Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment
Purpose : The purpose of this study is to report that commercially available eye shields (designed for orthovoltage x-rays) are inadequate to protect the ocular structures from penetrating electrons for electron beam energies equal to or greater than 6 MeV. Therefore, a prototype medium size tungste...
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| Veröffentlicht in: | International journal of radiation oncology, biology, physics biology, physics, 1996-06, Vol.35 (3), p.599-604 |
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| container_title | International journal of radiation oncology, biology, physics |
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| creator | Shiu, Almon S. Tung, Samuel S. Gastorf, Robert J. Hogstrom, Kenneth R. Morrison, William H. Peters, Lester J. |
| description | Purpose
: The purpose of this study is to report that commercially available eye shields (designed for orthovoltage x-rays) are inadequate to protect the ocular structures from penetrating electrons for electron beam energies equal to or greater than 6 MeV. Therefore, a prototype medium size tungsten eye shield was designed and fabricated. The advantages of the tungsten eye shield over lead are discussed.
Methods and Materials
: Electron beams (6–9 MeV) are often used to irradiate eyelid tumors to curative doses. Eye shields can be placed under the eyelids to protect the globe. Film and thermoluminescent dosimeters (TLDs) were used within a specially constructed polystyrene eye phantom to determine the effectiveness of various commercially available internal eye shields (designed for orthovoltage x-rays). The same procedures were used to evaluate a prototype medium size tungsten eye shield (2.8 mm thick), which was designed and fabricated for protection of the globe from penetrating electrons for electron beam energy equal to 9 MeV. A mini-TLD was used to measure the dose enhancement due to electrons backscattered off the tungsten eye shield, both with or without a dental acrylic coating that is required to reduce discomfort, permit sterilization of the shield, and reduce the dose contribution from backscattered electrons.
Results
: Transmission of a 6 MeV electron beam through a 1.7 mm thick lead eye shield was found to be 50% on the surface (cornea) of the phantom and 27% at a depth of 6 mm (lens). The thickness of lead required to stop 6–9 MeV electron beams is impractical. In place of lead, a prototype medium size tungsten eye shield was made. For 6 to 9 MeV electrons, the doses measured on the surface (cornea) and at 6 mm (lens) and 21 mm (retina) depths were all less than 5 % of the maximum dose of the open field (4 × 4 cm). Electrons backscattered off a tungsten eye shield without acrylic coating increased the lid dose from 85 to 123 % at 6 MeV and 87 to 119 % at 9 MeV. For the tungsten eye shield coated with 2∼3 m of dental acrylic, the lid dose was increased from 85 to 98.5% at 6 MeV and 86 to 106% at 9 MeV.
Conclusion
: Commercially available eye shields were evaluated and found to be clearly inadequate to protect the ocular structures for electron beam energies equal to or greater than 6 MeV. A tungsten eye shield has been found to provide adequate protection for electrons up to 9 MeV. The increase in lid dose due to electrons backscattered off |
| doi_str_mv | 10.1016/S0360-3016(96)80024-1 |
| format | Article |
| fullrecord | <record><control><sourceid>proquest_cross</sourceid><recordid>TN_cdi_proquest_miscellaneous_15681378</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><els_id>S0360301696800241</els_id><sourcerecordid>15681378</sourcerecordid><originalsourceid>FETCH-LOGICAL-c401t-66086031def66e5e6a417303b5ff5763f1891bb9ede68f75fd450c3fd8be35c73</originalsourceid><addsrcrecordid>eNqFkFtLHDEUgIO06Hr5CUIepNSHqTlmcpmnUtRWQZBSBd9CJjlpI3PRJLOw_95Zd9nXPp1zON-58BFyCuwbMJAXfxiXrOJz-rWR55qxy7qCPbIArZqKC_H8iSx2yAE5zPmFMQag6n2yr6UQXIsF-X095thjSdFRXNpusiWOAx0D7dB6agdPyzT8zQUHiiuk-V_Ezmca57JDV9IMt2h7WhLa0uNQjsnnYLuMJ9t4RJ5-3jxe3Vb3D7_urn7cV65mUCopmZaMg8cgJQqUtgbFGW9FCEJJHkA30LYNepQ6KBF8LZjjwesWuXCKH5Evm72vaXybMBfTx-yw6-yA45QNCKmBKz2DYgO6NOacMJjXFHubVgaYWas0HyrN2pNppPlQaWCeO90emNoe_W5q627un237NjvbhWQHF_MO41BzpdZ_ft9gOMtYRkwmu4iDQx_TLND4Mf7nkXf5UZA9</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>15681378</pqid></control><display><type>article</type><title>Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment</title><source>MEDLINE</source><source>ScienceDirect Journals (5 years ago - present)</source><creator>Shiu, Almon S. ; Tung, Samuel S. ; Gastorf, Robert J. ; Hogstrom, Kenneth R. ; Morrison, William H. ; Peters, Lester J.</creator><creatorcontrib>Shiu, Almon S. ; Tung, Samuel S. ; Gastorf, Robert J. ; Hogstrom, Kenneth R. ; Morrison, William H. ; Peters, Lester J.</creatorcontrib><description>Purpose
: The purpose of this study is to report that commercially available eye shields (designed for orthovoltage x-rays) are inadequate to protect the ocular structures from penetrating electrons for electron beam energies equal to or greater than 6 MeV. Therefore, a prototype medium size tungsten eye shield was designed and fabricated. The advantages of the tungsten eye shield over lead are discussed.
Methods and Materials
: Electron beams (6–9 MeV) are often used to irradiate eyelid tumors to curative doses. Eye shields can be placed under the eyelids to protect the globe. Film and thermoluminescent dosimeters (TLDs) were used within a specially constructed polystyrene eye phantom to determine the effectiveness of various commercially available internal eye shields (designed for orthovoltage x-rays). The same procedures were used to evaluate a prototype medium size tungsten eye shield (2.8 mm thick), which was designed and fabricated for protection of the globe from penetrating electrons for electron beam energy equal to 9 MeV. A mini-TLD was used to measure the dose enhancement due to electrons backscattered off the tungsten eye shield, both with or without a dental acrylic coating that is required to reduce discomfort, permit sterilization of the shield, and reduce the dose contribution from backscattered electrons.
Results
: Transmission of a 6 MeV electron beam through a 1.7 mm thick lead eye shield was found to be 50% on the surface (cornea) of the phantom and 27% at a depth of 6 mm (lens). The thickness of lead required to stop 6–9 MeV electron beams is impractical. In place of lead, a prototype medium size tungsten eye shield was made. For 6 to 9 MeV electrons, the doses measured on the surface (cornea) and at 6 mm (lens) and 21 mm (retina) depths were all less than 5 % of the maximum dose of the open field (4 × 4 cm). Electrons backscattered off a tungsten eye shield without acrylic coating increased the lid dose from 85 to 123 % at 6 MeV and 87 to 119 % at 9 MeV. For the tungsten eye shield coated with 2∼3 m of dental acrylic, the lid dose was increased from 85 to 98.5% at 6 MeV and 86 to 106% at 9 MeV.
Conclusion
: Commercially available eye shields were evaluated and found to be clearly inadequate to protect the ocular structures for electron beam energies equal to or greater than 6 MeV. A tungsten eye shield has been found to provide adequate protection for electrons up to 9 MeV. The increase in lid dose due to electrons backscattered off the tungsten eye shield should be considered in the dose prescription. A minimum thickness of 2 mm dental acrylic on the beam entrance surface of the tungsten eye shield was found to reduce the backscattered electron effect to acceptable levels.</description><identifier>ISSN: 0360-3016</identifier><identifier>EISSN: 1879-355X</identifier><identifier>DOI: 10.1016/S0360-3016(96)80024-1</identifier><identifier>PMID: 8655385</identifier><identifier>CODEN: IOBPD3</identifier><language>eng</language><publisher>New York, NY: Elsevier Inc</publisher><subject>Backscattered electrons ; Biological and medical sciences ; Electron beams ; Equipment Design ; Eye Protective Devices ; Eye shields ; Lead ; Medical sciences ; Radiation Dosage ; Radiation Protection - instrumentation ; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects) ; Technology. Biomaterials. Equipments. Material. Instrumentation ; Tungsten</subject><ispartof>International journal of radiation oncology, biology, physics, 1996-06, Vol.35 (3), p.599-604</ispartof><rights>1995</rights><rights>1996 INIST-CNRS</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c401t-66086031def66e5e6a417303b5ff5763f1891bb9ede68f75fd450c3fd8be35c73</citedby><cites>FETCH-LOGICAL-c401t-66086031def66e5e6a417303b5ff5763f1891bb9ede68f75fd450c3fd8be35c73</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktohtml>$$Uhttps://www.sciencedirect.com/science/article/pii/S0360301696800241$$EHTML$$P50$$Gelsevier$$H</linktohtml><link.rule.ids>314,776,780,3537,27901,27902,65306</link.rule.ids><backlink>$$Uhttp://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=3143777$$DView record in Pascal Francis$$Hfree_for_read</backlink><backlink>$$Uhttps://www.ncbi.nlm.nih.gov/pubmed/8655385$$D View this record in MEDLINE/PubMed$$Hfree_for_read</backlink></links><search><creatorcontrib>Shiu, Almon S.</creatorcontrib><creatorcontrib>Tung, Samuel S.</creatorcontrib><creatorcontrib>Gastorf, Robert J.</creatorcontrib><creatorcontrib>Hogstrom, Kenneth R.</creatorcontrib><creatorcontrib>Morrison, William H.</creatorcontrib><creatorcontrib>Peters, Lester J.</creatorcontrib><title>Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment</title><title>International journal of radiation oncology, biology, physics</title><addtitle>Int J Radiat Oncol Biol Phys</addtitle><description>Purpose
: The purpose of this study is to report that commercially available eye shields (designed for orthovoltage x-rays) are inadequate to protect the ocular structures from penetrating electrons for electron beam energies equal to or greater than 6 MeV. Therefore, a prototype medium size tungsten eye shield was designed and fabricated. The advantages of the tungsten eye shield over lead are discussed.
Methods and Materials
: Electron beams (6–9 MeV) are often used to irradiate eyelid tumors to curative doses. Eye shields can be placed under the eyelids to protect the globe. Film and thermoluminescent dosimeters (TLDs) were used within a specially constructed polystyrene eye phantom to determine the effectiveness of various commercially available internal eye shields (designed for orthovoltage x-rays). The same procedures were used to evaluate a prototype medium size tungsten eye shield (2.8 mm thick), which was designed and fabricated for protection of the globe from penetrating electrons for electron beam energy equal to 9 MeV. A mini-TLD was used to measure the dose enhancement due to electrons backscattered off the tungsten eye shield, both with or without a dental acrylic coating that is required to reduce discomfort, permit sterilization of the shield, and reduce the dose contribution from backscattered electrons.
Results
: Transmission of a 6 MeV electron beam through a 1.7 mm thick lead eye shield was found to be 50% on the surface (cornea) of the phantom and 27% at a depth of 6 mm (lens). The thickness of lead required to stop 6–9 MeV electron beams is impractical. In place of lead, a prototype medium size tungsten eye shield was made. For 6 to 9 MeV electrons, the doses measured on the surface (cornea) and at 6 mm (lens) and 21 mm (retina) depths were all less than 5 % of the maximum dose of the open field (4 × 4 cm). Electrons backscattered off a tungsten eye shield without acrylic coating increased the lid dose from 85 to 123 % at 6 MeV and 87 to 119 % at 9 MeV. For the tungsten eye shield coated with 2∼3 m of dental acrylic, the lid dose was increased from 85 to 98.5% at 6 MeV and 86 to 106% at 9 MeV.
Conclusion
: Commercially available eye shields were evaluated and found to be clearly inadequate to protect the ocular structures for electron beam energies equal to or greater than 6 MeV. A tungsten eye shield has been found to provide adequate protection for electrons up to 9 MeV. The increase in lid dose due to electrons backscattered off the tungsten eye shield should be considered in the dose prescription. A minimum thickness of 2 mm dental acrylic on the beam entrance surface of the tungsten eye shield was found to reduce the backscattered electron effect to acceptable levels.</description><subject>Backscattered electrons</subject><subject>Biological and medical sciences</subject><subject>Electron beams</subject><subject>Equipment Design</subject><subject>Eye Protective Devices</subject><subject>Eye shields</subject><subject>Lead</subject><subject>Medical sciences</subject><subject>Radiation Dosage</subject><subject>Radiation Protection - instrumentation</subject><subject>Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects)</subject><subject>Technology. Biomaterials. Equipments. Material. Instrumentation</subject><subject>Tungsten</subject><issn>0360-3016</issn><issn>1879-355X</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>1996</creationdate><recordtype>article</recordtype><sourceid>EIF</sourceid><recordid>eNqFkFtLHDEUgIO06Hr5CUIepNSHqTlmcpmnUtRWQZBSBd9CJjlpI3PRJLOw_95Zd9nXPp1zON-58BFyCuwbMJAXfxiXrOJz-rWR55qxy7qCPbIArZqKC_H8iSx2yAE5zPmFMQag6n2yr6UQXIsF-X095thjSdFRXNpusiWOAx0D7dB6agdPyzT8zQUHiiuk-V_Ezmca57JDV9IMt2h7WhLa0uNQjsnnYLuMJ9t4RJ5-3jxe3Vb3D7_urn7cV65mUCopmZaMg8cgJQqUtgbFGW9FCEJJHkA30LYNepQ6KBF8LZjjwesWuXCKH5Evm72vaXybMBfTx-yw6-yA45QNCKmBKz2DYgO6NOacMJjXFHubVgaYWas0HyrN2pNppPlQaWCeO90emNoe_W5q627un237NjvbhWQHF_MO41BzpdZ_ft9gOMtYRkwmu4iDQx_TLND4Mf7nkXf5UZA9</recordid><startdate>19960601</startdate><enddate>19960601</enddate><creator>Shiu, Almon S.</creator><creator>Tung, Samuel S.</creator><creator>Gastorf, Robert J.</creator><creator>Hogstrom, Kenneth R.</creator><creator>Morrison, William H.</creator><creator>Peters, Lester J.</creator><general>Elsevier Inc</general><general>Elsevier</general><scope>IQODW</scope><scope>CGR</scope><scope>CUY</scope><scope>CVF</scope><scope>ECM</scope><scope>EIF</scope><scope>NPM</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7U7</scope><scope>C1K</scope></search><sort><creationdate>19960601</creationdate><title>Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment</title><author>Shiu, Almon S. ; Tung, Samuel S. ; Gastorf, Robert J. ; Hogstrom, Kenneth R. ; Morrison, William H. ; Peters, Lester J.</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c401t-66086031def66e5e6a417303b5ff5763f1891bb9ede68f75fd450c3fd8be35c73</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>1996</creationdate><topic>Backscattered electrons</topic><topic>Biological and medical sciences</topic><topic>Electron beams</topic><topic>Equipment Design</topic><topic>Eye Protective Devices</topic><topic>Eye shields</topic><topic>Lead</topic><topic>Medical sciences</topic><topic>Radiation Dosage</topic><topic>Radiation Protection - instrumentation</topic><topic>Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects)</topic><topic>Technology. Biomaterials. Equipments. Material. Instrumentation</topic><topic>Tungsten</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Shiu, Almon S.</creatorcontrib><creatorcontrib>Tung, Samuel S.</creatorcontrib><creatorcontrib>Gastorf, Robert J.</creatorcontrib><creatorcontrib>Hogstrom, Kenneth R.</creatorcontrib><creatorcontrib>Morrison, William H.</creatorcontrib><creatorcontrib>Peters, Lester J.</creatorcontrib><collection>Pascal-Francis</collection><collection>Medline</collection><collection>MEDLINE</collection><collection>MEDLINE (Ovid)</collection><collection>MEDLINE</collection><collection>MEDLINE</collection><collection>PubMed</collection><collection>CrossRef</collection><collection>Toxicology Abstracts</collection><collection>Environmental Sciences and Pollution Management</collection><jtitle>International journal of radiation oncology, biology, physics</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Shiu, Almon S.</au><au>Tung, Samuel S.</au><au>Gastorf, Robert J.</au><au>Hogstrom, Kenneth R.</au><au>Morrison, William H.</au><au>Peters, Lester J.</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment</atitle><jtitle>International journal of radiation oncology, biology, physics</jtitle><addtitle>Int J Radiat Oncol Biol Phys</addtitle><date>1996-06-01</date><risdate>1996</risdate><volume>35</volume><issue>3</issue><spage>599</spage><epage>604</epage><pages>599-604</pages><issn>0360-3016</issn><eissn>1879-355X</eissn><coden>IOBPD3</coden><abstract>Purpose
: The purpose of this study is to report that commercially available eye shields (designed for orthovoltage x-rays) are inadequate to protect the ocular structures from penetrating electrons for electron beam energies equal to or greater than 6 MeV. Therefore, a prototype medium size tungsten eye shield was designed and fabricated. The advantages of the tungsten eye shield over lead are discussed.
Methods and Materials
: Electron beams (6–9 MeV) are often used to irradiate eyelid tumors to curative doses. Eye shields can be placed under the eyelids to protect the globe. Film and thermoluminescent dosimeters (TLDs) were used within a specially constructed polystyrene eye phantom to determine the effectiveness of various commercially available internal eye shields (designed for orthovoltage x-rays). The same procedures were used to evaluate a prototype medium size tungsten eye shield (2.8 mm thick), which was designed and fabricated for protection of the globe from penetrating electrons for electron beam energy equal to 9 MeV. A mini-TLD was used to measure the dose enhancement due to electrons backscattered off the tungsten eye shield, both with or without a dental acrylic coating that is required to reduce discomfort, permit sterilization of the shield, and reduce the dose contribution from backscattered electrons.
Results
: Transmission of a 6 MeV electron beam through a 1.7 mm thick lead eye shield was found to be 50% on the surface (cornea) of the phantom and 27% at a depth of 6 mm (lens). The thickness of lead required to stop 6–9 MeV electron beams is impractical. In place of lead, a prototype medium size tungsten eye shield was made. For 6 to 9 MeV electrons, the doses measured on the surface (cornea) and at 6 mm (lens) and 21 mm (retina) depths were all less than 5 % of the maximum dose of the open field (4 × 4 cm). Electrons backscattered off a tungsten eye shield without acrylic coating increased the lid dose from 85 to 123 % at 6 MeV and 87 to 119 % at 9 MeV. For the tungsten eye shield coated with 2∼3 m of dental acrylic, the lid dose was increased from 85 to 98.5% at 6 MeV and 86 to 106% at 9 MeV.
Conclusion
: Commercially available eye shields were evaluated and found to be clearly inadequate to protect the ocular structures for electron beam energies equal to or greater than 6 MeV. A tungsten eye shield has been found to provide adequate protection for electrons up to 9 MeV. The increase in lid dose due to electrons backscattered off the tungsten eye shield should be considered in the dose prescription. A minimum thickness of 2 mm dental acrylic on the beam entrance surface of the tungsten eye shield was found to reduce the backscattered electron effect to acceptable levels.</abstract><cop>New York, NY</cop><pub>Elsevier Inc</pub><pmid>8655385</pmid><doi>10.1016/S0360-3016(96)80024-1</doi><tpages>6</tpages></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 0360-3016 |
| ispartof | International journal of radiation oncology, biology, physics, 1996-06, Vol.35 (3), p.599-604 |
| issn | 0360-3016 1879-355X |
| language | eng |
| recordid | cdi_proquest_miscellaneous_15681378 |
| source | MEDLINE; ScienceDirect Journals (5 years ago - present) |
| subjects | Backscattered electrons Biological and medical sciences Electron beams Equipment Design Eye Protective Devices Eye shields Lead Medical sciences Radiation Dosage Radiation Protection - instrumentation Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects) Technology. Biomaterials. Equipments. Material. Instrumentation Tungsten |
| title | Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment |
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