ABSTRACT
This paper presents a new approach towards the quality assurance of external beam plans using in-house-developed DICOM import and export software in a clinical setup. The new approach is different from what is currently used in most clinics, viz., only MU and point dose are verified. The DICOM-RT software generates ASCII files to import/export structure sets, treatment beam data, and dose-volume histo-grams (DVH) from one treatment planning system (TPS) to the other. An efficient and reliable 3D planning system, ROPS, was used for verifying the accuracy of treatment plans and treatment plan parameters. With the use of this new approach, treatment plans planned using Varian Eclipse planning system were exported to ROPS planning system. Important treatment and dosimetrical data, such as the beam setup accuracy, target dose coverage, and dose to critical structures, were also quantitatively verified using DVH comparisons. Two external beam plans with diverse photon energies were selected to test the new approach. The satisfactory results show that the new approach is feasible, easy to use, and can be used as an adjunct test for patient treatment quality check.
Subject(s)
Imaging, Three-Dimensional/methods , Pelvic Neoplasms/radiotherapy , Quality Assurance, Health Care , Radiotherapy Planning, Computer-Assisted/methods , Uterine Cervical Neoplasms/radiotherapy , Cobalt Radioisotopes/therapeutic use , Female , Humans , Image Processing, Computer-Assisted , Organs at Risk/radiation effects , Prognosis , Radiotherapy Dosage , Radiotherapy, Intensity-Modulated , SoftwareABSTRACT
BACKGROUND: Early childhood exposure carries an enhanced radiation risk and estimated that the probability of induction of cancer especially leukemia is about two to three times as high as in adults. Hence, dose measurement is mandatory for optimization in radiation protection to comply with international reference levels. OBJECTIVES: To estimate pediatric patient's radiation dose arising from common diagnostic x-ray examinations by measuring Entrance Surface Dose, thereby, to compare the results from established reference values and other published studies. MATERIAL AND METHODS: A cross-sectional study was conducted on pediatric patients under 15 years of age in Black Lion and Yekatite 12 Hospitals on May and August, 2009 respectively. Exposure factors used for commonly performed x-ray examinations like, chest, skull, abdomen, pelvis and spine were obtained from each Hospital. For each examination four age groups 0-1, 1-5, 5-10 and 10-15 years were studied. Entrance Surface Dose in air was measured using dositime dx X-ray Digital Dosimeter and Exposure Time Meter. RESULT: In Black lion hospital, the lowest and the highest calculated mean Entrance Surface Doses in microGY were 104 and 2482 for chest Anteroposterior (0-1) years and lumbo-sacral lateral (10-15) years, respectively. In Yekatit 12 hospital, the lowest and the highest calculated mean Entrance Surface Doses in microGY were 200 and 3570 for chest antrioposterior (0-1) years and lumbo-sacral lateral (10-15)years, respectively. Wide variations of doses for the same type of examination and projection have been detected in each hospital. CONCLUSION: The wider dose variation suggests that there is a pressing need to seek dose optimization to children in order to reduce the detriment caused by the unnecessary high doses imparted to them.
