{"created":"2023-05-15T14:50:08.933644+00:00","id":68583,"links":{},"metadata":{"_buckets":{"deposit":"514d6855-9f08-4778-b743-4c87480cd012"},"_deposit":{"created_by":1,"id":"68583","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"68583"},"status":"published"},"_oai":{"id":"oai:repo.qst.go.jp:00068583","sets":["10:28"]},"author_link":["673105","673104"],"item_10005_date_7":{"attribute_name":"発表年月日","attribute_value_mlt":[{"subitem_date_issued_datetime":"2006-06-30","subitem_date_issued_type":"Issued"}]},"item_10005_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"In the past decade the hadron beams have attracted growing interest in cancer therapy. This could be attributed to their capability to deliver dose very selectively to a defined target volume while protecting the surrounding healthy tissue. In order to make the most use of their advantage and achieve accurate treatment, it is important to evaluate the range of incident ions and deposit dose distribution in a patients body. Although several methods have been proposed for this purpose, the utilization of positron emitters induced by therapeutic irradiation is at present the only feasible method for an in situ and non-invasive monitoring of hadron therapy. The annihilation gamma ray distribution can be obtained by annihilation events of the positron emitters with a PET apparatus or a positron camera. The detected distribution has information about the range of incident ions and deposit dose distribution in a target. In this study, we performed irradiation experiments with mono-energetic Bragg peak (MONO) beams of proton (160MeV), 12C (290MeV/u) and 16O (350MeV/u) to a water target. Pairs of annihilation gamma rays emitted from positron emitters induced in a target were detected with a positron camera and the annihilation gamma ray distributions were obtained. The maximum likelihood estimation (MLE) method was applied to these detected distributions for determining the ranges of incident ions. When the range of them was determined with the MLE procedure, the annihilation gamma ray distribution has to be calculated which gave the maximum value in likelihood against the detected distribution. The physical quantities need to be derived for estimating the deposit dose distribution, such as the fluence and the energy loss of all ions traveling in a target, have already been obtained in the calculation of the annihilation gamma ray distribution. Therefore, the determination of the particle range with the MLE method is corresponding to the derivation of most probable dose distribution deposit on a target by incident ions. The derived dose distributions for three species of MONO beams were compared with the ones measured with the ionization chamber in water. The good reproduction of measured ones implied that the deposit dose distribution in a target could be estimated from the detected annihilation gamma ray distribution with a positron camera.","subitem_description_type":"Abstract"}]},"item_10005_description_6":{"attribute_name":"会議概要（会議名, 開催地, 会期, 主催者等）","attribute_value_mlt":[{"subitem_description":"Imaging2006","subitem_description_type":"Other"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"metadata only access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_14cb"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Inaniwa, Taku"}],"nameIdentifiers":[{"nameIdentifier":"673104","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"稲庭 拓","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"673105","nameIdentifierScheme":"WEKO"}]}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"conference object","resourceuri":"http://purl.org/coar/resource_type/c_c94f"}]},"item_title":"Visualization of deposit dose with induced BETA+ activity in hadron therapy","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Visualization of deposit dose with induced BETA+ activity in hadron therapy"}]},"item_type_id":"10005","owner":"1","path":["28"],"pubdate":{"attribute_name":"公開日","attribute_value":"2006-07-07"},"publish_date":"2006-07-07","publish_status":"0","recid":"68583","relation_version_is_last":true,"title":["Visualization of deposit dose with induced BETA+ activity in hadron therapy"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-05-15T20:24:30.962543+00:00"}