bluuebunny/crossref_metadata_2025 huggingface dataset:
Liver transplantation with an uncommon full right hemiliver graft after hydatid cysts resection: Case report and review of the literature
Authors: Patrono Damiano , Tandoi Francesco , Rizza Giorgia , Catalano Giorgia , Mirabella Stefano , Celoria Piero , Corcione Silvia , De Rosa Francesco Giuseppe , Salizzoni Mauro , Romagnoli Renato
Published: February 2017

Because of widespread organ shortage, the transplant community has been exploiting more and more so‐called “extended criteria” donors. In this scenario, liver grafts harboring benign tumors or large cysts represent an infrequent but potentially valuable source of viable grafts. We depict a challenging case of liver transplantation performed using a graft harboring two large Echinococcus granulosus hydatid cysts in close proximity with the hilar plate and complicated by cystobiliary communication. Although liver transplantation using grafts with hydatid cyst has been rarely reported (three published cases), our case was peculiar as one of the cysts was located close to the hilum and was ruptured into the left hepatic duct. The graft was finally accepted taking into account the low risk profile of the recipient, the good quality and size of the remnant liver parenchyma, and only after complete resection of the cysts was achieved. Although the recipient had a complication due to biliary confluence necrosis, at 10‐months follow‐up he is in good health with normal hepatic function, and a graft that could have been otherwise discarded was successfully used. The decision process along with technical and management issues are discussed.
Effect of interfractional shoulder motion on low neck nodal targets for patients treated using volumetric‐modulated arc therapy (VMAT)
Authors: Casey Kevin E. , Wong Pei‐Fong , Tung Samuel S.
Published: February 2017

VMAT is an important tool in the treatment of head and neck cancers, many of which also require treatment to the supraclavicular lymph nodes. However, full VMAT arcs treating this nodal region necessarily cause entrance beam to pass through patients' shoulders. Thus, interfractional variations in shoulder position may cause unwanted dose perturbations. To assess this possibility, six patients undergoing treatment at our institution for head and neck cancers with associated supraclavicular lymph node treatment were imaged with in‐room CT‐on‐rails during the course of their treatments. This allowed for the establishment of a true record of the actual shoulder position during selected treatment fractions. Then, a full VMAT plan and a plan with VMAT arcs superior to the shoulder and a static anteroposterior field inferiorly were copied onto the patients' weekly image sets. The average one‐dimensional shoulder motion was generally within 10 mm of the simulated position, with some notable exceptions. The standard deviation in week‐to‐week shoulder position relative to simulation was 4.3 mm and 4.2 mm in the SI and AP dimensions, respectively. The average nodal target mean dose across all fractions sampled was within 5% of planned for all patients and both plans. Similarly, the average D95 for the nodal target was within 5% of planned across all fractions sampled, with the single exception of the full VMAT plan for one patient. In most cases, the standard deviation in both target mean dose and D95 was smaller with the VMAT+static AP field plan than it was with the full VMAT plan.

PACS number: 87.55.‐x
Amplitude gating for a coached breathing approach in respiratory gated 10 MV flattening filter‐free VMAT delivery
Authors: Viel Francis , Lee Richard , Gete Ermias , Duzenli Cheryl
Published: February 2017

The purpose of this study was to investigate amplitude gating combined with a coached breathing strategy for 10 MV flattening filter‐free (FFF) volumetric‐modulated arc therapy (VMAT) on the Varian TrueBeam linac. Ten patient plans for VMAT SABR liver were created using the Eclipse treatment planning system (TPS). The verification plans were then transferred to a CT‐scanned Quasar phantom and delivered on a TrueBeam linac using a 10 MV FFF beam and Varian's real‐time position management (RPM) system for respiratory gating based on breathing amplitude. Breathing traces were acquired from ten patients using two kinds of breathing patterns: free breathing and an interrupted ( pause) end of exhale coached breathing pattern. Ion chamber and Gafchromic film measurements were acquired for a gated delivery while the phantom moved under the described breathing patterns, as well as for a nongated stationary phantom delivery. The gate window was set to obtain a range of residual target motion from 2–5 mm. All gated deliveries on a moving phantom have been shown to be dosimetrically equivalent to the nongated deliveries on a static phantom, with differences in point dose measurements under 1% and average gamma agreement above 98.7%. Comparison with the treatment planning system also resulted in good agreement, with differences in point‐dose measurements under 2.5% and average gamma agreement of 97%. The use of a coached breathing pattern significantly increases the duty cycle, compared with free breathing, and allows for shorter treatment times. Patients' free‐breathing patterns contain considerable variability and, although dosimetric results for gated delivery may be acceptable, it is difficult to achieve efficient treatment delivery. A coached breathing pattern combined with a 5 mm amplitude gate, resulted in both high‐quality dose distributions and overall shortest gated beam delivery times.

PACS number: 87.55.Qr
Evaluation of monitor unit calculation based on measurement and calculation with a simplified Monte Carlo method for passive beam delivery system in proton beam therapy
Authors: Hotta Kenji , Kohno Ryosuke , Nagafuchi Kohsuke , Yamaguchi Hidenori , Tansho Ryohei , Takada Yoshihisa , Akimoto Tetsuo
Published: February 2017

Calibrating the dose per monitor unit (DMU) for individual patients is important to deliver the prescribed dose in radiation therapy. We have developed a DMU calculation method combining measurement data and calculation with a simplified Monte Carlo method for the double scattering system in proton beam therapy at the National Cancer Center Hospital East in Japan. The DMU calculation method determines the clinical DMU by the multiplication of three factors: a beam spreading device factor , a patient‐specific device factor , and a field‐size correction factor . We compared the calculated and the measured DMU for 75 dose fields in clinical cases. The calculated DMUs were in agreement with measurements in for all of 25 fields in prostate cancer cases, and in for 94% of 50 fields in head and neck (H&N) and lung cancer cases, including irregular shape fields and small fields. Although the in the DMU calculations is dominant as expected, we found that the patient‐specific device factor and field‐size correction also contribute significantly to the calculated DMU. This DMU calculation method will be able to substitute the conventional DMU measurement for the majority of clinical cases with a reasonable calculation time required for clinical use.

PACS number: 87.55.kh
Comparative evaluation of modern dosimetry techniques near low‐ and high‐density heterogeneities
Authors: Alhakeem Eyad A. , AlShaikh Sami , Rosenfeld Anatoly B. , Zavgorodni Sergei F.
Published: February 2017

The purpose of this study is to compare performance of several dosimetric methods in heterogeneous phantoms irradiated by 6 and 18 MV beams. Monte Carlo (MC) calculations were used, along with two versions of Acuros XB, anisotropic analytical algorithm (AAA), EBT2 film, and MOSkin dosimeters. Percent depth doses (PDD) were calculated and measured in three heterogeneous phantoms. The first two phantoms were a solid‐water slab that had an air‐gap of . The third phantom consisted of solid water slabs, two slabs of lung, and one solid water slab. Acuros XB, AAA, and MC calculations were within 1% in the regions with particle equilibrium. At media interfaces and buildup regions, differences between Acuros XB and MC were in the range of to . MOSkin and EBT2 measurements agreed to MC calculations within , except for the first centimeter of buildup where differences of 4.5% were observed. AAA did not predict the backscatter dose from the high‐density heterogeneity. For the third, multilayer lung phantom, 6 MV beam PDDs calculated by all TPS algorithms were within 2% of MC. 18 MV PDDs calculated by two versions of Acuros XB and AAA differed from MC by up to 2.8%, 3.2%, and 6.8%, respectively. MOSkin and EBT2 each differed from MC by up to 2.9% and 2.5% for the 6 MV, and by and for the 18 MV beams. All dosimetric techniques, except AAA, agreed within 3% in the regions with particle equilibrium. Differences between the dosimetric techniques were larger for the 18 MV than the 6 MV beam. MOSkin and EBT2 measurements were in a better agreement with MC than Acuros XB calculations at the interfaces, and they were in a better agreement to each other than to MC. The latter is due to their thinner detection layers compared to MC voxel sizes.

PACS numbers: 87.55.K‐, 87.55.kd, 87.55.km, 87.53.Bn, 87.55.k
Estimating and reducing dose received by cardiac devices for patients undergoing radiotherapy
Authors: Bourgouin Alexandra , Varfalvy Nicolas , Archambault Louis
Published: February 2017

The objectives of this project are to quantify the dose reduction effect provided by a lead shield for patients with cardiac implantable electronic devices (CIED) during a clinically realistic radiation treatment on phantom and to provide a simple model of dose estimation to predict dose received by CIED in a wide range of situations. The shield used in this project is composed of a lead sheet wrapped in thermoplastic. Dose measurements were made with a plastic scintillation detector (PSD). The phantom was treated with ten different plans. Three of these cases were treated with intensity‐modulated radiation therapy (IMRT) and the others received standard 3D conformal radiation therapy (3D CRT). Lateral dose measurement for photon fields was made to establish a dose prediction model. On average, the use of the lead shield reduced the dose to CIEDs by . Dose reduction was most important for breast cases, with a mean reduction of . In three cases, the total dose reduction was more than 25 cGy over the complete treatment. For the three IMRT cases, the mean dose reduction was . On average, the difference between the TPS prediction and the measurement was 71%, while it was only 14% for the dose prediction model. It was demonstrated that a lead shield can be efficiently used for reducing doses to CIED with a wide range of clinical plans. In patients treated with IMRT modality treatment, the shielding should be used only for those with more than two anterior fields over seven fields. In the case of 3D CRT patients, the shielding should be used for those with a dose on the CIED higher than 50 cGy and with a reduction of dose higher than 10 cGy. The dose prediction model developed in this study can be an easy way to have a better estimation of the out‐of‐field dose than the TPS.

PACS number(s): 87.55.N, 87.55.km
Constancy checks of well‐type ionization chambers with external‐beam radiation units
Authors: Hackett Sara L. , Davis Benjamin , Nixon Andrew , Wyatt Ruth
Published: February 2017

Constancy checks of a well‐type ionization chamber should be performed regularly as part of a quality assurance regime. The goal of this work was to test the feasibility of using a linear accelerator and an orthovoltage unit to check the constancy of a well‐type chamber's response to an external radiation source. The reproducibility, linearity with dose, variation with dose‐rate, and variation between energy‐matched units of the well‐type chamber response when exposed to 6 MV beams was examined. The robustness to errors in establishing the measurement conditions, including setting the source‐to‐surface distance and gantry angle, rotation of the chamber around the central axis of the beam, and the effect of changing the length of the chamber cable exposed to the field, were tested. The reproducibility and linearity with dose of the chamber response, and robustness to errors in establishing the measurement conditions for 100 kVp and 250 kVp beams from an orthovoltage unit, were also examined. The combined uncertainty, including contributions from errors in establishing the reference conditions, for well‐type chamber measurements using a 6 MV beam from a linear accelerator is 1.0%. The combined uncertainties for measurements using 100 and 250 kVp beams were 1.8% and 1.5%, respectively. When focus‐source distance errors were reduced to , the combined uncertainties for the 100 and 250 kVp beams were 1.2% and 1.1%, respectively, when the dose to the chamber was confined to the linear region of the dose‐response curve. The response of a well‐type chamber should remain constant to within 1.2% when exposed to a constant dose from an external beam unit, if reference conditions can be reproducibly established. However, the uncertainty for establishing reference conditions for output measurements for an orthovoltage unit can be reduced, which would justify a reduction of the tolerance for constancy measurements.

PACS numbers: 87.55.Qr, 87.56.Fc
Beam‐specific planning target volumes incorporating 4D CT for pencil beam scanning proton therapy of thoracic tumors
Authors: Lin Liyong , Kang Minglei , Huang Sheng , Mayer Rulon , Thomas Andrew , Solberg Timothy D. , McDonough James E. , Simone Charles B.
Published: February 2017

The purpose of this study is to determine whether organ sparing and target coverage can be simultaneously maintained for pencil beam scanning (PBS) proton therapy treatment of thoracic tumors in the presence of motion, stopping power uncertainties, and patient setup variations. Ten consecutive patients that were previously treated with proton therapy to 66.6/1.8 Gy (RBE) using double scattering (DS) were replanned with PBS. Minimum and maximum intensity images from 4D CT were used to introduce flexible smearing in the determination of the beam specific PTV (BSPTV). Datasets from eight 4D CT phases, using uncertainty in stopping power and uncertainty in patient setup in each direction, were used to create PBS plans for the evaluation of 10 patients. Plans were normalized to provide identical coverage between DS and PBS. The average lung V20, V5, and mean doses were reduced from 29.0%, 35.0%, and 16.4 Gy with DS to 24.6%, 30.6%, and 14.1 Gy with PBS, respectively. The average heart V30 and V45 were reduced from 10.4% and 7.5% in DS to 8.1% and 5.4% for PBS, respectively. Furthermore, the maximum spinal cord, esophagus, and heart doses were decreased from 37.1 Gy, 71.7 Gy, and 69.2 Gy with DS to 31.3 Gy, 67.9 Gy, and 64.6 Gy with PBS. The conformity index (CI), homogeneity index (HI), and global maximal dose were improved from 3.2, 0.08, 77.4 Gy with DS to 2.8, 0.04, and 72.1 Gy with PBS. All differences are statistically significant, with p‐values , with the exception of the heart V45 (). PBS with BSPTV achieves better organ sparing and improves target coverage using a repainting method for the treatment of thoracic tumors. Incorporating motion‐related uncertainties is essential.

PACS number: 87.55.D
A neural network‐based 2D/3D image registration quality evaluator for pediatric patient setup in external beam radiotherapy
Authors: Wu Jian , Su Zhong , Li Zuofeng
Published: February 2017

Our purpose was to develop a neural network‐based registration quality evaluator (RQE) that can improve the 2D/3D image registration robustness for pediatric patient setup in external beam radiotherapy. Orthogonal daily setup X‐ray images of six pediatric patients with brain tumors receiving proton therapy treatments were retrospectively registered with their treatment planning computed tomography (CT) images. A neural network‐based pattern classifier was used to determine whether a registration solution was successful based on geometric features of the similarity measure values near the point‐of‐solution. Supervised training and test datasets were generated by rigidly registering a pair of orthogonal daily setup X‐ray images to the treatment planning CT. The best solution for each registration task was selected from 50 optimizing attempts that differed only by the randomly generated initial transformation parameters. The distance from each individual solution to the best solution in the normalized parametrical space was compared to a user‐defined error tolerance to determine whether that solution was acceptable. A supervised training was then used to train the RQE. Performance of the RQE was evaluated using test dataset consisting of registration results that were not used in training. The RQE was integrated with our in‐house 2D/3D registration system and its performance was evaluated using the same patient dataset. With an optimized sampling step size (i.e., 5 mm) in the feature space, the RQE has the sensitivity and the specificity in the ranges of 0.865–0.964 and 0.797–0.990, respectively, when used to detect registration error with mean voxel displacement (MVD) greater than 1 mm. The trial‐to‐acceptance ratio of the integrated 2D/3D registration system, for all patients, is equal to 1.48. The final acceptance ratio is 92.4%. The proposed RQE can potentially be used in a 2D/3D rigid image registration system to improve the overall robustness by rejecting unsuccessful registration solutions. The RQE is not patient‐specific, so a single RQE can be constructed and used for a particular application (e.g., the registration for images acquired on the same anatomical site). Implementation of the RQE in a 2D/3D registration system is clinically feasible.

PACS numbers: 87.57.nj, 87.85.dq, 87.55.Qr
Confidence limits for patient‐specific IMRT dose QA: a multi‐institutional study in Korea
Authors: Kim Jung‐in , Chung Jin‐Beom , Song Ju‐Young , Kim Sung Kyu , Choi Yunseok , Choi Chang Heon , Choi Won Hoon , Cho Byungchul , Kim Jin Sung , Kim Sung Jin , Ye Sung‐Joon
Published: February 2017

This study aims to investigate tolerance levels for patient‐specific IMRT dose QA (DQA) using the confidence limits (CL) determined by a multi‐institutional study. Eleven institutions participated in the multi‐institutional study in Korea. A total of 155 DQA measurements, consisting of point‐dose differences (high‐ and low‐dose regions) and gamma passing rates (composite and per‐field) for IMRT patients with brain, head and neck (H&N), abdomen, and prostate cancers were examined. The Shapiro‐Wilk test was used to evaluate the normality of data grouped by the treatment sites and the DQA methods. The confidence limit coefficients in cases of the normal distribution, and the two‐sided Student's t‐distribution were applied to determine the confidence limits for the grouped data. The Spearman's test was applied to assess the sensitivity of DQA results within the limited groups. The differences in CLs between the two confidence coefficients based on the normal and t‐distributions were negligible for the point‐dose data and the gamma passing rates with criteria. However, with criteria, the difference in CLs were 1.6% and 2.2% for composite and per‐field measurements, respectively. This resulted from the large standard deviation and the more sensitive criteria of . There was no noticeable correlation among the different QA methods. Our multi‐institutional study suggested that the CL was not a suitable metric for defining the tolerance level when the statistics of the sample group did not follow the normality and had a large standard deviation.

PACS number: 87.55.Qr
Dosimetric effects of positioning shifts using 6D‐frameless stereotactic Brainlab system in hypofractionated intracranial radiotherapy
Authors: Jin Hosang , Keeling Vance P. , Ali Imad , Ahmad Salahuddin
Published: February 2017

Dosimetric consequences of positional shifts were studied using frameless Brainlab ExacTrac X‐ray system for hypofractionated (3 or 5 fractions) intracranial stereotactic radiotherapy (SRT). SRT treatments of 17 patients with metastatic intracranial tumors using the stereotactic system were retrospectively investigated. The treatments were simulated in a treatment planning system by modifying planning parameters with a matrix conversion technique based on positional shifts for initial infrared (IR)‐based setup (XC: X‐ray correction) and post‐correction (XV: X‐ray verification). The simulation was implemented with (a) 3D translational shifts only and (b) 6D translational and rotational shifts for dosimetric effects of angular correction. Mean translations and rotations (± 1 SD) of 77 fractions based on the initial IR setup (XC) were (lateral), (longitudinal), and (vertical); (pitch), (roll), and (yaw), respectively. These were , , , , , and , respectively, for the postcorrection (XV). Substantial degradation of the treatment plans was observed in of PTV (; simulated treatment versus treatment planning), of PTV (), and of CTV (, with the maximum error of 10.0%) from XC, while dosimetrically negligible changes were detected for both CTV and PTV from XV simulation. 3D angular correction significantly improved CTV dose coverage when the total angular shifts were greater than 2°. With the 6D stereoscopic X‐ray verification imaging and frameless immobilization, submillimeter and subdegree accuracy is achieved with negligible dosimetric deviations. 3D angular correction is required when the angular deviation is substantial. A CTV‐to‐PTV safety margin of 2 mm is large enough to prevent deterioration of CTV coverage.

PACS number: 87.55.dk
Commissioning and initial experience with the first clinical gantry‐mounted proton therapy system
Authors: Zhao Tianyu , Sun Baozhou , Grantham Kevin , Rankine Leith , Cai Bin , Goddu Sreekrishna M. , Santanam Lakshmi , Knutson Nels , Zhang Tiezhi , Reilly Michael , Bottani Beth , Bradley Jeffrey , Mutic Sasa , Klein Eric E.
Published: February 2017

The purpose of this study is to describe the comprehensive commissioning process and initial clinical experience of the Mevion S250 proton therapy system, a gantry‐mounted, single‐room proton therapy platform clinically implemented in the S. Lee Kling Proton Therapy Center at Barnes‐Jewish Hospital in St. Louis, MO, USA. The Mevion S250 system integrates a compact synchrocyclotron with a C‐inner gantry, an image guidance system and a 6D robotic couch into a beam delivery platform. We present our commissioning process and initial clinical experience, including i) CT calibration; ii) beam data acquisition and machine characteristics; iii) dosimetric commissioning of the treatment planning system; iv) validation through the Imaging and Radiation Oncology Core credentialing process, including irradiations on the spine, prostate, brain, and lung phantoms; v) evaluation of localization accuracy of the image guidance system; and vi) initial clinical experience. Clinically, the system operates well and has provided an excellent platform for the treatment of diseases with protons.

PACS number(s): 87.55.ne, 87.56.bd
Evaluation of the ΔV 4D CT ventilation calculation method usingin vivoxenon CT ventilation data and comparison to other methods
Authors: Zhang Geoffrey G. , Latifi Kujtim , Du Kaifang , Reinhardt Joseph M. , Christensen Gary E. , Ding Kai , Feygelman Vladimir , Moros Eduardo G.
Published: February 2017

Ventilation distribution calculation using 4D CT has shown promising potential in several clinical applications. This study evaluated the direct geometric ventilation calculation method, namely the ΔV method, with xenon‐enhanced CT (XeCT) ventilation data from four sheep, and compared it with two other published methods, the Jacobian and the Hounsfield unit (HU) methods. Spearman correlation coefficient (SCC) and Dice similarity coefficient (DSC) were used for the evaluation and comparison. The average SCC with one standard deviation waswith a range between 0.29 and 0.61 between the XeCT and DLV ventilation distributions. The average DSC value for lower 30% ventilation volumes between the XeCT and ΔV ventilation distributions waswith a range between 0.48 and 0.63. Ventilation difference introduced by deformable image registration errors improved with smoothing. In conclusion, ventilation distributions generated using ΔV‐4D CT and deformable image registration are in reasonably agreement with thein vivoXeCT measured ventilation distribution.

PACS number(s): 87.57.N‐,87.57.nj, 87.57.Q‐, 87.85.Pq
Improved setup and positioning accuracy using a three‐point customized cushion/mask/bite‐block immobilization system for stereotactic reirradiation of head and neck cancer
Authors: Wang He , Wang Congjun , Tung Samuel , Dimmitt Andrew Wilson , Wong Pei Fong , Edson Mark A. , Garden Adam S. , Rosenthal David I. , Fuller Clifton D. , Gunn Gary B. , Takiar Vinita , Wang Xin A. , Luo Dershan , Yang James N. , Wong Jennifer , Phan Jack
Published: February 2017

The purpose of this study was to investigate the setup and positioning uncertainty of a custom cushion/mask/bite‐block (CMB) immobilization system and determine PTV margin for image‐guided head and neck stereotactic ablative radiotherapy (HN‐SABR). We analyzed 105 treatment sessions among 21 patients treated with HN‐SABR for recurrent head and neck cancers using a custom CMB immobilization system. Initial patient setup was performed using the ExacTrac infrared (IR) tracking system and initial setup errors were based on comparison of ExacTrac IR tracking system to corrected online ExacTrac X‐rays images registered to treatment plans. Residual setup errors were determined using repeat verification X‐ray. The online ExacTrac corrections were compared to cone‐beam CT (CBCT) before treatment to assess agreement. Intrafractional positioning errors were determined using prebeam X‐rays. The systematic and random errors were analyzed. The initial translational setup errors were , , and in AP, CC, and LR directions, respectively, with a three‐dimensional (3D) vector of . The initial rotational errors were up to 2.4° if 6D couch is not available. CBCT agreed with ExacTrac X‐ray images to within 2 mm and 2.5°. The intrafractional uncertainties were , , and in AP, CC, and LR directions, respectively, and , , and in yaw, roll, and pitch direction, respectively. The translational vector was . The calculated PTV margins were within 1.6 mm when using image guidance for online setup correction. The use of image guidance for online setup correction, in combination with our customized CMB device, highly restricted target motion during treatments and provided robust immobilization to ensure minimum dose of 95% to target volume with 2.0 mm PTV margin for HN‐SABR.

PACS number(s): 87.55.ne
Initial evaluation of automated treatment planning software
Authors: Gintz Dawn , Latifi Kujtim , Caudell Jimmy , Nelms Benjamin , Zhang Geoffrey , Moros Eduardo , Feygelman Vladimir
Published: February 2017

Even with advanced inverse‐planning techniques, radiation treatment plan optimization remains a very time‐consuming task with great output variability, which prompted the development of more automated approaches. One commercially available technique mimics the actions of experienced human operators to progressively guide the traditional optimization process with automatically created regions of interest and associated dose‐volume objectives. We report on the initial evaluation of this algorithm on 10 challenging cases of locoreginally advanced head and neck cancer. All patients were treated with VMAT to 70 Gy to the gross disease and 56 Gy to the elective bilateral nodes. The results of post‐treatment autoplanning (AP) were compared to the original human‐driven plans (HDP). We used an objective scoring system based on defining a collection of specific dosimetric metrics and corresponding numeric score functions for each. Five AP techniques with different input dose goals were applied to all patients. The best of them averaged the composite score 8% lower than the HDP, across the patient population. The difference in median values was statistically significant at the 95% confidence level (Wilcoxon paired signed‐rank test ). This result reflects the premium the institution places on dose homogeneity, which was consistently higher with the HDPs. The OAR sparing was consistently better with the APs, the differences reaching statistical significance for the mean doses to the parotid glands () and the inferior pharyngeal constrictor (), as well as for the maximum doses to the spinal cord () and brainstem (). If one is prepared to accept less stringent dose homogeneity criteria from the RTOG 1016 protocol, nine APs would comply with the protocol, while providing lower OAR doses than the HDPs. Overall, AP is a promising clinical tool, but it could benefit from a better process for shifting the balance between the target dose coverage/homogeneity and OAR sparing.

PACS number(s): 87.55.D
Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation
Authors: Nevelsky Alexander , Borzov Egor , Daniel Shahar , Bar‐Deroma Raquel
Published: February 2017

Total skin electron irradiation (TSEI) is a complex technique which requires many nonstandard measurements and dosimetric procedures. The purpose of this work was to validate measured dosimetry data by Monte Carlo (MC) simulations using EGSnrc‐based codes (BEAMnrc and DOSXYZnrc). Our MC simulations consisted of two major steps. In the first step, the incident electron beam parameters (energy spectrum, FWHM, mean angular spread) were adjusted to match the measured data (PDD and profile) at for an open field. In the second step, these parameters were used to calculate dose distributions at the treatment distance of 400 cm. MC simulations of dose distributions from single and dual fields at the treatment distance were performed in a water phantom. Dose distribution from the full treatment with six dual fields was simulated in a CT‐based anthropomorphic phantom. MC calculations were compared to the available set of measurements used in clinical practice. For one direct field, MC calculated PDDs agreed within 3%/1 mm with the measurements, and lateral profiles agreed within 3% with the measured data. For the OF, the measured and calculated results were within 2% agreement. The optimal angle of 17° was confirmed for the dual field setup. Dose distribution from the full treatment with six dual fields was simulated in a CT‐based anthropomorphic phantom. The MC‐calculated multiplication factor (B12‐factor), which relates the skin dose for the whole treatment to the dose from one calibration field, for setups with and without degrader was 2.9 and 2.8, respectively. The measured B12‐factor was 2.8 for both setups. The difference between calculated and measured values was within 3.5%. It was found that a degrader provides more homogeneous dose distribution. The measured X‐ray contamination for the full treatment was 0.4%; this is compared to the 0.5% X‐ray contamination obtained with the MC calculation. Feasibility of MC simulation in an anthropomorphic phantom for a full TSEI treatment was proved and is reported for the first time in the literature. The results of our MC calculations were found to be in general agreement with the measurements, providing a promising tool for further studies of dose distribution calculations in TSEI.

PACS number(s): 87.10. Rt, 87.55.K, 87.55.ne
Dosimetric comparison between cone/Iris‐based and InCise MLC‐based CyberKnife plans for single and multiple brain metastases
Authors: Jang Si Young , Lalonde Ron , Ozhasoglu Cihat , Burton Steven , Heron Dwight , Huq M. Saiful
Published: February 2017

We performed an evaluation of the CyberKnife InCise MLC by comparing plan qualities for single and multiple brain lesions generated using the first version of InCise MLC, fixed cone, and Iris collimators. We also investigated differences in delivery efficiency among the three collimators. Twenty‐four patients with single or multiple brain mets treated previously in our clinic on a CyberKnife M6 using cone/Iris collimators were selected for this study. Treatment plans were generated for all lesions using the InCise MLC. Number of monitor units, delivery time, target coverage, conformity index, and dose falloff were compared between MLC‐ and clinical cone/Iris‐based plans. Statistical analysis was performed using the nonparametric Wilcoxon‐Mann‐Whitney signed‐rank test. The planning accuracy of the MLC‐based plans was validated using chamber and film measurements. The InCise MLC‐based plans achieved mean dose and target coverage comparable to the cone/Iris‐based plans. Although the conformity indices of the MLC‐based plans were slightly higher than those of the cone/Iris‐based plans, beam delivery time for the MLC‐based plans was shorter by . For smaller targets or cases with OARs located close to or abutting target volumes, MLC‐based plans provided inferior dose conformity compared to cone/Iris‐based plans. The QA results of MLC‐based plans were within 5% absolute dose difference with over 90% gamma passing rate using gamma criteria. The first version of InCise MLC could be a useful delivery modality, especially for clinical situations for which delivery time is a limiting factor or for multitarget cases.

PACS number(s): 87.53.Ly, 87.55.D‐
Characterization of a 2.5 MV inline portal imaging beam
Authors: Gräfe James L. , Owen Jennifer , Eduardo Villarreal‐Barajas J. , Khan Rao F.H.
Published: February 2017

A new megavoltage (MV) energy was recently introduced on Varian TrueBeam linear accelerators for imaging applications. This work describes the experimental characterization of a 2.5 MV inline portal imaging beam for commissioning, routine clinical use, and quality assurance purposes. The beam quality of the 2.5 MV beam was determined by measuring a percent depth dose, PDD, in water phantom for field at source‐to‐surface distance 100 cm with a CC13 ion chamber, plane parallel Markus chamber, and GafChromic EBT3 film. Absolute dosimetric output calibration of the beam was performed using a traceable calibrated ionization chamber, following the AAPM Task Group 51 procedure. EBT3 film measurements were also performed to measure entrance dose. The output stability of the imaging beam was monitored for five months. Coincidence of 2.5 MV imaging beam with 6 MV therapy beam was verified with hidden‐target cubic phantom. Image quality was studied using the Leeds and QC3 phantom. The depth of maximum dose, , and percent dose at 10 cm depth were, respectively, 5.7 mm and 51.7% for CC13, 6.1 mm and 51.9% for Markus chamber, and 5.1 mm and 51.9% for EBT3 film. The 2.5 MV beam quality is slightly inferior to that of a teletherapy beam; however, an estimated of 1.00 was used for output calibration purposes. The beam output was found to be stable to within 1% over a five‐month period. The relative entrance dose as measured with EBT3 films was 63%, compared to 23% for a clinical 6 MV beam for a field. Overall coincidence of the 2.5 MV imaging beam with the 6 MV clinical therapy beam was within 0.2 mm. Image quality results for two commonly used imaging phantoms were superior for the 2.5 MV beam when compared to the conventional 6 MV beam. The results from measurements on two TrueBeam accelerators show that 2.5 MV imaging beam is slightly softer than a therapeutic beam, it provides superior image quality than a 6 MV therapy beam, and has excellent output stability. These 2.5 MV beam characterization results can serve as reference for clinics planning to commission and use this novel energy‐image modality.

PACS number(s): 87.57.‐s, 87.59.‐e, 06.20.fb, 87.53.Bn
Factors Influencing Tuberculosis Treatment Outcome in Adult Patients Treated with Thrice-Weekly Regimens in India
Authors: Ramachandran Geetha , Agibothu Kupparam Hemanth Kumar , Vedhachalam Chandrasekaran , Thiruvengadam Kannan , Rajagandhi Vijayalakshmi , Dusthackeer Azger , Karunaianantham Ramesh , Jayapal Lavanya , Swaminathan Soumya
Published: February 2017

The Indian Revised National Tuberculosis (TB) Control Programme uses thrice-weekly treatment with standard drug dosages. The role of plasma drug levels and other factors in determining TB treatment outcomes is not well understood. We aimed to determine the factors influencing the concentrations of rifampin (RMP), isoniazid (INH), and pyrazinamide (PZA) at 2 h postdosing in adult TB patients and to study the factors impacting TB treatment outcome. We recruited 1,912 adult TB patients (newly treated and retreated patients) with pulmonary/extrapulmonary TB receiving antitubercular treatment (ATT) in the RNTCP in Chennai, India. At steady state, the concentrations of RMP, INH, and PZA were determined at 2 h postdosing after supervised drug administration. A total of 1,648 patients had a favorable outcome, while 264 (14%) had an unfavorable outcome. A total of 91%, 16%, and 17% of the patients had suboptimal concentrations of RMP (<8 μg/ml), INH (<3 μg/ml), and PZA (<20 μg/ml), respectively. Factors associated with treatment outcome were low RMP concentrations (adjusted odds ratio [aOR], 0.94; 95% confidence interval [CI], 0.89 to 0.99;
P
= 0.036), category II ATT (aOR, 2.39; 95% CI, 1.56 to 3.65;
P
< 0.001), low body weight (aOR, 0.96; 95% CI, 0.94 to 0.98;
P
< 0.001), alcohol use (aOR, 2.17; 95% CI, 1.42 to 3.31;
P
< 0.001), male gender (aOR, 1.92; 95% CI, 1.02 to 3.62;
P
= 0.043), and baseline INH resistance (aOR, 5.74; 95% CI, 3.12 to 10.59;
P
< 0.001), which significantly increased the likelihood of an unfavorable outcome in multivariate logistic regression analysis. Further studies are needed to optimize anti-TB drug dosages and improve cure rates. Drug susceptibility testing at the baseline and attention to undernutrition and alcohol dependence are other important interventions.
Disseminated cysticercosis incidentally diagnosed in a patient of fracture shaft of femur
Authors: Saeed Noora , Ehsan Aaliya , Vasenwala Shaista M
Published: February 2017

Cysticercosis is caused by the larval form ofTaenia soliumtape worm, cysticercus cellulose. The life cycle ofT. soliumconsists of 2 host, the definite host is a man who harbours the adult forms of the worm in the intestine, while the intermediate host is the pig, where the larval form (cysticercus cellulose) is found in the skeletal muscle. Cysticercosis develops when human beings incidentally become the intermediate host and the eggs mature within their small intestine. The route of entry of the eggs into the human intestine may occur through autoinfection or by ingestion of contaminated food or water. Further, these eggs develop into the larval form which spread throughout the intestinal wall and are disseminated by the blood stream to brain, muscles, subcutaneous tissues or any other organ. Until now, only 50 cases of disseminated forms have been reported in the literature, with the majority of the cases being from Indian subcontinent. Regarding the clinical presentations, symptoms usually depend on the location, size and number of cysts in the involved lesion. However, it may present occasionally with dementia, muscular hypertrophy or subcutaneous nodules with relative absence of focal neurological signs or raised intracranial pressure. We, here, report a case of disseminated cysticercosis, detected incidentally in a man aged 52 years who presented with an open fracture of the right femur.
Humanβ-Defensin 3 Reduces TNF-α-Induced Inflammation and Monocyte Adhesion in Human Umbilical Vein Endothelial Cells
Authors: Bian Tianying , Li Houxuan , Zhou Qian , Ni Can , Zhang Yangheng , Yan Fuhua
Published: February 2017

The aim of this study was to investigate the role of humanβ-defensin 3 (hBD3) in the initiation stage of atherosclerosis with human umbilical vein endothelial cells (HUVECs) triggered by tumor necrosis factor- (TNF-)α. The effects of hBD3 on TNF-α-induced endothelial injury and inflammatory response were evaluated. Our data revealed that first, hBD3 reduced the production of interleukin-6 (IL-6), IL-8, monocyte chemoattractant protein-1 (MCP-1), and macrophage migration inhibitory factor (MIF) in HUVECs in a dose-dependent manner. In addition, hBD3 significantly prevented intracellular reactive oxygen species (ROS) production by HUVECs. Second, western blot analysis demonstrated that hBD3 dose-dependently suppressed the protein levels of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in TNF-α-induced HUVECs. As a result, hBD3 inhibited monocyte adhesion to TNF-α-treated endothelial cells. Additionally, hBD3 suppressed TNF-α-induced F-actin reorganization in HUVECs. Third, hBD3 markedly inhibited NF-κB activation by decreasing the phosphorylation of IKK-α/β, IκB, and p65 subunit within 30 min. Moreover, the phosphorylation of p38 and c-Jun N-terminal protein kinase (JNK) in the mitogen-activated protein kinase (MAPK) pathway were also inhibited by hBD3 in HUVECs. In conclusion, hBD3 exerts anti-inflammatory and antioxidative effects in endothelial cells in response to TNF-αby inhibiting NF-κB and MAPK signaling.
Transbronchial Lung Cryobiopsy in Diffuse Parenchymal Lung Disease: Comparison between Biopsy from 1 Segment and Biopsy from 2 Segments - Diagnostic Yield and Complications
Authors: Ravaglia Claudia , Wells Athol U. , Tomassetti Sara , Dubini Alessandra , Cavazza Alberto , Piciucchi Sara , Sverzellati Nicola , Gurioli Carlo , Gurioli Christian , Costabel Ulrich , Tantalocco Paola , Ryu Jay H. , Chilosi Marco , Poletti Venerino
Published: February 2017

Background: Transbronchial lung cryobiopsy is an innovative method of obtaining samples from the parenchyma of patients with diffuse parenchymal lung diseases. However, the technique is not yet standardized, and uncertainty exists about the optimal protocol, including the number of samples, the biopsy size, and the choice of the biopsy site. Objectives: To compare the diagnostic yield and complications of cryobiopsy with different strategies adopted to sample lung tissue (number of samples, biopsy site, and sample size). Methods: We prospectively enrolled 46 patients with suspected diffuse parenchymal lung diseases for the diagnosis of which a biopsy was deemed useful. All patients underwent transbronchial lung cryobiopsy, and they were randomly assigned to group A (4 samples obtained from the same segment) or group B (2 samples obtained from one segment and 2 samples obtained from a different segment of the same lobe). Analysis of the samples was performed sequentially (from the first to the last sample), and pathologists reformulated their histopathologic diagnosis with the addition of each sample. Results: The mean diagnostic yield of the procedure combining the 2 groups and performing only the first sampling was 69%. When a second biopsy was performed as well, the mean diagnostic yield improved, but this increase was significant only when the 2 samples were obtained from 2 different segments (96%, group B). Conclusions: This study suggests that the strategy of performing 2 biopsies with a cryoprobe may be associated with an increased diagnostic yield in diffuse parenchymal lung diseases if these samples are obtained from 2 different segments within the same lobe.
Role of Periostin in Early Brain Injury After Subarachnoid Hemorrhage in Mice
Authors: Liu Lei , Kawakita Fumihiro , Fujimoto Masashi , Nakano Fumi , Imanaka-Yoshida Kyoko , Yoshida Toshimichi , Suzuki Hidenori
Published: February 2017

Background and Purpose—

A matricellular protein tenascin-C is implicated in early brain injury after experimental subarachnoid hemorrhage (SAH). This study first evaluated the role of another matricellular protein periostin and the relationships with tenascin-C in post-SAH early brain injury.

Methods—

Wild-type (n=226) and tenascin-C knockout (n=9) C57BL/6 male adult mice underwent sham or filament perforation SAH modeling. Vehicle, anti-periostin antibody, or recombinant periostin was randomly administrated by an intracerebroventricular injection at 30 minutes post-modeling. Neuroscores, SAH grading, brain water content, immunostaining, and Western blotting were blindly evaluated at 24 to 48 hours post-SAH.

Results—

Periostin was induced in brain capillary endothelial cells and neurons at 24 hours post-SAH. Anti-periostin antibody improved post-SAH neurobehavior, brain edema, and blood–brain barrier disruption associated with downregulation of tenascin-C, inactivation of p38, extracellular signal-related kinase 1/2 and matrix metalloproteinase-9, and subsequent preservation of zona occludens-1. Recombinant periostin aggravated post-SAH brain edema and tenascin-C induction. Tenascin-C knockout prevented post-SAH neurobehavioral impairments and periostin induction.

Conclusions—

Periostin may cause post-SAH early brain injury through activating downstream signaling pathways and interacting with tenascin-C, providing a novel approach for the treatment of early brain injury.
The Role of NR2B-CREB-miR212/132-CRTC1-CREB Signal Network in Pain Regulation In Vitro and In Vivo
Authors: Xia Tianjiao , Chu Shuaishuai , Cui Yin , Xu Fangxia , Liu Yue , Song Jia , Qian Yue , Shao Xueming , Li Xiuxiu , Gu Xiaoping , Ma Zhengliang
Published: February 2017

BACKGROUND:

Chronic pain is a debilitating threat to human health, and its molecular mechanism remains undefined. Previous studies have illustrated a key role of cAMP response element-binding protein (CREB) in pain regulation; CREB-regulated transcription coactivator 1 (CRTC1) and microRNA212/132 (miR212/132) are also vital in synaptic plasticity. However, little is known about the interaction among these factors in pain condition. We conducted this experiment mainly to determine the crosstalk between CREB, CRTC1, and miR212/132 in vitro. Moreover, we explored the changes in hyperalgesia on chronic constrictive injury (CCI) mouse in vivo when given CREB-related adenovirus vectors, CRTC1-related adenovirus vectors, and miR212/132-locked nucleic acid (LNA).

METHODS:

We cultured primary neurons in the spinal cord of mouse embryos. Exogenous glutamate was added to cultured neurons to simulate in vivo pain process. Real-time quantitative polymerase chain reaction was used to determine changes of NR2B, CRTC1, CREB, and miR212/132 at the mRNA level; Western blot was used to detect p-NR2B, p-CREB, and CRTC1 at protein level. Von Frey cilia were used to study mechanical hyperalgesia in a murine model of CCI. CREB-miR (adenovirus vector interfering CREB gene), CREB-AD (adenovirus vector overexpressing CREB gene); CRTC1-miR (adenovirus vector interfering CRTC1 gene), CRTC1-AD (adenovirus vector overexpressing CRTC1 gene), and miR212/132-LNA were injected intrathecally.

RESULTS:

In vitro, 100 μmol/L glutamate induced p-CREB and miR212/132-LNA. CRTC1 protein was downregulated by CREB-miR and miR212/132-LNA. CRTC1 mRNA was upregulated by CREB-AD and downregulated by CREB-miR and miR212-LNA. P-CREB was upregulated by CRTC1-AD and downregulated by miR212/132. CREB mRNA was upregulated by CRTC1-AD and downregulated by CRTC1-miR. MiR212/132 was upregulated by CRTC1-AD and CREB-AD; downregulated by CREB-miR. In vivo, CRTC1-miR, CREB-miR, and miR212/132-LNA increased paw withdrawal mechanical threshold in various degrees.

CONCLUSIONS:

The NR2B-CREB-miR212/132-CRTC1-CREB signal network plays an important role in the regulation of pain. Intervening with any molecule in this signal network would reduce pain perception.
The canine microbiome
Authors: Ackerman Nicola
Published: February 2017

It is estimated that the average human contains 100 trillion microbes in the gut, which is ten times more than the cells of the human body. Each individual is made up of more microbe cells than their own. Identification of the bacteria within the microbiome has only until recently become more specific, the majority of bacteria being unable to be cultured following faecal sampling techniques utilised in veterinary practice. The manipulation of the microbiome can be achieved, but is difficult to quantify due to the multifactorial cause and effects of the populations.