The aims of this study are to investigate the variation in the mechanical behaviour of the primary cancer from cancer relapse, and measuring the therapeutic resistance acquired by cancer relapse. A431-cultured cells were irradiated for 7 months until 85 Gy. Then, a selected single cell was left to grow as stable A431-R cell line. 106 cells of A431 cells and 106 of A431-R cells suspended in 100 μL of medium were injected into subcutaneous tissues on the right thigh of athymic mice to generate tumor xenografts models of primary cancer (A431-P) and cancer relapse (A431-R). Radiotherapy of a low-dose of 30Gy was applied on xenoimplanted tumors after one week from inoculation. A mock process was performed on untreated groups of mice for controls. Tumor size was monitored starting from inoculation and tumor growth was measured along 42 days. Rates of mitosis and apoptosis and the histologic grade (HG) that characterize the tumor response were determined as described in earlier studies. Alterations induced on tumor HG in the treated models were 100% identical to the energy of the applied doses. The differences in response energy between cancer relapse and primary cancer irrespectively of the treatment (untreated vs. treated) or origin of the cells (A431-P vs. A431-R) in all phases of tumor responses (growth, shrinkage or regrowth) were 100% identical to the total differences in the administered regimens applied on those groups during those phases. Cancer relapse is characterized by a delay in growth before second line therapy for its relatively lower rate of mitosis compared by the primary cancer inducing a corresponding delay in the early detection. The therapeutic resistance of the cancer relapse is equivalent to the energy of the doses which have been delivered in the prior therapies, and requires increasing the administered dose by an amount equivalent to that resistance. Show less

Purpose The purpose of this study was to assess the efficacy (overall survival, local control, progression free survival (PFS) and toxicities between two dimension (2D) and three dimension (3D) CT guided brachytherapy without using interstitial needles in cervical cancer patients. Material and Methods A retrospective case-control study was performed in Figo stage IB-IVA cervical cancer patients treated between March 1990 and August 2018. Concurrent chemoradiation using external beam radiotherapy followed by brachytherapy (BT) was the treatment method used in all patients. Clinical endpoints were overall survival, local control, progression free survival, acute toxicities and late toxicities. Results A 102 cervical cancer patients were included,52 patients have been treated with 2D and 50 patients with 3D using CT scan brachytherapy without interstitial needles. Baseline characteristics were similar between both groups. External beam was used in all patients during concurrent chemoradiation period before brachytherapy. All patients completed the treatment. Similar 3-year overall survival and local control was reported between 2D and 3D techniques. Overall 3-year survival rate was 95.7% in 2D and 91.8% in 3D brachytherapy (P value = 0.188). Local control at the 3 year follow up was 88.6% in 2D and 93.3% in 3D (P value = 0.571). Progression free survival was better in 2D rather than 3D (86.13% in 2D vs 27.4% in 3D, p value = 0.006). No grade 3 or 4 toxicity in 3D technique was observed whereas there are 1.9% of grade 3 acute GI toxicity and grade 3 late GI and GU toxicities in 2D technique (7.7% and 5.8 %). The 3D brachytherapy significantly reduced acute grade 2-3 GI side effect and grade 2-3 late GU side effect (acute GI 25% in 2D vs 4% in 3D, late GU (56% in 2D vs 16% in 3D). Conclusion Using CT guided 3D brachytherapy in treatment of cervical cancer showed similar outcomes in survival and local control but reduced toxicity compared to the 2D technique. Disease progression including metastasis was found better in the 2D brachytherapy technique. CT guided brachytherapy helped reduce dose to organs at risk and long term follow up for survival outcome and toxicities was needed. Show less

Introduction Given the high radiation tissue sensitivity of pediatric patients, it is necessary to monitor their received dose in order to optimize radiation protection. The first aim of this study was to evaluate of the entrance surface dose (ESD) in pediatric patients undergoing chest x-ray at the main hospital of Dezful, Iran. The second aim was to compare our results with the established dose reference levels (DRL). Materials and Methods The studied population included 204 pediatric patients less than 15 year who were referred to chest x-ray. A calibrated dose area product meter (DAP-meter) with permanent installation on x-ray unit was used to radiation dose measurements. For each patient, the demographic data, exposure parameters and the dose read by DAP-meter were recorded and ESD was calculated using standard mathematical formula. Results The average value of ESD was 119 μGy in patients less than 15 years. This value was 51.3, 122.3, 131.5 and 171.2 μGy for the age groups less than 1 year, 1 to 5 year, 5 to 10 year and 10 to 15 year, respectively. A statistical significant difference was seen between ESD values ​​in different age groups (P<0.001), whereas no statistical difference was seen between ESD values in ​ girls and boys (P =0.993). Conclusion Pediatric patients in hospital investigated (except age group less than 1 year) are subjected to unnecessary radiation exposure, especially due to use of non-optimize x-ray protocols. Show less

A practice review discusses factors limiting the use of gastric emptying scintigraphy in diabetic gastroparesis, including protocols, access, and patient preparation, with suggestions to improve utility. Show less