Heat release rate of enhanced large-scale open oil slick fires with Outdoor Gas Emission Sampling (OGES) system.

The Outdoor Gas Emission Sampling (OGES) system was developed to serve as an economical alternative to expensive industrial gas monitoring equipment. By establishing a sampling plane with four discrete sampling points along the radial direction of the smoke plume, the heat release rate (HRR) was measured for large-scale open oil slick fires. This newfound technique was particularly noteworthy during enhanced burns involving Flame Refluxer™ technology, where it is believed that partial premixing of the fuel and air by the apparatus resulted in a higher HRR than existing flame height correlations would suggest, evident by the HRR calculated using mass burning rate and gas analysis methods, which were in good agreement. Results from OGES show the potential of using point sampling within the plume regime to measure the HRR of fires that exceed the capabilities of conventional hood-based calorimeters, especially when it pertains to large-scale open burns.

Evaluation of dosimetric and volumetric changes in target volumes and organs at risk during adaptive radiotherapy in head and neck cancer: A prospective study.

BACKGROUND: During radiation therapy for head and neck malignancies, most patients experience significant anatomical alterations due to loss of weight, changes in tumor volumes, and immobilization issues. Adaptive radiotherapy adapts to the patient's actual anatomy through repetitive imaging and replanning. In the present study, dosimetric and volumetric changes in target volumes and organs at risk during adaptive radiotherapy in head and neck cancer was evaluated. MATERIAL AND METHODS: Thirty-four locally advanced Head and neck carcinoma patients with histologically proven Squamous Cell Carcinoma for curative treatment were included. Rescan was done at the end of 20 fractions of treatment. All quantitative data were analyzed with paired t-Test and Wilcoxon Signed Rank (Z) test. RESULTS: Most patients had oropharyngeal carcinoma (52.9%). There were significant volumetric changes in all the parameters - GTV-primary (10.95, p < 0.001), GTV- nodal (5.81, p = 0.001), PTV High Risk (26.1, p < 0.001), PTV - Intermediate Risk (46.9, p = 0.006), PTV - Low Risk (43.9, p = 0.003), lateral neck diameter (0.9, p < 0.001), right parotid volumes (6.36, p < 0.001) and left parotid volumes (4.93, p < 0.001). Dosimetric changes in the organs at risk were non-significant. CONCLUSION: Adaptive replanning has been seen to be labour intensive. However, the changes in the volumes of both target and the OARs credit a mid-treatment replanning to be done. Long term follow-up is required to assess locoregional control after adaptive radiotherapy in head and neck cancer.

Analysis of prognostic factors in patients with brain metastases affecting survival.

INTRODUCTION: Brain metastases (BM) are associated with dismal prognosis as they cause significant morbidity and affect the quality of life of patients. Management of BM depends on the following factors: age, patient performance, size and the number of lesions, location of the tumor, comorbidities, primary tumor type, and extracranial disease burden. In the present study, the pattern of occurrence, clinical characteristics, treatment outcome of brain metastases, and factors, tumor characteristics, and treatment that may impact BM patients' overall survival were analyzed. METHODS: Retrospective analysis of medical records of 116 patients with histologically proven primary site solid tumors with brain metastases was done in the present study. Clinicoradiological and pathological parameters were documented. The relationship between variables and outcome was assessed by univariate analysis using the Cox proportional regression model to reach a significance of p < 0.05, to determine independent predictors of overall survival. RESULTS: One hundred sixteen patients of BM from various solid malignancies were included. Age ranged from 18 to 81 years (median 53.5). One hundred four patients received WBRT with a dose range of 8-40Gy/1-15fr, 7 received SRS with a dose of 18-24Gy depending on the size of the metastatic lesion, and 2 received SRT 27-33Gy/3fr. At the time of final analysis, 47 patients with BM had expired, 60 were lost to follow-up, and 9 were alive. Median survival was 8.25 (0.5-32.5 months) months. Female gender (χ2 = 8.423; p = 0.015), RPA I (χ2 = 9.353; p = 0.05), and metachronous BM (χ2 = 3.793; p = 0.03) were associated with better survival. Patients with age 41-50 years, adenocarcinoma lung histology, and supratentorial location survived more than 2 years but did not show any statistical significance. CONCLUSION: Brain metastases portend a very dismal prognosis. Certain clinicoradiological and pathologic factors have been identified to affect survival. More prospective multicentric trials, with a larger sample size, need to be conducted to assess the benefit of radiation in patients with limited life expectancy and identify prognostic and predictive factors for survival.