Matches in SemOpenAlex for { <https://semopenalex.org/work/W2079605470> ?p ?o ?g. }
Showing items 1 to 62 of
62
with 100 items per page.
- W2079605470 abstract "Purpose: An anatomic aperture‐based IMRT optimization program, named Ballista, was developed at our institution. Even though studies previously published concluded local minima in full‐IMRT optimization were not problematic, early observations with Ballista revealed their nuisance. The purpose of the present study was to evaluate the extent of local minima and their impact on the optimization. Method and Materials: In Ballista beam weights are optimized by quasi‐Newton algorithm, which cannot escape local minima, even with a quadratic dose‐based objective function. Therefore, a large number of descents were launched with random initial weights to explore the solution space for a varying number of beams. Treatment plan DVHs of different local minima were also analyzed. Results: When four beam weights were optimized, only a few but very distinctive local minima were found. For a case of 20 beam weights, the optimization revealed an astonishing number of local minima. DVH analysis showed local minima generally favor one or more organs‐at‐risk (OARs) while the other objectives are less than optimal compared with the global minimum. It was found that limiting the initial beam weights to small values eliminates the majority of the solution space containing local minima. Conclusion: With Ballista local minima proved to be a major problem. Plans corresponding to different minima differed drastically. In order to give the optimization a “clear shot” at the global minimum, initial beam weights must be limited to small values. The optimization thus focuses on improving the target volume objectives since all OARs objectives are initially met." @default.
- W2079605470 created "2016-06-24" @default.
- W2079605470 creator A5017572322 @default.
- W2079605470 creator A5049072127 @default.
- W2079605470 creator A5063138480 @default.
- W2079605470 creator A5065902978 @default.
- W2079605470 date "2005-06-23" @default.
- W2079605470 modified "2023-10-18" @default.
- W2079605470 title "Po-Poster - 19: Local minima in anatomic aperture-based IMRT optimization" @default.
- W2079605470 doi "https://doi.org/10.1118/1.2030998" @default.
- W2079605470 hasPublicationYear "2005" @default.
- W2079605470 type Work @default.
- W2079605470 sameAs 2079605470 @default.
- W2079605470 citedByCount "0" @default.
- W2079605470 crossrefType "journal-article" @default.
- W2079605470 hasAuthorship W2079605470A5017572322 @default.
- W2079605470 hasAuthorship W2079605470A5049072127 @default.
- W2079605470 hasAuthorship W2079605470A5063138480 @default.
- W2079605470 hasAuthorship W2079605470A5065902978 @default.
- W2079605470 hasConcept C120665830 @default.
- W2079605470 hasConcept C121332964 @default.
- W2079605470 hasConcept C126255220 @default.
- W2079605470 hasConcept C127413603 @default.
- W2079605470 hasConcept C134306372 @default.
- W2079605470 hasConcept C137836250 @default.
- W2079605470 hasConcept C168834538 @default.
- W2079605470 hasConcept C186633575 @default.
- W2079605470 hasConcept C188198153 @default.
- W2079605470 hasConcept C24890656 @default.
- W2079605470 hasConcept C33923547 @default.
- W2079605470 hasConcept C78336883 @default.
- W2079605470 hasConcept C78519656 @default.
- W2079605470 hasConceptScore W2079605470C120665830 @default.
- W2079605470 hasConceptScore W2079605470C121332964 @default.
- W2079605470 hasConceptScore W2079605470C126255220 @default.
- W2079605470 hasConceptScore W2079605470C127413603 @default.
- W2079605470 hasConceptScore W2079605470C134306372 @default.
- W2079605470 hasConceptScore W2079605470C137836250 @default.
- W2079605470 hasConceptScore W2079605470C168834538 @default.
- W2079605470 hasConceptScore W2079605470C186633575 @default.
- W2079605470 hasConceptScore W2079605470C188198153 @default.
- W2079605470 hasConceptScore W2079605470C24890656 @default.
- W2079605470 hasConceptScore W2079605470C33923547 @default.
- W2079605470 hasConceptScore W2079605470C78336883 @default.
- W2079605470 hasConceptScore W2079605470C78519656 @default.
- W2079605470 hasLocation W20796054701 @default.
- W2079605470 hasOpenAccess W2079605470 @default.
- W2079605470 hasPrimaryLocation W20796054701 @default.
- W2079605470 hasRelatedWork W1971242297 @default.
- W2079605470 hasRelatedWork W2001088856 @default.
- W2079605470 hasRelatedWork W2005305266 @default.
- W2079605470 hasRelatedWork W2076426639 @default.
- W2079605470 hasRelatedWork W2113201845 @default.
- W2079605470 hasRelatedWork W2171768024 @default.
- W2079605470 hasRelatedWork W2748952813 @default.
- W2079605470 hasRelatedWork W2770701828 @default.
- W2079605470 hasRelatedWork W2899084033 @default.
- W2079605470 hasRelatedWork W2184418691 @default.
- W2079605470 isParatext "false" @default.
- W2079605470 isRetracted "false" @default.
- W2079605470 magId "2079605470" @default.
- W2079605470 workType "article" @default.