Accelerated Partial Breast Irradiation With 3d-conformal and Image-guided Intensity Modulated Radiotherapy With Low-risk Invasive Breast Cancer After Breast Conserving Surgery

Az elmúlt évtizedekben az emlőrákok komplex onkológiai kezelésében jelentős változások történtek. A korábbi betegségközpontú megközelítést mára felváltotta a betegközpontú megközelítés a daganat biológiai viselkedésének és metasztázisképződés folyamatának legmesszemenőbb figyelembevételével. Az elmúlt évtizedekben világszerte általánosan elfogadottá váltak az emlőmegtartó műtétek és 3- 5 hétig tartó TERT, melynek célja az esetlegesen az emlőben maradt mikroszkopikus daganatsejtek elpusztítása. Számos prospektív, randomizált vizsgálat, és azok meta analízise is igazolta, hogy a maradék emlő sugárkezelése az azonos oldali emlőrecidíva arányát harmadára-negyedére csökkenti, és ezáltal az úgynevezett másodlagos disszemináció megelőzésével a teljes túlélést is javítja. Ezen eredmények alapján a korábban általánosan alkalmazott teljesemlő-eltávolítás (radikális masztektómia) helyét átvette a BCS és a TERT

Does inverse planning improve plan quality in interstitial high-dose-rate breast brachytherapy?

Purpose: To investigate the effect of input parameters for an inverse optimization algorithm, and dosimetrically evaluate and compare clinical treatment plans made by inverse and forward planning in high-dose-rate interstitial breast implants. Material and methods: By using a representative breast implant, input parameters responsible for target coverage and dose homogeneity were changed step-by-step, and their optimal values were determined. Then, effects of parameters on dosimetry of normal tissue and organs at risk were investigated. The role of dwell time modulation restriction was also studied. With optimal input parameters, treatment plans of forty-two patients were re-calculated using an inverse optimization algorithm (HIPO). Then, a pair-wise comparison between forward and inverse plans was performed using dose-volume parameters. Results: To find a compromise between target coverage and dose homogeneity, we recommend using weight factors in the range of 70-90 for minimum dose, and in the range of 10-30 for maximum dose. Maximum dose value of 120% with a weight factor of 5 is recommended for normal tissue. Dose constraints for organs at risk did not play an important role, and the dwell time gradient restriction had only minor effect on target dosimetry. In clinical treatment plans, at identical target coverage, the inverse planning significantly increased the dose conformality (COIN, 0.75 vs. 0.69, p < 0.0001) and improved the homogeneity (DNR, 0.35 vs. 0.39, p = 0.0027), as compared to forward planning. All dosimetric parameters for non-target breast, ipsilateral lung, ribs, and heart were significantly better with inverse planning. The most exposed small volumes for skin were less in HIPO plans, but without statistical significance. Volume irradiated by 5% was 173.5 cm(3) in forward and 167.7 cm(3) in inverse plans (p = 0.0247). Conclusions: By using appropriate input parameters, inverse planning can provide dosimetrically superior dose distributions over forward planning in interstitial breast implants

Mean annual totals of precipitation during the period 1991–2015 with respect to cyclonic situations in Slovakia

Atmospheric precipitation during cyclonic situations was analyzed using weather types classification. Based on data from the period 1991 to 2015, the observed cyclonic situations were analyzed in terms of their frequency of days with a given weather type. Cyclonic situations with airflow direction from the west and northwest, north and northeast, east and southeast, and south and southwest were analyzed. We identified a declining number of days that can be classified as cyclonic situations. The distributions of the mean annual precipitation totals for these cyclonic situations have been investigated. The highest mean annual precipitation totals occurred during the west cyclonic, northeast cyclonic, and east cyclonic weather types. The lowest mean annual precipitation totals were identified during the southwest cyclonic (with fronts moving from north to northeast) and north cyclonic weather types. The percentage of the individual cyclonic weather types and supertypes in the mean annual precipitation total was calculated. The directional supertype west + northwest with the west cyclonic type occurred with the highest percentage, although variations may arise due to windward and leeward effects

External beam accelerated partial breast irradiation: dosimetric assessment of conformal and three different intensity modulated techniques

Background The aim of the study was to evaluate and compare four different external beam radiotherapy techniques of accelerated partial breast irradiation (APBI) considering target coverage, dose to organs at risk and overall plan quality. The investigated techniques were three dimensional conformal radiotherapy (3D-CRT), "step and shoot" (SS) and "sliding window" (SW) intensity-modulated radiotherapy (IMRT), intensity-modulated arc therapy (RA). Patients and methods CT scans of 40 APBI patients were selected for the study. The planning objectives were set up according to the international recommendations. Homogeneity, conformity and plan quality indices were calculated from volumetric and dosimetric parameters of target volumes and organs at risk. The total monitor units and feasibility were also investigated. Results There were no significant differences in the coverage of the target volume between the techniques. The homogeneity indices of 3D-CRT, SS, SW and RA plans were 0.068, 0.074, 0.058 and 0.081, respectively. The conformation numbers were 0.60, 0.80, 0.82 and 0.89, respectively. The V50% values of the ipsilateral breast for 3D-CRT, SS, SW and RA were 47.5%, 40.2%, 39.9% and 31.6%, respectively. The average V10% and V40% values of ipsilateral lung were 13.1%, 28.1%, 28%, 36% and 2.6%, 1.9%, 1.9%, 3%, respectively. The 3D-CRT technique provided the best heart protection, especially in the low dose region. All contralateral organs received low doses. The SW technique achieved the best plan quality index (PQI). Conclusions Good target volume coverage and tolerable dose to the organs at risk are achievable with all four techniques. Taking into account all aspects, we recommend the SW IMRT technique for APBI

An 8-hydroxyquinoline–proline hybrid with multidrug resistance reversal activity and the solution chemistry of its half-sandwich organometallic Ru and Rh complexes

Herein the design and synthesis of a new 8-hydroxyquinoline derivative, (S)-5-chloro-7-((proline-1-yl)methyl)8-hydroxyquinoline (HQCl-Pro), with good water solubility and multidrug resistance reversal activity are reported. In this work the proton dissociation processes of HQCl-Pro and its complex formation with [Rh(η5-C5Me5)(H2O)3]2+, [Ru(η6-p-cymene)(H2O)3]2+and [Ru(η6-toluene)(H2O)3]2+were investigated by the combined use of pH-potentiometry, UV-visible spectrometry and1H NMR spectroscopy. Our results revealed the prominent solution stability of the complexes in all cases. The lipophilicity of the complexes increased with the chloride ion concentration, and the complexes showed moderate log Dvalues (−0.8 to +0.4) at pH 7.4 at all tested Cl−concentrations. The formation of mixed hydroxido complexes from the aqua complexes was characterized by relatively high pKavalues (8.45-9.62 in chloride-free medium). Complexation processes are much slower with the Ru(η6-arene) triaqua cations than with [Rh(η5-C5Me5)(H2O)3]2+. Both the pKavalues and H2O/Cl−exchange constants of the Ru-complexes are lower by 0.5-1.0 orders of magnitude than those of the Rh analogue. Arene loss (p-cymene and toluene) and oxidation were found in the case of Ru-complexes when an excess of HQCl-Pro and aromatic (N,N) bidentate ligands was added. The cytotoxicity and antiproliferative effect of HQCl-Pro and its complexes were assayedin vitro. In contrast to the structurally familiar 8-hydroxyquinoline, HQCl-Pro and its Rh(η5-C5Me5) complex were somewhat more effective against drug resistant Colo 320 adenocarcinoma human cells compared to the drug sensitive Colo 205 cells. The Ru- and Rh-complexes showed a similar metal uptake level after 4 h, while a longer incubation time resulted in higher cellular Rh concentration

Hőszivattyús fűtő és páramentesítő készülék tervezése

Számos lakóingatlanban, azokon belül is főként a fürdőszobákban alkalmaznak – akár kiegészítő jelleggel – elektromos fűtőegységeket. Ezek jellemzően igen magas hatásfokkal üzemelnek, hiszen a legtöbb esetben az elektromos áramot Joule-hővé alakítják át villamos ellenállás segítségével. Mivel a fürdőszoba levegőjének páratartalma jellemzően magas értékeket is elérhet annak használata közben, ezért célszerű lenne egy olyan fűtőkészüléket alkalmazni, amely nem csupán a levegő hőmérsékletét növeli, hanem egyúttal annak abszolút páratartalmát is csökkenti. Amennyiben egy hőszivattyút alkalmazunk fűtési célra úgy, hogy annak mind a hőfelvevő, mind pedig a hőleadó egysége ugyanazon légtérben található, úgy a hőelvonás helyszínén kialakuló – az adott légállapothoz tartozó – harmatpont alatti hőmérsékletű felületen kondenzáció jön létre, tehát a levegő páratartalmának egy része kicsapódik. Ezzel egyrészt csökkenthető a levegő abszolút páratartalma (amely higiéniás szempontok miatt is célszerű), továbbá a kondenzációkor felszabaduló látens-hő következtében pedig akár jelentős hőtöbblet jelenhet meg a hőleadó oldalon, ezzel 100%-os érték felé növelve a fűtési hatásfokot. Egy ilyen elven üzemelő hőszivattyús fűtőkészülékprototípus felépítését és működését ismertetjük jelen tanulmányban, kitérve a jellemző klímatechnikai paraméterekre, összefüggésekre, a tervezéshez elvégzett számításokra. Abstract: Many residential building use electrical heaters mainly in bathrooms, even as a supplement heating device. These devices typically operate at very high efficiency, since in most cases, electrical current is converted into Joule-heat by means of electrical resistances. The humidity of the air in bathrooms is often very high. Therefore, it would be useful to apply such heating devices, which not only increase the temperature of the air, but also reduces the absolute humidity of it. If a heat pump is used for heating purposes where both the heat absorber and the heat exchanger are placed in the same airspace, condensation occurs at a temperature below the dew point of the given air condition at the point of heat extraction thus some of the humidity precipitates. Along with this the absolute humidity of the air can be reduced (which is also recommended for hygiene reasons). Furthermore, due to the latent heat released during the condensation a significant excess of heat appears on the heat exchanger, increasing the heating efficiency over 100%. The design and operation of a heat pump heater operating on such a principle is described in this study, addressing the typical air-conditioning parameters, correlations, calculations performed for the design

Hőszivattyús fűtő és páramentesítő készülék tervezése

Many residential building use electrical heaters mainly in bathrooms, even as a supplement heating device. These devices typically operate at very high efficiency, since in most cases, electrical current is converted into Joule-heat by means of electrical resistances. The humidity of the air in bathrooms is often very high. Therefore, it would be useful to apply such heating devices, which not only increase the temperature of the air, but also reduces the absolute humidity of it. If a heat pump is used for heating purposes where both the heat absorber and the heat exchanger are placed in the same airspace, condensation occurs at a temperature below the dew point of the given air condition at the point of heat extraction thus some of the humidity precipitates. Along with this the absolute humidity of the air can be reduced (which is also recommended for hygiene reasons). Furthermore, due to the latent heat released during the condensation a significant excess of heat appears on the heat exchanger, increasing the heating efficiency over 100%. The design and operation of a heat pump heater operating on such a principle is described in this study, addressing the typical air-conditioning parameters, correlations, calculations performed for the design.Számos lakóingatlanban, azokon belül is főként a fürdőszobákban alkalmaznak – akár kiegészítő jelleggel – elektromos fűtőegységeket. Ezek jellemzően igen magas hatásfokkal üzemelnek, hiszen a legtöbb esetben az elektromos áramot Joule-hővé alakítják át villamos ellenállás segítségével. Mivel a fürdőszoba levegőjének páratartalma jellemzően magas értékeket is elérhet annak használata közben, ezért célszerű lenne egy olyan fűtőkészüléket alkalmazni, amely nem csupán a levegő hőmérsékletét növeli, hanem egyúttal annak abszolút páratartalmát is csökkenti. Amennyiben egy hőszivattyút alkalmazunk fűtési célra úgy, hogy annak mind a hőfelvevő, mind pedig a hőleadó egysége ugyanazon légtérben található, úgy a hőelvonás helyszínén kialakuló – az adott légállapothoz tartozó – harmatpont alatti hőmérsékletű felületen kondenzáció jön létre, tehát a levegő páratartalmának egy része kicsapódik. Ezzel egyrészt csökkenthető a levegő abszolút páratartalma (amely higiéniás szempontok miatt is célszerű), továbbá a kondenzációkor felszabaduló látens-hő következtében pedig akár jelentős hőtöbblet jelenhet meg a hőleadó oldalon, ezzel 100%-os érték felé növelve a fűtési hatásfokot. Egy ilyen elven üzemelő hőszivattyús fűtőkészülékprototípus felépítését és működését ismertetjük jelen tanulmányban, kitérve a jellemző klímatechnikai paraméterekre, összefüggésekre, a tervezéshez elvégzett számításokra