The IAEA/WHO TLD postal programme for radiotherapy hospitals
Identifieur interne : 000F31 ( Istex/Corpus ); précédent : 000F30; suivant : 000F32The IAEA/WHO TLD postal programme for radiotherapy hospitals
Auteurs : Joanna Izewska ; Pedro AndreoSource :
- Radiotherapy and Oncology [ 0167-8140 ] ; 2000.
English descriptors
Abstract
Background and purpose: Since 1969 the International Atomic Energy Agency (IAEA), together with the World Health Organization (WHO), has performed postal TLD audits to verify the calibration of radiotherapy beams in developing countries. Materials and methods: A number of changes have recently been implemented to improve the efficiency of the IAEA/WHO TLD programme. The IAEA has increased the number of participants and reduced significantly the total turn-around time to provide results to the hospitals within the shortest possible time following the TLD irradiations. The IAEA has established a regular follow-up programme for hospitals with results outside acceptance limits of ±5%. Results: The IAEA has, over 30 years, verified the calibration of more than 3300 clinical photon beams at approximately 1000 radiotherapy hospitals. Only 65% of those hospitals who receive TLDs for the first time have results within the acceptance limits, while more than 80% of the users that have benefited from a previous TLD audit are successful. The experience of the IAEA in TLD audits has been transferred to the national level. The IAEA offers a standardized TLD methodology, provides guidelines and gives technical back-up to the national TLD networks. Conclusion: The unsatisfactory status of the dosimetry for radiotherapy, as noted in the past, is gradually improving; however, the dosimetry practices in many hospitals in developing countries need to be revised in order to reach adequate conformity to hospitals that perform modern radiotherapy in Europe, USA and Australia.
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DOI: 10.1016/S0167-8140(99)00164-4
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<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">The IAEA/WHO TLD postal programme for radiotherapy hospitals</title><author><name sortKey="Izewska, Joanna" sort="Izewska, Joanna" uniqKey="Izewska J" first="Joanna" last="Izewska">Joanna Izewska</name><affiliation><mods:affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</mods:affiliation></affiliation></author><author><name sortKey="Andreo, Pedro" sort="Andreo, Pedro" uniqKey="Andreo P" first="Pedro" last="Andreo">Pedro Andreo</name><affiliation><mods:affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</mods:affiliation></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">ISTEX</idno><idno type="RBID">ISTEX:199BC55583D40B7C17F7D7386F54A60A615FD32C</idno><date when="2000" year="2000">2000</date><idno type="doi">10.1016/S0167-8140(99)00164-4</idno><idno type="url">https://api.istex.fr/document/199BC55583D40B7C17F7D7386F54A60A615FD32C/fulltext/pdf</idno><idno type="wicri:Area/Istex/Corpus">000F31</idno><idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Corpus" wicri:corpus="ISTEX">000F31</idno></publicationStmt><sourceDesc><biblStruct><analytic><title level="a" type="main" xml:lang="en">The IAEA/WHO TLD postal programme for radiotherapy hospitals</title><author><name sortKey="Izewska, Joanna" sort="Izewska, Joanna" uniqKey="Izewska J" first="Joanna" last="Izewska">Joanna Izewska</name><affiliation><mods:affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</mods:affiliation></affiliation></author><author><name sortKey="Andreo, Pedro" sort="Andreo, Pedro" uniqKey="Andreo P" first="Pedro" last="Andreo">Pedro Andreo</name><affiliation><mods:affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</mods:affiliation></affiliation></author></analytic><monogr></monogr><series><title level="j">Radiotherapy and Oncology</title><title level="j" type="abbrev">RADION</title><idno type="ISSN">0167-8140</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="2000">2000</date><biblScope unit="volume">54</biblScope><biblScope unit="issue">1</biblScope><biblScope unit="page" from="65">65</biblScope><biblScope unit="page" to="72">72</biblScope></imprint><idno type="ISSN">0167-8140</idno></series><idno type="istex">199BC55583D40B7C17F7D7386F54A60A615FD32C</idno><idno type="DOI">10.1016/S0167-8140(99)00164-4</idno><idno type="PII">S0167-8140(99)00164-4</idno></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">0167-8140</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>Beam output checks</term><term>High energy photons</term><term>QA in radiotherapy</term><term>TLD audits</term></keywords></textClass><langUsage><language ident="en">en</language></langUsage></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">Background and purpose: Since 1969 the International Atomic Energy Agency (IAEA), together with the World Health Organization (WHO), has performed postal TLD audits to verify the calibration of radiotherapy beams in developing countries. Materials and methods: A number of changes have recently been implemented to improve the efficiency of the IAEA/WHO TLD programme. The IAEA has increased the number of participants and reduced significantly the total turn-around time to provide results to the hospitals within the shortest possible time following the TLD irradiations. The IAEA has established a regular follow-up programme for hospitals with results outside acceptance limits of ±5%. Results: The IAEA has, over 30 years, verified the calibration of more than 3300 clinical photon beams at approximately 1000 radiotherapy hospitals. Only 65% of those hospitals who receive TLDs for the first time have results within the acceptance limits, while more than 80% of the users that have benefited from a previous TLD audit are successful. The experience of the IAEA in TLD audits has been transferred to the national level. The IAEA offers a standardized TLD methodology, provides guidelines and gives technical back-up to the national TLD networks. Conclusion: The unsatisfactory status of the dosimetry for radiotherapy, as noted in the past, is gradually improving; however, the dosimetry practices in many hospitals in developing countries need to be revised in order to reach adequate conformity to hospitals that perform modern radiotherapy in Europe, USA and Australia.</div></front></TEI><istex><corpusName>elsevier</corpusName><author><json:item><name>Joanna Izewska</name><affiliations><json:string>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</json:string></affiliations></json:item><json:item><name>Pedro Andreo</name><affiliations><json:string>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</json:string></affiliations></json:item></author><subject><json:item><lang><json:string>eng</json:string></lang><value>QA in radiotherapy</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>TLD audits</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>Beam output checks</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>High energy photons</value></json:item></subject><language><json:string>eng</json:string></language><originalGenre><json:string>Full-length article</json:string></originalGenre><abstract>Background and purpose: Since 1969 the International Atomic Energy Agency (IAEA), together with the World Health Organization (WHO), has performed postal TLD audits to verify the calibration of radiotherapy beams in developing countries. Materials and methods: A number of changes have recently been implemented to improve the efficiency of the IAEA/WHO TLD programme. The IAEA has increased the number of participants and reduced significantly the total turn-around time to provide results to the hospitals within the shortest possible time following the TLD irradiations. The IAEA has established a regular follow-up programme for hospitals with results outside acceptance limits of ±5%. Results: The IAEA has, over 30 years, verified the calibration of more than 3300 clinical photon beams at approximately 1000 radiotherapy hospitals. Only 65% of those hospitals who receive TLDs for the first time have results within the acceptance limits, while more than 80% of the users that have benefited from a previous TLD audit are successful. The experience of the IAEA in TLD audits has been transferred to the national level. The IAEA offers a standardized TLD methodology, provides guidelines and gives technical back-up to the national TLD networks. Conclusion: The unsatisfactory status of the dosimetry for radiotherapy, as noted in the past, is gradually improving; however, the dosimetry practices in many hospitals in developing countries need to be revised in order to reach adequate conformity to hospitals that perform modern radiotherapy in Europe, USA and Australia.</abstract><qualityIndicators><score>7.856</score><pdfVersion>1.2</pdfVersion><pdfPageSize>595 x 794 pts</pdfPageSize><refBibsNative>true</refBibsNative><keywordCount>4</keywordCount><abstractCharCount>1578</abstractCharCount><pdfWordCount>5203</pdfWordCount><pdfCharCount>31349</pdfCharCount><pdfPageCount>8</pdfPageCount><abstractWordCount>238</abstractWordCount></qualityIndicators><title>The IAEA/WHO TLD postal programme for radiotherapy hospitals</title><pii><json:string>S0167-8140(99)00164-4</json:string></pii><genre><json:string>research-article</json:string></genre><host><volume>54</volume><pii><json:string>S0167-8140(00)X0060-6</json:string></pii><pages><last>72</last><first>65</first></pages><issn><json:string>0167-8140</json:string></issn><issue>1</issue><genre><json:string>journal</json:string></genre><language><json:string>unknown</json:string></language><title>Radiotherapy and Oncology</title><publicationDate>2000</publicationDate></host><categories><wos><json:string>ONCOLOGY</json:string><json:string>RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING</json:string><json:string>REHABILITATION</json:string></wos></categories><publicationDate>2000</publicationDate><copyrightDate>2000</copyrightDate><doi><json:string>10.1016/S0167-8140(99)00164-4</json:string></doi><id>199BC55583D40B7C17F7D7386F54A60A615FD32C</id><score>0.051857434</score><fulltext><json:item><original>true</original><mimetype>application/pdf</mimetype><extension>pdf</extension><uri>https://api.istex.fr/document/199BC55583D40B7C17F7D7386F54A60A615FD32C/fulltext/pdf</uri></json:item><json:item><original>false</original><mimetype>application/zip</mimetype><extension>zip</extension><uri>https://api.istex.fr/document/199BC55583D40B7C17F7D7386F54A60A615FD32C/fulltext/zip</uri></json:item><istex:fulltextTEI uri="https://api.istex.fr/document/199BC55583D40B7C17F7D7386F54A60A615FD32C/fulltext/tei"><teiHeader><fileDesc><titleStmt><title level="a" type="main" xml:lang="en">The IAEA/WHO TLD postal programme for radiotherapy hospitals</title></titleStmt><publicationStmt><authority>ISTEX</authority><publisher>ELSEVIER</publisher><availability><p>©2000 Elsevier Science Ireland Ltd</p></availability><date>2000</date></publicationStmt><notesStmt><note type="content">Fig. 1: The world-wide TLD-based quality assurance networks for radiotherapy. Countries marked in grey participate in the IAEA/WHO TLD postal dose audit programme. Countries marked in black have either their national TLD networks or participate in an international network other than the IAEA/WHO. White dots indicate TLD networks co-operating with the IAEA. Countries not coloured either do not have radiotherapy or do not participate in the existing TLD networks.</note><note type="content">Fig. 2: The distribution of the percentage of beam checks in different regions in 1969–1998. The results pertain to 101 countries, 1003 hospitals in which 3307 beams were checked.</note><note type="content">Fig. 3: Percentage of TLD audits for different photon beam qualities, Co-60 and high energy photons up to 25 MV, which were checked in 1991–1998, i.e. since the high energy X-rays were included in the TLD programme. The results pertain to 1338 beam checks.</note><note type="content">Fig. 4: Improvement in return rate from hospitals in the IAEA/WHO dosimetry programme.</note><note type="content">Fig. 5: Distribution of the results of the IAEA/WHO TLD postal dose audits of radiotherapy hospitals for the delivery of absorbed dose to water under reference conditions during 1969–1998. Data in the graph correspond to ratios of the IAEA's determined dose (DTLD) relative to the dose stated by the hospital (Dstat). Each data point corresponds to the average of three dosimeters (two after 1998). A total of 3307 beam calibrations were checked in 1003 hospitals. The mean distribution is 1.013 and the standard deviation is 8.8%. The deviations vary between a minimum DTLD/Dstat ratio of 0.535 and a maximum of 2.188. Fifteen deviations outside ±40% are not shown in the graph. Approximately 32% of the results are outside the ±5% acceptance limits.</note><note type="content">Fig. 6: Results of the IAEA/WHO TLD postal dose audits of radiotherapy hospitals for the delivery of absorbed dose to water under reference conditions during 1996–1998. Data in the graph correspond to ratios of the IAEA's determined dose (DTLD) relative to the dose stated by the hospital (Dstat). Each data point corresponds to the average of two dosimeters (three before 1998). A total of 688 beam calibrations were checked. Approximately 19% of the results were found outside the ±5% acceptance level. The black dots indicate the deviations which have not been yet corrected in follow-up actions. The two extreme deviations have been explained and corrected: DTLD/Dstat=1.79 was due to an accident in radiotherapy; DTLD/Dstat=1.99 was due to double irradiation of the TLDs and had no clinical relevance.</note><note type="content">Fig. 7: The TLD results for Latin America and Caribbean region. The column bar graph shows the cumulative number of the beam audits in the region. The curve shows the percentage of beams checked in each period with the results within the ±5% acceptance limit. The results pertain to 1221 beam checks in 1969–1998.</note><note type="content">Fig. 8: The percentage of results of beam audits within ±5%, 5–10%, 10–20% and outside 20%. The upper pie chart (a) shows the results for 1969–1998 and the lower one (b) shows the results for 1996–1998. The results within ±5% correspond to the required level for ‘acceptable radiotherapy treatment’ [15]. The results within 5–10% limits are considered within the ‘tolerable’ category, whereas for the results within 10–20% benefit from the radiation treatment is questionable; the results showing discrepancies larger than 20% might be considered accidents in radiotherapy.</note><note type="content">Table 1: Percentage of beams checked in Africa in 1969–1998 with results within the ±5% acceptance limit</note></notesStmt><sourceDesc><biblStruct type="inbook"><analytic><title level="a" type="main" xml:lang="en">The IAEA/WHO TLD postal programme for radiotherapy hospitals</title><author xml:id="author-1"><persName><forename type="first">Joanna</forename><surname>Izewska</surname></persName><note type="correspondence"><p>Corresponding author</p></note><affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</affiliation></author><author xml:id="author-2"><persName><forename type="first">Pedro</forename><surname>Andreo</surname></persName><affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</affiliation></author></analytic><monogr><title level="j">Radiotherapy and Oncology</title><title level="j" type="abbrev">RADION</title><idno type="pISSN">0167-8140</idno><idno type="PII">S0167-8140(00)X0060-6</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="2000"></date><biblScope unit="volume">54</biblScope><biblScope unit="issue">1</biblScope><biblScope unit="page" from="65">65</biblScope><biblScope unit="page" to="72">72</biblScope></imprint></monogr><idno type="istex">199BC55583D40B7C17F7D7386F54A60A615FD32C</idno><idno type="DOI">10.1016/S0167-8140(99)00164-4</idno><idno type="PII">S0167-8140(99)00164-4</idno></biblStruct></sourceDesc></fileDesc><profileDesc><creation><date>2000</date></creation><langUsage><language ident="en">en</language></langUsage><abstract xml:lang="en"><p>Background and purpose: Since 1969 the International Atomic Energy Agency (IAEA), together with the World Health Organization (WHO), has performed postal TLD audits to verify the calibration of radiotherapy beams in developing countries. Materials and methods: A number of changes have recently been implemented to improve the efficiency of the IAEA/WHO TLD programme. The IAEA has increased the number of participants and reduced significantly the total turn-around time to provide results to the hospitals within the shortest possible time following the TLD irradiations. The IAEA has established a regular follow-up programme for hospitals with results outside acceptance limits of ±5%. Results: The IAEA has, over 30 years, verified the calibration of more than 3300 clinical photon beams at approximately 1000 radiotherapy hospitals. Only 65% of those hospitals who receive TLDs for the first time have results within the acceptance limits, while more than 80% of the users that have benefited from a previous TLD audit are successful. The experience of the IAEA in TLD audits has been transferred to the national level. The IAEA offers a standardized TLD methodology, provides guidelines and gives technical back-up to the national TLD networks. Conclusion: The unsatisfactory status of the dosimetry for radiotherapy, as noted in the past, is gradually improving; however, the dosimetry practices in many hospitals in developing countries need to be revised in order to reach adequate conformity to hospitals that perform modern radiotherapy in Europe, USA and Australia.</p></abstract><textClass xml:lang="en"><keywords scheme="keyword"><list><head>Keywords</head><item><term>QA in radiotherapy</term></item><item><term>TLD audits</term></item><item><term>Beam output checks</term></item><item><term>High energy photons</term></item></list></keywords></textClass></profileDesc><revisionDesc><change when="1999-10-12">Modified</change><change when="2000">Published</change></revisionDesc></teiHeader></istex:fulltextTEI><json:item><original>false</original><mimetype>text/plain</mimetype><extension>txt</extension><uri>https://api.istex.fr/document/199BC55583D40B7C17F7D7386F54A60A615FD32C/fulltext/txt</uri></json:item></fulltext><metadata><istex:metadataXml wicri:clean="Elsevier, elements deleted: ce:floats; body; tail"><istex:xmlDeclaration>version="1.0" encoding="utf-8"</istex:xmlDeclaration><istex:docType PUBLIC="-//ES//DTD journal article DTD version 4.5.2//EN//XML" URI="art452.dtd" name="istex:docType"><istex:entity SYSTEM="gr1" NDATA="IMAGE" name="gr1"></istex:entity><istex:entity SYSTEM="gr2" NDATA="IMAGE" name="gr2"></istex:entity><istex:entity SYSTEM="gr3" NDATA="IMAGE" name="gr3"></istex:entity><istex:entity SYSTEM="gr4" NDATA="IMAGE" name="gr4"></istex:entity><istex:entity SYSTEM="gr5" NDATA="IMAGE" name="gr5"></istex:entity><istex:entity SYSTEM="gr6" NDATA="IMAGE" name="gr6"></istex:entity><istex:entity SYSTEM="gr7" NDATA="IMAGE" name="gr7"></istex:entity><istex:entity SYSTEM="gr8" NDATA="IMAGE" name="gr8"></istex:entity></istex:docType><istex:document><converted-article version="4.5.2" docsubtype="fla" xml:lang="en"><item-info><jid>RADION</jid><aid>2433</aid><ce:pii>S0167-8140(99)00164-4</ce:pii><ce:doi>10.1016/S0167-8140(99)00164-4</ce:doi><ce:copyright type="full-transfer" year="2000">Elsevier Science Ireland Ltd</ce:copyright></item-info><head><ce:title>The IAEA/WHO TLD postal programme for radiotherapy hospitals</ce:title><ce:author-group><ce:author><ce:given-name>Joanna</ce:given-name><ce:surname>Izewska</ce:surname><ce:cross-ref refid="CORR1">*</ce:cross-ref></ce:author><ce:author><ce:given-name>Pedro</ce:given-name><ce:surname>Andreo</ce:surname></ce:author><ce:affiliation><ce:textfn>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</ce:textfn></ce:affiliation><ce:correspondence id="CORR1"><ce:label>*</ce:label><ce:text>Corresponding author</ce:text></ce:correspondence></ce:author-group><ce:date-received day="14" month="6" year="1999"></ce:date-received><ce:date-revised day="12" month="10" year="1999"></ce:date-revised><ce:date-accepted day="12" month="11" year="1999"></ce:date-accepted><ce:abstract><ce:section-title>Abstract</ce:section-title><ce:abstract-sec><ce:simple-para><ce:italic>Background and purpose</ce:italic>: Since 1969 the International Atomic Energy Agency (IAEA), together with the World Health Organization (WHO), has performed postal TLD audits to verify the calibration of radiotherapy beams in developing countries.</ce:simple-para><ce:simple-para><ce:italic>Materials and methods</ce:italic>: A number of changes have recently been implemented to improve the efficiency of the IAEA/WHO TLD programme. The IAEA has increased the number of participants and reduced significantly the total turn-around time to provide results to the hospitals within the shortest possible time following the TLD irradiations. The IAEA has established a regular follow-up programme for hospitals with results outside acceptance limits of ±5%.</ce:simple-para><ce:simple-para><ce:italic>Results</ce:italic>: The IAEA has, over 30 years, verified the calibration of more than 3300 clinical photon beams at approximately 1000 radiotherapy hospitals. Only 65% of those hospitals who receive TLDs for the first time have results within the acceptance limits, while more than 80% of the users that have benefited from a previous TLD audit are successful. The experience of the IAEA in TLD audits has been transferred to the national level. The IAEA offers a standardized TLD methodology, provides guidelines and gives technical back-up to the national TLD networks.</ce:simple-para><ce:simple-para><ce:italic>Conclusion</ce:italic>: The unsatisfactory status of the dosimetry for radiotherapy, as noted in the past, is gradually improving; however, the dosimetry practices in many hospitals in developing countries need to be revised in order to reach adequate conformity to hospitals that perform modern radiotherapy in Europe, USA and Australia.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:keywords class="keyword" xml:lang="en"><ce:section-title>Keywords</ce:section-title><ce:keyword><ce:text>QA in radiotherapy</ce:text></ce:keyword><ce:keyword><ce:text>TLD audits</ce:text></ce:keyword><ce:keyword><ce:text>Beam output checks</ce:text></ce:keyword><ce:keyword><ce:text>High energy photons</ce:text></ce:keyword></ce:keywords></head></converted-article></istex:document></istex:metadataXml><mods version="3.6"><titleInfo lang="en"><title>The IAEA/WHO TLD postal programme for radiotherapy hospitals</title></titleInfo><titleInfo type="alternative" lang="en" contentType="CDATA"><title>The IAEA/WHO TLD postal programme for radiotherapy hospitals</title></titleInfo><name type="personal"><namePart type="given">Joanna</namePart><namePart type="family">Izewska</namePart><affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</affiliation><description>Corresponding author</description><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Pedro</namePart><namePart type="family">Andreo</namePart><affiliation>Dosimetry and Medical Radiation Physics Section, International Atomic Energy Agency, Wagramer Strasse 5, 1400 Vienna, Austria</affiliation><role><roleTerm type="text">author</roleTerm></role></name><typeOfResource>text</typeOfResource><genre type="research-article" displayLabel="Full-length article"></genre><originInfo><publisher>ELSEVIER</publisher><dateIssued encoding="w3cdtf">2000</dateIssued><dateModified encoding="w3cdtf">1999-10-12</dateModified><copyrightDate encoding="w3cdtf">2000</copyrightDate></originInfo><language><languageTerm type="code" authority="iso639-2b">eng</languageTerm><languageTerm type="code" authority="rfc3066">en</languageTerm></language><physicalDescription><internetMediaType>text/html</internetMediaType></physicalDescription><abstract lang="en">Background and purpose: Since 1969 the International Atomic Energy Agency (IAEA), together with the World Health Organization (WHO), has performed postal TLD audits to verify the calibration of radiotherapy beams in developing countries. Materials and methods: A number of changes have recently been implemented to improve the efficiency of the IAEA/WHO TLD programme. The IAEA has increased the number of participants and reduced significantly the total turn-around time to provide results to the hospitals within the shortest possible time following the TLD irradiations. The IAEA has established a regular follow-up programme for hospitals with results outside acceptance limits of ±5%. Results: The IAEA has, over 30 years, verified the calibration of more than 3300 clinical photon beams at approximately 1000 radiotherapy hospitals. Only 65% of those hospitals who receive TLDs for the first time have results within the acceptance limits, while more than 80% of the users that have benefited from a previous TLD audit are successful. The experience of the IAEA in TLD audits has been transferred to the national level. The IAEA offers a standardized TLD methodology, provides guidelines and gives technical back-up to the national TLD networks. Conclusion: The unsatisfactory status of the dosimetry for radiotherapy, as noted in the past, is gradually improving; however, the dosimetry practices in many hospitals in developing countries need to be revised in order to reach adequate conformity to hospitals that perform modern radiotherapy in Europe, USA and Australia.</abstract><note type="content">Fig. 1: The world-wide TLD-based quality assurance networks for radiotherapy. Countries marked in grey participate in the IAEA/WHO TLD postal dose audit programme. Countries marked in black have either their national TLD networks or participate in an international network other than the IAEA/WHO. White dots indicate TLD networks co-operating with the IAEA. Countries not coloured either do not have radiotherapy or do not participate in the existing TLD networks.</note><note type="content">Fig. 2: The distribution of the percentage of beam checks in different regions in 1969–1998. The results pertain to 101 countries, 1003 hospitals in which 3307 beams were checked.</note><note type="content">Fig. 3: Percentage of TLD audits for different photon beam qualities, Co-60 and high energy photons up to 25 MV, which were checked in 1991–1998, i.e. since the high energy X-rays were included in the TLD programme. The results pertain to 1338 beam checks.</note><note type="content">Fig. 4: Improvement in return rate from hospitals in the IAEA/WHO dosimetry programme.</note><note type="content">Fig. 5: Distribution of the results of the IAEA/WHO TLD postal dose audits of radiotherapy hospitals for the delivery of absorbed dose to water under reference conditions during 1969–1998. Data in the graph correspond to ratios of the IAEA's determined dose (DTLD) relative to the dose stated by the hospital (Dstat). Each data point corresponds to the average of three dosimeters (two after 1998). A total of 3307 beam calibrations were checked in 1003 hospitals. The mean distribution is 1.013 and the standard deviation is 8.8%. The deviations vary between a minimum DTLD/Dstat ratio of 0.535 and a maximum of 2.188. Fifteen deviations outside ±40% are not shown in the graph. Approximately 32% of the results are outside the ±5% acceptance limits.</note><note type="content">Fig. 6: Results of the IAEA/WHO TLD postal dose audits of radiotherapy hospitals for the delivery of absorbed dose to water under reference conditions during 1996–1998. Data in the graph correspond to ratios of the IAEA's determined dose (DTLD) relative to the dose stated by the hospital (Dstat). Each data point corresponds to the average of two dosimeters (three before 1998). A total of 688 beam calibrations were checked. Approximately 19% of the results were found outside the ±5% acceptance level. The black dots indicate the deviations which have not been yet corrected in follow-up actions. The two extreme deviations have been explained and corrected: DTLD/Dstat=1.79 was due to an accident in radiotherapy; DTLD/Dstat=1.99 was due to double irradiation of the TLDs and had no clinical relevance.</note><note type="content">Fig. 7: The TLD results for Latin America and Caribbean region. The column bar graph shows the cumulative number of the beam audits in the region. The curve shows the percentage of beams checked in each period with the results within the ±5% acceptance limit. The results pertain to 1221 beam checks in 1969–1998.</note><note type="content">Fig. 8: The percentage of results of beam audits within ±5%, 5–10%, 10–20% and outside 20%. The upper pie chart (a) shows the results for 1969–1998 and the lower one (b) shows the results for 1996–1998. The results within ±5% correspond to the required level for ‘acceptable radiotherapy treatment’ [15]. The results within 5–10% limits are considered within the ‘tolerable’ category, whereas for the results within 10–20% benefit from the radiation treatment is questionable; the results showing discrepancies larger than 20% might be considered accidents in radiotherapy.</note><note type="content">Table 1: Percentage of beams checked in Africa in 1969–1998 with results within the ±5% acceptance limit</note><subject lang="en"><genre>Keywords</genre><topic>QA in radiotherapy</topic><topic>TLD audits</topic><topic>Beam output checks</topic><topic>High energy photons</topic></subject><relatedItem type="host"><titleInfo><title>Radiotherapy and Oncology</title></titleInfo><titleInfo type="abbreviated"><title>RADION</title></titleInfo><genre type="journal">journal</genre><originInfo><dateIssued encoding="w3cdtf">20000101</dateIssued></originInfo><identifier type="ISSN">0167-8140</identifier><identifier type="PII">S0167-8140(00)X0060-6</identifier><part><date>20000101</date><detail type="volume"><number>54</number><caption>vol.</caption></detail><detail type="issue"><number>1</number><caption>no.</caption></detail><extent unit="issue pages"><start>1</start><end>89</end></extent><extent unit="pages"><start>65</start><end>72</end></extent></part></relatedItem><identifier type="istex">199BC55583D40B7C17F7D7386F54A60A615FD32C</identifier><identifier type="DOI">10.1016/S0167-8140(99)00164-4</identifier><identifier type="PII">S0167-8140(99)00164-4</identifier><accessCondition type="use and reproduction" contentType="copyright">©2000 Elsevier Science Ireland Ltd</accessCondition><recordInfo><recordContentSource>ELSEVIER</recordContentSource><recordOrigin>Elsevier Science Ireland Ltd, ©2000</recordOrigin></recordInfo></mods></metadata><serie></serie></istex></record>Pour manipuler ce document sous Unix (Dilib)
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