{"created":"2023-05-15T14:52:04.500642+00:00","id":71162,"links":{},"metadata":{"_buckets":{"deposit":"fa0024f2-3d73-490a-9efb-e66afb830cb3"},"_deposit":{"created_by":1,"id":"71162","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"71162"},"status":"published"},"_oai":{"id":"oai:repo.qst.go.jp:00071162","sets":["10:28"]},"author_link":["699587","699586"],"item_10005_date_7":{"attribute_name":"発表年月日","attribute_value_mlt":[{"subitem_date_issued_datetime":"2013-06-08","subitem_date_issued_type":"Issued"}]},"item_10005_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Aim\nTo treat moving tumors 4DCT imaging is mandatory to perform an adequate planning. Generally the 4DCT consists of ten 3DCTs associated to ten phases. Within a CT phase the motion is frozen and errors in geometry and range are inevitable while performing treatment. The use of amplitude spaced 4DCT allows for a better control of these errors. With this study we want to investigate how many CTs are required for adequate planning since the workload increases significantly for the clinical staff if 4DCT based treatment planning becomes the standard.\n\\nMethods\nFor the numerical NCAT phantom dose distributions for a moving liver tumor have been planned and simulated for various spacing between the CT images. The resultant dose distributions have been compared and evaluated on target coverage and dose homogeneity. This metrics were used to find the optimal spacing that yielded to a good treatment planning dose distribution while keeping treatment planning manageable in terms of time and effort.\n\\nResults\nA CT spacing of 1mm served as reference case which is though unfeasible in daily practice since it will lead to 21 CT images for a motion amplitude of 1 cm. The dose distributions and target coverage for 2mm and 3mm were closely similar and almost all voxels within the CTV passed the gamma index criteria (3mm, 3% dose) as compared to the reference dose distribution. For a larger spacing (4mm, 6mm, 12mm) the dose distributions started to differ significantly. This is mainly due to a smaller target volume used in the treatment planning process and associated range uncertainties caused by a lower 4DCT resolution.\n\\nConclusions\nWe think that 4DCT for treatment planning should be amplitude spaced but current CT scanners do generally not yet provide this option. Regarding treatment planning we are confident that a spacing of 3-4 mm between the CTs of a 4DCT is sufficient for Liver tumors. However, for tumors at different sites, such as lung, we will need a separate analysis due to the high variability in density.","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":"PTCOG52","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":"Marius, Zenklusen Silvan"}],"nameIdentifiers":[{"nameIdentifier":"699586","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"Ｚｅｎｋｌｕｓｅｎ Ｓｉｌｖａｎ Ｍａｒｉｕｓ","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"699587","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":"Impact of different number of CT images on 4DCT based treatment planning dose distributions for scanned particle beams","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Impact of different number of CT images on 4DCT based treatment planning dose distributions for scanned particle beams"}]},"item_type_id":"10005","owner":"1","path":["28"],"pubdate":{"attribute_name":"公開日","attribute_value":"2013-06-20"},"publish_date":"2013-06-20","publish_status":"0","recid":"71162","relation_version_is_last":true,"title":["Impact of different number of CT images on 4DCT based treatment planning dose distributions for scanned particle beams"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-05-15T19:54:28.846683+00:00"}