Global convergence analysis of fast multiobjective gradient-based dose optimization algorithms for high-dose-rate brachytherapy

Lahanas, M; Baltas, D; Giannouli, S

dc.contributor.author	Lahanas, M	en
dc.contributor.author	Baltas, D	en
dc.contributor.author	Giannouli, S	en
dc.date.accessioned	2014-03-01T01:19:01Z
dc.date.available	2014-03-01T01:19:01Z
dc.date.issued	2003	en
dc.identifier.issn	0031-9155	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15326
dc.subject.classification	Engineering, Biomedical	en
dc.subject.classification	Radiology, Nuclear Medicine & Medical Imaging	en
dc.subject.other	Algorithms	en
dc.subject.other	Computational methods	en
dc.subject.other	Convergence of numerical methods	en
dc.subject.other	Dosimetry	en
dc.subject.other	Respiratory therapy	en
dc.subject.other	Simulated annealing	en
dc.subject.other	Brachytherapy	en
dc.subject.other	Radiotherapy	en
dc.subject.other	algorithm	en
dc.subject.other	article	en
dc.subject.other	brachytherapy	en
dc.subject.other	controlled study	en
dc.subject.other	dosimetry	en
dc.subject.other	implant	en
dc.subject.other	intermethod comparison	en
dc.subject.other	mathematical computing	en
dc.subject.other	priority journal	en
dc.subject.other	process optimization	en
dc.subject.other	prostate	en
dc.subject.other	radiation dose	en
dc.subject.other	simulation	en
dc.subject.other	time	en
dc.subject.other	treatment planning	en
dc.subject.other	Algorithms	en
dc.subject.other	Brachytherapy	en
dc.subject.other	Humans	en
dc.subject.other	Male	en
dc.subject.other	Prostatic Neoplasms	en
dc.subject.other	Quality Control	en
dc.subject.other	Radiometry	en
dc.subject.other	Radiotherapy Dosage	en
dc.subject.other	Radiotherapy Planning, Computer-Assisted	en
dc.subject.other	Reproducibility of Results	en
dc.subject.other	Sensitivity and Specificity	en
dc.title	Global convergence analysis of fast multiobjective gradient-based dose optimization algorithms for high-dose-rate brachytherapy	en
heal.type	journalArticle	en
heal.identifier.primary	10.1088/0031-9155/48/5/304	en
heal.identifier.secondary	http://dx.doi.org/10.1088/0031-9155/48/5/304	en
heal.language	English	en
heal.publicationDate	2003	en
heal.abstract	We consider the problem of the global convergence of gradient-based optimization algorithms for interstitial high-dose-rate (HDR) brachytherapy dose optimization using variance-based objectives. Possible local minima could lead to only sub-optimal solutions. We perform a configuration space analysis using a representative set of the entire non-dominated solution space. A set of three prostate implants is used in this study. We compare the results obtained by conjugate gradient algorithms, two variable metric algorithms and fast-simulated annealing. For the variable metric algorithm BFGS from numerical recipes, large fluctuations are observed. The limited memory L-BFGS algorithm and the conjugate gradient algorithm FRPR are globally convergent. Local minima or degenerate states are not observed. We study the possibility of obtaining a representative set of non-dominated solutions using optimal solution rearrangement and a warm start mechanism. For the surface and volume dose variance and their derivatives, a method is proposed which significantly reduces the number of required operations. The optimization time, ignoring a preprocessing step, is independent of the number of sampling points in the planning target volume. Multiobjective dose optimization in HDR brachytherapy using L-BFGS and a new modified computation method for the objectives and derivatives has been accelerated, depending on the number of sampling points, by a factor in the range 10-100.	en
heal.publisher	IOP PUBLISHING LTD	en
heal.journalName	Physics in Medicine and Biology	en
dc.identifier.doi	10.1088/0031-9155/48/5/304	en
dc.identifier.isi	ISI:000181958500004	en
dc.identifier.volume	48	en
dc.identifier.issue	5	en
dc.identifier.spage	599	en
dc.identifier.epage	617	en