Clinical advantages of using unfl attened 6-MV and 10-MV photon beams generated by the medical accelerator Elekta Versa HD based on their dosimetric parameters in comparison to conventional beams

Photon beams with wide energy ranges from 4 MV to 25 MV are commonly used in radiotherapy nowadays. In recent years, there has been a strong interest in a certain modifi cation of a radiotherapeutic apparatus by the application of the so-called fl attening fi lter-free (FFF) beam. Several advantages of FFF beams over standard fl attening fi lter (FF) beams are noticed, and this technical solution has aroused great interest among radiotherapeutic facilities. The goal of the present study is to investigate the differences between the conventional FF and unfl attened FFF 6-MV and 10-MV photon beams in some basic dosimetric parameters and their infl uence on the whole radiotherapeutic treatment. The data provided here include the detailed characteristics as follows: percent depth dose (PDD), beam profi le, edge of a half-profi le, total scatter correction factor (TSCF) and head scatter correction factor (HSCF) for FF and FFF 6-MV and 10-MV photon beams from the Elekta Versa HD accelerator in the Katowice Oncology Center in Poland

Investigation of the influence of chamber construction parameters on radon exhalation rate

Radon exhalation from ground is a process dependent on the emanation and migration of radon through ambient air. Most studies on radon exhalation from soil were performed regarding the influence of meteorological and soil parameters. As radon exhalation rate can be affected by the internal properties of the sample, it may also be influenced by the exhalation chamber geometry such as volume-to-area (V/S) ratio or other construction parameters. The measurements of radon exhalation from soil were made using different constructions of accumulation chamber and two types of radon monitors: RAD7 (Durridge) and AlphaGUARD PQ2000PRO (Genitron). The measurements were performed on one site in two locations and approximately at the same time. The first tests did not show the correlations of exhalation rate values and the chamber's construction parameters and their geometrical dimensions. However, when examining the results, it seems that there are still too many factors that might have affected the process of radon exhalation. The future experiments are planned to be conducted in controlled laboratory conditions

Wpływ parametrów pracy kolimatora wielolistkowego MLC na weryfikację dynamicznych planów leczenia w radioterapii

The doctoral dissertation presents the impact of the parameters of the MLC Agility medical accelerator Elekta Versa HD on the verification of dynamic treatment plans in radiotherapy. This effect was checked clinically by performing validation measurements for 30 days, at two times of the day (morning and evening), and mechanically by performing MLC tests. The treatment plans were made in the VMAT technique using the MONACO treatment planning system for three locations: chest, head/ncck and pelvis. MLC quality control tests were performed for the IMRT SMLC and 1MR.T DMLC techniques, statically for 0° gantry angle and dynamically with full gantry rotation on the linear accelerator. Measurements of the effect of MLC offsets on the obtained dose values in selected MLC tests and treatment plans for all areas were also performed. Information on the impact of the time of day on the result of the verification of VMAT dynamic treatment plan has been obtained. As the research has shown, the differences resulting from the work of the MLC may have a significant impact on the dose absorbed in a patient during the treatment with the use of a linear accelerator. Thereafter, the evidence for the effects of different collimator leaf offset values on the MLC tests and on the verification results was confirmed. By using the obtained measurements, it was proposed to introduce periodic quality control tests of the MLC

Clinical advantages of using unflattened 6-MV and 10-MV photon beams generated by the medical accelerator Elekta Versa HD based on their dosimetric parameters in comparison to conventional beams

Photon beams with wide energy ranges from 4 MV to 25 MV are commonly used in radiotherapy nowadays. In recent years, there has been a strong interest in a certain modification of a radiotherapeutic apparatus by the application of the so-called flattening filter-free (FFF) beam. Several advantages of FFF beams over standard flattening filter (FF) beams are noticed, and this technical solution has aroused great interest among radiotherapeutic facilities. The goal of the present study is to investigate the differences between the conventional FF and unflattened FFF 6-MV and 10-MV photon beams in some basic dosimetric parameters and their influence on the whole radiotherapeutic treatment. The data provided here include the detailed characteristics as follows: percent depth dose (PDD), beam profile, edge of a half-profile, total scatter correction factor (TSCF) and head scatter correction factor (HSCF) for FF and FFF 6-MV and 10-MV photon beams from the Elekta Versa HD accelerator in the Katowice Oncology Center in Poland