Impact of discrete source step size on the 3D dosimetry of interstitial implants with high dose rate brachytherapy

ABSTRACTBackground: High dose rate remote after loading brachytherapy machines have seen tremendous advancement both technologically and their clinical applications during the last 25 years. With the introduction of computerized remote after loading machines and computerized planning system, stepping source dosimetry system (SSDS) has become the system of choice making almost all traditional dosimetry systems obsolete. In this study we evaluated the impact of source step size on dosimetry of interstitial implant using parameters of ICRU-58 and various quality indices (QI).Material & Methods: For this study, 10 implant cases which have 3-D CT image based planning were selected. Contouring of clinical target volume and various organs were done following standard guidelines for the same. Plans were optimized to achieve the desired clinical outcome using different source step sizes of 2.5, 5 and 10 mm respectively. Cumulative DVH’s were calculated for the estimation of various ICRU-58 parameters and quality indices.Results and Conclusion: The mean values of the target volumes, minimum target doses, treated volumes, low dose volumes; high dose volumes, overdose volumes, reference volumes, coverage, external volume, relative dose homogeneity, overdose volume and COIN indices have been presented for the source step sizes of 2.5 mm, 5 mm and 10 mm respectively. Among source step sizes used in this study, most favorable clinically acceptable dose distributions & dose homogeneity occurs around step size of 5 mm as predicted by the various parameters of ICRU-58 and dose quality indices. Keywords: Brachytherapy, interstitial implant, source step-size, remote after loading, optimization, quality indices

Indian common krait envenomation presenting as fulminant myocarditis and coma: a case report

Fulminant myocarditis is an unusual manifestation of cardiotoxicity with severe elapid snake envenoming and is meagrely reported with snake bite due to Indian common krait. We report a 12-year-old boy who was admitted in complete locked-in state and hemodynamic instability after severe neurotoxic snake envenoming by Bungarus caeruleus (Indian common krait). His hospital course was complicated with recurrent episodes of sustained ventricular tachycardia requiring defibrillation; and cardiogenic shock requiring inotropes, vasopressors and intraaortic balloon counterpulsation. Severe heart failure features secondary to fulminant toxic myocarditis persisted even after full neurological recovery requiring prolonged standard medical heart failure therapy. Patient subsequently achieved full clinical recovery and regained normal left ventricular systolic function. We also reviewed the literature on cardiac manifestations, possible mechanisms and treatment of patients with cardiotoxicity due to elapid snake bites. The importance of anticipating severe cardiovascular complications is highlighted to help formulate appropriate therapeutic strategy

Fungal infection profile in burn patients at a tertiary care centre of India

Background: Burn patients are at high risk of infections and burn wound infection is one of the most important factor responsible for their morbidity and mortality. Burn patients have increased incidence of fungal infection in comparison to others. Fungal infection is difficult to diagnose because it has similar symptoms like bacterial infections. Common fungal organism causing burn wounds infections are Candida sp., Aspergillus sp., non albicans Candida, Zygomycetes etc.Methods: This prospective study was carried out in Department of Burn, Plastic and Reconstructive Surgery, J.N.M.C.H., Aligarh Muslim University, India from December 2015 to June 2017. Patients having 20 to 60% body surface area involvement with more than 5 years of age with no comorbidity were included in this study.Results: In our study, total 126 patients were included, 9 male patients (18.37%) were found fungal culture positive whereas 14 females (18.18%) were culture positive. 12 patients (9.52%) were found to be positive for Candida albicans, 6 patients (4.76%) were Aspergillus flavus positive, 3 patients (2.38%) were positive for Non Candida albicans and 2 patients (1.59%) were positive for Aspergillus niger.Conclusions: Fungal burn wound infections are one of the most common cause of late onset morbidity and mortality in burn patients. So, high level of suspicion and tissue culture are essential in making early diagnosis and treatment. Judicious use of antibiotics are also necessary for decreasing its incidence

When to branch: seasonal control of shoot architecture in trees

Long-lived perennial plants optimize their shoot architecture by responding to seasonal cues. The main strategy used by plants of temperate and boreal regions with respect to surviving the extremely unfavourable conditions of winter comprises the protection of their apical and lateral meristematic tissues. This involves myriads of transcriptional, translational and metabolic changes in the plants because shoot architecture is controlled by multiple pathways that regulate processes such as bud formation and flowering, small RNAs, environmental factors (especially light quality, photoperiod and temperature), hormones, and sugars. Recent studies have begun to reveal how these pathways are recruited for the seasonal adaptation and regulation of shoot architecture in perennial plants, including the role of a regulatory module consisting of antagonistic players terminal flower 1 (TFL1) and like-ap1 (LAP1) in the hybrid aspen. Here, we review recent progress in our understanding of the genetic control of shoot architecture in perennials compared to in annuals

Growth, photoluminescence, lifetime, and laser damage threshold studies of 1, 3, 5-triphenylbenzene (TPB) single crystal for scintillation application

The 1, 3, 5-triphenylbenzene (TPB) single crystal has been grown using slow cooling seed rotation technique. Optical transmittance of the grown crystal was obtained from UV-Visible analysis. The grown TPB crystal has good transmission in the entire visible region with a lower cutoff wavelength of 330 nm. The solubility of TPB material was determined using toluene as a solvent with different temperatures. The full width at half maximum is 18 arcsec, which indicates that the crystal is of good quality. The TPB crystal was excited (lambda (exc)) at 307 nm, and the corresponding emission (lambda (em)) has been observed at 352 nm. The laser-induced damage threshold (LDT) value of grown crystal is 1.25 GW/cm(2). Third-order nonlinear optical susceptibility chi (3) is determined using the Z-scan technique as 3.07422x10(-09) esu. The TPB crystal proves its suitability for scintillation applications and optoelectronic device fabrications

Lightning generated sferics: diagnostics tools to study upper atmosphere

Atmospherics or sferics that originate from lightning discharges on propagating large distances in the Earth-ionosphere waveguide or in the dispersive regions of ionosphere and magnetosphere form dispersed sferics called tweeks and whistlers respectively. Tweeks are novel diagnostic tool to monitor the nighttime D-region ionosphere. In this paper the lightning sferics (tweeks) recorded at a low latitude station, Suva (18.2o S,178.3oE, geomag. lat. 22.2o S, L = 1.17)) Fiji, in the South Pacific region and Allahabad (geomag. lat. 16.490 N, L=1.09) in India, will be presented and shown how they could be used to probe the night time D-region of the ionosphere. The computed D-region electron density is then compared with the electron density profile obtained from International Reference Ionosphere (IRI) 2007 model. Typical records of whistlers observed in Fiji and in India are presented

Response of the low-latitude D region ionosphere to extreme space weather event of 14–16 December 2006

The response of the D region low-latitude ionosphere has been examined for extreme space weather event of 14–16 December 2006 associated with a X1.5 solar flare and an intense geomagnetic storm (Dst =�146 nT) using VLF signals from Northwest Cape, Australia (NWC) (19.8 kHz) and Lualualei, Hawaii (callsign NPM) (21.4 kHz) transmitters monitored at Suva (Geographic Coordinates, 18.10°S, 178.40°E), Fiji. Modeling of flare associated amplitude and phase enhancements of NWC (3.6 dB, 223°) and NPM (5 dB, 153°) using Long-Wave Propagation Capability code shows reduction in the D region reflection height (H′) by 11.1 km and 9.4 km, and enhancement in ionization gradients described by increases in the exponential sharpness factor (β) by 0.122 and 0.126 km�1, for the NWC and NPM paths, respectively. During the storm the daytime signal strengths of the NWC and NPM signals were reduced by 3.2 dB on 15 and 16 December (for about 46 h) and recovered by 17 December. Modeling for the NWC path shows that storm time values of H′ and β were reduced by 1.2 km and 0.06 km�1, respectively. Morlet wavelet analysis of signal amplitudes shows no clearly strong signatures of gravity wave propagation to low latitudes during the main and recovery phases. The reduction in VLF signal strength is due to increased signal attenuation and absorption by the Earth-ionosphere waveguide due to storm-induced D region ionization changes and hence changes in D region parameters. The long duration of the storm effect results from the slow diffusion of changed composition/ionization at D region altitudes compared with higher altitudes in the ionosphere

Evaluation of physicians and junior residents’ knowledge and awareness of radiation dose and its risks: a cross-sectional survey in tertiary health centre of central India

Background: The frequency of radiological investigations increases to many fold now-a-days, so it is necessary to know the knowledge of all physicians about radiation dose, safety measures and regulations which governs the use and practice of radiation examination and their therapeutic use. The objectives comprise to investigate amongst all Physicians: (1) level of knowledge and awareness of radiation dose of radiological investigations and radiobiology of radiation exposure, and (2) to assess physicians’ knowledge about the risks associated with the use of radiological examinations and their safety measures.Methods: A questionnaire targeting about knowledge, safety measures, and radiation biology about some commonly performed radiological procedures was addressed: (1) Relative radiation doses, (2) Associated risks of radiation exposure, (3) What safety measures should be considered before examination. (4) What risk and hazards all physicians considered when requesting radiological examinations.Results: A questionnaire answered by physicians demonstrates loops in knowledge. In all, 15% (14/92) incorrectly believed that magnetic resonance imaging involved radiation exposure and 3% (3/92) incorrectly believed that ultrasound involved radiation exposure; 38% (35/92) stated that they always explain the benefits and risk of radiation to their patients when obtaining informed consent for examinations involving radiation.Conclusions: This study concluded a deficit of knowledge about radiation dose exposure, and hazards among Physicians, which may cause them to request more radiological investigations than appropriate and high-dose investigations instead of lower dose alternatives. Providing better radiation protection training may help improve their basic knowledge on the subject and reduce unnecessary patient exposure to radiation

Psychological impact among cancer patients undergoing chemotherapy in Bundelkhand region, Central India

Background: A cancer diagnosis can have a significant impact on mental health and wellbeing. Cancer is the second most common cause of death after heart diseases and it accounted for 9.6 million deaths worldwide in 2018. Various individual psychosocial and contextual factors potentially contribute to the development of anxiety and depression among people with cancer. In comparison with general people, the prevalence of anxiety and depression is frequently found to be higher among cancer patient, but estimates vary due to various factors, such as the type of cancer, treatment setting, and prognosis of disease. The present study was conducted to find out the estimate of depression in cancer patients undergoing chemotherapy and determine the various factors associated with depression.Methods: A cross-sectional study was conducted amongst cancer patients undergoing chemotherapy at Department of Oncology, Government Bundelkhand Medical College and Hospital, Sagar from January to April 2019. 150 participants were interviewed using predesigned questionnaire based on the Beck’s depression inventory.Results: Out of 150 cancer patients, 83 (55.3%) were found to be depressed. Depression was comparatively higher in patients’ ≥50 years; in males. Among the study patients, 83 (55.33%) had depression of which 21 (25.3%) had borderline clinical depression, 54 (65.06%) had moderate depression and 08 (9.6%) had severe depression.Conclusions: The study revealed depression in majority of patients receiving chemotherapy. Treatment of cancer patients need to be complemented by psychological support. Research is urgently needed into the possible impacts of long term effects of cancer treatment on mental health