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Radiotherapy plays an important role in the treatment of tumors, and enteritis is a common side effect of this therapy. The aim of present study was to evaluate the protective effect of melatonin and probiotics on radiation-induced intestinal tissue damage in rats. Histopathological, biochemical and microbiological samples were examined.Thirty-two Wistar Albino rats were randomly distributed into four groups: the control group, only radiotherapy (RT) group, radiotherapy plus melatonin (RT + MEL) groups and radiotherapy plus probiotics (RT + PROB) groups. The abdominal-pelvic region of the experimental rat was irradiated with in a single dose of 16 Gy. The melatonin was administered at a single dose of 50 mg/kg through intraperitoneal injection, 15 min before radiation exposure. The probiotic was administered orally every day to the rats for 5 days starting before radiotherapy.There was a statistically significant changes in histopathological (villus atrophy, mitotic activity, apoptotic index, goblet cell swelling, degenerative changes, atypia) and biochemical (oxidant and antioxidant status, IL-1β, IL-6 and TNF- α levels) parameters in the small intestine in the radiotherapy group G2 compared to the G1 control group (p < 0.05). However, a significant decrease was observed with the administration of probiotics and melatonin (p < 0.05). In addition, although positive bacterial growth was detected in the mesenteric lymph node of all rats in the radiotherapy group, there was no statistically significant difference between all groups (p > 0.05).Melatonin and probiotics were found to have a potent radioprotective effect against radiotherapy-induced acute small intestinal tissue damage. However, their superiority over each other was not observed. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the radiation knowledge and awareness levels of healthcare workers working in a single center in Mogadishu, Somalia, in terms of age, gender and education levels of the participants.Materials and methods: The research involved 274 healthcare professionals, comprising volunteer physician and other healthcare personnel working at the Somali-Turkey Recep Tayyip Erdoğan Training and Research Hospital in Mogadishu. The face-to-face questionnaire consists of 13 questions covering radiation-sensitive or resistant tissues, radiation status of medical imaging devices, biological effects of radiation, ionizing and non-ionizing radiation symbols and radiation protection principles. The study was limited to the health personnel in the hospital. The survey had 274 participants, comprising 126 (46%) women and 148 (54%) men. Of these, 82 (29.9%) were physicians and 192 (70.1%) were other healthcare professionals.Results: It was found that health workers under the age of thirty demonstrated a significantly higher level of knowledge about radiation protection principles than their counterparts over the age of thirty (p = 0.003). Similarly, it was observed that the level of awareness regarding the extent of knowledge about radiation protection was higher in health workers under thirty years of age than in those over thirty years of age (p: 0.001). It was found to be statistically significant that males were more aware of the potential harms of radiation than females (p: 0.004). It was found to be statistically significant that men were more aware of the radiation content of mammography and X-ray imaging methods than women (p: 0.002 and p: 0.029, respectively).Conclusions: To enhance the number of healthcare professionals in Mogadishu, Somalia, who are aware of the risks associated with radiation and the methods for its mitigation, it was postulated that a comprehensive radiation information and awareness training program could be beneficial. [ABSTRACT FROM AUTHOR]

AbstractBackgroundMethodsResultsConclusionsRadiotherapy is a widely used treatment method in oncology, applied by delivering high-energy particles or waves to the tumor tissue. Although tumor cells are targeted with radiotherapy, it can cause acute or long-term damage to healthy tissues. Therefore, the preservation of healthy tissues has been an important subject of various scientific researches. Melatonin has been shown to have a radioprotective effect on many tissues and organs such as liver, parotid gland, brain, and testicles. This study aimed to evaluate the protective effect of melatonin against the radiation at various doses and rates administered to the lung tissue of healthy mice.This study was a randomized case-control study conducted with 80 rats comprising 10 groups with eight animals per group. Of the 10 groups, first is the control group, which is not given any melatonin, and second is the group that does not receive RT, which is given only melatonin, and the other eight groups are RT groups, four with melatonin and four without melatonin.There was no statistical difference in terms of histopathological findings in the lung tissue between the second group, which did not receive radiotherapy and received only melatonin, and the control group. Lung damage due to radiotherapy was statistically significantly higher in the groups that did not receive melatonin compared to the groups that received melatonin.This study revealed that melatonin has a protective effect against the cytotoxic damage of RT in rats receiving RT. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the effects of Modified Batho and Equivalent Tissue-Air Ratio (ETAR) correction-based algorithms on dose distributions in the inhomogeneous media and left-sided breast and lung cancer. Distribution profiles at lateral depth and percentage depth dose (PDD) values were obtained for soft tissue, bone and air rectilinear virtual phantoms in the Eclipse treatment planning system (TPS). In addition, intensity modulated radiotherapy (IMRT) treatment planning technique was applied to 20 patients with left-sided breast and lung cancer diagnosis on computed tomography (CT) sections. The maximum dose, mean dose, D95, Monitor Unit (MU) and segment numbers in planning target volume (PTV) were calculated. Although the effect of correction-based algorithms on (PDD) values and dose distribution profiles in lateral depth were calculated below 1% in soft tissue virtual phantom, dose profiles were obtained as approximately 20% in bone and air media. No statistical differences were observed in dosimetric parameters except for PTVmean and D95 values due to the differences in correction-based algorithms in left-sided breast IMRT treatment planning (p>0.05). However, significant statistical differences were obtained in the values of lung IMRT treatment plans (p<0.05). It was concluded that correction-based algorithms in the different inhomogeneous mediums have a significant effect on the dose values calculated in TPS. [ABSTRACT FROM AUTHOR]

Objective: This study compares standard commercial bolus material (Superflab) to custom prepared silicone dental impression material (CDIM) and play dough material (PDM) with respect to dosimetric properties and applicability by using ion chamber measurement and calculated dose values. Materials and Methods: The CDIM bolus was prepared by mixing dental impression silicone material with enough water to maintain a density of about 1.0 g/cm3. The prepared bolus material is applied on an RW3 solid phantom by covering 10x10 cm2 area with 0.5-1 cm thickness. Ion chamber measurements were performed separately with and without bolus material application. The setup was scanned in CT and the same procedure was repeated in the TPS using the scan data, in which the Pencil Beam Convolution dose calculation algorithm was used. To compare the effect of bolus material on tissue, the Superflab bolus and CDIM bolus were applied with 1 cm of thickness on postmastectomy scar and dose calculations on TPS were performed. Results: After comparison of the dosimetric values for Superflab, CDIM and PDM, we obtained statistically meaningful results between superflab and CDIM. For PDM, the results obtained with TPS and ion chamber measurements indicated that, it is not suitable to use in radiotherapy application due to its material properties. For the simulated skin dose values obtained at five random points on the scar tissue, the comparison of Superflab and CDIM TPS calculation results were not statistically significant. Conclusion: The CDIM is easy to prepare and apply on irregular mastectomy scar tissue and it prevents formation of air gaps in the application surface. Especially for curved anatomical regions such as scar tissue, inclusion of the bolus material in treatment planning protocol will reduce dose uncertainty in application. It is safe to use CDIM as an alternative to Superflab in radiotherapy application, whereas PDM is not useful in clinical practice due to its material properties. [ABSTRACT FROM AUTHOR]

In this study, the effects of various bolus materials on dose distributions were compared in electron conformal radiotherapy (ECRT). Superflab, Super Stuff pink wax and Paraffin wax bolus materials are used with 15 MeV electron energy for dosimetric comparison. Additionally, 10 mm thick Super Stuff pink wax bolus and paraffin wax bolus materials were placed on the right eyelid of a patient. Using electron dose calculation algorithm and ion chamber measurements, dosimetric comparisons were made in the Eclipse treatment planning system (TPS). Both for measured and calculated dose, values were acquired 3 times and averaged for each case. Resulting differences are expressed as percentage differences. Dose differences were obtained in measurements with and without using bolus at several locations of the solid phantom, performed by the Roos Ion chamber. Dosimetric differences of 7-7.5% for Superflab, 10-10.5% for paraffin bolus and 13-14% for Super Stuff pink wax bolus are obtained. Besides, when dosimetric comparisons are made in the treatment planning system for cases with and without bolus; Dose differences were calculated to be 2-2.5% for superflab silicon bolus, 3-3.5% for paraffin wax bolus and 5- 6% for Super Stuff pink wax bolus. To increase skin dose in curved anatomical structures in radiotherapy, it is safe to use the paraffin wax bolus material in radiotherapy clinic, as an alternative to Superflab silicon bolus and Super Stuff pink wax bolus materials, due to its low cost and ease of conforming to body surface contours. [ABSTRACT FROM AUTHOR]

Objective: To compare 3-dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) techniques on the target tissue and critical organ doses in terms of dosimetry, during treatment planning of patient's post-mastectomy radiotherapy (PMRT) to the left chest wall. Materials and Methods: Twenty breast cancer patients with left-sided post-mastectomy have selected for PMRT both 3D-CRT and IMRT techniques. Dosimetric calculation of dose simulation in Eclipse treatment planning system have been performed. Organs at risk with the maximum dose, minimum dose, mean dose, D95, conformity and homogeneity indexes and total monitor unit for the Planning Target Volume were compared in terms of the critical organ doses. Results: There was no significant difference between the two treatment planning techniques in terms of maximum, minimum, mean dose and heterogeneity index (p>0.05). At low doses, the dose received at the heart was significantly lower with the 3D-CRT technique, but there was no statistically significant difference between the two techniques at the maximum and average doses in the high dose regions. Conclusion: For PMRT to the left chest wall, IMRT significantly improves the conformity of plan and reduce the high-dose volumes of ipsilateral lung and heart compared to 3D-CRT, but 3D-CRT is superior in terms of low-dose volume. [ABSTRACT FROM AUTHOR]

Amaç: Bu çalışmanın amacı, NOD SCID gama (NSG) fare modelleri üzerinde radyoterapi sonrası larenks kanserinin (LKa) altında yatan radyobiyolojik mekanizmaları araştırmak için Flattening Filter (FF) ve Flattening Filter Free (FFF) ışınlarının histopatolojik değişiklikler ve Ki-67 ekspresyon seviyeleri üzerindeki etkisini analiz etmektir. Gereç ve Yöntem: Kırk yetişkin NSG fare modelleri, sham kontrol, sadece LKa, FF ve FFF olmak üzere rastgele dört gruba ayrıldı. FF ve FFF gruplarındaki (LKa artı RT grupları) farelerin baş ve boyun bölgesine 400 MU/min ve 1400 MU/min doz hızlarında 18 Gy tek doz radyoterapi uygulandı. NSG farelerine tümör transplantasyonundan (Hep-2 kanser hücre hattı, 0.1 ml, 1 X106 hücre/ml) 30 gün sonra radyoterapi uygulandı ve histopatoloji parametrelerinin ve Ki-67 ekspresyon seviyelerinin analizi için radyoterapiden 2 gün sonra sakrifiye edildi. Bulgular: LKa, FF ve FFF grupları, sham grubu ile karşılaştırıldığında tümör dokusu ve doz hızına bağlı olarak histopatolojik parametrelerde istatistiksel olarak anlamlı farklılıklar gözlendi (p<0.05). FF ışınının LKa dokusu üzerindeki histopatolojik etkileri, FFF ışınıyla karşılaştırıldığında istatistiksel olarak anlamlı farklılıkların oluştuğu görüldü (p <0.05). LKa grubu, sham grubu ile karşılaştırıldığında Ki-67 düzeyinin kanser gelişimine bağlı olarak anlamlı düzeyde etkilediği görüldü ve doz hızları arasında istatistiksel olarak anlamlı farklılıklar gözlendi (p <0.01). Sonuç: FF ve FFF ışınlarının histopatolojik parametrelerde ve Ki-67 ifade düzeylerinde önemli değişikliklere neden olduğu sonucuna varıldı. FFF ışınının Ki-67 seviyeleri, hücre çekirdeği ve sitoplazmik bulgular üzerindeki etkileri, FF ışınıyla karşılaştırıldığında önemli radyobiyolojik farklılıklar gözlendi. [ABSTRACT FROM AUTHOR]