Titre :	Design and 3D printing of dedicated phantom for the collection of radiotherapy data on PLA dose bolus material
Type de document :	document électronique
Auteurs :	Naoures Nourhane Khellaf, Auteur ; Fayçal Kharfi, Directeur de thèse
Editeur :	Setif:UFA
Année de publication :	2024
Importance :	1 vol (64 f.)
Format :	29 cm
Langues :	Français (fre)
Catégories :	Thèses & Mémoires:Physique
Mots-clés :	Radiotherapy  Reference data  PLA dose Bolus  3D printing  Thermoluminescence dosimetry  Dose response.
Index. décimale :	530 - Physique
Résumé :	References data and quality assurance (QA) are essential in external radiotherapy to ensure accurate treatment planning and dose delivery. 3D phantoms made from water or other materials are indispensable to check the beam’s data and the diametrical properties of the materials used for the fabrication of different tools of dose modulation in radiotherapy such as boluses. This study investigates the practical use of Polylactic Acid (PLA) as a dose bolus material in radiotherapy treatment planning. The main objective is to characterize the dose-response of this biocompatible material for dose modulating and compensation. By using thermoluminescence dosimetry (TLD) and through the design and 3D printing of a dedicated phantom, this practical work aims to establish the central Percentage Depth Dose (PDD) profile of PLA and its main characteristics in terms of Hounsfield Unit (HU) and Coefficient of Equivalent Thickness to water (CET). Thus, a 3D phantom was designed, 3D printed, and characterized around the Varian Clinac iX linear accelerator.
Note de contenu :	Content ACKNOWLEDGEMENT .......................................................................................... I ABSTRACT.............................................................................................................III RESUME ................................................................................................................ IV ملخص . ....................................................................................................................... V Content. ................................................................................................................. VII List of Figures ........................................................................................................... X List of Tables ........................................................................................................ XIII ABBREVIATIONS ................................................................................................... 1 INTRODUCTION..................................................................................................... 2 External radiotherapy and reference data ........................................................................ 5 BACKGROUND ............................................................................................... 5 1.1 External beam radiotherapy ........................................................................ 5 1.2 Types of radiation used in external beam radiotherapy ............................... 6 1.2.1 Photon radiation ................................................................................... 6 1.3 The objective of external radiotherapy......................................................... 7 1.4 Workflow of Radiotherapy ........................................................................... 7 1.4.1 CT scans acquisition ............................................................................ 8 1.4.2 Definition of target volumes and OAR .................................................. 8 1.4.3 Treatment planning ............................................................................ 10 1.4.4 Dose delivery ..................................................................................... 10 1.5 Dosimetry in Radiotherapy ....................................................................... 11 1.5.1 Phantom dosimetry ............................................................................ 11 1.5.2 Relative dose measurements with ionization chambers ..................... 12 1.5.3 Ionization chambers ........................................................................... 13 1.5.4 Dosimetric functions ........................................................................... 13 1.6 Introduction of Radiotherapy PDD and Off-Axis Phantom ........................ 14 1.6.1 Depth Dose Distribution ..................................................................... 15 1.6.2 Percentage depth dose ...................................................................... 15 VI | P a g e 1.6.3 Off-Axis Beam Profile Data ................................................................ 18 1.7 Dosimetry of external beam sources ......................................................... 19 Thermoluminescence dosimetry .......................................................................... 20 Radiation dosimetry........................................................................20 2.1 General information on Crystals ................................................................ 21 2.1.1 Perfect Crystal ................................................................................... 22 2.1.2 The Real Crystal ................................................................................ 22 2.1.3 Different types of punctual defects ..................................................... 22 2.2 Thermoluminescence ................................................................................ 23 2.2.1 General the phenomenon of thermoluminescence (TL) ...................... 23 2.2.2 Thermoluminescence Dosimetry ........................................................ 23 2.2.3 Simplified theory of thermoluminescence dosimetry ........................... 24 2.3 Thermoluminescent Dosimeter Systems ................................................... 24 2.3.1 Lithium Fluoride ................................................................................. 24 2.3.2 TL Signal ............................................................................................ 25 2.3.3 Application of Thermoluminescence Dosimetry .................................. 25 2.3.3.1 Applications of TLDs in Radiotherapy ............................................. 25 2.3.3.2 Radiation Protection ....................................................................... 26 2.3.3.2.1 TLD used for personnel dosimetry............................................. 26 2.3.3.2.2 Environmental Monitoring .......................................................... 26 2.3.4 Advantages and disadvantages of TLD .............................................. 26 3D printing technology ...................................................................... 28 History Of 3D Printing .........................................................................28 3.1 3D printing............................................................................ 28 3.2 The Process Of 3D Printing ....................................................................... 29 3.3 Benefits Of 3D Printing .............................................................................. 30 3.4 Types of 3D printing technologies ............................................................. 30 3.4.1 Fused Deposition Modeling (FDM) ..................................................... 31 3.4.2 Stereolithography (SLA) ..................................................................... 31 3.4.3 Polymer Jetting Technology (PJT) ..................................................... 31 VI | P a g e 3.5 FDM in 3DP .............................................................................................. 31 3.5.1 Principles ........................................................................................... 31 3.5.2 Components of an FDM 3D Printer .................................................... 32 3.5.3 The Process of FDM ......................................................................... 33 3.5.4 Common FDM materials .................................................................... 34 3D printing and test of radiotherapy PDD phantom .......................................... 35 BACKGROUND ..............................................................................35 4.1 Design and fabrication of the physical PDD Phantom by 3D printing ........ 36 4.1.1 Choice of 3D printing material ............................................................ 36 4.1.1.1 Production of PLA ............................................................ 36 4.1.1.2 The physical properties of polylactic acid (PLA) .............................. 37 4.1.1.3 The benefits of using PLA (Polylactic Acid) ..................................... 38 4.1.2 Phantom Design ................................................................................ 39 4.1.3 Slicing the 3D volume ........................................................................ 40 4.1.4 3D printing of The PDD Phantom ....................................................... 42 4.2 III. Establishment of the PDD of the 3D printed PLA Phantom by thermoluminescence dosimetry ........................................................................... 45 4.2.1 Calibration of TLDs ............................................................................ 46 4.2.1.1 TL and OSL signals reading ........................................................... 46 4.2.1.2 TL measurements........................................................................... 46 4.2.1.3 Calibration Correction Factors (CCF) .............................................. 47 4.2.1.4 Determination of Calibration Correction Factors (CCF): .................. 47 4.2.2 Establishment of Central PDD ............................................................ 49 4.2.2.1 Data Analysis and PDD Calculation: ............................................... 51 4.2.2.2 Measured Corrected TL Integral Intensities and PDD Values ......... 51 4.2.3 Results Discussion .............................................................55 CONCLUSION & PERSPECTIVE ..................................................................... 56 Bibliography ....................................................................................58
Côte titre :	MAPH/0626

Design and 3D printing of dedicated phantom for the collection of radiotherapy data on PLA dose bolus material [document électronique] / Naoures Nourhane Khellaf, Auteur ; Fayçal Kharfi, Directeur de thèse . - [S.l.] : Setif:UFA, 2024 . - 1 vol (64 f.) ; 29 cm.
Langues : Français (fre)

Catégories :	Thèses & Mémoires:Physique
Mots-clés :	Radiotherapy  Reference data  PLA dose Bolus  3D printing  Thermoluminescence dosimetry  Dose response.
Index. décimale :	530 - Physique
Résumé :	References data and quality assurance (QA) are essential in external radiotherapy to ensure accurate treatment planning and dose delivery. 3D phantoms made from water or other materials are indispensable to check the beam’s data and the diametrical properties of the materials used for the fabrication of different tools of dose modulation in radiotherapy such as boluses. This study investigates the practical use of Polylactic Acid (PLA) as a dose bolus material in radiotherapy treatment planning. The main objective is to characterize the dose-response of this biocompatible material for dose modulating and compensation. By using thermoluminescence dosimetry (TLD) and through the design and 3D printing of a dedicated phantom, this practical work aims to establish the central Percentage Depth Dose (PDD) profile of PLA and its main characteristics in terms of Hounsfield Unit (HU) and Coefficient of Equivalent Thickness to water (CET). Thus, a 3D phantom was designed, 3D printed, and characterized around the Varian Clinac iX linear accelerator.
Note de contenu :	Content ACKNOWLEDGEMENT .......................................................................................... I ABSTRACT.............................................................................................................III RESUME ................................................................................................................ IV ملخص . ....................................................................................................................... V Content. ................................................................................................................. VII List of Figures ........................................................................................................... X List of Tables ........................................................................................................ XIII ABBREVIATIONS ................................................................................................... 1 INTRODUCTION..................................................................................................... 2 External radiotherapy and reference data ........................................................................ 5 BACKGROUND ............................................................................................... 5 1.1 External beam radiotherapy ........................................................................ 5 1.2 Types of radiation used in external beam radiotherapy ............................... 6 1.2.1 Photon radiation ................................................................................... 6 1.3 The objective of external radiotherapy......................................................... 7 1.4 Workflow of Radiotherapy ........................................................................... 7 1.4.1 CT scans acquisition ............................................................................ 8 1.4.2 Definition of target volumes and OAR .................................................. 8 1.4.3 Treatment planning ............................................................................ 10 1.4.4 Dose delivery ..................................................................................... 10 1.5 Dosimetry in Radiotherapy ....................................................................... 11 1.5.1 Phantom dosimetry ............................................................................ 11 1.5.2 Relative dose measurements with ionization chambers ..................... 12 1.5.3 Ionization chambers ........................................................................... 13 1.5.4 Dosimetric functions ........................................................................... 13 1.6 Introduction of Radiotherapy PDD and Off-Axis Phantom ........................ 14 1.6.1 Depth Dose Distribution ..................................................................... 15 1.6.2 Percentage depth dose ...................................................................... 15 VI | P a g e 1.6.3 Off-Axis Beam Profile Data ................................................................ 18 1.7 Dosimetry of external beam sources ......................................................... 19 Thermoluminescence dosimetry .......................................................................... 20 Radiation dosimetry........................................................................20 2.1 General information on Crystals ................................................................ 21 2.1.1 Perfect Crystal ................................................................................... 22 2.1.2 The Real Crystal ................................................................................ 22 2.1.3 Different types of punctual defects ..................................................... 22 2.2 Thermoluminescence ................................................................................ 23 2.2.1 General the phenomenon of thermoluminescence (TL) ...................... 23 2.2.2 Thermoluminescence Dosimetry ........................................................ 23 2.2.3 Simplified theory of thermoluminescence dosimetry ........................... 24 2.3 Thermoluminescent Dosimeter Systems ................................................... 24 2.3.1 Lithium Fluoride ................................................................................. 24 2.3.2 TL Signal ............................................................................................ 25 2.3.3 Application of Thermoluminescence Dosimetry .................................. 25 2.3.3.1 Applications of TLDs in Radiotherapy ............................................. 25 2.3.3.2 Radiation Protection ....................................................................... 26 2.3.3.2.1 TLD used for personnel dosimetry............................................. 26 2.3.3.2.2 Environmental Monitoring .......................................................... 26 2.3.4 Advantages and disadvantages of TLD .............................................. 26 3D printing technology ...................................................................... 28 History Of 3D Printing .........................................................................28 3.1 3D printing............................................................................ 28 3.2 The Process Of 3D Printing ....................................................................... 29 3.3 Benefits Of 3D Printing .............................................................................. 30 3.4 Types of 3D printing technologies ............................................................. 30 3.4.1 Fused Deposition Modeling (FDM) ..................................................... 31 3.4.2 Stereolithography (SLA) ..................................................................... 31 3.4.3 Polymer Jetting Technology (PJT) ..................................................... 31 VI | P a g e 3.5 FDM in 3DP .............................................................................................. 31 3.5.1 Principles ........................................................................................... 31 3.5.2 Components of an FDM 3D Printer .................................................... 32 3.5.3 The Process of FDM ......................................................................... 33 3.5.4 Common FDM materials .................................................................... 34 3D printing and test of radiotherapy PDD phantom .......................................... 35 BACKGROUND ..............................................................................35 4.1 Design and fabrication of the physical PDD Phantom by 3D printing ........ 36 4.1.1 Choice of 3D printing material ............................................................ 36 4.1.1.1 Production of PLA ............................................................ 36 4.1.1.2 The physical properties of polylactic acid (PLA) .............................. 37 4.1.1.3 The benefits of using PLA (Polylactic Acid) ..................................... 38 4.1.2 Phantom Design ................................................................................ 39 4.1.3 Slicing the 3D volume ........................................................................ 40 4.1.4 3D printing of The PDD Phantom ....................................................... 42 4.2 III. Establishment of the PDD of the 3D printed PLA Phantom by thermoluminescence dosimetry ........................................................................... 45 4.2.1 Calibration of TLDs ............................................................................ 46 4.2.1.1 TL and OSL signals reading ........................................................... 46 4.2.1.2 TL measurements........................................................................... 46 4.2.1.3 Calibration Correction Factors (CCF) .............................................. 47 4.2.1.4 Determination of Calibration Correction Factors (CCF): .................. 47 4.2.2 Establishment of Central PDD ............................................................ 49 4.2.2.1 Data Analysis and PDD Calculation: ............................................... 51 4.2.2.2 Measured Corrected TL Integral Intensities and PDD Values ......... 51 4.2.3 Results Discussion .............................................................55 CONCLUSION & PERSPECTIVE ..................................................................... 56 Bibliography ....................................................................................58
Côte titre :	MAPH/0626