Search results for "sädehoito"
showing 10 items of 15 documents
Dosimetric effect of respiratory motion on planned dose in whole-breast volumetric modulated arc therapy using moderate and ultra-hypofractionation.
2021
Abstract Background and purpose The interplay effect of respiratory motion on the planned dose in free-breathing right-sided whole-breast irradiation (WBI) were studied by simulating hypofractionated VMAT treatment courses. Materials and methods Ten patients with phase-triggered 4D-CT images were included in the study. VMAT plans targeting the right breast were created retrospectively with moderately hypofractionated (40.05 Gy in 15 fractions of 2.67 Gy) and ultra-hypofractionated (26 Gy 5 fractions of 5.2 Gy) schemes. 3D-CRT plans were generated as a reference. All plans were divided into respiratory phase-specific plans and calculated in the corresponding phase images. Fraction-specific d…
Stereotaktisten annossuunnitelmien verifiointi Compass-järjestelmällä
2016
RapidArc-hoitotekniikka eturauhassyövän sädehoidossa
2012
Eturauhasen sädehoito on perinteisesti tehty konformaalisella 3D-CRT-tekniikalla. Nykyään on mahdollista hyödyntää RapidArc-, FIMRT-kaarihoito tai IMRT–tekniikkaa, jotka mahdollistavat pienemmät annokset terveeseen kudokseen ja kriittisiin elimiin, kuin perinteinen tekniikka. RapidArc:issa käytetään yhtä tai useampaa 360 asteen kaarikenttää ja IMRT:n käänteistä optimointia. Hoidon aikana muunnellaan moniliuskarajaimien asentoja, gantryn kierto- ja annosnopeutta parhaan mahdollisen annosjakauman aikaansaamiseksi. RapidArc nostaa matalien annosten tilavuusosuutta terveessä kudoksessa. RapidArc:issa pyritään lyhyeen hoitoaikaan ja säteilytys on päällä koko hoidon ajan. Tutkielmassa analysoitii…
Robustness of radiation beam profile measurements
2023
In this master’s thesis, profile measurements of PTW Semiflex 3D and PTW Semiflex ionisation chambers in addition to IBA MatriXX matrix detector were compared to each other using different measurement set-ups. The ionisation chamber measure- ments were done in a water phantom in horizontal and vertical orientations. Using two different set-ups in the horizontal orientation. The first horizontal set-up used the current clinical quality assurance program in Tampere University Hospital with the wire of the chamber lying deep in the water phantom. The second horizontal measurements were done with more of the wire in the radiation field by having the wire closer to the surface of the water. Meas…
Radioactive Beams for Image-Guided Particle Therapy : The BARB Experiment at GSI
2021
Several techniques are under development for image-guidance in particle therapy. Positron (β+) emission tomography (PET) is in use since many years, because accelerated ions generate positron-emitting isotopes by nuclear fragmentation in the human body. In heavy ion therapy, a major part of the PET signals is produced by β+-emitters generated via projectile fragmentation. A much higher intensity for the PET signal can be obtained using β+-radioactive beams directly for treatment. This idea has always been hampered by the low intensity of the secondary beams, produced by fragmentation of the primary, stable beams. With the intensity upgrade of the SIS-18 synchrotron and the isotopic separati…
Sädehoidon annossuunnitelmien poikkeavuuksien havaitseminen neuroverkoilla
2013
Sädehoidossa potilaalle tehdään yksilöllinen annossuunnitelma, jonka mukaan hoito toteutetaan. Kaikilta annokseen vaikuttavilta tekijöiltä vaaditaan suurta tarkkuutta. Uusi lähestymistapa annossuunnitelmien laadunvarmistukseen on tiedonlouhintaan ja koneoppimiseen perustuvien menetelmien hyödyntäminen. Kyseisillä menetelmillä voidaan muodostaa hoidossa aiemmin toteutetuista annossuunnitelmista malli, jonka avulla voidaan havaita uusien annossuunnitelmien poikkeavuudet, ja näin lisätä sädehoidon turvallisuutta. Tutkimuksen tavoitteena oli muodostaa SOM- ja PNN-neuroverkoilla malli, jolla voidaan havaita poikkeavuuksia annossuunnitelmista. Mallia varten haettiin rinnanpoiston jälkeisten ko…
Ionisaatiokammiomatriisin käyttö intensiteettimuokatun sädehoidon laadunvarmistuksessa
2008
Radiotherapy before or during androgen-deprivation therapy does not blunt the exercise-induced body composition protective effects in prostate cancer…
2021
Background Androgen deprivation therapy (ADT) contributes to lean mass loss and adiposity increases in prostate cancer patients. Radiotherapy during ADT might act synergistically and further worsen body composition. Previous investigations have shown that resistance training is an effective method of preserving body composition during ADT, however, most have not accounted for direct or indirect effects of other therapies, such as radiotherapy. Therefore, the purpose of this study was to examine training adaptations of the tissue composition in patients receiving radiation therapy (RT) prior or during ADT. Methods Analyses were performed by combining data from two previous trials for a total…