Convolution and model-based dose calculation methods in radionuclide and external-beam photon therapy

Joakim Pyyry

Convolution and model-based dose calculation methods in radionuclide and external-beam photon therapy

Julkaisun otsikon käännös: Konvoluutio- sekä mallipohjaiset annoslaskentamenetelmät isotooppi- ja ulkoisessa sädehoidossa

Joakim Pyyry

Neurotieteen ja lääketieteellisen tekniikan laitos

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Sädehoito on laajasti käytössä oleva syövän hoitomuoto. Potilaita hoidetaan joko ulkoisilla tai sisäisillä säteilylähteillä. Väitöskirja käsittelee sekä sisäisen että ulkoisen sädehoidon laskennallisia menetelmiä. Tutkimuksessa kehitettiin yleinen menetelmä isotooppihoitojen kolmiulotteiseen annossuunnitteluun ja sovellettiin tätä menetelmää isotooppihoitojen annosten analysointiin. Lisäksi kehitettiin ulkoisen sädehoidon annoslaskentamenetelmä, joka huomioi epähomogeenisen väliaineen vaikutukset säteilyn kulkeutumisessa. Tutkimuksessa analysoitiin isotooppihoitojen aktiivisuusjakaumia, isotooppien biologisia poistumia ja säteilyannoksia useissa potilastapauksissa SPECT-kuvantamisen avulla. Potilaskohtaisia annoslaskentoja suoritettiin konvoluutiomenetelmällä ja näitä verrattiin yleisesti käytössä olevan MIRD S -mallin tuloksiin. Analyysissä havaittiin isoja eroja potilastapausten välillä sekä annoslaskennan että isotoopin biologisten poistuma-aikojen suhteen. Tutkimuksessa kehitettiin uusi annoslaskentamenetelmä ulkoiseen fotonisädehoitoon. Kehitetty Pencil Beam -pohjainen menetelmä sisältää uuden tiheydestä riippuvan tavan mallintaa epähomogeenistä väliainetta. Annoslaskennan tulokset vastaavat hyvin Monte Carlo-menetelmällä laskettuja tuloksia useissa eri tapauksissa. Havaitut erovaisuudet olivat pienempiä kuin 2% (tai 2 mm). Kehitetty menetelmä on laskennallisesti tehokas ja soveltuu hyvin annossuunnittelukäyttöön sädehoidossa.

Julkaisun otsikon käännös	Konvoluutio- sekä mallipohjaiset annoslaskentamenetelmät isotooppi- ja ulkoisessa sädehoidossa
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Parkkonen, Lauri, Vastuuprofessori Kairemo, Kalevi, Ohjaaja, Ulkoinen henkilö Tenhunen, Mikko, Ohjaaja, Ulkoinen henkilö
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-6727-8
Sähköinen ISBN	978-952-60-6728-5
Tila	Julkaistu - 2016
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

sädehoito
annossuunnittelu
isotooppihoidot

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http://urn.fi/URN:ISBN:978-952-60-6728-5Lisenssi: Määrittelemätön

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@phdthesis{fa10031df2634b27b5e681c3a8d1283c,

title = "Convolution and model-based dose calculation methods in radionuclide and external-beam photon therapy",

abstract = "Radiotherapy is an established treatment modality of cancer. Radiation is delivered to the patients from internal or external sources. This thesis explores and introduces improvements to computational methods that are used in the application of internal and external radiotherapy. The aims of the work were to develop a general methodology for 3D treatment planning of internal radionuclide therapy, to apply 3D treatment planning to analyze radionuclide therapy cases, and to develop a pencil-beam dose kernel based calculation method for external photon therapy that also accounts for local variations in tissue material densities in 3D space. The variability of biological uptake and clearance of the therapy agent were analyzed in various patients undergoing radionuclide therapy by serial single-photon emission computed tomography (SPECT), and estimates of absorbed doses were calculated. Patient-specific dose calculation with the dose kernel method was compared with the widely used MIRD S-factor model. Large inter-patient variation of biological clearance and localized differences for individual patients were observed. The dose estimates from the S-factor model and point dose kernel approach agreed on average, but at an individual patient level there were large variations between the methods.For external photon therapy, an advanced pencil beam dose calculation method was developed. The resulting Analytical Anisotropic Algorithm (AAA) includes a density-scaling method of both lateral and depth-dependent components of the model. The results indicate generally good agreement between the calculations utilizing the presented method and Monte Carlo simulations in various heterogeneous geometries. Most of the observed discrepancies were within 2% (or 2 mm). The method is computationally very efficient and suitable for routine use in clinical setting.",

keywords = "radiotherapy, radionuclide, pencil beam, point kernel, treatment planning, s{\"a}dehoito, annossuunnittelu, isotooppihoidot, radiotherapy, radionuclide, pencil beam, point kernel, treatment planning",

author = "Joakim Pyyry",

year = "2016",

language = "English",

isbn = "978-952-60-6727-8",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "57",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Convolution and model-based dose calculation methods in radionuclide and external-beam photon therapy

AU - Pyyry, Joakim

PY - 2016

Y1 - 2016

N2 - Radiotherapy is an established treatment modality of cancer. Radiation is delivered to the patients from internal or external sources. This thesis explores and introduces improvements to computational methods that are used in the application of internal and external radiotherapy. The aims of the work were to develop a general methodology for 3D treatment planning of internal radionuclide therapy, to apply 3D treatment planning to analyze radionuclide therapy cases, and to develop a pencil-beam dose kernel based calculation method for external photon therapy that also accounts for local variations in tissue material densities in 3D space. The variability of biological uptake and clearance of the therapy agent were analyzed in various patients undergoing radionuclide therapy by serial single-photon emission computed tomography (SPECT), and estimates of absorbed doses were calculated. Patient-specific dose calculation with the dose kernel method was compared with the widely used MIRD S-factor model. Large inter-patient variation of biological clearance and localized differences for individual patients were observed. The dose estimates from the S-factor model and point dose kernel approach agreed on average, but at an individual patient level there were large variations between the methods.For external photon therapy, an advanced pencil beam dose calculation method was developed. The resulting Analytical Anisotropic Algorithm (AAA) includes a density-scaling method of both lateral and depth-dependent components of the model. The results indicate generally good agreement between the calculations utilizing the presented method and Monte Carlo simulations in various heterogeneous geometries. Most of the observed discrepancies were within 2% (or 2 mm). The method is computationally very efficient and suitable for routine use in clinical setting.

AB - Radiotherapy is an established treatment modality of cancer. Radiation is delivered to the patients from internal or external sources. This thesis explores and introduces improvements to computational methods that are used in the application of internal and external radiotherapy. The aims of the work were to develop a general methodology for 3D treatment planning of internal radionuclide therapy, to apply 3D treatment planning to analyze radionuclide therapy cases, and to develop a pencil-beam dose kernel based calculation method for external photon therapy that also accounts for local variations in tissue material densities in 3D space. The variability of biological uptake and clearance of the therapy agent were analyzed in various patients undergoing radionuclide therapy by serial single-photon emission computed tomography (SPECT), and estimates of absorbed doses were calculated. Patient-specific dose calculation with the dose kernel method was compared with the widely used MIRD S-factor model. Large inter-patient variation of biological clearance and localized differences for individual patients were observed. The dose estimates from the S-factor model and point dose kernel approach agreed on average, but at an individual patient level there were large variations between the methods.For external photon therapy, an advanced pencil beam dose calculation method was developed. The resulting Analytical Anisotropic Algorithm (AAA) includes a density-scaling method of both lateral and depth-dependent components of the model. The results indicate generally good agreement between the calculations utilizing the presented method and Monte Carlo simulations in various heterogeneous geometries. Most of the observed discrepancies were within 2% (or 2 mm). The method is computationally very efficient and suitable for routine use in clinical setting.

KW - radiotherapy

KW - radionuclide

KW - pencil beam

KW - point kernel

KW - treatment planning

KW - sädehoito

KW - annossuunnittelu

KW - isotooppihoidot

KW - radiotherapy

KW - radionuclide

KW - pencil beam

KW - point kernel

KW - treatment planning

M3 - Doctoral Thesis

SN - 978-952-60-6727-8

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Convolution and model-based dose calculation methods in radionuclide and external-beam photon therapy

Abstrakti

Tutkimusalat

YK:n kestävän kehityksen tavoitteet

Pääsy asiakirjaan

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