Manickam Ravikumar

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The purpose of this study is to examine the plan quality and monitor unit with sliding window IMRT and RapidArc (RA) treatment plans using American Association Physicists in Medicine TG119 test suite DICOM-RT images and structure sets. The structure set includes multi-target (superior, central, inferior), prostate, head and neck and C-shape. Plans were(More)
HDR brachytherapy treatment planning often involves optimization methods to calculate the dwell times and dwell positions of the radioactive source along specified afterloading catheters. The purpose of this study is to compare the dose distribution obtained with geometric optimization (GO) and volume optimization (VO) combined with isodose reshaping. This(More)
To analyze backscattered dose enhancements near different metallic interfaces for cobalt-60 (60Co) gamma rays and 6- and 18-MV photon beams. Measurements were carried out with a PTW thin-window, parallel-plate ionization chamber and an RDM-1F electrometer. Thin sheets of aluminum, mild steel, copper, cadmium and lead were used as inhomogeneities. The(More)
Since the skin dose becomes the limiting factor while deciding the tumorcidal dose, the detailed analysis of dose distribution in the build-up region is necessary for high-energy photon beams. In this study the beam characteriwstics affecting the build-up and skin dose for 6- and 18-MV photons are analyzed. Materials and Methods: Measurements were made with(More)
Dose delivery accuracy at low monitor units (LMU) was evaluated for photon and electron beams. Knowledge of this study is required for few dosimetric applications and to know the dose delivered to the patient when the treatment is delivered with few monitor units (MU). Dose measurements were carried out for photon and electron beams with 0.6 cm3 PTW ion(More)
Implementation of Intensity Modulation Radiotherapy (IMRT) and patient dose verification was carried out with film and I'mariXX using linear accelerator with 120-leaf Millennium dynamic multileaf collimator (dMLC). The basic mechanical and electrical commissioning and quality assurance tests of linear accelerator were carried out. The leaf position accuracy(More)
The photons and electrons backscattered from the upper and lower secondary collimator jaws give rise to a significant increase in the ion charge measured by the monitor chamber, and this increase varies between different accelerators. We have studied the effect of backscatter into the monitor chamber at 6 MV and 18 MV photon energies for the linear(More)
Endometrial carcinoma is the most common malignancy arising in the female genital tract. Intracavitary vaginal cuff irradiation may be given alone or with external beam irradiation in patients determined to be at risk for locoregional recurrence. Vaginal cylinders are often used to deliver a brachytherapy dose to the vaginal apex and upper vagina or the(More)
In this study forward scattering effects near different metallic interfaces are measured for Co-60 gamma and 6 and 18 MV photon beams. The studied effects are the transport of secondary electrons across the metallic interface and the scattering of photons by the metallic inhomogeneity. Materials and Methods: All measurements were carried out with a PTW(More)