Comparison between Clinically Used Irregular Fields Shielded by Cerrobend and Standard Lead Blocks
Introduction: In radiation therapy centers across Iran, protection of normal tissues is usually accomplished by either Cerrobend or lead block shielding. In this study, the influence of these two shielding methods on central axis dose distribution of photon beam a Cobalt unit was investigated in...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Shiraz University of Medical Sciences
2015-06-01
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| Series: | Journal of Biomedical Physics and Engineering |
| Subjects: | |
| Online Access: | http://www.jbpe.org/Journal_OJS/JBPE/index.php/jbpe/article/view/302 |
| Summary: | Introduction: In radiation therapy centers across Iran, protection of normal
tissues is usually accomplished by either Cerrobend or lead block shielding. In this
study, the influence of these two shielding methods on central axis dose distribution of
photon beam a Cobalt unit was investigated in clinical conditions.
Materials and Methods: All measurements were performed for 60Co γ-ray
beams and the Cerrobend blocks were fabricated by commercial Cerrobend materials.
Standard lead block shields belonged to Cobalt unit. Data was collected through a calibrated
ionization chamber, relative dosimetry systems and a TLD dosimetery.
Results: Results of the percent depth dose (PDD) measurements at depths of 0.5,
1, 5, 10, 15 and 20 cm for 23 different field sizes of patients with head and neck cancer
showed no significant differences between lead and Cerrobend shielding methods.
Measurement results of absolute dosimetry in depths of 1.5, 3, 5, 7, 10 and 12 cm also
showed no significant differences between these two shielding methods. The same
results were obtained by TLD dosimetry on patient skin.
Conclusion: Use of melt shielding methods is a very easy and fast shield-making
technique with no differences in PDD, absolute and skin dose between lead and Cerrobend
block shielding methods. |
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| ISSN: | 2251-7200 2251-7200 |