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  • Author: Tomasz Adamczyk x
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Modelling the effects of lung cancer motion due to respiration

Abstract

Background and objectives: To justify the concept of validating conformal versus intensity-modulated approach in the treatment of non-small cell lung cancer (NSCLC). Materials and methods: For 10 patients representative of the spectrum of tumour sizes and locations, two plans were prepared: one with three-dimensional conformal radiation therapy (3DCRT) technique and the other with intensity-modulated radiation therapy (IMRT) technique. Preliminary measurements were performed in static conditions. For each of the field angles considered, the motion kernel was generated to simulate tumour motion trajectories, with the largest amplitude in the cranio-caudal direction of 4, 6, and 8 mm. The measurement results determined the agreement between the planned and measured doses. Results: No statistically significant differences were found between the motion patterns, with the smallest amplitudes for clinical target volume in 3DCRT. For IMRT, the significant differences between 0 mm vs. 6 mm and 0 mm vs. 8 mm amplitudes were found. The motion impact on delivered vs. planned doses had less effect on the oesophagus in 3DCRT compared to that in IMRT. The observed differences were comparable for the heart. Interpretation and conclusions: For maximal amplitudes below 4 mm, the disagreement between planned and delivered doses can be neglected. However, the amplitudes above 5 mm and 7 mm lead to significant changes in IMRT and 3DCRT dose distribution, respectively.

Open access
Intended Use of Real Estate as a Time Changeable Attribute for Determining Compensation for Nationalized and Expropriated Lands

Abstract

Constitutional transformation in Poland, which took place at the turn of the eighties and nineties of the past century, was directed, among others, at creating a civil society and a free market. Changes in people’s mentality quickly brought about economic changes based on the concept of private ownership. Yet one should remember that in the period preceding this time, personal assets were significantly limited. Many people’s assets were repossessed by the state in nationalization or expropriation processes.

Present regulations permit getting these assets back. This is possible in cases when the repossessed real estate was misused with the purpose of expropriation, or it became needless. Real estate is also reacquired via invalidation of administrative decisions or provisions of law. Real estate owners and their legal successors can apply to get back real estate. It is possible to get compensation for assets which cannot be taken back in actuality, which should correspond with the actual value of the lost rights. The level of compensation should be determined on the basis of real estate market value. This value is determined for the day the decision to determine compensation is issued, taking into account the state and purpose of the real estate on the day the document approving the repossession of the real estate was prepared.

The authors present changes in law provisions connected with spatial planning in Poland from the year 1946, when the first decree connected with this topic entered into force, to this day. They describe documents kept in state archives which should be used by valuers. They also show, on the basis of examples, how important the correct determination of the intended use of real estate is, taking into account documents that have been created over the years.

Open access
Principles and Criteria for using Statistical Parametric Models and Conditional Models for Valuation of Multi-Component Real Estate

Abstract

The complexity of multi-component real properties results from the possibility of identifying various components in legal, physical or functional terms. The possibility of distinguishing various functional elements of real properties, combined with the specificity resulting from their market properties, is problematic when applying the comparative approach to real estate valuation. In this case, the valuation procedure can be implemented using statistical models: the parametric model or the conditional one.

This research paper demonstrates the construction of the parametric and conditional models taking into account the geometric and pricing attributes of multi-component real estate. The authors paid attention to adjusting the models to the available market data. They also specified the conditions for the use of statistical models in the real estate valuation process. Based on the analytical and accounting considerations, the estimation criteria for the parametric model and the conditional model were defined, which allow the correct application of these models at the stages of the real estate market analysis and the real estate valuation process.

Open access
Appraisal of Real Estate with Various Functions in the Context of Sustainable Development

Abstract

The value of a piece of real estate depends on the purpose it is used for and on its function in planning documents. Unfortunately, current land development trends and the provisions of the law that are applicable in these documents often lead to real estate with heterogeneous functions. The valuation of such properties requires a special approach. One method is to divide the prices of real estate similar to the appraised real estate into components that correspond to areas with certain functions. The aim of this paper is to present statistical methods that can facilitate such a solution. The valuation models (parametric and conditional) presented in this article come from geodetic methods for the reconciliation of results. The presented calculations suggest that it is necessary to verify whether the heterogeneous functions of real estate should be considered in its appraisal.

Open access
Perception of environment in farm animals – A review

Abstract

Perception of the environment by farm animals is fundamental for expression of behaviour and of their adaptation to different environmental conditions. From a breeding-environmental perspective, perception becomes increasingly important when a production system negatively impacts on animals such that their normal expression of behaviour is compromised. Therefore, research on the perceptual abilities of farm animals is of crucial importance to understand the animalenvironment relationship. This review is focused on research related to sensory perception of farm animals. It should be stressed that the world of animal senses is very difficult to explore, we have limited knowledge of the complexity of the animal’s ability to perceive and process environmental stimuli.

Open access
Measurements of doses from photon beam irradiation and scattered neutrons in an anthropomorphic phantom model of prostate cancer: a comparison between 3DCRT, IMRT and tomotherapy

Abstract

Introduction. The rapid development of new radiotherapy technologies, such as intensity modulated radiotherapy (IMRT) or tomotherapy, has resulted in the capacity to deliver a more homogenous dose in the target. However, the higher doses associated with these techniques are a reason for concern because they may increase the dose outside the target. In the present study, we compared 3DCRT, IMRT and tomotherapy to assess the doses to organs at risk (OARs) resulting from photon beam irradiation and scattered neutrons.

Material and methods. The doses to OARs outside the target were measured in an anthropomorphic Alderson phantom using thermoluminescence detectors (TLD 100) 6Li (7.5%) and 7Li (92.5%). The neutron fluence rate [cm−2·s−1] at chosen points inside the phantom was measured with gold foils (0.5 cm diameter, mean surface density of 0.108 g/cm3).

Results. The doses [Gy] delivered to the OARs for 3DCRT, IMRT and tomotherapy respectively, were as follows: thyroid gland (0.62 ± 0.001 vs. 2.88 ± 0.004 vs. 0.58 ± 0.003); lung (0.99 ± 0.003 vs. 4.78 ± 0.006 vs. 0.67 ± 0.003); bladder (80.61 ± 0.054 vs. 53.75 ± 0.070 vs. 34.71 ± 0.059); and testes (4.38 ± 0.017 vs. 6.48 ± 0.013 vs. 4.39 ± 0.020). The neutron dose from 20 MV X-ray beam accounted for 0.5% of the therapeutic dose prescribed in the PTV. The further from the field edge the higher the contribution of this secondary radiation dose (from 8% to ~45%).

Conclusion. For tomotherapy, all OARs outside the therapeutic field are well-spared. In contrast, IMRT achieved better sparing than 3DCRT only in the bladder. The photoneutron dose from the use of high-energy X-ray beam constituted a notable portion (0.5%) of the therapeutic dose prescribed to the PTV.

Open access