Thesis (Ph. D.)--University of Wisconsin--Madison, 2000. / Includes bibliographical references (leaves 205-212). Also available on the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 2000. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 205-212).

Abstract The use of image-guidance in surgery and radiotherapy has significantly improved patient outcome in neurosurgery and radiotherapy treatments. This work developed volume definition and verification techniques for image-guided applications, using a number of algorithms ranging from image processing to visualization. Stereoscopic visualization, volumetric tumor model overlaid on an ultrasound image, and visualization of the treatment geometry were experimented with on a neurosurgical workstation. Visualization and volume definition tools were developed for radiotherapy treatment planning system. The magnetic resonance inhomogeneity correction developed in this work, possibly the first published data-driven method with wide applicability, automatically mitigates the RF field inhomogeneity artefact present in magnetic resonance images. Correcting the RF inhomogeneity improves the accuracy of the generated volumetric models. Various techniques to improve region growing are also presented. The simplex search method and combinatory similarity terms were used to improve the similarity function with a low additional computational cost and high yield in region correctness. Moreover, the effects of different priority queue implementations were studied. A fast algorithm for calculating high-quality digitally reconstructed radiographs has been developed and shown to better meet typical radiotherapy needs than the two alternative algorithms. A novel visualization method, beam's light view, is presented. It uses texture mapping for projecting the fluence of a radiation field on an arbitrary surface. This work suggests several improved algorithms for image processing, segmentation, and visualization used in image-guided treatment systems. The presented algorithms increase the accuracy of image-guidance, which can further improve the applicability and efficiency of image-guided treatments.

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

Thesis--University of Oklahoma. / Bibliography: leaves 115-119.

Thesis--University of Oklahoma. / Bibliography: leaves 90-92.

<p>Studija je imala za cilj da pokaže značaj primene PET/CT pregleda u planiranju radiolo&scaron;ke terapije kod pacijenata obolelih od Hočkinovog linfoma. U Vojvodini je 2009. godine prema podacima Registra za maligne neoplazme Vojvodine incidence za Hočkinov limfom iznosila 2,7 na 100 000 dok je mortalitet bio 1,1 na 100 000 stanovnika. Na osnovu dostupnih podataka Registra za maligne neoplazme Vojvodine beleži se porast incidence u protekloj deceniji. Procenat obolelih u Vojvodini u korelaciji je sa podacima koje navodi i Međunarodna agencija za istraživanje raka iz Liona (IARC). U Evropi i u Sjedinjenim Američkim Državama postoji bimodularna kriva incidence po starosti koja pokazuje maksimalne vrednosti u period između 20 i 30 godina i nakon 55. godine. S obzirom da od Hočkinovog limfoma dominantnije obolevaju mlađe osobe a da bolest ima dobru prognozu neophodno je iznaći nove načine za inicijalno određivanje stadijuma bolesti, kao i metode koje mogu da unaprede kvalitet lečenja. Jedan od načina je primena &scaron;to savremenijih dijagnostičkih metoda. PET-CT je imidžing metoda koja poslednjih godina zauzima značajno mesto u određivanju stadijuma malignih bolesti kao i u proceni odgovora na primenjenu terapiju. Fuzionisanjem skenova PET-a i CT-a dobija se PET-CT slika koja prikazuje funkcionalno stanje pojedinih tkiva i organa (PET) sa anatomskim detaljima (CT). Cilj istraživanja je bio da se utvrdi prednost PET-CT pregleda u planiranju radioterapije kod pacijenata sa supradijafragmalnom lokalizacijom bolesti. Nakon postavljanja dijagnoze Hočkinovog limfoma kod pacijenata je urađen PET-CT i planiranje radiolo&scaron;ke terapije. Zračna terapija je planirana na osnovu nalaza PET-CT-a i njegovom fuzijom sa CT-om za planiranje radiolo&scaron;kog lečenja. Dobijeni planovi su poređeni sa onim koji su rađeni standardnom 3D konformalnom tehnikom bez fuzije. Poređeni su klinički volumeni (CTV) i planirani volumen (PTV) kao i razlike u njihovoj obuhvaćenosti preskribovanom dozom. Pokazano je da postoji statistički značajna razlika u ciljnim volumenima kao i u njihovoj obuhvaćenosti. Posmatrani su takođe i rizični organi- srce, pluća, dojke, &scaron;titasta žlezda, kičmena moždina i doze koje oni prime. Dokazano je da su sa statističkom značajno&scaron;ću dozna opterećenja na navedene rizične organe manja kada se planiranje vr&scaron;i na osnovu fuzije sa PET-CT-om, te se na osnovu toga može reći da će i očekivane manifestacije kasne toksičnosti biti manje. Istraživanjem je potvrđena hipoteza da PET/CT ima veliku prednost u planiranju radioterapije jer smanjuje zapremine ciljnih volumena i doprinosi pobolj&scaron;anju kvaliteta radiolo&scaron;kog lečenja.</p> / <p>This study aimed to prove that the use of PET/CT in radiotherapy planning makes a material change in the course of the treatment of the patients with Hodgkin&#39;s lymphoma. According to the data from the Registry of malignant neoplasms in Vojvodina, incidence of Hodgkin&#39;s lymphoma in Vojvodina in 2009 was 2.7 per 100 000, while the mortality rate was 1.1 per 100 000 inhabitants. Based on the available data, the said Register recorded an increase in the incidence over the past decade. The percentage of patients who were registered in Vojvodina is in correlation with the data cited by the International Agency for Research on Cancer in Lyon (IARC).In Europe and in the United States the disease has a bi-modular distribution distribution with the highest frequency rate in persons ageing from 20-30 years and people older than 55 years. Due to the fact that the dominant Hodgkin&#39;s lymphoma affects young people and having in mind the good prognosis of the disease, it is necessary to find a new modality for the initial staging of disease and methods which can improve the quality of treatment. PET/CT is the imaging method which has in recent years had an important role in the staging of malignancies, as well in the evaluation of response to therapy. PET/CT image is obtained by fusing PET scans with CT and it show functional status of certain tissues and organs (PET) with anatomical details (CT).The object of this study was to show that PET/CT examinations are preferred imaging method in radiotherapy planning in patients with localized disease above the diaphragm. After they had been diagnosed with HL, patients underwent PET/CT scan which was later used for delineation in radiotherapy planning. In this study, radiation therapy was planned on the basis of the findings of PET /CT and its fusion with CT for planning radiological treatment. The resulting plans were compared with those made using standard 3D conformal technique without fusion. Clinical volume (CTV) and the planned volume (PTV) and the differences in their coverage with the prescription dose in both plans were also compared. The study has shown a statistically significant difference in the target volume and their coverage. In addition, the dose which receive organs at risk was also examined. It has been shown that organs at risk were exposed to lower doses when using PET/CT fusion in radiotherapy planning and consequently, less incidence of late toxicity is to be expected. The study confirmed the hypothesis that PET /CT has a great advantage in the planning of radiotherapy because it reduces the volume of the target volume and improves the quality of radiation treatment.</p>

<p>Uvod: Učestalost neželjenih efekata uzrokovanih zračenjem kod pacijenata sa karcinomom glave i vrata zavisi od tehnike planiranja, sprovođenja radioterapije kao i primarne lokalizacije tumora. Cilj: Osnovna uloga na&scaron;eg istraživanja je da se utvrdi učestalost neželjenih efekata tokom zračne terapije kod pacijenata sa tumorom glave i vrata tretiranih 2D konvencionalnom radioterapijom, 3D konformalnom radioterapijom planiranoj samo na osnovu CT-a nasuprot 3D konformalnoj terapiji planiranoj na osnovu fuzije kompjuterizovane tomografije sa magnetno rezontnim imidžingom (CT-MRI). Metode: Prospektivno je analizirano 90 pacijenata sa karcinomom glave i vrata kod kojih je sprovedena zračna terapija. 30 pacijenata sa karcinomom glave i vrata je zračeno 2D konvencionalnom tehnikom, drugih 30 pacijenata je zračeno 3D konformalom tehnikom na osnovu CT-a, a preostalih 30 pacijenata sa fuzijom CT-MRI. Kod svih bolesnika je primenjena standardna frakcionacija sa 2 Gy dnevno, pet dana sedmično. Rezultati: Od ukupno 90 pacijenata lečenih primenom zračne terapije, kod 72 pacijenta (72/90; 64,8%) su zabeleženi neželjeni efekti zračne terapije a učestalost komplikacija je veća kod primene 2D tehnike zračenja (28/72; 38,9% for 2D RT vs 24/72; 33,3% for 3D CT RT vs 20/72; 27,8% for 3D CT-MRI; p=0,015). Zaključak: 3D tehnika radioterapije planirana samo na osnovu CT-a je povezana sa visokom stopom toksičnosti koje znatno utiču na kvalitet života zračenih pacijenata. 3D konformalna tehnika radioterapije planirana sa CT-MRI fuzijom smanjuje pojavu oralnih komplikacija. Slično razvijenim zemljama, trebalo bi razmotriti uvođenje ove tehnike kao standardnu metodu zračenja bolesnika sa tumorom glave i vrata. Za isporuku vi&scaron;ih tumorskih doza uz manju učestalost komplikacija je podesnija tehnika planiranja sa fuzionisanom tehnikom pomoću MR imidžinga. 2D tehnika radioterapije glave i vrata se preporučuje samo za palijativne zračne tretmane.</p> / <p>Introduction: The incidence of radiation-induced side effects in patients with head and neck cancer (H&amp;N) depends on technique of planning and the irradiation dose as well as primary tumor location within the H&amp;N region. Objective: The aim of our research is to establish the incidence of side effects in patients with head and neck cancer treated with 2D- conventional radiotherapy, 3D-conformal radiotherapy planning with computed tomography (CT) or computed tomography fusion with magnetic resonance imaging (CT-MRI fusion). Methods: Prospective analysis was performed on 90 patients with head and neck carcinoma prospectively followed after radiotherapy. 30 patients with H&amp;N cancer were irradiated by using 2D conventional radiotherapy, other 30 patients irradiated with 3D conformal radiotherapy planning with CT, while other 30 patients were treated using 3D conformal radiotherapy planning with CT-MRI fusion. In all cases standard fractionation was used at 2 Gy per day /5 days a week. Results: Of the total number (n=90) of treated patients, 72 patients (72/90; 64,8%) reported a side effect and the incidence of complications was higher in patients irradiated with 2D technique planning radiotherapy (28/72; 38,9% for 2D RT vs 24/72; 33,3% for 3D CT RT vs 20/72; 27,8% for 3D CT-MRI; p=0,015). Conclusion: 3D radiotherapy technique planned solely on the basis of CT is related to high incidence of toxicity which significantly affects the quality of life of irradiated patients. 3D conformal radiotherapy planned with CT-MRI fusion reduces the incidence of oral complications. Following the example of developed countries, this technique should be considered as a standard method for irradiating patients with head and neck cancer. Planning technique with fusion technique using MR imaging is more suitable for delivering higher doses to the tumor with fewer side effects. Recommendation 2D conventional radiotherapy is more for palliative treatments.</p>