101
|
Ma CM, Lin MH, Dai XF, Koren S, Klayton T, Wang L, Li JS, Chen L, Price RA. Investigation of pulsed low dose rate radiotherapy using dynamic arc delivery techniques. Phys Med Biol 2012; 57:4613-26. [PMID: 22750648 DOI: 10.1088/0031-9155/57/14/4613] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
There has been no consensus standard of care to treat recurrent cancer patients who have previously been irradiated. Pulsed low dose rate (PLDR) external beam radiotherapy has the potential to reduce normal tissue toxicities while still providing significant tumor control for recurrent cancers. This work investigates the dosimetry feasibility of PLDR treatment using dynamic arc delivery techniques. Five treatment sites were investigated in this study including breast, pancreas, prostate, head and neck, and lung. Dynamic arc plans were generated using the Varian Eclipse system and the RapidArc delivery technique with 6 and 10 MV photon beams. Each RapidArc plan consisted of two full arcs and the plan was delivered five times to achieve a daily dose of 200 cGy. The dosimetry requirement was to deliver approximately 20 cGy/arc with a 3 min interval to achieve an effective dose rate of 6.7 cGy min⁻¹. Monte Carlo simulations were performed to calculate the actual dose delivered to the planning target volume (PTV) per arc taking into account beam attenuation/scattering and intensity modulation. The maximum, minimum and mean doses to the PTV were analyzed together with the dose volume histograms and isodose distributions. The dose delivery for the five plans was validated using solid water phantoms inserted with an ionization chamber and film, and a cylindrical detector array. Two intensity-modulated arcs were used to efficiently deliver the PLDR plans that provided conformal dose distributions for treating complex recurrent cancers. For the five treatment sites, the mean PTV dose ranged from 18.9 to 22.6 cGy/arc. For breast, the minimum and maximum PTV dose was 8.3 and 35.2 cGy/arc, respectively. The PTV dose varied between 12.9 and 27.5 cGy/arc for pancreas, 12.6 and 28.3 cGy/arc for prostate, 12.1 and 30.4 cGy/arc for H&N, and 16.2 and 27.6 cGy/arc for lung. Advanced radiation therapy can provide superior target coverage and normal tissue sparing for PLDR reirradiation of recurrent cancers, which can be delivered using dynamic arc delivery techniques with ten full arcs and an effective dose rate of 6.7 ± 4.0 cGy min⁻¹.
Collapse
|
102
|
Li JS, Lin MH, Ma CM. SU-E-T-464: Impact of the Treatment Margin on Tumor Control and Normal Tissue Complication for Prostate Treatment. Med Phys 2012; 39:3811. [PMID: 28517482 DOI: 10.1118/1.4735553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To investigate the consequence of treatment margin reduction on normal tissue complication probability (NTCP) and tumor control probability (TCP) of prostate external beam treatment. METHODS Intensity modulated rotational radiotherapy plans were generated for 10 prostate patients with 6 different posterior margin sizes from 5mm to 0. The prescription dose is 80Gy for 40 treatment fractions. The dose distributions were recalculated with consideration of the intrafractional motion and the localization error. The statistical uncertainties of the intrafractional motion and the localization error were derived based on the motion tracking data recorded by the Calypso 4D localization system for a large patient population. The TCP and NTCP were calculated based on the dose volume histograms (DVH) of prostate and rectum for plans with different margins using an equivalent uniform dose (EUD) based biological model. The 50% tumor control dose (TCD50) of 60Gy for prostate and the median toxic dose (TD50) of 55Gy for rectum were used in the calculation. RESULTS The minimum dose of the prostate and the mean dose of the rectum dropped with the decrease of the treatment margin. When the posterior treatment margin was reduced from 5mm to zero, the EUD of prostate decreased from 83Gy (±0.5Gy) to 81Gy (±0.5Gy) and the TCP dropped from 93.2% (±0.1%) to 91.7% (±0.1%), the EUD of the rectum decreased more significantly from 48.9Gy (±0.4Gy) to 32.5Gy (±0.5Gy) and the NTCP dropped from 13.3% (±1.5%) to 0.03% (± 0.01%). CONCLUSIONS The treatment margin size affects the dose to the target and the nearby critical structure. More significant impact on NTCP has been observed than on TCP. This gives us some room to consider the quality of the patient's after-treatment life. A wise choice of treatment margin can be made based on physician's opinion and patient's preference on the tumor control and the quality of life.
Collapse
|
103
|
Li JS, Buyyounouski M, Horwitz E, Ma CM. WE-A-BRB-11: How Certain Can the Real-Time Plan Predict the Post Dosimetry for Prostate Seed Implant? Med Phys 2012. [DOI: 10.1118/1.4736052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
104
|
Chen CH, Li JS, Hosseini A, Gadikota HR, Gill TJ, Li G. Anteroposterior stability of the knee during the stance phase of gait after anterior cruciate ligament deficiency. Gait Posture 2012; 35:467-71. [PMID: 22169387 PMCID: PMC3299839 DOI: 10.1016/j.gaitpost.2011.11.009] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 11/01/2011] [Accepted: 11/03/2011] [Indexed: 02/02/2023]
Abstract
Quadriceps avoidance and higher flexion strategies have been assumed as effects of ACL deficiency on knee joint function during gait. However, the effect of ACL deficiency on anteroposterior stability of the knee during gait is not well defined. In this study, 10 patients with unilateral acute ACL ruptures and the contralateral side intact performed gait on a treadmill. Flexion angles and anteroposterior translation of the ACL injured and the intact controlateral knees were measured at every 10% of the stance phase of the gait (from heel strike to toe-off) using a combined MRI and dual fluoroscopic imaging system (DFIS). The data indicated that during the stance phase of the gait, the ACL-deficient knees showed higher flexion angles compared to the intact contralateral side, consistent with the assumption of a higher flexion gait strategy. However, the data also revealed that the ACL-deficient knees had higher anterior tibial translation compared to the intact contralateral side during the stance phase of the gait. The higher flexion gait strategy was not shown to correlate to a reduction of the anterior tibial translation in ACL deficient knees. These data may provide indications for conservative treatment or surgical reconstruction of the ACL injured knees in restoration of the knee kinematics during daily walking activities.
Collapse
|
105
|
Li JS. Bufei Yishen Granule combined with acupoint-sticking therapy in patients with stable chronic obstructive pulmonary disease: study protocol of a multicenter, randomized, double-blind, active-controlled trial. ACTA ACUST UNITED AC 2011. [DOI: 10.3736/jcim20111206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
106
|
Jiang H, Wang XB, Li CY, Li JS, Xu FJ, Mao C, Yang WT, Shen J. Improvement of hemocompatibility of polycaprolactone film surfaces with zwitterionic polymer brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:11575-11581. [PMID: 21851101 DOI: 10.1021/la202101q] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Polycaprolactone (PCL) has been widely adopted as a scaffold biomaterial, but further improvement of the hemocompatibility of a PCL film surface is still needed for wide biomedical applications. In this work, the PCL film surface was functionalized with zwitterionic poly(3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate) (P(DMAPS)) brushes via surface-initiated atom transfer radical polymerization (ATRP) for enhancing hemocompatibility. Kinetics study revealed an approximately linear increase in graft yield of the functional P(DMAPS) brushes with polymerization time. The blood compatibilities of the modified PCL film surfaces were studied by platelet adhesion tests of platelet-rich plasma and human whole blood, hemolysis assay, and plasma recalcification time (PRT) assay. The improvement of hemocompatibility is dependent on the coverage of the grafted P(DMAPS) brushes on the PCL film. Lower or no platelet and blood cell adhesion was observed on the P(DMAPS)-grafted film surfaces. The P(DMAPS) grafting can further decrease hemolysis and enhance the PRT of the PCL surface. With the versatility of surface-initiated ATRP and the excellent hemocompatibility of zwitterionic polymer brushes, PCL films with desirable blood properties can be readily tailored to cater to various biomedical applications.
Collapse
|
107
|
Zhu WM, Li Y, Yu C, Li N, Li JS. Antimouse CD52 monoclonal antibody inhibits established spontaneous colitis in IL-10-deficient mice. Inflamm Bowel Dis 2011; 17:E72-3. [PMID: 21538714 DOI: 10.1002/ibd.21733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 03/21/2011] [Indexed: 12/09/2022]
|
108
|
Jin L, Li JS, Wang L, Fan J, Price R, Ma C. SU-E-T-402: Modulated Electron Radiotherapy Dose Delivery Using Photon Multileaf Collimators. Med Phys 2011. [DOI: 10.1118/1.3612356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
109
|
Li JS, Lin MH, Wang L, Ma CM. SU-E-T-431: Dosimetric Uncertainties in RapidArc Treatment. Med Phys 2011. [DOI: 10.1118/1.3612385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
110
|
Li JS, Fan J. SU-E-T-544: Dosimetric Evaluation of a Micro-MLC Developed for a Robotic Stereotactic Radiosurgery/Radiotherapy Machine. Med Phys 2011. [DOI: 10.1118/1.3612506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
111
|
Li JD, Feng QC, Li JS. Differential gene expression profiling of oesophageal squamous cell carcinoma by DNA microarray and bioinformatics analysis. J Int Med Res 2011; 38:1904-12. [PMID: 21226993 DOI: 10.1177/147323001003800603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Differential gene expression profiling was carried out on primary tumour tissues and adjacent non-neoplastic tissues from patients with oesophageal squamous cell carcinoma (ESCC). RNA extracted from ESCC tissues and matched normal oesophageal epithelium of four ESCC patients was analysed using whole-genome microarrays. Bioinformatics analysis was also carried out to ascertain which genes and pathways may be important in the carcinogenesis of ESCC. A total of 570 genes were identified that differed significantly in expression: 303 genes were up-regulated and 267 genes were down-regulated in ESCC tissues compared with normal oesophageal epithelium. Gene ontology analysis showed that the primary molecular functions of these genes were related to the extracellular region, collagen and endopeptidase inhibitor activity. Pathway analysis revealed seven pathways or networks highly associated with the differential expression profile. Gene set analysis showed that the POD1_KO_UP gene set was significantly enriched, containing 15 matching genes. Thus, a large number of genes are involved in the carcinogenesis of ESCC and participate in various cell processes and pathways.
Collapse
|
112
|
Li JS, Lin T, Chen L, Price R, Ma CM. SU-GG-T-181: Effects of the MLC Characteristics on IMRT Dose Distribution. Med Phys 2010. [DOI: 10.1118/1.3468571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
113
|
Li JS, Lin T, Chen L, Price R, Ma CM. SU-GG-T-190: Effects of the MLC Leaf Offset on IMRT Dose Distribution. Med Phys 2010. [DOI: 10.1118/1.3468579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
114
|
Baker-Smith CM, Benjamin DK, Califf RM, Murphy MD, Li JS, Smith PB. Cough in pediatric patients receiving angiotensin-converting enzyme inhibitor therapy or angiotensin receptor blocker therapy in randomized controlled trials. Clin Pharmacol Ther 2010; 87:668-71. [PMID: 20130570 DOI: 10.1038/clpt.2009.231] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The incidence of cough in children receiving antihypertension therapy with angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs) is unknown. We analyzed patient-level data from eight randomized trials for the treatment of pediatric hypertension, six of them involving ACEis and two involving ARBs. The incidence of cough in children receiving ACEis (reported cough, 3.2%) was similar to that in children receiving ARBs (reported cough, 1.8%) (P = 0.34). Reports of cough were lower in children than in adults.
Collapse
|
115
|
Li JS. Effects of Naomaitong combined with mobilization of bone marrow mesenchymal stem cells on neuron apoptosis and expressions of Fas, FasL and caspase-3 proteins in rats with cerebral ischemia. JOURNAL OF CHINESE INTEGRATIVE MEDICINE 2009; 7:860-867. [DOI: 10.3736/jcim20090912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
|
116
|
Gu YD, Ren XJ, Li JS, Lake MJ, Zhang QY, Zeng YJ. Computer simulation of stress distribution in the metatarsals at different inversion landing angles using the finite element method. INTERNATIONAL ORTHOPAEDICS 2009; 34:669-76. [PMID: 19685241 DOI: 10.1007/s00264-009-0856-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/01/2009] [Accepted: 07/28/2009] [Indexed: 11/25/2022]
Abstract
Metatarsal fracture is one of the most common foot injuries, particularly in athletes and soldiers, and is often associated with landing in inversion. An improved understanding of deformation of the metatarsals under inversion landing conditions is essential in the diagnosis and prevention of metatarsal injuries. In this work, a detailed three-dimensional (3D) finite element foot model was developed to investigate the effect of inversion positions on stress distribution and concentration within the metatarsals. The predicted plantar pressure distribution showed good agreement with data from controlled biomechanical tests. The deformation and stresses of the metatarsals during landing at different inversion angles (normal landing, 10 degree inversion and 20 degree inversion angles) were comparatively studied. The results showed that in the lateral metatarsals stress increased while in the medial metatarsals stress decreased with the angle of inversion. The peak stress point was found to be near the proximal part of the fifth metatarsal, which corresponds with reported clinical observations of metatarsal injuries.
Collapse
|
117
|
Li JS, Xu Q, Ma CM. SU-FF-J-58: Inter-Transponder Distance Change and Its Effect On Prostate Localization. Med Phys 2009. [DOI: 10.1118/1.3181350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
118
|
Jin L, Ma CM, Fan J, Eldib A, Price RA, Chen L, Wang L, Chi Z, Xu Q, Sherif M, Li JS. Dosimetric verification of modulated electron radiotherapy delivered using a photon multileaf collimator for intact breasts. Phys Med Biol 2008; 53:6009-25. [DOI: 10.1088/0031-9155/53/21/008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
119
|
Wei H, Zhao MQ, Dong W, Yang Y, Li JS. Expression of c-kit Protein and Mutational Status of the c-kit Gene in Osteosarcoma and Their Clinicopathological Significance. J Int Med Res 2008; 36:1008-14. [PMID: 18831895 DOI: 10.1177/147323000803600518] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We examined c-kit protein expression and mutations of the c-kit gene in 40 human osteosarcoma samples to their relationship with clinicopathology and prognosis of the disease. The expression of c-kit protein was evaluated by immunohistochemistry and single-strand conformational polymorphism was performed to evaluate c-kit gene mutations in exons 11 and 17. Expression of c-kit protein occurred in 25 (62.5%) osteosarcoma samples. Patients with osteosarcomas with higher c-kit protein expression levels were significantly more likely to experience local disease recurrence and had a significantly lower survival time than patients with lower c-kit expression. We found no evidence of mutations in exons 11 or 17. This study suggests that c-kit protein expression might serve as a prognostic marker for osteosarcoma, however exons 11 and 17 might not be suitable targets for osteosarcoma treatments based on suppression of c-kit tyrosine kinase activity.
Collapse
|
120
|
Li JS. Effects of rhubarb aglycone on matrix metalloproteinase in cerebral ischemic tissue in rats with bone marrow mesenchymal stem cell transplantation. JOURNAL OF CHINESE INTEGRATIVE MEDICINE 2008; 6:810-816. [DOI: 10.3736/jcim20080808] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
|
121
|
Chen Y, Cho MR, Mak AFT, Li JS, Wang M, Sun S. Morphology and adhesion of mesenchymal stem cells on PLLA, apatite and apatite/collagen surfaces. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:2563-7. [PMID: 17665108 DOI: 10.1007/s10856-007-3195-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Accepted: 05/22/2007] [Indexed: 05/16/2023]
Abstract
Biomimetic apatite/collagen composite coating, previously reported particularly with regard to its fabrication, characterization and interaction with osteoblast-like cells, has been investigated in this study to understand the response of human mesenchymal stem cells (hMSC) to such surface. PLLA films and PLLA films with apatite coating were compared with PLLA films with apatite/collagen composite coating. The hMSC morphology in response to such conditions was first observed using fluorescence microscopy. To further understand such cell-material interactions at a molecular level, integrin expression, actin assembly and vinculin-positive focal adhesion plaques were examined. Our results demonstrated that spreading of stem cells on the apatite/collagen composite surface was determined best among the three types of surfaces, followed by the apatite surface and then the PLLA control. Integrin expression on the apatite/collagen surface was higher than those on the apatite surface and PLLA surface. Immunostaining for vinculin and actin suggested that the composite coating on PLLA enhanced the formation of focal adhesion.
Collapse
|
122
|
Li JS, Fan J, Ma CM. SU-GG-T-314: Monte Carlo Investigation of the New Cyberknife with a High Dose Rate. Med Phys 2008. [DOI: 10.1118/1.2962066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
123
|
Li JS, Price R, Jin L, Ma CM. SU-GG-J-176: The Accuracy and Stability of the Calypso System for Prostate Localization and Motion Tracking. Med Phys 2008. [DOI: 10.1118/1.2961725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
124
|
Chen Y, Mak AFT, Wang M, Li JS, Wong MS. In vitro behavior of osteoblast-like cells on PLLA films with a biomimetic apatite or apatite/collagen composite coating. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:2261-2268. [PMID: 18058196 DOI: 10.1007/s10856-007-3335-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 11/21/2007] [Indexed: 05/25/2023]
Abstract
To investigate the methods to improve the cell-material interaction of devices or tissue engineering scaffolds made of poly(L-lactic acid) (PLLA) polymer, apatite and apatite/collagen composite coatings were formed on PLLA films within 24 h through accelerated biomimetic processes. In vitro investigation using Saos-2 osteoblast-like cells through cell culture was conducted to assess the biological performance of these biomimetic coatings. The cell morphology on three types of surfaces, viz., PLLA film, PLLA film with the apatite coating, and PLLA film with the apatite/collagen composite coating, was studied using scanning electron microscopy (SEM). Cell viability was estimated using the MTT assay. The differentiated cell function was assessed by measuring the alkaline phosphatase (ALP) activity. The results obtained indicated that the biomimetic apatite and apatite/collagen composite coatings could significantly enhance the proliferation and differentiation of osteoblast-like cells. The apatite/collagen composite coating appears to be promising for the surface modification of PLLA-based devices with much improved interactions with osteoblastic cells.
Collapse
|
125
|
Ma CM, Li JS, Deng J, Fan J. Implementation of Monte Carlo Dose calculation for CyberKnife treatment planning. ACTA ACUST UNITED AC 2008. [DOI: 10.1088/1742-6596/102/1/012016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|