Optimized Planning Target Volume Margin in Helical Tomotherapy for Prostate Cancer: Is There a Preferred Method?

Yuan Jie Cao,이석,장경환,심장보,김광현,장민선,윤원섭,양대식,박영제,김철용 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.1

We compare the dosimetrical differences between plans generated for helical tomotherapy by using the 2D or 3D the margining technique for the treatment of prostate cancer. Ten prostate cancer patients were included in this study. For 2D plans, the planning target volume (PTV) was created by adding 5 mm (lateral/anterior-posterior) to the clinical target volume (CTV). For 3D plans, a 5-mm margin was added not only lateral/anterior-posterior, but also superior-inferior, to the CTV. Various dosimetrical indices, including the prescription isodose to target volume (PITV) ratio, conformity index (CI), homogeneity index (HI), target coverage index (TCI), modified dose homogeneity index (MHI), conformation number (CN), critical organ scoring index (COSI), and quality factor (QF) were determined to compare the different treatment plans. Differences between the 2D and the 3D PTV indices were not significant except for the CI (p = 0.023). 3D margin plans (11195 MUs) resulted in higher (13.0%) monitor units than 2D margin plans (9728 MUs). There were no significant differences in any organs at risk (OARs) between the 2D and the 3D plans. Overall, the average dose for the 2D plan was slightly lower than that for the 3D plan dose. Compared to the 2D plan, the 3D plan increased the average treatment time by 1.5 minutes; however, this difference was not statistically significant (p = 0.082). We confirmed that the 2D and the 3D margin plans were not significantly different with regard to various dosimetric indices such as the PITV, CI, and HI for PTV and the OARs with tomotherapy

In Vivo Biocompatibility and Improved Compression Strength of Reinforced Keratin/Hydroxyapatite Scaffold

Jie Fan,Meng-Yan Yu,Tong-da Lei,Yong-Heng Wang,Fu-Yuan Cao,Xiao Qin,Yong Liu 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.2

A rapid freezing/lyophilizing/reinforcing process is suggested to fabricate reinforced keratin/hydroxyapatite (HA) scaffold with improved mechanical property and biocompatibility for tissue engineering. The keratin, extracted from human hair, and HA mixture were rapidly frozen with liquid nitrogen and then lyophilized to prepare keratin/HA laminar scaffold. The scaffold was then immersed in PBS for reinforcement treatment, and followed by a second lyophilization to prepare the reinforced keratin/HA scaffold. The morphology, mechanical, chemical, crystal and thermal property of the keratin/HA scaffold were investigated by SEM, FTIR, XRD, DSC, respectively. The results showed that the keratin/HA scaffold had a high porosity of 76.17 ± 3%. The maximum compressive strength and compressive modulus of the reinforced scaffold is 0.778 and 3.3 MPa respectively. Subcutaneous implantation studies in mice showed that in vivo the scaffold was biocompatible since the foreign body reaction seen around the implanted scaffold samples was moderate and became minimal upon increasing implantation time. These results demonstrate that the keratin/HA reinforced scaffold prepared here is promising for biomedical utilization.

Keratin/PEO/hydroxyapatite Nanofiber Membrane with Improved Mechanical Property for Potential Burn Dressing Application

Jie Fan,Tong-da Lei,Meng-Yan Yu,Yong-Heng Wang,Fu-Yuan Cao,Qingqi Yang,Faming Tian,Yong Liu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.2

Keratin, as a promising substitute for tissue engineering due to its excellent biocompatibility and bioactivity, is used to combine one or more other polymers together. However, compound nanofibers with high keratin content (normally>90 wt.%) may result in the poor elongation of nanofiber membranes such as wound dressing. In this work, different ratios of hydroxyapatites (HA) modified by sodium hexametaphosphate were blended with keratin/polyethylene oxide (PEO) spinning solution to produce reinforced keratin blend nanofiber nonwoven membranes as a potential candidate wound dressing. The tensile strength of keratin blend nanofiber membrane with 15 % modified HA addition was two times higher than that without HA. The morphologies and chemical structure of keratin/PEO/HA nanofiber membranes were investigated using SEM, FTIR, and TG. The biocompatibility and the burn repairing performance of keratin/PEO/HA nanofiber mat were also investigated by cell culture and animal burn model. The results showed that the Keratin/PEO/HA nanofiber membranewas beneficial to enhance the proliferation of L929 cell, exhibiting an advantages in reducing inflammatory response in the infective stage and enhancing skin repairing process in the following recover stages. Our data suggested that keratin/PEO/HA nanofiber membrane could serve as a promising burn dressing for treatment of the skin burn.

Treatment Plan Comparison of Linac Step and Shoot, Tomotherapy, RapidArc, and Proton Therapy for Prostate Cancer by Using the dosimetrical and the biological indices

이석,Yuan Jie Cao,장경환,심장보,김광현,이남권,박영제,김철용,조삼주,이상훈,민철기,김우철,조광환,허현도,임상욱,신동호 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.1

The purpose of this study was to use various dosimetrical indices to determine the best intensitymodulated radiation therapy (IMRT) modality - for treating patients with prostate cancer. Ten patients with prostate cancer were included in this study. IMRT plans were designed to include different modalities, including the linac step and shoot, tomotherapy, RapidArc, and proton systems. Various dosimetrical indices, like the prescription isodose to target volume (PITV) ratio, conformity index (CI), homogeneity index (HI), target coverage index (TCI), modified dose homogeneity index (MHI), conformation number (CN), critical organ scoring index (COSI), and quality factor (QF), were determined to compare the different treatment plans. Biological indices, such as the generalized equivalent uniform dose (gEUD) based the tumor control probability (TCP), and the normal tissue complication probability (NTCP), were also calculated and used to compare the treatment plans. The RapidArc plan attained better PTV coverage, as evidenced by its superior PITV, CI, TCI, MHI, and CN values. Regarding organ at risks (OARs), proton therapy exhibited superior dose sparing for the rectum and the bowel in low dose volumes, whereas the tomotherapy and RapidArc plans achieved better dose sparing in high dose volumes. The QF scores showed no significant difference among these plans (p = 0.701). The average TCPs for prostate tumors in the RapidArc, linac and proton plans were higher than the average TCP for Tomotherapy (98.79%, 98.76%, and 98.75% vs. 98.70%, respectively). Regarding the rectum NTCP, RapidArc showed the most favorable result (0.09%) whereas linac resulted in the best bladder NTCP (0.08%).

Detection of the expression of a Bombyx mori Atypical Protein Kinase C in BmPLV-Infected Larval Midgut

( Jian Cao ),( Yuan Qing He ),( Guo Hui Li ),( Ke Ping Chen ),( Jie Kong ),( Feng Hua Wang ),( Jing Shi ),( Qin Yao ) 한국잠사학회 2011 International Journal of Industrial Entomology Vol.22 No.2

Protein kinase C (PKC) is involved in many cellular signaling pathways, it participates in many physiological processes, such as cell cycle, growth, proliferation, differentiation and apoptosis. To investigate the effect of PKC on the silkworm midgut tissue infection of Bombyx mori parvo-like virus (BmPLV), a B. mori atypical protein kinase C (BmaPKC) gene was cloned from larval midgut tissue, expressed in E. coli and purified. Additionally, the BmPLV susceptible silkworm strain and resistant silkworm strain were used to test the effect of the B. mori infection on BmPLV. The result showed that BmaPKC encodes a predicted 586 amino acid protein, which contains a C-terminal kinase domain and an N-terminal regulatory domain. The maximum expression amount of the soluble (His)6-tagged fusion protein was detected after 0.8 mmol/L IPTG was added and cultured at 21˚C. The (His) 6-tagged fusion protein revealed about 73 kDa molecular weight which confirmed by western blot and mass spectrography. Furthermore BmaPKC protein were detected at 0-72 h post-infection in BmPLVinfected larval midgut tissue, western blot showed that as time went on, the expression of BmaPKC increased gradually in susceptible strain, the expression quantity on 72 h is 5 times of 0 h. However, in resistant strain, the expression quantity is slightly lower than susceptible strain. But no significant change in resistant strain was observed as time went on. The available data suggest that BmaPKC may involve in the regulation of BmPLV proliferation.

Evaluation of the Accuracy of Different Combinations of Automatic Registration Selection Factors in Obtaining Tomotherapy Megavoltage Computed Tomography Images

이석,Yuan Jie Cao,심장보,장경환,양대식,박영제,윤원섭,김철용,Kwang Hwan Cho,C. K. Min,김용호 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.11

The purpose of our study is to find the potential best options for the registration selection parameters when performing automatic registration between kilovoltage computed tomography (KVCT) and megavoltage computed tomography (MVCT) images in helical tomotherapy. We compared nine different combinations of automatic registration parameters, including technique and resolution in automatic registration control and tomoimage filtering in scan image control. In the phantom study, we compared the translational and the rotational adjustments between the original position (lateral 0 cm; longitudinal 0 cm; vertical 0 cm) and the manually moved position (lateral 1 cm; longitudinal 1 cm; vertical 1 cm). In the patient study, we compared translational (lateral, longitudinal, vertical) and rotational (pitch, roll, yaw) adjustments between the KVCT and the MVCT images for different anatomic treatment sites. The ranges of translational and rotational displacements in the phantom study were 14.87 ± 0.12 ∼ 15.70 ± 0.04 mm and 0° ∼ 1.03 ± 0.58°, respectively. In cranial cases, the ranges of translational and rotational root-mean-square values were 4.3 ± 0.4 mm ∼ 5.3 ± 0.6 mm, and 0.3 ± 0.3° ∼ 0.7 ± 0.4°, respectively. In the extra cranial cases, the ranges of translational and rotational root-mean-square values were 14.1 ± 3.6 mm − 16.1 ± 2.5 mm, and 0.5 ± 0.3° ∼ 1.0 ± 0.5°, respectively. We found that the combination of “full image - super fine” could minimize the mechanical deviations in the cranial case, and that both the combinations of “bone tissue - super fine” and “full image - super fine” were the best options in extra cranial cases.

Comparison of the BANGkitTM and the PRESAGETM Gel Dosimeters for Use with a CCD-based Optical CT Scanner

장경환,이석규,Yuan Jie Cao,심장보,이지은,이남권,이정애,양대식,박영재,윤원섭,김철용,조삼주,Sang Hoon Lee,김우철,민철기,조광환,허현도 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.5

We compared the basic characteristics of two commercially-available scattering gel (BANGkitTM)and non-scattering gel (PRESAGETM) dosimeters with a spectrophotometer to investigate each device’sdosimetric properties. The two types of gel dosimeters were spectrophotometrically analyzed. For each gel dosimeter, the absorbance, dose linearity, reproducibility, dose rate dependency, andoxygen effect were evaluated at various wavelengths and doses. The best dose linearities of theBANGkitTM and the PRESAGETM gel dosimeters gave R2 values of 0.97 and 0.98 at wavelengthsof 485 nm and 600 nm, respectively, over the range of doses. The BANGkitTM gel showed no peaksensitivity within the studied range of wavelengths whereas the PRESAGETM gel demonstratedpeak sensitivity at a wavelength of 630 nm. The reproducibilities and the dose-rate dependencesof the two gel dosimeters were within the range of ± 2% and ± 3%, respectively. We have shownthat the peak sensitivities of the two gel dosimeters were significantly different; the BANGkitTMgel showed no peak sensitivity within the studied range of wavelengths whereas the PRESAGETMgel demonstrated a peak sensitivity at a wavelength of 630 nm. We have confirmed that the radiochromicgel dosimeter was appropriate for use with a CCD-based optical CT scanner.

Development of a Patient-specific 3D Dose Evaluation Program for QA in Radiation Therapy

이석,장경환,Yuan Jie Cao,심장보,양대식,박영제,윤원섭,김철용 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.6

We present preliminary results for a 3-dimensional dose evaluation software system (P DRESS,patient-specific 3-dimensional dose real evaluation system). Scanned computed tomography (CT)images obtained by using dosimetry were transferred to the radiation treatment planning system(ECLIPSE, VARIAN, Palo Alto, CA) where the intensity modulated radiation therapy (IMRT)nasopharynx plan was designed. We used a 10 MV photon beam (CLiX, VARIAN, Palo Alto,CA) to deliver the nasopharynx treatment plan. After irradiation, the TENOMAG dosimeterwas scanned using a VISTATM scanner. The scanned data were reconstructed using VistaReconsoftware to obtain a 3D dose distribution of the optical density. An optical-CT scanner was used toreadout the dose distribution in the gel dosimeter. Moreover, we developed the PDRESS by usingFlatform, which were developed by our group, to display the 3D dose distribution by loading theDICOM RT data which are exported from the radiotherapy treatment plan (RTP) and the optical-CT reconstructed VFF file, into the independent PDRESS with an ionization chamber and EBTfilm was used to compare the dose distribution calculated from the RTP with that measured byusing a gel dosimeter. The agreement between the normalized EBT, the gel dosimeter and RTP datawas evaluated using both qualitative and quantitative methods, such as the isodose distribution,dose difference, point value, and profile. The profiles showed good agreement between the RTPdata and the gel dosimeter data, and the precision of the dose distribution was within ±3%. Theresults from this study showed significantly discrepancies between the dose distribution calculatedfrom the treatment plan and the dose distribution measured by a TENOMAG gel and by scanningwith an optical CT scanner. The 3D dose evaluation software system (P DRESS, patient specificdose real evaluation system), which were developed in this study evaluates the accuracies of thethree-dimensional dose distributions. Further applications of the system utility are expected toresult from future studies.

Optimization of Beam Orientation and Virtual Organ Delineation for Lung IMRT

장경환,이석,Yuan Jie Cao,심장보,이지은,이정애,양대식,박영제,윤원섭,김철용,조삼주,Sang Hoon Lee,김우철,민철기,조광환,허현도 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.7

This study demonstrates the feasibility of the proposed intensity-modulated radiotherapy (IMRT)techniques for minimizing the dose to the lungs and organs at risk (OARs) for variations in thenumber of beams, the orientations of the beams, the virtual organ delineation (VOD) position, theVOD size and the dose constraints in order to optimize the treatment plan for lung cancer. Weused 5, 7, 9 and 14 equiangularly-spaced beams and 7 and 9 non-equiangularly-spaced beams. Wemeasured the volume of the lungs receiving at least 20 Gy and 25 Gy (V20 and V25) for variationsin the orientations of the beams, the VOD position, and the size of the tumor and the contra-laterallung. For the tumor and the contra-lateral lung, the V20 and the V25 values of 14 equiangularlyspacedports were slightly lower than those of other equiangularly-spaced beam orientations. Fornon-equiangularly-spaced beam orientations, the lowest V20 and V25 values in the tumor and thecontral-lateral lung were recorded in ports 7, and 9, respectively. For tumors of the lung, the averagevalues of 7 non-equiangularly-spaced ports were lower than those for 14 equiangularly- spaced ports. The values of V20 and V25 for variations in the VOD size and the VOD position showed nosignificant differences for the lung tumor of patient 1 when the dose constraint of the VOD was 10,25 and 30 Gy. For the lung tumor, the values of V20 and V25 for various VOD sizes and positionsranged from 15 to 37% in patient 2 and from 28 to 45% in patient 3. The values of V20 and V25were within 7% for the contra-lateral lung of patient 1. For patient 2, the values of V20 and V25ranged from 7 to 18%. For the contra-lateral lung of patient 3, the V20 and V25 values ranged from12 to 25%. IMRT techniques with various VOD and beam orientations are important for determinein treatment plans.

Spectrophotometric Determination of the Optimal Wavelength for a Polymer-gel Dosimeter

장경환,이석,Yuan Jie Cao,심장보,이정애,양대식,박영제,김철용,조삼주,이상훈,김우철,민철기,조광환,허현도,윤원섭 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.8

The purpose of this study was to determine the optimal wavelength for a polymer-gel dosimeter previously developed by our research groups; this was done through a spectrophotometric characterization of its dosimetric properties. A gel sample was irradiated with a 6-MV photon beam from a linear accelerator, and its response was spectrophotometrically analyzed. The absorbance,dose linearity, reproducibility, and dose-rate dependence of the dosimeter were evaluated at various wavelengths and doses. The absorbance of the polymer-gel dosimeter did not show any peak sensitivity within the studied range of wavelengths. For the range of doses studied, the best dose linearity was recorded, with an R2 of 0.9701 at a wavelength of 400 nm. The reproducibility of the results was excellent, and the error in the dose-rate dependence was within the range of ± 3%. The gel dosimeter displayed a very stable response, thus confirming the efficiency of this 3D dosimeter.