{"created":"2023-05-15T14:47:55.895882+00:00","id":65693,"links":{},"metadata":{"_buckets":{"deposit":"3b75c8d5-9e0c-437f-9264-9cefa8865682"},"_deposit":{"created_by":1,"id":"65693","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"65693"},"status":"published"},"_oai":{"id":"oai:repo.qst.go.jp:00065693","sets":["10:29"]},"author_link":["647132","647133"],"item_10005_date_7":{"attribute_name":"発表年月日","attribute_value_mlt":[{"subitem_date_issued_datetime":"2012-12-08","subitem_date_issued_type":"Issued"}]},"item_10005_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Introduction: Prostate treatment by charged particles\noffers a high conformity due to their characteristic\ndepth dose distribution known as the Bragg\npeak. This results in good local control with minimal\ndosages to the surrounding normal tissue. To benefit\nmaximally from a highly conformal treatment precise\nknowledge of the tumor position and its adjacent\norgans at risk such as the rectum is mandatory.\nRespiratory motion changes anatomical and tumor\nposition as a function of time, hence the dose to\nnormal tissues is increased. To our knowledge, the\ndosimetric effect due to intrafractional motion has\nnot yet been evaluated for prostate therapy. Our institution\nuses a carbon-ion beam for prostate therapy\nunder free-breathing conditions. It may be affected\nby intrafractional motion.\nWe quantified prostate motion and water equivalent\npathlength (WEPL) due to respiratory induced\nintrafractional motion by using 4DCT.\nMaterials and Methods: Each patient lay on the\nCT couch in supine position with immobilization\nshell device to be similar situation to treatment.\n4DCT scans of 20 patients (mean, 66.7 y; s.d. 5.5 y)\nwere acquired under free-breathing conditions using\na 256 multi-slice CT scanner. The CTV was defined\nas the prostate and the seminal vesicle. PTV was\ndefined by adding 10 mm to the anterior and lateral\nsides and 5 mm to the posterior side of the CTV\nWe evaluated the prostate center of mass (COM)\ntrajectory in a single respiratory motion.\nWEPL, which is calculated by mapping the physical\nlength to the radiological water equivalent pathlength,\nfor a single respiratory cycle were calculated.\nWe set the ROI1, ROI2 and ROI3 projected region\nover the PTV, the anterior side and posterior side,\nrespectively, to evaluate WEPL.\nResults: Intrafractional prostate motion average\nover all patients was 0.1mm (<0.2mm), 0.0mm\n(<0.2mm), 0.0mm (<0.2mm), 0.2mm (<0.5mm),\n0.1mm (<0.7mm), 0.1mm (<0.5mm) for left, right,\nanterior, posterior, superior and inferior directions,\nrespectively.\nThe abdominal thickness variation map (Tn minus\nT50) were increased around inhalation phase.\nThe variations of the abdominal thickness averaged\nover all patients are 0.7±0.6mm WEPL for ROI1,\n1.2±0.4mm WEPL for ROI2 and 0.3mm±0.4mm\nWEPL for ROI3.\nConclusion: Prostate motion were not significantly\naffected by respiration, however, a respiratory-\ninduced abdominal thickness change was identified\nas a factor affecting dose variation even though\nthe prostate motion was small (<0.7mm). It is important\nto consider the geometrical changes from the\nbeam entrance to the target as well as the target motion\nespecially in particle therapy.","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":"MICRO- MINI- AND NANO- DOSIMETRY  &  INTERNATIONAL PROSTATE CANCER TREATMENT WORKSHOP","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":"Mori, Shinichiro"}],"nameIdentifiers":[{"nameIdentifier":"647132","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"森 慎一郎","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"647133","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":"Four-dimensional measurement of intrafractional respiratory prostate motion using 4DCT","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Four-dimensional measurement of intrafractional respiratory prostate motion using 4DCT"}]},"item_type_id":"10005","owner":"1","path":["29"],"pubdate":{"attribute_name":"公開日","attribute_value":"2015-06-30"},"publish_date":"2015-06-30","publish_status":"0","recid":"65693","relation_version_is_last":true,"title":["Four-dimensional measurement of intrafractional respiratory prostate motion using 4DCT"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-05-15T20:57:18.329871+00:00"}