ABSTRACT
Purpose: The aim of the present study was to compare the positional accuracy of varian's exact-arm (E-arm) and retractable-arm (R-arm) supporting electronic portal imaging device (EPID) systems (amorphous silicon flat-panel detector) using the intensity-modulated radiotherapy (IMRT) graticule phantom. Materials and Methods: The known shifts of 0.5, 1.0, and 1.5 cm were introduced to the given phantom in longitudinal, lateral, and vertical directions, respectively, with respect to treatment couch of medical linear accelerator. The experiment was repeated for different gantry angle and varying source to imager distances (SIDs). The images were acquired for each shift at varying SIDs and beam orientations for both EPID supporting systems. The corresponding shifts obtained from treatment planning system (TPS) were recorded and compared. Results: The known (expected) and observed (recorded from TPS) shifts obtained for different beam angles (namely, 0°, 90°, 180°, and 270° for anterior, left lateral, posterior, and right-lateral portal images, respectively) in the longitudinal, lateral, and vertical direction at varying SID were compared. The maximum shift in the observed value from the expected one was 3 and 2 mm, respectively, out of the all beam configuration for R-arm and E-arm. These shifts were randomly observed for all imager position and beam orientation. Conclusion: The IMRT graticule phantom is an effective tool to check the mechanical characteristic and consistency of different EPID supporting arms. The effect of EPID sag due to gravity (gantry and treatment couch) was not significant for detection of shift in patient's position. The E-arm support EPID has better mechanical stability and accuracy in detection of patient's position than that of R-arm
ABSTRACT
Introduction: Tobacco is the most common form of nicotine. It is smoked most commonly in cigarettes,then, in descending order, cigars, snuff, chewing tobacco, and in pipes. Effective treatments have now beenidentified and should be used with every current and former smoker. Guidelines that are available mightnot be specific and tailor made for patient population we come across. Hence, we reviewed and criticallyappraised available guidelines, systemic reviews, meta-analysis, review articles etc and we designed ourevidence-based treatment protocols accordingly and this study will test the treatment effectiveness innicotine use disorder.Material & Methods: It was a prospective observational study. Individuals aged above 18 years withnicotine use disorder were enrolled into the study. The participants were assessed using structuredPerforma including demographic data, quit attempts and severity of Nicotine dependence using theFagerström Nicotine Dependence Scale. Group A includes participants who were given Bupropion andGroup B were given varenicline. Follow up was done at 1 and 3 month and patients assessed for relapse.Results: Out of 90 participants 40 patients dropped out and 50 patients who completed the study, at 1month of follow up there was no significant difference in relapse between two groups but at 3 monthsfollow up compared to Group B (Varenicline), in group A (Bupropion) number of relapse is significantlyhigher (p value = 0.044).Conclusion: At the end of the 3 months, significant difference was found between the medications interms of the success of smoking cessation. Patients taking Bupropion had significantly higher relapse rateas compare to varenicline.