http://localhost:8080/xmlui/handle/123456789/487 Fri, 27 Mar 2026 08:25:00 GMT 2026-03-27T08:25:00Z http://localhost:8080/xmlui/handle/123456789/836 Title: Investigation of Treatment Planning and Dose Verification Procedures Using Unflat Linac Photon Beams Authors: Dwivedi, Shekhar Abstract: The current research work was carried out in order to investigate the appropriate detectors for small field dosimetry; the optimised methods of treatment planning techniques for lung and spinal SBRT; and the suitability of pretreatment dose verification tools for a 6 MV FFF photon beam. The results of this study suggest that all three treatment techniques, i.e., FFF-VMAT, FFF-IMRT, and FFF-3DCRT were able to deliver conformal SBRT plans while meeting the RTOG dose constraints. On the other hand, based on the comparison of dosimetric indices, such as CI, D2cm, HI, and HDV, FFF-VMAT provides a superior treatment plan to FFF-IMRT and FFF-3DCRT in the treatment of peripheral and central lung PTVs. Dosimetric indices, such as R50% and GI, were improved for FFF-3DCRT compared with those of FFF-VMAT. It is also clear that despite the requirement for higher MUs in the FFF-VMAT plans compared to FFF-3DCRT, the treatment delivery time is much shorter because of the superior gantry speed of the VMAT technique. The study suggests that the treatment dose calculated using Acuros XB is more accurate than that of AAA in a heterogeneous medium, such as the lung. The outcome of these studies provided some insight about the selection of appropriate detector to be used for dosimetry of small FFF photon field, the optimized method of the treatment planning of SBRT treatment plans and appropriateness of dose verification procedures in FFF photon beam. Sun, 01 Jan 2023 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/836 2023-01-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/489 Title: Radiological Risk Assessment in the Environs of Moga and Barnala Disricts of Punjab Authors: Supriya Rani; Supervisor; Kansal, Sandeep; Co-Supervisor; Mehra, Rohit Abstract: The conclusion of this study is that in the studied area 32.5% of the dwellings have higher annual average radon concentration than the recommended value of 40 Bqm -3 by UNSCEAR, 2008. All (100%) the dwellings have higher annual average thoron concentration than the world average value of 10 Bqm -3 . Only 9% of the dwellings have higher annual average radon progeny concentration (EERC) than the worldwide average value of 15 Bqm -3 while 96% of the dwellings have higher annual average thoron progeny concentration (EETC) than the world average value of 0.5 Bqm -3 . The measured values of radon mass exhalation rates are lower than 57 mBqkg -1 h -1 and 98% of samples have higher thoron surface exhalation rates than the worldwide average value of 3.60 kBqm -2 h -1 . Uranium concentration in 99.5% of water samples have higher value than the recommended safe limit of 30 µgl -1 and in 79% of samples have higher value than 60 µgl -1 . As some of the areas have been found to have higher values than the recommended safe limit hence, such areas may be explored further for radiological health effects to the residents of the area. The available data will contribute for the uranium and radon mapping of the country which is being carried out by BARC Mumbai. Sat, 01 Jan 2022 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/489 2022-01-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/488 Title: Natural radioactivity studies in the environs of northern Rajasthan Authors: Singla, Amit Kumar; Supervisor; Kansal, Sandeep; Co-Supervisor; Mehra, Rohit Abstract: The overall conclusion of this study is that in the studied area, most of the values have been found to be within the permissible recommended levels and hence may not pose any radiological health risk to the local population. The available data will further contribute for the radon mapping of the country and for carrying out vifurther studies in the areas, where values have been found to be on higher side for radiation related risk assessment. Sat, 01 Jan 2022 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/488 2022-01-01T00:00:00Z