides more detailed vascular information of osteosarcoma r feeding arteries, draining veins and invaded vessels, which is good for diagnosis and therapy of osteosarcoma.