PURPOSE: We have created an automated process using real-time tracking data to evaluate the adequacy of planning target volume ( @entity343 ) margins in @entity263 , allowing a process of adaptive radiotherapy with minimal physician workload. We present an analysis of @entity343 adequacy and a proposed adaptive process. METHODS AND MATERIALS: Tracking data were analyzed for 15 @entity1 who underwent step-and-shoot multi-leaf collimation (SMLC) intensity-modulated radiation therapy (IMRT) with uniform 5-mm @entity343 margins for @entity263 using the Calypso   Localization System. Additional plans were generated with 0- and 3-mm margins. A custom software application using the planned dose distribution and structure location from computed tomography (CT) simulation was developed to evaluate the dosimetric impact to the target due to motion. The dose delivered to the prostate was calculated for the initial three, five, and 10 fractions, and for the entire treatment. Treatment was accepted as adequate if the minimum delivered prostate dose (D(min)) was at least 98% of the planned D(min). RESULTS: For 0-, 3-, and 5-mm @entity343 margins, adequate treatment was obtained in 3 of 15, 12 of 15, and 15 of 15 @entity1 , and the delivered D(min) ranged from 78% to 99%, 96% to 100%, and 99% to 100% of the planned D(min). Changes in D(min) did not correlate with magnitude of prostate motion. Treatment adequacy during the first 10 fractions predicted sufficient dose delivery for the entire treatment for all @entity1 and margins. CONCLUSIONS: Our adaptive process successfully used real-time tracking data to predict the need for @entity343 modifications, without the added burden of physician contouring and image analysis. Our methods are applicable to other uses of real-time tracking, including hypofractionated treatment.

Practical method of adaptive radiotherapy for XXXX using real-time electromagnetic tracking.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity263 :: ('MESH:D011471', 'Disease') :: ['prostate cancer'] @entity343 :: ('187978', 'Species') :: ['PTV']
@entity263 :: (MESH:D011471,Disease) :: ['prostate cancer']
