Does conformal therapy improve dose distribution in comparison to old techniques in teleradiotherapy of cervical cancer patients?

SummaryBackgroundThe use of a combined modality approach – chemotherapy and radiation therapy – in the treatment of patients with cervical cancer is associated with significant toxicity, mainly haematological and gastrointestinal. Conformal radiotherapy has the potential to deliver an adequate dose to the target structures while sparing the normal tissue. Both the radiation dose to the small bowel and the volume are factors known to influence the risk of complications.AimThe aim of this study was to determine whether the implementation of conformal modality can reduce the volume of normal tissue included in the RT field.Methods and Materials14 cervical cancer patients (FIGO IIB and IIIB) treated with conformal radiotherapy concurrently with cisplatin (40 mg/m2) administration once a week were analyzed. According to ICRU 50 recommendations target volumes and the organs at risk were contoured on CT slices. For the gross tumour volume (GTV) the tumour of the uterus and cervix was traced. The clinical target volume (CTV) was defined as the vessels and lymph nodes from the obturator level to the aortic bifurcation, presacral region, and upper 1/3 of the vagina. The margin for planning target volume (PTV) was added. The normal tissue region included the small bowel, large bowel and bladder. Using a 3D system and multi-leaf collimator a four-field treatment plan was performed for each patient. All 14 patients were treated with radiotherapy using these conformal 3D plans. Additionally (just for study purposes) for each patient we prepared two simpler plans with (1) two-field: anterior-posterior (A-P) and posterior-anterior (P-A); and (2) four-field box techniques. Dose-volume histograms of target volumes and organs at risk were calculated for each three plans for every patient and compared. Analysis of variance was performed to compute the statistical significance.ResultsThere is no statistical difference between doses received by target volumes – in each plan PTV is covered by the 95% isodose. Significantly different volumes of critical organs were included in the treatment field, depending on radiotherapy technique (conformal 3D method vs AP–PA two-field method): rectum 96.82% vs 38.23%, bowels 61.37% vs 30.79%.ConclusionThese data suggest that implementation of conformal radiotherapy can reduce the irradiated volume in all the contoured critical organs, especially the bowels, compared to old techniques

Hope of recovery in patients in the terminal phase of cancer under palliative and hospice care in Poland

Introduction. The objective of the presented research is to characterize hope in the situational dimension, i.e., health, in the patients with cancer in the terminal phase of the disease, being treated in hospices and palliative care centers. Hope is very important for all the patients, especially for patients with cancer in various phases of the disease. Giving up on oncologic therapy and causal treatment is often associated with a transition into palliative care. When death and a loss of values become a threat, the individual has got hope to rely on. Material and Methods. The study relies on the Test to Measure Hope in the Health Context (NCN-36) by B.L. Block. 246 patients in the terminal phase of cancer participated in the study. Results. The internal structure of hope of recovery in the patients’ group was varied. The patients showed low levels of hope of recovery since they do not believe in the effectiveness of treatment. They were also not convinced of the effectiveness of modifications in dieting, lifestyle, or the use of nonconventional medicine. They trusted the doctor in charge and were moderately satisfied with the therapy in use. The intensity of hope of recovery was on the low level in the patients in the terminal phase of cancer. Age, sex, place of living, and marital status had a significant influence on the level of hope of recovery. Variables such as living on one’s own or living with one’s family, socioeconomic status, education, or profession did not affect the level of hope of recovery. Conclusions. The presented results allowed as to conclude that the assessment of hope in terminally ill cancer patients can be considered as one of the important tools enabling the personalization and the improvement of palliative care

Does conformal therapy improve dose distribution in comparison to old techniques in teleradiotherapy of cervical cancer patients?

BackgroundThe use of a combined modality approach – chemotherapy and radiation therapy – in the treatment of patients with cervical cancer is associated with significant toxicity, mainly haematological and gastrointestinal. Conformal radiotherapy has the potential to deliver an adequate dose to the target structures while sparing the normal tissue. Both the radiation dose to the small bowel and the volume are factors known to influence the risk of complications.AimThe aim of this study was to determine whether the implementation of conformal modality can reduce the volume of normal tissue included in the RT field.Methods and Materials14 cervical cancer patients (FIGO IIB and IIIB) treated with conformal radiotherapy concurrently with cisplatin (40 mg/m2) administration once a week were analyzed. According to ICRU 50 recommendations target volumes and the organs at risk were contoured on CT slices. For the gross tumour volume (GTV) the tumour of the uterus and cervix was traced. The clinical target volume (CTV) was defined as the vessels and lymph nodes from the obturator level to the aortic bifurcation, presacral region, and upper 1/3 of the vagina. The margin for planning target volume (PTV) was added. The normal tissue region included the small bowel, large bowel and bladder. Using a 3D system and multi-leaf collimator a four-field treatment plan was performed for each patient. All 14 patients were treated with radiotherapy using these conformal 3D plans. Additionally (just for study purposes) for each patient we prepared two simpler plans with (1) two-field: anterior-posterior (A-P) and posterior-anterior (P-A); and (2) four-field box techniques. Dose-volume histograms of target volumes and organs at risk were calculated for each three plans for every patient and compared. Analysis of variance was performed to compute the statistical significance.ResultsThere is no statistical difference between doses received by target volumes – in each plan PTV is covered by the 95% isodose. Significantly different volumes of critical organs were included in the treatment field, depending on radiotherapy technique (conformal 3D method vs AP–PA two-field method): rectum 96.82% vs 38.23%, bowels 61.37% vs 30.79%.ConclusionThese data suggest that implementation of conformal radiotherapy can reduce the irradiated volume in all the contoured critical organs, especially the bowels, compared to old techniques

Forecasting model of Corylus, Alnus, and Betula pollen concentration levels using spatiotemporal correlation properties of pollen count

The aim of the study was to create and evaluate models for predicting high levels of daily pollen concentration of Corylus, Alnus, and Betula using a spatiotemporal correlation of pollen count. For each taxon, a high pollen count level was established according to the first allergy symptoms during exposure. The dataset was divided into a training set and a test set, using a stratified random split. For each taxon and city, the model was built using a random forest method. Corylus models performed poorly. However, the study revealed the possibility of predicting with substantial accuracy the occurrence of days with high pollen concentrations of Alnus and Betula using past pollen count data from monitoring sites. These results can be used for building (1) simpler models, which require data only from aerobiological monitoring sites, and (2) combined meteorological and aerobiological models for predicting high levels of pollen concentration

Grass pollen seasons in Poland against a background of the meteorological conditions

Artykuł dotyczy oceny sezonów pyłkowych Poaceae w Polsce w wybranych regionach. Celem pracy było przedstawienie wieloletniej zmienności początku, końca i długości sezonów pyłkowych traw oraz sezonowego indeksu pyłkowego (wartość SPI) w Polsce na tle warunków meteorologicznych. Badania były prowadzone w ośmiu miastach Polski, w okresie 1992-2014 (sezony 2003-2012 były wspólne dla wszystkich miast). Początek sezonu pyłkowego był względnie stały w okresie badawczym, sezony rozpoczynały się około 10 maja, nieco wcześniej w południowej części Polski. Koniec sezonu pyłkowego był bardziej zmienny w porównaniu do początku, jego termin wahał się od połowy lipca do połowy września. SPI wyraźnie zależał od temperatury i opadów w okresie kwiecień–sierpień. Dobowe stężenie maksymalne pyłku były odnotowywane pomiędzy końcem maja a pierwszą dekadą lipca, nie wykazano wyraźnej zależności pomiędzy dniem stężenia maksymalnego i warunkami pogodowymi, z wyjątkiem 2004 roku.The paper refers to the estimation of Poaceae pollen seasons in Poland in selected areas. The aim of the study was to present the long-term variability of the start, end and duration of grass pollen seasons and the seasonal pollen index (SPI) in Poland against a background of the meteorological conditions over pollen seasons. The study was performed in eight Polish cities in 1992-2014 (the common seasons were 2003-2012). Pollen season start was relatively stable in the studied period, the seasons began about the 10th of May, a bit earlier in the south part of Poland. Pollen season ends were more changeable in comparison to the season start and fluctuated from the middle of July to the middle of September. SPI clearly depended on temperature and precipitation in April-August. Daily maximum pollen concentrations were achieved between the end of May and the first decade of July and no evident relationship between this day and weather conditions was found, apart from 2004

Grass pollen seasons in Poland against a background of the meteorological conditions

The paper refers to the estimation of Poaceae pollen seasons in Poland in selected areas. The aim of the study was to present the long-term variability of the start, end and duration of grass pollen seasons and the seasonal pollen index (SPI) in Poland against a background of the meteorological conditions over pollen seasons. The study was performed in eight Polish cities in 1992-2014 (the common seasons were 2003-2012). Pollen season start was relatively stable in the studied period, the seasons began about the 10th of May, a bit earlier in the south part of Poland. Pollen season ends were more changeable in comparison to the season start and fluctuated from the middle of July to the middle of September. SPI clearly depended on temperature and precipitation in April-August. Daily maximum pollen concentrations were achieved between the end of May and the first decade of July and no evident relationship between this day and weather conditions was found, apart from 2004

Co-occurrence of Artemisia and Ambrosia pollen seasons against the background of the synoptic situations in Poland

The Asteraceae family is one of the largest families, comprising 67 genera and 264 species in Poland. However, only a few genera, including Artemisia and Ambrosia are potential allergenic sources. The aim of the study was to estimate how often and to what degree Artemisia and Ambrosia pollen seasons co-occur intensifying human health risk, and how synoptic situations influence frequency of days with high pollen concentrations of both taxa. Artemisia and Ambrosia pollen data were collected, using the volumetric method, at 8 sites in Poland. Daily concentrations of Artemisia pollen equal to 30 grains or more and Ambrosia pollen equal to 10 grains or more were accepted as high values. Concentrations of more than 10 pollen grains were defined as high in the case of Ambrosia because its allergenicity is considered higher. High concentrations were confronted with synoptic situations. Analysis was performed on the basis of two calendars on circulation types of atmosphere in Poland (Niedźwiedź, 2006, 2015). Co-occurrence of Artemisia and Ambrosia pollen seasons is being found most often, when Ambrosia pollen season starts in the first half of August. If it happens in the last 10 days of August high pollen concentrations of Artemisia and Ambrosia do not occur at the same days. At three sites (Sosnowiec, Rzeszów, Lublin) high Ambrosia pollen concentrations during the Artemisia pollen season appear more often than in other sites under question. The high Artemisia pollen concentrations occur, when continental or polar maritime old air masses inflow into Poland. The impact of air masses on high Ambrosia pollen concentrations depends on site localizations. It is likely, that in the south-eastern part of Poland high Ambrosia pollen concentrations result from the pollen transport from east-south-south-westerly directions and the local sources. Co-occurrence of both taxa pollen seasons depends on the air masses inflow and appears more often in a southeastern part of Poland

Drying Characteristics, Kinetic Modeling, Energy and Exergy Analyses of Water Yam (Dioscorea alata) in a Hot Air Dryer

In this study, drying characteristics, kinetic modelling, energy and exergy analyses of a convective hot air dryer are presented for water yam. The drying experiments were carried out at temperature levels of 50, 60, and 70 ◦C and slice thicknesses of 3, 6, and 9 mm. The effects of drying variables on the drying rate (DR), moisture diffusivity (Deff), activation energy (Ea), energy utilization (EU), energy utilization ratio (EUR), exergy loss (EXL), exergy efficiency (EXeff), improvement potential (IP), and exergetic sustainability index (ESI) were investigated. The results showed that increasing air temperature increased the DR, Deff, EU, EUR, EXL, EXeff, IP, and ESI, while increasing the slice thickness increased Deff and Ea, but decreased the DR. The highest Deff and Ea values were 4.2 × 10−8 m2/s, and 53 KJ/mol, respectively. EU and EUR varied from 10 to 150 J/s and 0.39 to 0.79, respectively. EXL and EXeff varied between 2 and 12.5 J/s and 58 to 75%, respectively. Midilli’s model had the best performance in predicting the moisture ratio of water yam with coefficient of determination (R2 = 0.9998), root mean square error (RMSE = 0.0049), and sum of square error (SSE = 0.0023). Keywords: exergy efficiency; exergy sustainability index; water yam; drying rate; exergy los

The analysis of hornbeam (Carpinus) pollen count in selected Polish cities in 2007

Praca przedstawia przebieg sezonu pylenia grabu w 2007 r. w Sosnowcu, Białymstoku, Krakowie, Lublinie, Łodzi, Olsztynie, Warszawie, we Wrocławiu i w Szczecinie. Badania prowadzono metodą objętościową przy zastosowaniu aparatów typu Burkard i Lanzoni. Sezon pyłkowy wyznaczono metodą 98%. Najwcześniej pyłek grabu zarejestrowano w Lublinie (24 marca), a we Wrocławiu, w Warszawie, Krakowie i Szczecinie w ciągu kolejnych trzech dni. Najwyższe wartości stężeń średniodobowych zanotowano w Lublinie 19 kwietnia (133 z/m3), najniższe w Łodzi (29 z/m3).The article presents a record of the 2007 hornbeam pollination season in Sosnowiec, Białystok, Kraków, Łódź, Olsztyn, Warszawa, Wrocław and Szczecin. The research was carried out by means of the volumetric method with the use of Burkard and Lanzoni devices. The pollen season was determined by means of the 98 % method. Hornbeam pollen was earliest recorded in Lublin (24 March), it was recorded in Wrocław, Warszawa, Kraków and Szczecin during the next three days and latest in Łódź – on 4 April. The highest concentration values were recorded in Lublin on 19 April (133 grains/m3) and the lowest in Łódź (29 grains/m3)