High dose three-dimensional conformal boost (3DCB) using an orthogonal diagnostic X-ray set-up for patients with gynecological malignancy: a new application of real-time tumor-tracking system.

摘要

The feasibility and accuracy of high dose three-dimensional conformal boost (3DCB) using three internal fiducial markers and a two-orthogonal X-ray set-up of the real-time tumor-tracking system on patients with gynecological malignacy were investigated in 10 patients. The standard deviation of the distribution of systematic deviations (Sigma) was reduced from 3.8, 4.6, and 4.9mm in the manual set-up to 2.3, 2.3 and 2.7mm in the set-up using the internal markers. The average standard deviation of the distribution of random deviations (sigma) was reduced from 3.7, 5.0, and 4.5mm in the manual set-up to 3.3, 3.0, and 4.2mm in the marker set-up. The appropriate PTV margin was estimated to be 10.2, 12.8, and 12.9mm in the manual set-up and 6.9, 6.7, and 8.3mm in the gold marker set-up, respectively, using the formula 2Sigma+0.7sigma. Set-up of the patients with three markers and two fluoroscopy is useful to reduce PTV margin and perform 3DCB.