An on-line replanning scheme for interfractional variations. Med Phys 2008 Aug;35(8):3607-15
Date
09/10/2008Pubmed ID
18777921DOI
10.1118/1.2952443Scopus ID
2-s2.0-48349124822 (requires institutional sign-in at Scopus site) 115 CitationsAbstract
Ability of online adaptive replanning is desirable to correct for interfraction anatomic changes. A full-scope replanning/reoptimization with the current planning techniques takes too long to be practical. A novel online replanning strategy to correct for interfraction anatomic changes in real time is presented. The scheme consists of three steps: (1) rapidly delineating targets and organs at risk on the computed tomography of the day by modifying original planning contours using robust tools in a semiautomatic manner, (2) online segment aperture morphing (SAM) (adjusting beam/ segment apertures) by applying the spatial relationship between the planning target contour and the apertures to the new target contour, and (3) performing segment weight optimization (SWO) for the new apertures if necessary. The entire scheme was tested for direct-aperture-based IMRT on representative prostate and abdomen cases. Dose volume histograms obtained with the online scheme are practically equivalent to those obtained with full-scope reoptimization. For the days of small to moderate organ deformations, only the SAM is necessary, while for the large deformation days, both SAM and SWO are required to adequately account for the deformation. Both the SAM and SWO programs can be completed within 1 min, and the overall process can be completed within 10 min. The proposed SAM-SWO scheme is practically comparable to full-scope reoptimization, but is fast enough to be implemented for on-line adaptive replanning, enabling dose-guided RT.
Author List
Ahunbay EE, Peng C, Chen GP, Narayanan S, Yu C, Lawton C, Li XAAuthors
Ergun Ahunbay PhD Professor in the Radiation Oncology department at Medical College of WisconsinGuang-Pei Chen PhD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AutomationHumans
Male
Pancreatic Neoplasms
Prostate
Prostatic Neoplasms
Radiation Dosage
Radiography, Abdominal
Radiotherapy, Computer-Assisted
Rectum
Tomography, X-Ray Computed
Urinary Bladder
