Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 143
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 209
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 994
Function: getPubMedXML
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3134
Function: GetPubMedArticleOutput_2016
File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
As complex treatment techniques such as intensity modulated radiotherapy (IMRT) entail the modeling of rounded leaf-end transmission in the treatment planning system, it is important to accurately determine the dosimetric leaf gap (DLG) value for a precise calculation of dose. The advancements in the application of the electronic portal imaging device (EPID) in quality assurance (QA) and dosimetry have facilitated the determination of DLG in this study. The DLG measurements were performed using both the ionization chamber (DLGion) and EPID (DLGEPID) for sweeping gap fields of different widths. The DLGion values were found to be 1.133 mm and 1.120 mm for perpendicular and parallel orientations of the 0.125 cm(3) ionization chamber, while the corresponding DLGEPID values were 0.843 mm and 0.819 mm, respectively. It was found that the DLG was independent of volume and orientation of the ionization chamber, depth, source to surface distance (SSD), and the rate of dose delivery. Since the patient-specific QA tests showed comparable results between the IMRT plans based on the DLGEPID and DLGion, it is concluded that the EPID can be a suitable alternative in the determination of DLG.
Download full-text PDF |
Source |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4594381 | PMC |
http://dx.doi.org/10.4103/0971-6203.165072 | DOI Listing |
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