tailieunhanh - Báo cáo khoa học: "Planning target volume margins for prostate radiotherapy using daily electronic portal imaging and implanted fiducial markers"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Planning target volume margins for prostate radiotherapy using daily electronic portal imaging and implanted fiducial markers. | Skarsgard et al. Radiation Oncology 2010 5 52 http content 5 1 52 RADIATION ONCOLOGY RESEARCH Open Access Planning target volume margins for prostate radiotherapy using daily electronic portal imaging and implanted fiducial markers ri .i ie l Qlz3rcd3rH1 t dmrn2 Ạ Ii p _rs .i oe l -ũLĩr C 4 PeìtricTni5 i l .K loorr Pon ov4 Inekcew A I1 Ddvid okdisydiu Pat Lduman All El Gdyed Robert Pedrcey Pdtricid Idi NdUcciii Pervez Jdckson 1 wu Abstract Background Fiducidl mdrkers dnd ddily electronic portdl imdging EPI cdn reduce the risk of geographic miss in prostdte cdncer radiotherapy. The purpose of this study wds to estimdte CTV to PTV mdrgin requirements without dnd with the use of this imdge guiddnce strategy. Methods 46 pdtients underwent pldcement of 3 rddio-opdque fiducidl mdrkers prior to prostdte RT. Ddily pre-tredtment EPIs were tdken dnd isocenter pldcement errors were corrected if they were 3 mm dlong the left-right or superior-inferior dxes dnd or 2 mm dlong the dnterior-posterior dxis. During-tredtment EPIs were then obtdined to estimdte intrd-frdction motion. Results Without imdge guiddnce mdrgins of cm cm dnd cm dlong the left-right superior-inferior dnd dnterior-posterior dxes respectively dre required to give 95 probdbility of complete CTV coverage edch ddy. With the dbove imdge guiddnce strategy these mdrgins cdn be reduced to cm cm dnd cm respectively. Correction of dll isocenter pldcement errors regdrdless of size would permit minimdl ddditiondl reduction in mdrgins. Conclusions Imdge guiddnce using impldnted fiducidl mdrkers dnd ddily EPI permits the use of ndrrower PTV mdrgins without compromising coverdge of the tdrget in the rddiotherdpy of prostdte cdncer. Background Several randomized trials have shown improved biochemical relapse-free survival with the use of higher doses of radiotherapy RT in subsets of patients with organ-confined prostate cancer 1-3 . Although such higher doses may result in a .