Banca de QUALIFICAÇÃO: HUDSON GEOVANE DE MEDEIROS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : HUDSON GEOVANE DE MEDEIROS
DATE: 10/12/2019
TIME: 14:00
LOCAL: Auditório I - DIMAp
TITLE:

A multiobjective approach to the leaf sequencing problem on intensity modulated radiation therapy

KEY WORDS:

Radiation therapy, Multileaf collimator, Leaf sequencing

PAGES: 66
BIG AREA: Ciências Exatas e da Terra
AREA: Ciência da Computação
SUBÁREA: Sistemas de Computação
SPECIALTY: Arquitetura de Sistemas de Computação
SUMMARY:

Algorithms are an essential part of the radiation therapy planning which consists of three major problems: beam angle and fluence map optimization, and realization. The issue of this study is the third problem, also called leaf sequencing.  It consists in defining a sequence of configurations of a device (called multileaf collimator) that correctly delivers radiation to the patient.  A usual model for this problem is the decomposition of a matrix into a weighted sum of (0,1)-matrices, called segments, in which the ones in each row appear consecutively. Other constraints can also be considered. Each (0,1)-matrix corresponds to a configuration of the device.  The realization problem has three objectives. The first one is to minimize the sum of weights assigned to the (0,1)-matrices. The second is to minimize the number of segments. Finally, the third one is to find the best order to apply those configurations. This study presents a greedy and randomized algorithm to this problem and compares it to other multi-objective algorithm presented previously in the literature. Statistical tests show that our algorithm outperformed the previous one on all indicators.

BANKING MEMBERS:
Presidente - 1201268 - ELIZABETH FERREIRA GOUVEA GOLDBARG
Interno - 1149561 - MARCO CESAR GOLDBARG
Externa ao Programa - 1885001 - ANNA GISELLE CAMARA DANTAS RIBEIRO RODRIGUES
Externa à Instituição - THALITA MONTEIRO OBAL - UTFPR