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Panduranga S Rao,1 Julie A Wright Nunes,1 Brenda W Gillespie,2 Rachel L Perlman,1 Rajan Ravichandran3 1Division of Nephrology, Department of Internal Medicine, University of Michigan Health System, 2Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA; 3Department of Nephrology, Madras Institute of Nephrology, Madras Institute of Orthopedics and Trauma Hospitals, Chennai, India Background: There is a paucity of information on kidney education and screening programs in Indian youth.Methods: Participants (n=2,158) from Chennai colleges were educated about the kidneys and chronic kidney disease (CKD) and screened in a pilot program from April to May 2013. This entailed: 1) a presentation and educational video and 2) an on-site assessment of weight, blood pressure, and demographic information. Urinalysis (UA) kits were distributed and returned in ≤48 hours. We examined participant characteristics and their association with dipstick proteinuria using logistic regression.Results: The mean (standard deviation [SD]) age was 18.9 (1.6) years, and 1,451 (68%) were men. Mean (SD) body mass index (BMI) was 21.9 (4.3) kg/m2; 745 (36%) had a BMI consistent with being overweight or obese. Mean (SD) systolic blood pressure (SBP) was 118.7 (13.1) mm Hg, and 94 (5%) of the participants had SBP ≥140. Mean (SD) diastolic blood pressure (DBP) was 70.9 (11.4) mm Hg, with 119 participants (6%) having ≥90 mm Hg. A total of 136 participants had glycosuria (UA≥1+) and 120 (6%) had proteinuria (UA≥1+). In unadjusted analyses, sex (odds ratio [OR]=1.64 [confidence interval, CI 1.06–2.55]; p=0.026 men vs. women) and age (OR=1.13 per year [CI 1.01–1.26]; p=0.032) were significantly associated with proteinuria. In the analysis adjusted for age, sex, SBP, DBP, glycosuria, and BMI, age remained independently associated with higher odds for proteinuria (OR=1.14 per year [1.02–1.29]; p=0.026). Males showed a trend of higher risk compared with women (OR=1.57 [CI 1.00–2.50]; p=0.051).Conclusion: This education and screening pilot program in a population of college students offers unique opportunities for identification, education, and early intervention for CKD. Keywords: screening, youth, CKD, proteinuria, glycosuria, education, hypertension, BMI, Indian youth

Bleeding is the most dreaded complication after percutaneous nephrolithotomy (PCNL). We report a case of post PCNL hematuria managed with selective angioembolization of the pseudoaneurysm. During the embolization, the emolization coil along with the glue migrated into the pelvicalyceal system from the pseudoaneurysmal cavity. The pseudoaneurysm was again embolized using cyanoacrylate glue and a screening computed tomography was immediately performed which showed the migrated coil along with the glue into the pelvicalyceal system resulting in pelviureteric junction obstruction. The coil was retrieved endoscopically, after the patient was stabilized. To our knowledge, this is the first reported case of an immediate migration of the coil and the urologists should be aware of it., Author(s): D. Paul Vincent [1]; R. Ravichandran [1]; Abhineet Gupta (corresponding author) [1] INTRODUCTION Severe renal hemorrhage is among the most serious complications of percutaneous nephrolithotomy (PCNL), reported in approximately [...]

Rajeswari Ravichandran,1,2 Jayarama Reddy Venugopal,1 Subramanian Sundarrajan,1,2 Shayanti Mukherjee,1 Seeram Ramakrishna1,21Healthcare and Energy Materials Laboratory, 2Department of Mechanical Engineering, National University of Singapore, SingaporeAbstract: Myocardial infarction (MI) is characterized by heart-wall thinning, myocyte slippage, and ventricular dilation. The injury to the heart-wall muscle after MI is permanent, as after an abundant cell loss the myocardial tissue lacks the intrinsic capability to regenerate. New therapeutics are required for functional improvement and regeneration of the infarcted myocardium, to overcome harmful diagnosis of patients with heart failure, and to overcome the shortage of heart donors. In the past few years, myocardial tissue engineering has emerged as a new and ambitious approach for treating MI. Several left ventricular assist devices and epicardial patches have been developed for MI. These devices and acellular/cellular cardiac patches are employed surgically and sutured to the epicardial surface of the heart, limiting the region of therapeutic benefit. An injectable system offers the potential benefit of minimally invasive release into the myocardium either to restore the injured extracellular matrix or to act as a scaffold for cell delivery. Furthermore, intramyocardial injection of biomaterials and cells has opened new opportunities to explore and also to augment the potentials of this technique to ease morbidity and mortality rates owing to heart failure. This review summarizes the growing body of literature in the field of myocardial tissue engineering, where biomaterial injection, with or without simultaneous cellular delivery, has been pursued to enhance functional and structural outcomes following MI. Additionally, this review also provides a complete outlook on the tissue-engineering therapies presently being used for myocardial regeneration, as well as some perceptivity into the possible issues that may hinder its progress in the future.Keywords: cardiac-tissue engineering, injectable system, myocardial infarction, biomaterials

The objective of the present study is to establish radiation standards for absorbed doses, for clinical high energy linear accelerator beams. In the nonavailability of a cobalt-60 beam for arriving at Nd, water values for thimble chambers, we investigated the efficacy of perspex mounted extrapolation chamber (EC) used earlier for low energy x-rays and beta dosimetry. Extrapolation chamber with facility for achieving variable electrode separations 10.5mm to 0.5mm using micrometer screw was used for calibrations. Photon beams 6 MV and 15 MV and electron beams 6 MeV and 15 MeV from Varian Clinac linacs were calibrated. Absorbed Dose estimates to Perspex were converted into dose to solid water for comparison with FC 65 ionisation chamber measurements in water. Measurements made during the period December 2006 to June 2008 are considered for evaluation. Uncorrected ionization readings of EC for all the radiation beams over the entire period were within 2% showing the consistency of measurements. Absorbed doses estimated by EC were in good agreement with in-water calibrations within 2% for photons and electron beams. The present results suggest that extrapolation chambers can be considered as an independent measuring system for absorbed dose in addition to Farmer type ion chambers. In the absence of standard beam quality (Co-60 radiations as reference Quality for Nd,water) the possibility of keeping EC as Primary Standards for absorbed dose calibrations in high energy radiation beams from linacs should be explored. As there are neither Standard Laboratories nor SSDL available in our country, we look forward to keep EC as Local Standard for hospital chamber calibrations. We are also participating in the IAEA mailed TLD intercomparison programme for quality audit of existing status of radiation dosimetry in high energy linac beams. The performance of EC has to be confirmed with cobalt-60 beams by a separate study, as linacs are susceptible for minor variations in dose output on different days.

This paper describes the initial experience of quality assurance (QA) tests performed on the millennium multi-leaf collimator (mMLC) for clinical implementation of intensity-modulated radiotherapy (IMRT) using sliding window technique. The various QA tests verified the mechanical and dosimetric stability of the mMLC of linear accelerator when operated in dynamic mode (dMLC). The mechanical QA tests also verified the positional accuracy and kinetic properties of the dMLC. The stability of dMLC was analyzed qualitatively and quantitatively using radiographic film and Omnipro IMRT software. The output stability, variation in output for different sweeping gap widths, and dosimetric leaf separation were measured. Dose delivery with IMRT was verified against the dose computed by the treatment planning system (TPS). Monitor units (MUs) calculated by the planning system for the IMRT were cross-checked with independent commercial dose management software. Visual inspection and qualitative analysis showed that the leaf positioning accuracy was well within the acceptable limits. Dosimetric QA tests confirmed the dosimetric stability of the mMLC in dynamic mode. The verification of MUs using commercial software confirmed the reliability of the IMRT planning system for dose computation. The dosimetric measurements validated the fractional dose delivery.

The objective of this study was to conduct an audit on QA aspects of treatment delivery by the verification of the treatment fields′ position on different days to document the efficiency of immobilization methods and reproducibility of treatment. A retrospective study was carried out on 60 patients, each 20 treated for head and neck, breast, and pelvic sites; and a total of 506 images obtained by electronic portal imaging device (EPID) were analyzed. The portal images acquired using the EPID systems attached to the Varian linear accelerators were superimposed on the reference images. The anatomy matching software (Varian portal Vision. 6.0) was used, and the displacements in two dimensions and rotation were noted for each treated field to study the patient setup errors. The percentages of mean deviations more than 3 mm in ′lateral (X) and longitudinal (Y)′ directions were 17.5%, 11.25%, and 7.5% for breast, pelvis, and head and neck cases respectively. In all cases, the percentage of mean deviation with more than 5 mm error was 0.83%. The maximum average mean deviation in all the cases was 1.87. The average mean SD along X and Y directions in all the cases was less than 2.65. The results revealed that the ranges of setup errors are site specific and immobilization methods improve reproducibility. The observed variations were well within the limits. The study confirmed the accuracy and quality of treatments delivered to the patients.

For radiotherapy of para-aortic and abdominal regions in male patients, gonads are to be protected to receive less than 2% of the prescribed dose. A testicular shield was fabricated for abdominal radiotherapy with 15 MV X-rays ((Clinac 2300 CD, Varian AG) with low melting point alloy (Cerroband). The dimensions of the testicular shield were 6.5 cm diameter and 3.5 cm depth with 1.5 cm wall thickness. During treatment, this shield was held in position by a rectangular sponge and Styrofoam support. Phantom measurement was carried out with a humanoid phantom and a 0.6 cc ion chamber. The mean energy of the scattered photon was calculated for single scattering at selected distances from the beam edge and with different field dimensions. One patient received radiotherapy with an inverted Y field and gonad doses were estimated using calibrated thermo-luminescent detector (TLD) chips. Measured doses with the ion chamber were 7.1 and 3.5% of the mid-plane doses without a shield at 3 and 7.5 cm off-field respectively. These values decreased to 4.6 and 1.7% with the bottom shield alone, and to 1.7 and 0.8% with both bottom and top shields covering the ion chamber. The measured doses at the gonads during the patient′s treatment were 0.5-0.92% for the AP field (0.74 ± 0.17%, n = 5) and 0.5-1.2% for the PA field (0.88 ± 0.24%, n = 5). The dose received by the testis for the full course of treatment was 32 cGy (0.8%) for a total mid-plane dose of 40 Gy. The first-scatter energy estimated at the gonads is around 1.14 MeV for a primary beam of 15 MV for a long axis dimension of 37 cm of primary field. During the patient′s treatment, the estimated absorbed doses at the gonads were comparable with reported values in similar treatments. The testicular shield reported in this study is of light weight and could be used conveniently in treatments of abdominal fields.

3 Dimensional Conformal Radiotherapy (3D-CRT) planning software helps in displaying the 3D dose distribution at different levels in the planned target volume (PTV). Physical or dynamic wedges are commonly applied to obtain homogeneous dose distribution in the PTV. Despite all these planning efforts, there are about 10% increased dose hot spots encountered in final plans. To overcome the effect of formation of hot spots, a manual forward planning method has been used. In this method, two more beams with multi-leaf collimator (MLC) of different weights are added in addition to medial and lateral wedged tangent beams. Fifteen patient treatment plans were taken up to check and compare the validity of using additional MLC fields to achieve better homogeneity in dose distributions. The resultant dose distributions with and without presence of MLC were compared objectively. The dose volume histogram (DVH) of each plan for the PTV was evaluated. The 3D dose distributions and homogeneity index (HI) values were compared. The 3D dose maximum values were reduced by 4% to 7%, and hot spots assumed point size. Optimizations of 3D-CRT plans with MLC fields improved the homogeneity and conformability of dose distribution in the PTV. This paper outlines a method of obtaining optimal 3D dose distribution within the PTV in the 3D-CRT planning of breast cases.

There is need for simple methods for checking consistency of beam outputs and energy in linear accelerators used for radiotherapy. A method was designed by the department using perspex phantom with which the dosimetric data of two medical linear accelerators (Clinac 600 CD, Clinac 2300 CD) were evaluated over a period of 30 months. The efficacy of methods followed was checked. Routine beam consistency checks were designed for photon beams with 15 cm/ 5 cm depth ionizations in perspex phantom and variable depth combinations for electron beams. Calculated ionization ratios were compared with measured values to show their significance. The dose/MU for all radiation beams was maintained within 2% accuracy over the period of 30 months. Clinac 600 CD machine showed decreasing trend of cGy/MU, while Clinac 2300 CD showed increasing trend of cGy/MU over a period, which needed tuning of monitor chamber two times each. Tuning of output to achieve standard value was carried out once, for all electron energies when the output dose/MU exceeded 3%. During one week (June 2005), there were slight changes in electron energy detected using the ratio method, which did not recur anytime afterwards. The methods designed are adequate to find the consistency in the beam output and energies in the radiotherapy linacs.

The present paper illustrates our attempt to design and test the reproducibility of low-cost patient positioning devices prepared in-house in our radiotherapy department. Rigid thermocole boards with angulations, scales and support were designed as breast, pelvis and head positioning devices. Reproducibility and accuracy were tested by serial electronic portal imaging detector imaging. The positioning devices (with or without superimposed moulds) showed variations within 2-3 mm on serial treatment days which were within acceptable limits. It is therefore concluded that low-cost patient positioning devices for head, breast and pelvis (the common sites of treatments in radiotherapy) can be fabricated from available materials in-house. These have been shown to be resulting in accurate immobilization, can be customized for particular techniques and are considerably cheaper than commercially available solutions.

Techniques are being standardized in our department for total body irradiation (TBI) with six MV photons in linear accelerator for preconditioning to bone marrow transplantation (BMT). Individualized shields with low melting point alloy are to be fabricated for shielding critical organs such as lungs, kidneys etc. A method to mount diminished dimension of shields in a tray at 3.75m is designed in the department for a teletreatment distance of four meters with magna field with A simulator image taken with the patient′s midplane (MP) at one meter distance is used to mark the dimensions of lung, scaled down by a factor of 3.75/4.0. These lung dimensions are reprinted from the digital simulator image for making the shield. The methodology of the technique using digitized minification in radiography is the first of its kind to be used for shield cutting in magna field radiotherapy.

Intensity-modulated radiotherapy (IMRT) clinical dose delivery is based on computer-controlled multileaf movements at different velocities. To test the accuracy of modulation of the beam periodically, quality assurance (QA) methods are necessary. Using a cylindrical phantom, dose delivery was checked at a constant geometry for sweeping fields. Repeated measurements with an in-house designed methodology over a period of 1 year indicate that the method is very sensitive to check the proper functioning of such dose delivery in medical linacs. A cylindrical perspex phantom with facility to accurately position a 0.6-cc (FC 65) ion chamber at constant depth at isocenter, (SA 24 constancy check tool phantom for MU check, Scanditronix Wellhofer) was used. Dosimeter readings were integrated for 4-mm, 10-mm, 20-mm sweeping fields and for 3 angular positions of the gantry periodically. Consistency of standard sweeping field output (10-mm slit width) and the ratios of outputs against other slit widths over a long period were reported. A 10-mm sweeping field output was found reproducible within an accuracy of 0.03% (n = 25) over 1 year. Four-millimeter, 20-mm outputs expressed as ratio with respect to 10-mm sweep output remained within a mean deviation of 0.2% and 0.03% respectively. Outputs at 3 gantry angles remained within 0.5%, showing that the effect of dynamic movements of multileaf collimator (MLC) on the output is minimal for angular positions of gantry. This method of QA is very simple and is recommended in addition to individual patient QA measurements, which reflect the accuracy of dose planning system. In addition to standard output and energy checks of linacs, the above measurements can be complemented so as to check proper functioning of multileaf collimator for dynamic field dose delivery.

Friction Stir Welding (FSW) is a relatively novel welding technology that, because of its many advantages and strong industrial potential, has caught the imagination of many industrial sectors. Experiments were carried out by AA6061T6 is a workpiece material, the input parameters, such as rotational speed, welding speed, and tool depth, play a key role in the weld quality determination. The tensile strength prediction in a friction stir welded joint using Artificial Neural Networks (ANN) is discussed in this article. A total factorial model was used for the design of tests. Three distinct neural forms architectures of networks, including tangent sigmoid transfer function (TANSIG), log-sigmoid transfer function (LOGSIG), and linear transfer function (PURLINE) performed using ANN was used in predicting the FSW process’s tensile strength. A distinction is made between measured and predicted details. The results indicate that the estimation results are in good alignment with the experimental evidence, suggesting that the log-sigmoid transfer function neural network can be used as an alternative way to measure the parameters of the repetitive procedure. [ABSTRACT FROM AUTHOR]