M Abdollahi , B Nabaei , Mh Saeid Modaghegh ,
Volume 58, Issue 1 (4-2000)
Abstract
Different aspects of the effect of trauma on the health status of populations have been studied annually 35 millions deaths, 3.5 millions disabilities and a sum of 500 billions $ cost. Evaluating different modes of prevention, a comprehensive study was carried out in the US during the 7th and 8th decades, introducing the TRISS method for the purpose of comparing the outcomes of trauma cases among multiple centers. This study has been carried out during 1996-97 in there hospitals of Tehran. After entering the hospital, all trauma cases were traced by trained interviewers until leaving the hospital. Based on the TRISS model, probability of survival was calculated for each patient and compared with the results of the MTOS study. Among 4863 cases evaluated, 300 (6.2%) deaths were observed, which is significantly more than the expected number (222 deaths, 2.7%) calculated under TRISS model. This difference may indicate a difference in the quality of trauma care.
Amin Banaei, Bijan Hashemi, Mohsen Bakhshandeh, Bahram Mofid,
Volume 77, Issue 2 (5-2019)
Abstract
Background: Intensity-modulated radiotherapy (IMRT) is one of the most usable methods in prostate radiotherapy that is used with different techniques. The aim of this study was to evaluate and compare the dosimetric and radiobiological effects of prostate IMRT techniques regarding to joint volume between the target tissue and organs at risk as a patients anatomical parameter.
Methods: This research was a cross-sectional, analytical, and quantitative study that was carried out from April 2016 to June 2018 at the radiotherapy and oncology center of Shoheday-e-Tajrish Hospital and Medical Physics Department of Tarbiat Modarres University Tehran, Iran. Four various prostate IMRT techniques (9, 7 and 5 fields and automatic) were planned on 63 prostate cancer patients CT scans. Radiobiological effects were calculated using Relative Seriality model for the organs at risk (bladder and rectum) and target tissue. Results of mentioned prostate IMRT techniques were compared based on the patient’s anatomical parameter.
Results: For the patients with joint volumes ranged from 0 to 15%, statistical differences were not observed among various IMRT techniques. The tumor control probability and complication free tumor control probability values decreased as a function of joint volume. The normal tissue complication probability value increased as a function of joint volume. The 9 and 7 fields IMRT techniques had not any significant differences (P=0.06) in all of the joint volume ranges. In patients with the joint volumes higher than 30%, the 9 and 7 fields techniques showed significantly better radiobiological values in comparison with 5 fields and automatic techniques (P=0.009).
Conclusion: In the patients with lower percentage of joint volume, all the mentioned prostate IMRT techniques showed same radiobiological effects; however, in the patients with higher joint volume percentages (> 30%), the 9 and 7 fields techniques have better results. It is proposed to use the 7 fields technique instead of the 9 fields technique, especially in prostate cancer cases with high uncertainty in patients’ setup.
