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Purpose: To establish the early prediction models of radiation-induced oral mucositis (RIOM) based on baseline CT-based radiomic features (RFs), dosimetric data, and clinical features by machine learning models for head and neck cancer (HNC) patients. Methods: In this single-center prospective study, 49 HNCs treated with curative intensity modulated radiotherapy (IMRT) were enrolled. Baseline CT images (i.e., CT simulation), dosimetric, and clinical features were collected. RIOM was assessed using CTCAE v.5.0. RFs were extracted from manually-contoured oral mucosa structures. Minimum-redundancy-maximum-relevance (mRMR) method was applied to select the most informative radiomics, dosimetric, and clinical features. Then, binary prediction models were constructed for predicting acute RIOM based on the top mRMR-ranked radiomics, dosimetric, and clinical features alone or in combination, using random forest classifier algorithm. The predictive performance of models was assessed using the area under the receiver operating curve (AUC), accuracy, weighted-average based sensitivity, precision, and F1-measure. Results: Among extracted features, the top 10 RFs, the top 5 dose-volume features, and the top 5 clinical features were selected using mRMR method. The model exploiting the integrated features (10-radiomics + 5-dosimetric + 5-clinical) achieved the best prediction with AUC, accuracy, sensitivity, precision, and F1-measure values of 91.7 %, 90.0 %, 83.0 % 100.0 %, and 91.0 %, respectively. The model developed using baseline CT RFs alone provided the best performance compared to dose-volume features or clinical features alone, with an AUC of 87.0 %. Conclusion: Our results suggest that the integration of baseline CT radiomic features with dosimetric and clinical features showed promising potential to improve the performance of machine learning models in early prediction of RIOM. The ultimate goal is to personalize radiotherapy for HNC patients.

Background: The purpose of this study is to evaluate the effective dose (ED) for computed tomography (CT) examination in different age groups and medical exposure in pediatric imaging centers in Tehran, Iran. Methods: Imaging data were collected from 532 pediatric patients from four age groups subjected to three prevalent procedures. National Cancer Institute CT (NCICT) software was used to calculate the ED value. Results: The mean ED values were 1.60, 4.16, and 10.56 mSv for patients' procedures of head, chest, and abdomen–pelvis, respectively. This study showed a significant difference of ED value among five pediatric medical imaging centers (P < 0.05). In head, chest, and abdomen–pelvis exams, a reduction in ED was evident with decreasing patients' age. Conclusion: As there were significant differences among ED values in five pediatric medical imaging centers, optimizing this value is necessary to decrease this variation. For head CT in infants and also abdomen–pelvis, further reduction in radiation exposure is required.

Purpose: Evaluating organ radiation doses and also lifetime risk (LAR) of breast cancer from lung CT scans of 735 female patients from the age of 20-50 with Covid19 surveyed by four Corona center hospitals in Tehran, Iran. Patients’ data and exposure information were extracted from dose report pages in picture archiving and communication systems. Materials and methods: Patients were divided into six age groups 20-25; 25-30; 30-35; 35–40; 40-45 and 45–50 years. Breast, thyroid, lung and heart doses were calculated by NCICT, and LAR of breast cancer incidence has been evaluated by BEIR VII report. Results: The average dose of breast, thyroid, lung and heart were 3.97, 4.75, 4.10 and 3.37 mGy and also the average of the effective dose was 2.56 mSv. Also, the average LAR of breast cancer in female patients was 7.45 per 100,000 exposures and it decreased with age. Conclusion: Although CT scan is a useful instrument in the diagnosis and treatment of Corona disease, but it should be recommended with caution due to the increased risk of breast cancer, especially in younger women.

Aims: Training and improving the surgical team's awareness of radiation protection is necessary to prevent severe and irreparable damage. Therefore, the purpose of the present study was to compile and psychometrically evaluate (content and face validity) the educational booklet on the principles of radiation protection to promote the knowledge and culture of radiation safety of the operating room staff and prevent injuries. Materials and Methods: The current research is a methodology carried out in Iran University of Medical Sciences in 2022-2023 in three stages: first, the content of the educational booklet was selected based on the needs of the target audience, and the related articles and sources were reviewed. Then, the initial draft of the educational manual was designed and prepared. After that, expert judges in related fields as well as anesthesia and operating room technologists evaluated the formal and content validity of the manual. The content validity index at the item level (I-CVI) and the content validity index at the scale level (S-CVI) equal to or greater than 0.78 and 0.9, respectively, were considered as criteria for validity of the booklet. The binomial test was used to check the reliability of the content validity index of the items so that the significance level was 0.05 and the expected agreement ratio was 0.8. Data were analyzed using SPSS 26 software. Findings: In this research, 22 experts in related fields and 22 anesthesia and operating room technologists with an average work experience of 13.8±4.3 years and 15.6±6.3 years participated, respectively. After sending and receiving the draft version of the booklet along with its evaluation scale, the specialists and experts participating in the study were given the minimum values of I-CVI and S-CVI values for the desired scale items to check the face validity and content of the booklet. According to experts, it was equal to 0.9 and 0.97, respectively. The minimum observed agreement ratio of the binomial test was 0.9, which was more than the expected agreement ratio (0.8). The values of I-CVI, S-CVI, and agreement ratio between anesthesia and operating room technologists were all equal to 1. Conclusion: The present educational booklet has an acceptable form and content validity based on the research findings. Therefore, it can be used as a simple tool to promote radiation safety culture and prevent radiation damage in operating rooms.

Background Ionizing and non-ionizing radiation are widely used in the diagnosis and treatment of diseases. Considering the potential risks of radiation, radiation safety training courses are important for medical staff. Objective The aim of this study was to investigate the effectiveness of one-day radiation safety training program in increasing the radiation safety knowledge of physicians. Methods In this descriptive-analytical study, subjects were 12 physicians (6 general practitioners and 6 nonradiologist specialists) participated in the training program organized by Qazvin University of Medical Sciences in 2018. A researcher-made questionnaire was used for surveying physicians before and after the training. The mean and standard deviation of the scores were first calculated. Then, the pre- and post-test scores were compared using Wilcoxon signed-rank test, and the correlation of these scores with their age, gender, expertise area, and work experience was examined by Spearman's correlation test. Findings The mean total scores of the physicians before and after training were 7.00±2.56 (ranged 3-11) and 11.92± 2.31 (ranged 8-15) out of 18, respectively. The radiation safety knowledge of physicians significantly increased after training (P

Thyroid exposure to radiation in brain computed tomography (CT) scan is of great value since it is considered as a vital organ. This study aimed to investigate the absorbed dose of thyroid by various protocols of head CT in patients referring to 64-slice CT scan center and to compare the values with the calculated dose by imaging performance and assessment of CT (ImPACT) method. Also, the values of CT scan dose index (CTDI) were calculated with semiconductor detector. In this cross-sectional study, 120 outpatients including three groups of forty individuals over 40 years old referring to the hospital radiology centers in Tehran for head CT were chosen and 3 thermo-luminescence dosimeter (TLD-GR200) were applied on thyroid gland of each patient. For brain CT, Absorbed and effective doses of thyroid gland were calculated by ImPACT software. In addition, semiconductor detector in head CTDI phantom calculated CTDI for the applied protocols. Mean effective dose of thyroid gland in brain scan group was calculated by TLD and ImPACT software which showed no significant difference (P < 0.001). Mean effective dose of thyroid gland in unidirectional and bi-directional sinus scan by TLD and ImPACT software were different significantly (P < 0.001). Also, the differences between CTDI values shown by brain and sinus scan protocol with semiconductor detector and those CTDI were significant (P < 0.001). The calculated values of absorbed dose and effective doses of thyroid by TLD and ImPACT software were not significantly different. Mean effective dose calculated for thyroid gland in head scans by TLD and ImPACT was less than the annual permissive level for thyroid gland suggested by International Committee on Radiological Protection. In this study, calculated values of thyroid effective dose in brain scan with 64-slice scanner were less than the calculated values in a similar study.

Background and Aim: Estimation of radon density in underground centers is very important. Considering the use of high-energy medical accelerators, radiotherapy departments are usually located in underground floors. The aim of this study was to evaluate staff exposure to radon gas in these centers in Tehran in 2015-2016. Materials and Methods: This is a descriptive, cross-sectional survey. In radiotherapy centers of Tehran, 32 radon gas diffusion chamber detectors were installed for a period of 3 months. After collecting the detectors, radon gas concentrations were calculated. The annual effective dose of personnel was evaluated using staff’s working hours per week. Results: The minimum and maximum concentrations recorded in this study during one year were 22.14 and 398.52 Bq/m3, respectively, with an average of 87.01 ± 80.68 Bq/m3. Also, radiotherapy personnel’s annual effective dose was 0.34 ± 0.43 mSv per year with the minimum and maximum amounts of 0.02 and 2.35 mSv per year, respectively. Conclusion: The results indicate that radon level in radiotherapy centers and also that the annual effective dose of personnel in these centers are permissible, and no special action is needed. However, if more attention is paid to certain factors such as air-conditioning, the amount of the gas can even be brought to less than this limit.

Background and Aim: To reduce surgical site infections and its complications, hand antiseptic is performed on the basis of product type either by rubbing or washing method. Silver Nanocolloid is a wide range disinfectant entered in world and also Iran markets as a surgical hand antiseptic, but any study about this subject hasn’t yet conducted. The aim of this study is comparing of Betadine, Sterillium and Silver Nanocolloid immediate effect on surgical hand antiseptic. Materials and Methods: This study design was randomized cross-over trial. Betadine, Sterillium, and Silver Nanocolloid with specific volume, duration (according to manufacturers’ instructions), and intervals (at least 24 hours) is conducted on 30 volunteer's hands. They occupy in operating room of hospital. Immediately after hands antisepsis, the samples were taken from the subject’s hands, transported to the blood agar plate, and plates were taken to the laboratory. In laboratory was incubated in 36 ± 1 degrees centigrade for 24 hours. For any growth medium, positive or negative of colony forming is surveyed and statistical analyses were conducted by SPSS software. Results: There’s not a statistically significant difference between negative cultures of Betadine and Sterillium, but negative culture of Betadine 20 (66.7%) and Sterillium 18 (60%), each of them separately, is significantly greater than Silver Nanocolloid 30 (10%) (P < 0.0001). 1 and 4 subjects experience much allergic reaction on their hands, respectively by using Sterillium and Silver Nanocolloid.Conclusions: The immediate antiseptic effects of Betadine and Sterillium are the same that conform to other studies and more than Silver Nanocolloid.