R EACTIVE oxygen species (ROS) are generated in response to endogenous or exogenous stimuli. Antioxidants defense system resists for balancing ROS-mediated injury; if oxidation exceeds the defense mechanisms, oxidative stress is generated. Oxidative stress may be involved in the development of breast cancer. Moreover, radiationtherapy (RT), used for the treatment of breast cancer, works by the production of reactive oxygen species at the site of radiation which leads to local oxidative stress. Studies which detect one or few oxidant and antioxidant markers failed to detect the overall oxidant/antioxidant status of the subjects. The authors aim at studying the impact of radiotherapy on the total oxidant status (TOS), total antioxidant status (TAS) with calculation of oxidative stress index (OSI), and measure the lipid peroxidation (MDA) in breast cancer patients. TAS, TOS, MDA and OSI in healthy and breast cancer groups are measured. In breast cancer group, all parameters were measuredbefore and after radiation therapy. In the breast cancer group, TOS, OSI and MDA levels have increased significantly (P<0.001) and the TAS level has decreased (P<0.001) in the breast cancer patients after radiotherapy than before radiotherapy. Breast cancer group TAS after RT reaches about forth its level measured inthe control group. Radiotherapy in breast cancer patients depletes the total antioxidants (TAS), increases total oxidative status (TOS), lipid peroxidation (MDA) and OSI. Breast cancer and its treatment modalities display the patients in a state of severe oxidative stress which requires the supplementation of antioxidants.

Aim and Objective: To estimate the relationship between Coronary Calcium Scoring (CCS)and presence of different degrees of obstructive coronary artery disease (CAD) to avoid unnecessary examinations and hence unnecessary radiation exposure and contrast injection. Background: Coronary Calcium Scoring (CCS) is a test uses x-ray equipment to produce pictures of the coronary arteries to determine the degree of its narrowing by the build-up of calcified plaques. Despite the lack of definitive data linking ionizing radiation with cancer, the American Heart Association supports widely that practitioners of Computed tomography Coronary Angiography (CTCA) should keep “patient radiation doses as low as reasonably achievable but consistent with obtaining the desired medical information”. Methods: Data obtained from 275 CTCA examinations were reviewed. Radiation effective doses were estimated for both CCS and CTCA, measures to keep it as low as possible were presented, CCS and Framingham risk estimate were compared to the final results of CTCA to detect sensitivity and specificity of each one in detecting obstructive lesions. Results: CCS is a strong discriminator for obstructive CAD and can with high sensitivity and specificity and correlates well with the degree of obstruction even more than Framingham risk estimate which has high sensitivity and low specificity. Conclusion: CCS helps reducing the effective radiation dose if properly evaluated to skip unnecessary CTCA if obstructive lesions was unlikely, and as a test does not use contrast material, harmful effect on the kidney will be avoided as most of coronary atherosclerotic patients have renal problems.

Background and Objectives: Accurate breast tumor sizing is very important in treatment planning; as a result, ultrasound (US) plays an important role in diagnosing breast masses, due to its non-magnified image and its availability. The continuous change in the disease pathogenesis of breast cancer and tremendous advances in US imaging technology require the continuous evaluation of this imaging modality. In this study, our aim was to determine the accuracy of US in measuring the size of breast mass, and if there is an influence of the different pathological types on this accuracy. Materials and Methods: This study contained 66 specimens of breast masses that underwent surgical excision and pathological examination of the resected masses; the mean difference between the size taken by US and the size taken by pathology was calculated to the patients as a whole and for each tumor type in this study. Results: The result was that US underestimates the size of the tumor by 0.5 cm for all pathological types, and the US size is in agreement with the pathology size. Conclusions: US is an accurate method in measuring breast lesions with a degree of underestimation that may be related to many factors such as the tumor type, size, and margins. Complementary MRI is recommended in case of ILC and architectural distortion.

The aim of our study was to evaluate the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) in prediction of response to neoadjuvant chemotherapy (NAC) in pediatric osteosarcoma (OS) patients compared to percentage of tumor necrosis after surgical excision of the tumor. Forty-six pediatric OS patients treated with neoadjuvant chemotherapy and surgery were underwent PET/CT and MRI before, after 3 cycles, and after the completion of neoadjuvant chemotherapy. Imaging parameters include maximum standardized uptake value (SUVmax1, 2, and 3), tumor liver ratio (TLR 1, 2, and 3), and MRI tumor volume (MRTV 1, 2, and 3) at initial assessment before starting NAC, after finishing three cycles and after finishing 6 cycles before tumor excision, respectively. Cutoff values of the PET/CT and MRI parameters were determined using receiver operating characteristic (ROC) curve analysis and percentage of tumor necrosis of postsurgical specimen. Fourteen patients were good responders (30.4%), with more than 90% tumor necrosis, while 31 patients were poor responders (67.4%). The results of one patient were missed. We noticed that higher sensitivity for detecting poor responders was detected by SUVmax3/1, TLR3/1, and MRTV2/1 ratio cutoff values, while higher specificity was detected by TRL2 and SUVmax3 cutoff values. ROC curve analysis of MRTV2/1 and MRTV3/1 ratio was fair in predicting poor responders. PET/CT parameters are capable of predicting histological response to NAC in OS patients with overall sensitivity and specificity higher than MRI parameters.

I T IS ESSENTIAL for cardiologists, technologists, and nurses working in the cardiac catheterization laboratory to understand radiation protection. However, protective equipment usage is still low, wearing dosimeters is also low, and thier needs to be more aware of radiation protection in practice. This study aims at assessing the awareness and knowledge of medical staff (cardiologists, nurses, and technicians) working in the cardiac catheterization laboratory of occupational radiation protection tools and detecting areas of defects in their knowledge. Therefore a validated questionnaire to 180 medical staff working in a cardiac catheterization laboratory was conducted.A total of 180 subjects from different institutions were surveyed. There were 103 (57.2%) cardiologists, 53 (29.4%) nurses, and 24 (13.3%) technologists. Although almost all staff members 176 (97.8%) always wear a lead apron, only 43 (23.9%) wear a thyroid collar and lead glasses 17(9.4%). The rate of wearing a radiation dosimeter was insufficient at 85 (47.2%). A few subjects know the radiation exposure dose of the procedure 33 (18.3%), and slightly about 46 (25.6%) had attended lectures on radiation protection. Cardiologists who were aware of the radiation exposure dose of each procedure were significantly more likely to wear dosimeters than those who were not (P<0.005). Experienced cardiac catheterization staff wear dosimeters more than the staff with fewer years of experience (P<0.011).In conclusion, it could be noticed that medical staff in cardiac catheterization laboratories need more radiation protection knowledge and education.