Background and purposeIn developing countries like Pakistan the cost effectiveness and patient convenience in any treatment modality is a question of major concern. The purpose of this study was two-fold; first to report our experience with a high-dose rate Iridium-192 surface mould brachytherapy of keloid scars after surgical excision, using different radiation treatment regimen and second to establish the most convenient and cost effective treatment protocol having no compromise on the treatment outcomes.Materials and methodsFrom January 2012 to April 2015 a total 51 patients with 65 keloid lesions underwent postoperative Iridium-192 high-dose rate surface mould brachytherapy. The dose regimen used was: 8 Gy in a single fraction, 10 Gy in a single fraction, 15 Gy in three fractions and 18 Gy in three fractions. The median follow-up period was 33 months (range 15–53 months).ResultsThe success rates were 57·2, 89·5, 85 and 89·5% for the treatment regimen of 8 Gy/F×1, 10 Gy/F×1, 5 Gy/F×3 and 6 Gy/F×3, respectively. Grade 2 or above radiation induced toxicity was not observed.FindingsThe results of this study show that a dose regimen of 10 Gy (biological effective dose=20 Gy) in a single fraction have comparable results with a dose regimen of 15 Gy in three fractions or 18 Gy in three fractions. 10 Gy in a single fraction is therefore the most convenient and cost effective dose regimen for the management of keloid scars in developing countries like Pakistan, while 8 Gy in a single fraction is considered suboptimal and discouraged in practice.
Introduction: Radiochemical purity (RCP) is a routine quality control test carried out at nuclear medicine to determine the concentration of various chemical species present in the radiopharmaceuticals (RPs). The present work describes three years of experience in a single institute for the measurement of these impurities in the RPs preparations. Methods: The RCP of different cold kit preparations were performed by chromatographic methods. Specifically, a small drop of the aliquot was spotted on the specific paper acting as the stationary phase and then developed in different solvents as mobile phases. The developed chromatograms were then quantified for various chemical species by Mini TLC scanner or well type counter. Results: The retention factor (Rf) values for the different chemical species in the labeling of RP were measured by using single, double or triple solvent systems. It was observed that 2.70% of the kits had RCP less than the acceptable limit whereas 97.30% kits were found within the permissible levels. Conclusion: Chromatographic techniques used for the assessment of RCP offer sufficiently good results for identification and separation of different chemical impurities.
The goal of radiotherapy is to deliver prescribed dose to the target volume and simultaneously minimize the dose to the healthy organs. The purpose of this work was to verify the accuracy of calculations carried out with a treatment planning system (TPS). Measurements carried out with thermoluminescence detectors (TLDs) were compared with doses calculated with TPS. Doses were measured and calculated both in the open beam’s region and under individual blocks. Measurements were performed in the Randophantom. The work was carried out for photon beams generated in the Varian CLINAC 2100C accelerator. The maximum / minimum percentage differences between measured and calculated doses were 4.9/0.6%, 2.6/0%, and 3.5%/0.5% in open, shielded and partially shielded points, respectively. Differences between the measured and calculated doses were within acceptable limits.
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