Thesis (Ph.D.)--University of Wisconsin--Madison, 1993. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 199-207).

Two-dimensional transmission dosimetry in radiotherapy has been discussed in the literature for some time as being a potential method for in vivo dosimetry. However, it still remains to become a wide spread practice in radiotherapy clinics. This is most likely due to the variety in radiotherapy treatment sites and the challenges they would present in terms of detection and interpretation at the transmitted dose level. Thus, the full potential and limitations of applying transmission dosimetry in the presence of dosimetry errors still need to be demonstrated. This thesis is a theoretical evaluation of transmission dosimetry using the Pinnacle3 treatment planning system. The accuracy of predicting reliable and accurate absolute transmitted dose maps using the planning system dose algorithm for comparison with measured transmitted dose maps was initially investigated. The resolution in the dose calculations at the transmitted level was then evaluated for rectilinear and curved homogeneous phantoms and rectilinear inhomogeneous phantoms, followed by studies combining both surface curvature and heterogeneities using anthropomorphic phantoms. In order to perform transmitted dose calculations at clinically relevant beam focus-to-transmitted dose plane distances using clinical patient CT data it was first necessary to extend the CT volume. Finally, the thesis explored the efficacy of applying transmission dosimetry in the clinic by simulating realistic dosimetry errors in the planning system using patient treatment plans for a prostate, head and neck, and breast CRT (Conformal Radiotherapy) treatment. Any differences at the transmitted dose level were interpreted and quantified using the gamma formalism. To determine whether the transmitted dose alone was a sufficient indicator of the dosimetry errors, the magnitude in transmission dose differences were compared with those predicted at the midplane of the patient. Dose-Volume Histograms (DVHs) were also used to evaluate the clinical significance of the dose delivery errors on the target volume and surrounding healthy tissue structures. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339807 / Thesis (Ph.D.) - University of Adelaide, School of Chemistry and Physics, 2008

BACKGROUND : Radiation oncology was these 20 last years revolutionized by the 3-dimensional conformal radiotherapy (3D-CRT) and its technical evolution, the intensity modulated radiotherapy (IMRT). Thanks to steep dose gradient dose distribution, these techniques allow to conform the prescribed dose to the Planning Target Volume (PTV) while significantly decreasing the dose delivered to the Organs at Risk (OAR). One critical step remains the accurate definition of the Gross Tumor Volume (GTV). If the GTV is underestimated, there is a risk of missing part of the target. If the GTV is overestimated, the risk is to overirradiate normal tissues. Today's gold standard for GTV definition is the Computed Tomography (CT) scanner. We though know that its poor soft tissues contrast is a factor of variability for target definition purpose. AIMS : It can be hypothesized that, for Head and Neck Squamous Cell Carcinomas located in the oropharynx or the laryngo-hypopharynx, the use of other anatomical (like Magnetic Resonance Imaging – MRI) or functional (like positron emission tomography with either 11C-methionine – MET-PET- or 18F-fluorol-deoxy-glucose – FDG-PET) imaging modalities could complement CT for GTV delineation, and have an impact on subsequent CTV and PTV delineation and dose distribution to the non target tissues outside the PTV. RESULTS : We could demonstrate that, providing an adequate and controlled methodology concerning image coregistration and tumor volume delineation on functional images, differences were observed for the delineation of primary tumor volume or GTV according to the modality used. Moreover, the trends were the same for both locations studied (oropharyngeal and laryngo-hypopharyngeal) : CT, MRI and MET-PET volumes were not significantly different in absolute volumes, but there was no total overlap, each imaging modality having the tendency to visualize different types and relatively specific pathways of tumor extension (e.g. : cartilages in MRI). What was very interesting was the significantly smaller FDG-PET volume which could have a real impact on radiation oncology practice by (1) allowing to reduce dose distribution and (2) providing fast and reproducible GTV delineation based on its functional characteristic. Furthermore, we could demonstrate on the subset of operated patients that these smaller FDG-PET volumes were not the fact of a volume underestimating delineation algorithm but well the reflection of true tumor extension. But one must keep in mind that because of spatial resolution limitations, there was still a significant overestimate of this true GTV. Also, none of the imaging modalities was able to visualize very small tumor extensions. This last fact put in the light the need for strict guidelines for CTV prediction based on GTV extension. This is what was done with the help of both anatomical and histo-pathological literature data. These guidelines were used to delineate CTVs on our images, allowing to perform comparative planning on primary tumor. It could be concluded that differences in GTV had not only an impact on CTV and subsequent PTV, but also on dose distribution, either on total irradiated volume or -perhaps more important- on mean dose to parotid glands. No significant effect could be observed on maximal dose to spinal cord. Compared to planning performed on macroscopy-based volumes, no significant difference could be found with what was done on PET-derived planning. CONCLUSION : This research paves the way for the use of FDG-PET for GTV delineation in planning the patients with oropharyngeal and laryngo-hypopharyngeal squamous cell carcinomas. / INTRODUCTION : La radiothérapie moderne a terriblement évolué ces 20 dernières années grâce au développement de la radiothérapie conformationnelle tridimensionnelle (3D-CRT) et de son évolution technique, la radiothérapie par modulation d'intensité (IMRT). Grâce à la création de gradients de dose très raides, ces techniques permettent de conformer au mieux la distribution de la dose au “Planning Target Volume” (PTV) tout en diminuant de manière significative la dose délivrée aux Organes à Risque (OAR). La précision de la définition du “Gross Tumor Volume” (GTV) ou volume tumoral macroscopique reste une étape cruciale dans le sens où une sous-estimation du volume augmente le risque de sous-doser la dose délivrée à la tumeur. Dans l'autre sens, la surestimation du volume tumoral conduit immanquablement à une surirradiation des tissus sains. La tomographie computée par scanner (CT) est l'imagerie de référence pour la définition du GTV. Cependant, le manque de constraste entre tissus mous – à fortiori entre la tumeur et les tissus environnants- constitue un facteur de variabilité reconnu quant à la précision de délimitation du GTV. BUTS : Pour les cancers de la sphère cervico-maxillo-faciale, en particulier pour les tumeurs épithéliales oropharyngées et laryngo-hypopharyngées, démontrer que l'usage complémentaire d'une autre imagerie anatomique comme la résonance magnétique (IRM) ou fonctionnelle comme la tomographie par émission de positrons utilisant soit la méthionine marquée au carbone 11 (MET-TEP), soit le fluoro-déoxy-glucose marqué au fluor 18 (FDG-TEP) peut améliorer la précision de la délimitation GTV. Dans ce cas, démontrer également que cela a un impact sur la délimitation des CTV et PTV sous-jacents et, in fine, sur la distribution de la dose aux tissus sains extérieurs au PTV. RESULTATS : Moyennant l'utilisation adéquate et contrôlée de méthodes de corégistration des images et de délimitation automatique des volumes en imagerie fonctionnelle, nous avons pu démontrer des différences en terme de GTV délimité selon les différentes modalités d'imagerie, avec une tendance identique que l'on se situe au niveau oropharyngé ou laryngo-hypopharyngé. Les GTV délimités sur CT, IRM et MET-TEP n'étaient pas significativement différents en valeurs absolues, mais chaque modalité avait tendance, au-delà d'une zone de congruence s'élevant en moyenne à 50% du volume total, à visualiser des extensions vers des zones anatomiques lui étant propre (ex. : les cartilages en IRM). Les volumes délimités en FDG-TEP étaient significativement plus petits que ceux délimités sur les autres modalités d'imagerie. Nous pûmes de plus démontrer sur un ensemble de patients opérés par laryngectomie totale que le FDG-TEP était aussi la plus précise des modalités d'imagerie. Cependant, par manque de résolution spatiale, aucune des modalités d'imagerie ne fut en mesure de couvrir totalement le GTV. Ce fait met en lumière le besoin de recommendations claires pour la prédiction du CTV sur base de l'extension du GTV. Ce travail fut réalisé sur base des données de la littérature anatomique (normale et pathologique). Ces recommendations furent utilisées pour délimiter les CTV sur les images CT, FDG-TEP et du spécimen chirurgical (les imageries IRM et MET-TEP ne furent pas analysées puisque n'apportant rien en regard du CT). Les PTV furent ensuite générés et une planification tridimensionnelle réalisée. Tant les CTV que les PTV délimités sur le FDG-TEP restaient significativement plus petits que leurs homologues délimités sur CT. Cette réduction permettait une réduction de la dose délivrée aux glandes parotides en particulier, aux tissus hors PTV de manière plus générale. CONCLUSION : Cette recherche ouvre la voie à l'utilisation du FDG-TEP pour la délimitation du GTV chez les patients atteints de tumeurs épithéliales des sphères oropharyngée et laryngo-hypopharyngée.

L'objectif de notre thèse est de contribuer à une meilleure délimitation de la forme et de l'extension de tumeurs intracrâniennes afin de pouvoir mieux les traiter par radiothérapie conformationnelle. Plusieurs approches ont été utilisées. Par une étude anatomo-pathologique autopsique, nous avons pu démontrer que les métastases cérébrales de plusieurs types de tumeurs s'étendent au moins 1 mm au-delà de leur bord macroscopiquement visible. Les métastases de tumeurs pulmonaires à petites cellules sont celles pour lesquelles nous observons la plus grande extension. En utilisant des techniques de spectroscopie et de l'imagerie par RMN, nous avons observé que des discordances existent dans 47% des voxels examinés. Le plus souvent, l'image apparaît pathologique en RMN et normale en spectroscopie, peut-être en raison d'un oedème périlésionnel important. Une troisième approche a été l'analyse comparative de l'extension de méningiomes intracrâniens par la RMN et par une nouvelle méthode d'imagerie métabolique (PET scan à un acide aminé marqué au fluor 18). Tous les méningiomes sont bien visualisés par le PET scan. Une concordance complète entre image de RMN et de PET scan est observée dans 54% des cas, l'image est plus étendue en PET scan dans 38 % des cas et la situation inverse est observée dans 8% des cas. Enfin, nous avons validé toute la chaîne de traitement en radiochirurgie sur des neurinomes de l'acoustique. Nous obtenons des résultats cliniques comparables à ceux de grandes séries publiées. En conclusion, nos travaux montrent que l'image anatomique seule (la RMN) est insuffisante pour délimiter la plupart des tumeurs intracrâniennes et que des méthodes complémentaires (spectroscopie, imagerie dite métabolique) sont nécessaires pour la préparation au traitement par radiothérapie de précision.

Αντικείμενο αυτής της διδακτορικής διατριβής είναι η μελέτη της δυναμικής σύμμορφης ακτινοθεραπείας με χρήση φυσικών διαμορφωτών δέσμης. Η δυναμική διαμόρφωση δέσμης επιτυγχάνεται με δύο ειδών φυσικούς διαμορφωτές δέσμης: τους προστατευτές, που είναι αντίγραφα σε σμίκρυνση του υπό προστασία οργάνου, κατασκευασμένα από υλικό μεγάλου ατομικού αριθμού, και διατηρούν διεύθυνση παράλληλη σε αυτό κατά την περιστροφή, και τους διαμορφωτές, που τοποθετούνται και στις δύο πλευρές του προστατευτή εξασφαλίζοντας ομοιόμορφη δόση στην περιοχή του όγκου. Για τον σκοπό αυτό αναπτύχθηκε μαθηματικό μοντέλο που περιγράφει τις βέλτιστες διαστάσεις και τις ακριβείς θέσεις των διαμορφωτών κατά τη διάρκεια της περιστροφής της ακτινογραφικής κεφαλής με βάση τις αρχές που διέπουν την κίνησή τους. Παράλληλα αναπτύχθηκε ένα εργαλείο λογισμικού, που ενσωματώνει το μαθηματικό υπόβαθρο και διευκολύνει την εισαγωγή των παραμέτρων θέσης και σύστασης των διαμορφωτών δέσμης. Το εργαλείο λογισμικού ενσωματώθηκε στον προσομοιωτή θεραπείας ακτινοβολίας Monte Carlo (MCRTS), που χρησιμοποιήθηκε για την προσομοίωση της διάδοσης της ακτινοβολίας στη γεωμετρία του σχεδιασμένου συστήματος. Πραγματοποιήθηκαν μελέτες προσομοίωσης για την αποτελεσματικότητα της φυσικής διαμόρφωσης δέσμης στην περίπτωση όγκων στη περιοχή της κεφαλής και του αυχένα, βασισμένες σε γεωμετρική περιγραφή είτε με αναλυτικά αντικείμενα, είτε με στοιχειώδεις όγκους. Μελετήθηκε επίσης η επίδραση των διαμορφωτών στην τροποποίηση της κατανομής δόσης στις περιοχές που περιβάλλουν την προστατευμένη περιοχή. Οι μελέτες αυτές έδειξαν ότι η περιστροφική θεραπεία με διαμόρφωση δέσμης προσφέρει την επαρκή προστασία και ομοιόμορφη κατανομή δόσεων έξω από την προστατευμένη περιοχή. Προσομοιώσεις που χρησιμοποίησαν διαμορφωτές διαφορετικών υλικών οδήγησαν σε παρόμοιες κατανομές δόσεων. Επιπλέον μελετήθηκε η επίδραση των παραμέτρων του προστατευτή στη κατανομή δόσης στην περιστροφική θεραπεία. Εξετάστηκε η επίδραση μιας σειράς υλικών, που συνήθως χρησιμοποιούνται για προστασία στην ακτινοθεραπεία, καθώς επίσης και η επίδραση μερικών νέων μέταλλο-πολυμερών σύνθετων υλικών. Τα μέταλλο-πολυμερή σύνθετα παρέχουν προστασία στα ζωτικής σημασίας όργανα, συγκρίσιμη με αυτή του μολύβδου, εάν η πυκνότητα τους είναι υψηλή. Η τεχνική που μελετήθηκε έδωσε πολύ ικανοποιητικά αποτελέσματα από άποψη κατανομής δόσης και σχέσης κόστους-αποτελέσματος. / This doctoral thesis addresses dynamic intensity modulation by means of physical beam modifiers. The principles of gravity-oriented devices were generalized and extended, preserving principles of a beam shaping, but introducing motor-driven “patient-oriented” beam modifying devices. Beam modifying devices were divided in two categories: protectors and shapers. The protectors are diminished copies of the Organs At Risk (OARs) and stay parallel to them during gantry rotation, keeping them in the attenuated field for every gantry angle. Shapers are placed at the both sides of the protector to ensure uniform dose in the Planning Target Volume (PTV). Mathematical formalism for calculations of the dimensions and the initial coordinates of the beam modifying devices was developed as well as the laws of their motion during gantry rotation were derived. A software tool, incorporating the mathematical background, with user interface to facilitate the introduction of the input parameters was created. The software module was subsequently integrated into a Monte Carlo Radiation Therapy Simulator (MCRTS), used to simulate particle transport through the designed system. Simulation studies of field shaping in rotational therapy by means of beam modifying devices were carried out. Dose distributions in solid-geometry and voxel-based neck models were evaluated. Furthermore, the effectiveness of the shapers to modify the dose distribution outside the protected area was studied. The results of simulation studies showed that rotational therapy with beam modifying devices offers adequate protection of the OAR and a uniform dose distribution outside the protected region. Studies using shapers of different materials were also carried out and resulted in similar dose distributions. Additionally, the effect of protector’s parameters on the dose distribution in rotational therapy was studied in the thesis. A range of materials, consisting of commonly used for protection in radiotherapy, as well as by some new metal-polymer composites was under investigation. The metal-polymer composites can rival the lead in the protection of vital organs if the density provided is high. The presented technique has showed promising results in terms of conformal dose delivery and can be a preferred choice in radiotherapy departments due to comprehensive and adequate protection of the OAR and uniform dose in PTV ensured as well as of its cost effectiveness.

Diss. (sammanfattning) Umeå : Umeå universitet, 2008. / Härtill 4 uppsatser.

Orientador: Marco Antônio Rodrigues Fernandes / Resumo: O presente estudo consiste na análise da viabilidade econômica e financeira da implantação da radioterapia de intensidade modulada (IMRT) no tratamento do câncer de próstata e comparar seus benefícios clínicos frente aos procedimentos similares custeados pelos sistemas de saúde públicos e privados. Para tanto, foram analisadas as distribuições de dose de radiação preconizadas nos planejamentos radioterápicos com as técnicas de radioterapia conformacional tridimensional (3D-CRT) e de intensidade modulada (IMRT), prescrita para 20 pacientes com câncer de próstata tratados em um serviço de radioterapia privado. Para verificação da qualidade da distribuição de dose de radiação no volume de tratamento, foram analisados os índices de homogeneidade (IH) e de conformidade (IC) de cada um dos planos radioterápicos estudados. Em comparação com a técnica 3D-CRT, a técnica de IMRT permitiu uma melhor cobertura e conformação da dose prescrita no volume alvo de planejamento (PTV), porém distribuída de forma mais heterogênea. Além disso, avaliou-se os custos financeiros para aquisição dos equipamentos de irradiação e manutenção dos tratamentos, bem como os valores de repasses feitos pelos sistemas de saúde para os procedimentos de radioterapia em próstata. / Mestre

Submitted by ISABELLA PAZIAM FERNANDES NUNES null (ipaziam@me.com) on 2018-03-14T12:47:35Z No. of bitstreams: 1 dissertacao - nunes ipf.pdf: 3167962 bytes, checksum: bd9df494a7b84197900f4be8d90cd090 (MD5) / Approved for entry into archive by Luciana Pizzani null (luciana@btu.unesp.br) on 2018-03-19T11:47:25Z (GMT) No. of bitstreams: 1 nunes_ipf_me_bot.pdf: 3167962 bytes, checksum: bd9df494a7b84197900f4be8d90cd090 (MD5) / Made available in DSpace on 2018-03-19T11:47:25Z (GMT). No. of bitstreams: 1 nunes_ipf_me_bot.pdf: 3167962 bytes, checksum: bd9df494a7b84197900f4be8d90cd090 (MD5) Previous issue date: 2018-02-23 / O presente estudo consiste na análise da viabilidade econômica e financeira da implantação da radioterapia de intensidade modulada (IMRT) no tratamento do câncer de próstata e comparar seus benefícios clínicos frente aos procedimentos similares custeados pelos sistemas de saúde públicos e privados. Para tanto, foram analisadas as distribuições de dose de radiação preconizadas nos planejamentos radioterápicos com as técnicas de radioterapia conformacional tridimensional (3D-CRT) e de intensidade modulada (IMRT), prescrita para 20 pacientes com câncer de próstata tratados em um serviço de radioterapia privado. Para verificação da qualidade da distribuição de dose de radiação no volume de tratamento, foram analisados os índices de homogeneidade (IH) e de conformidade (IC) de cada um dos planos radioterápicos estudados. Em comparação com a técnica 3D-CRT, a técnica de IMRT permitiu uma melhor cobertura e conformação da dose prescrita no volume alvo de planejamento (PTV), porém distribuída de forma mais heterogênea. Além disso, avaliou-se os custos financeiros para aquisição dos equipamentos de irradiação e manutenção dos tratamentos, bem como os valores de repasses feitos pelos sistemas de saúde para os procedimentos de radioterapia em próstata. / The present study consists in analyzing the economic and financial viability to establish the intensity modulated radiotherapy (IMRT) in the treatment for prostate cancer and compare its clinical benefits to similar procedures funded by public and private health systems. In order to do so, the radiation absorbed-dose distributions recommended in the radiotherapy plans with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) techniques, prescribed for 20 patients with prostate cancer treated in a private radiotherapy clinic, were evaluated. To verify the quality of the radiation dose distribution in the treatment volume, the homogeneity index (HI) and the conformity index (CI) of each radiotherapy plans studied were analyzed. In contrast to the 3D-CRT technique, the IMRT technique allowed a better coverage and conformation of the radiation dose prescribed in the planning target volume (PTV), but distributed in a more heterogeneous way. It was also evaluated the financial costs for the acquisition of the irradiation equipment and for the maintenance of the treatments, as well as the values of the on-lending made by the health systems for the radiotherapy procedures for the prostate.

Le présent travail de thèse décrit le développement d'un protocole d'irradiation stéréotaxique combinée à une radiothérapie conformationnelle avec modulation d'intensité. Ce projet a été initiée dans le service de radiothérapie-oncologie du Centre Hospitalier Lyon Sud. La première partie de ce travail fait état d'une revue de littérature sur les techniques d'irradiation du cancer de la prostate. Trois grands thèmes de recherche ont été identifiés et developpés : un premier thèse de recherche portant sur la définition optimale des volumes à irradier lors d'une irradiation stéréotaxique de la prostate et la fiabilité d'uin repérage de l'oragane par des marqueurs intra-prostatiques. La deuxième thématique de recherche était dédiée à la planification du traitement stéréotaxique de la prostate avec pour principal objectif une protection optimale de la paroi rectale avec deux approches différentes : a) une augmentation focalisée de la dose d'irradiation uniquement sur la tumeur macroscopiquement visible, ou b) l'utilisation d'un gel injecté entre la paroi du rectum et la prostate. Le nombre optimal de faisceaux à utiliser ainsi que l'énergie la mieux adaptée ont été évalués dans le cadre de la première approche avec uin boost intégré.. La trosième thématique portait sur les contrôles qualité à réaliser dans le cadre de la mise en route de cette technique d'irradiation. Trois détecteur dédiés aux contrôles de la distribution de dose sous l'accélarateur ont été évalués. L'ensemble de ces travaux serviront de supports à la réalisation d'une étude de phase II intégrant une irradiation stéréotaxique des cancers de la prostate avec injection de gel d'acide hyaluronique entre le rectum et la prostate / The current work decribes the implementation of a protocol for stereotactic body radiotherapy (SBRT) combined with an intensity-modulated radiation therapy technique (IMRT). the project was initiated in the Department of Radiation-Oncology from Lyon Sud Hospital. The first part summarizes the state of the art of prostate cancer with a literature review on irradiation techniques. Three research themes were described and developped : The first theme discusses the optimal definition of the volumes to be irradiated during a prostate SBRT and the accuracy of the target localization using intraprostatic markers. The second theme of research describes the treatment planning for prostate SBRT having as main purpose an optimal protection of the rectal-wall with two different approaches: a) an augmentation of the dose with simultaneous integrated boost only into visible macroscopic tumor, or b) the use of a gel injected between the rectal-wall and the prostate. The optimal number of fields, as well as the most favorable energy, was evaluated in the context of the first approach with a simultaneous integrated boost. The third theme discusses the quality assurance (QA) that needs to be performed for an IMRT-SBRT technique. Three detectors that ara dedicated to the QA of dose distribution under accelerator were evaluated. The results of all these studies will be used for the implementation of a phase II study for prostate SBRT with an injection of hyaluronic acid between the rectum and the prostate.

Made available in DSpace on 2014-12-17T15:47:46Z (GMT). No. of bitstreams: 1 FrederikoSLNA.pdf: 5281687 bytes, checksum: 9fe12b6bcc355f7c67cf2f2c3ad9812b (MD5) Previous issue date: 2006-02-16 / This work performs an algorithmic study of optimization of a conformal radiotherapy plan treatment. Initially we show: an overview about cancer, radiotherapy and the physics of interaction of ionizing radiation with matery. A proposal for optimization of a plan of treatment in radiotherapy is developed in a systematic way. We show the paradigm of multicriteria problem, the concept of Pareto optimum and Pareto dominance. A generic optimization model for radioterapic treatment is proposed. We construct the input of the model, estimate the dose given by the radiation using the dose matrix, and show the objective function for the model. The complexity of optimization models in radiotherapy treatment is typically NP which justifyis the use of heuristic methods. We propose three distinct methods: MOGA, MOSA e MOTS. The project of these three metaheuristic procedures is shown. For each procedures follows: a brief motivation, the algorithm itself and the method for tuning its parameters. The three method are applied to a concrete case and we confront their performances. Finally it is analyzed for each method: the quality of the Pareto sets, some solutions and the respective Pareto curves / O presente trabalho realiza um Estudo Algor?tmico para Otimiza??o do Plano de Tratamento da Radioterapia Conformal. Inicialmente s?o apresentadas: uma vis?o geral sobre o c?ncer, o tratamento com radioterapia e no??es sobre a intera??o do feixe de radia??es ionizantes com a mat?ria. Uma proposta para Otimiza??o do Plano de Tratamento Radioter?pico ? desenvolvida de modo sistem?tico. ? apresentado o paradigma de problemas multicrit?rio, os conceitos de Pareto otimalidade e Pareto Domin?ncia. Um modelo Gen?rico de Otimiza??o para o Plano de Tratamento Radioter?pico ? proposto. S?o constru?das suas entradas, ? calculada a dose depositada no corpo do paciente atrav?s do conceito de matriz de dose, e ? apresentada a fun??o objetivo deste modelo. A complexidade dos problemas de otimiza??o do tratamento radioter?pico s?o classificados como de complexidade NP, este resultado justifica o desenvolvimento de m?todos heur?sticos para a sua resolu??o. S?o propostas tr?s metaheur?sticas para a Otimiza??o do Plano de Tratamento Radioter?pico: MOGA, MOSA e MOTS de acordo como o modelo gen?rico de otimiza??o proposto. Os projetos desses procedimentos metaheur?sticos s?o devidamente apresentados. Para cada m?todo se faz uma introdu??o liter?ria, dos seus algoritmos e a da metodologia usada para a afina??o dos par?metros. Os m?todos s?o aplicados a um caso concreto e confrontados atrav?s de medidas de performance. Finalmente ? analisado a qualidade dos conjuntos de Pareto produzidos por cada m?todo, s?o exibidas algumas solu??es geradas e as respectivas curvas de Pareto associadas