1.Spinal fusion of lumbar intertransverse process in rabbits by using bone marrow stromal stem cells in conjunction with bone morphogenetic protein with freeze-dried demineralized bone matrix as scaffold
Wei HU ; Xueli ZHANG ; Xinfeng GAO ; Zijian GUI ; Tianwei SUN
Chinese Journal of Orthopaedics 2011;31(7):800-805
Objective To discuss spinal fusion effect of lumbar intertransverse process in rabbits by using bone marrow stromal stem cells(MSCs)in conjunction with bone morphogenetic protein(BMP)and freeze-dried demineralized bone matrix(FDBM)as scaffold.Methods To separate and cultivate MSCs in vitro,with FDBM as scaffold,osteogenesis was induced by BMP.Sixty Japan white rabbits were randomly divided into three groups.Group A was MSCs+FDBM+BMP,group B was FDBM,group C was autogenous ilium cancellous bone(AIB).Lumbar intertransverse process was fused in lumbar five to six.Rabbits were killed at 8 weeks after operation.The general observation and imageology were used to assess the fusion condition.To estimate the implantation using DR image.Gray scale analysis of DR image caculated the osteogenic density and acreage.The CT scan and three-dimensional reconstruction was used to observe the fusion configuration of lumbar intertransverse process.Results The fusion mass character in group A and C was hard,the morphology was not regulation.The fusion mass was almost absorbed in group B beside little tissue approach transverse process.There were high density image between intertransverse processes,osteogenic density were nonuniform in group A and C.There were nonunion in group B.Consistent callus were existed between intertransverse process in group A and C.There were not consistent callus in group B.Group A was similar to group C in osteogenesis density and acreage.Group B was the worst.There were cartilage and newly born bone trabecular formation in group A and group C.Between transverse process were mainly fiber tissue in group B.Conclusion MSCs in conjunction with BMP and FDBM has the similar osteogenic capability to the AIB and better osteogenic capability than that of FDBM alone when spinal fusion of lumbar intertransverse process is performed in rabbits.
2.Dosimetric comparison of intensity-modulated arc radiotherapy and fixed beam dynamic intensity-modulated radiation therapy in nasopharyngeal carcinoma.
Zhen YANG ; Shizhen BIN ; Mingjun LEI ; Gui LIU ; Zijian ZHANG ; Zhiping LU
Journal of Central South University(Medical Sciences) 2012;37(5):474-480
OBJECTIVE:
To compare the dosimetric differences of dosiology between intensity-modulated arc radiotherapy (IMAT) and dynamic intensity-modulated radiation therapy (dIMRT) in nasopharyngeal carcinoma.
METHODS:
CT data from 25 patients treated in our radiotherapy center were selected randomly for this study. For each patient, the IMAT technique and the fixed beam dIMRT technique were accomplished by the simultaneously integrated boost. Dose volume histogram (DVH) data, isodose distribution, monitor units (MUs) and treatment time were compared in the two techniques.
RESULTS:
There was no significant difference between the IMAT and the dIMRT in dose received by 95% of target volumes (D(95)) (P>0.05). Overall, the mean dose (D(mean)), maximal dose (D(max)) and volume percentage receiving at least of 107% of the prescribed dose (V(107%)) of planning target volume (PTV) for the IMAT were increased slightly ,compared with the dlMRT (P<0.05). There were no significant differences in dosimetric indices of organs at risk (OARs) including spinal cord,optical nerves,lens and temporomandibular joints in the two techniques (P>0.05). Compared with the dlMRI, the D(max) of brain stem for the IMAT was increased slightly (P<0.05). Similar trends was observed for the D(mean) and dose received by 50% of volume (D(50)) of the left and right parotid glands (P<0.05). Healthy tissue (defined as the volume of the body minus PTV,B-P) irradiated from 800 cGy in the IMAT was higher, and that from 1200-4500 cGy was lower compared with the dlMRI (P<0.05).The average number of MUs was reduced by 62.7% per fraction, and the treatment time was on average reduced by 60.1% per fraction in the IMAT compared with the dlMRI.
CONCLUSION
There is a slight difference in dosiology between the two radiotherapy techniques investigated, but they both meet the clinical requirement. Compared with the dIMRT, the IMAT delivers less irradiation to healthy tissue, uses fewer MUs and takes less time during radiotherapy for nasopharyngeal carcinoma.
Carcinoma, Squamous Cell
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radiotherapy
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Dose Fractionation, Radiation
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Female
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Humans
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Male
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Middle Aged
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Nasopharyngeal Neoplasms
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radiotherapy
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Radiometry
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Radiotherapy Dosage
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Radiotherapy Planning, Computer-Assisted
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methods
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Radiotherapy, Intensity-Modulated
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methods