Teletherapy cobalt 60 machines vs linear acceleratorAmin Amin
Linear accelerators have advanced significantly since the 1950s while cobalt machines have remained largely the same. Modern linacs offer higher energies, more precise beams, electron beams, and variable dose rates. They also allow advanced techniques like IMRT. However, cobalt machines still have advantages in lower cost and less reliance on power infrastructure, making them preferable in some developing countries. Overall, linacs provide superior beam characteristics and treatment capabilities compared to cobalt machines.
The document discusses the evolution of radiation therapy techniques for treating prostate cancer. 3D-CRT from 1995 used 4 fixed beams but exposure of nearby organs limited safe dose. IMRT from 2000 used up to 8 beam directions for better targeting but still some rectal/bladder exposure. VMAT since 2009 uses continuous 360-degree arcs for highly conformal dose distribution in only 2 minutes of treatment time, minimizing nearby organ exposure.
This slide includes physical, biological properties of proton and its advantage over the photon. It also provides information from beam production to treatment planning system of proton therapy, its potential applications, cost effectiveness and demerits.
This document summarizes the expectations and key learnings from a linear accelerator acceptance, commissioning, and annual QA training that occurred from September to November 2008. The training covered:
1. Fundamental concepts of linear accelerators, beam production, safety features, and the acceptance testing process.
2. Techniques for collecting beam data needed for commissioning, including measurements and data definitions.
3. Procedures for linear accelerator QA and other treatment machine QA on an annual basis.
Key topics included the beamline components that produce photon and electron beams, characteristics of linear accelerator beams, the importance of acceptance testing and commissioning the machine properly, and techniques for annual QA tests.
This document provides definitions and examples of random and systematic errors that can occur during the radiotherapy treatment process. It discusses various sources of errors including patient setup, organ motion, and target deformation. Methods for managing errors such as offline and online correction techniques, immobilization devices, and image-guidance are presented. The importance of distinguishing between random and systematic errors when establishing appropriate planning target volume margins is also emphasized.
This document discusses image-guided radiation therapy (IGRT) and various IGRT techniques. It describes how IGRT aims to increase the accuracy and precision of radiotherapy delivery by applying image-based target relocalization. Common IGRT techniques mentioned include portal imaging, on-board cone-beam CT (CBCT), in-room CT, ultrasound and real-time tumor tracking. CBCT allows visualization of the tumor location using kilovoltage or megavoltage X-rays rotating around the patient. Real-time tumor tracking involves synchronizing radiation delivery with the respiratory cycle using implanted fiducial markers and fluoroscopy.
This document discusses target volume definitions in radiotherapy planning according to ICRU reports. It defines key volumes including the gross tumor volume (GTV), clinical target volume (CTV), internal target volume (ITV), planning target volume (PTV), treated volume, and irradiated volume. The CTV accounts for subclinical spread around the GTV, while margins are added to the CTV to create the ITV and PTV to account for organ motion and set-up uncertainties respectively. Together these volumes aim to ensure the prescribed dose is delivered to the tumor while minimizing dose to surrounding healthy tissues.
Quality Assurance in Radiotherapy. Web-based quality assurance; using medical web instrument to facilitate the education, collaboration and peer review, providing an environment in which clinical investigators can receive, share and analyse treatment planning digital data.
Teletherapy cobalt 60 machines vs linear acceleratorAmin Amin
Linear accelerators have advanced significantly since the 1950s while cobalt machines have remained largely the same. Modern linacs offer higher energies, more precise beams, electron beams, and variable dose rates. They also allow advanced techniques like IMRT. However, cobalt machines still have advantages in lower cost and less reliance on power infrastructure, making them preferable in some developing countries. Overall, linacs provide superior beam characteristics and treatment capabilities compared to cobalt machines.
The document discusses the evolution of radiation therapy techniques for treating prostate cancer. 3D-CRT from 1995 used 4 fixed beams but exposure of nearby organs limited safe dose. IMRT from 2000 used up to 8 beam directions for better targeting but still some rectal/bladder exposure. VMAT since 2009 uses continuous 360-degree arcs for highly conformal dose distribution in only 2 minutes of treatment time, minimizing nearby organ exposure.
This slide includes physical, biological properties of proton and its advantage over the photon. It also provides information from beam production to treatment planning system of proton therapy, its potential applications, cost effectiveness and demerits.
This document summarizes the expectations and key learnings from a linear accelerator acceptance, commissioning, and annual QA training that occurred from September to November 2008. The training covered:
1. Fundamental concepts of linear accelerators, beam production, safety features, and the acceptance testing process.
2. Techniques for collecting beam data needed for commissioning, including measurements and data definitions.
3. Procedures for linear accelerator QA and other treatment machine QA on an annual basis.
Key topics included the beamline components that produce photon and electron beams, characteristics of linear accelerator beams, the importance of acceptance testing and commissioning the machine properly, and techniques for annual QA tests.
This document provides definitions and examples of random and systematic errors that can occur during the radiotherapy treatment process. It discusses various sources of errors including patient setup, organ motion, and target deformation. Methods for managing errors such as offline and online correction techniques, immobilization devices, and image-guidance are presented. The importance of distinguishing between random and systematic errors when establishing appropriate planning target volume margins is also emphasized.
This document discusses image-guided radiation therapy (IGRT) and various IGRT techniques. It describes how IGRT aims to increase the accuracy and precision of radiotherapy delivery by applying image-based target relocalization. Common IGRT techniques mentioned include portal imaging, on-board cone-beam CT (CBCT), in-room CT, ultrasound and real-time tumor tracking. CBCT allows visualization of the tumor location using kilovoltage or megavoltage X-rays rotating around the patient. Real-time tumor tracking involves synchronizing radiation delivery with the respiratory cycle using implanted fiducial markers and fluoroscopy.
This document discusses target volume definitions in radiotherapy planning according to ICRU reports. It defines key volumes including the gross tumor volume (GTV), clinical target volume (CTV), internal target volume (ITV), planning target volume (PTV), treated volume, and irradiated volume. The CTV accounts for subclinical spread around the GTV, while margins are added to the CTV to create the ITV and PTV to account for organ motion and set-up uncertainties respectively. Together these volumes aim to ensure the prescribed dose is delivered to the tumor while minimizing dose to surrounding healthy tissues.
Quality Assurance in Radiotherapy. Web-based quality assurance; using medical web instrument to facilitate the education, collaboration and peer review, providing an environment in which clinical investigators can receive, share and analyse treatment planning digital data.
A novel technique of radiation delivery with ultrahigh dose rate radiation therapy delivered in milisecond of time. Although, still in investigational phase
Beam modification devices are used in radiotherapy to modify the spatial distribution of radiation within the patient. The main types of beam modification are shielding to eliminate dose to some areas, compensation to allow for irregular surfaces and tissues, wedge filtration to modify isodose curves, and flattening filters to modify the natural beam profile. Beam modification devices can alter the dose distribution due to effects of primary radiation attenuation and scattering. Common beam modification devices include shielding blocks, compensators, wedges, and multileaf collimators.
This document summarizes the goals and process of modeling treatment beams in a treatment planning system (TPS) during a radiation oncology rotation. The goals were to model one photon beam, one electron beam, and wedges, and then validate the modeled beams. Modeling involved collecting beam data, defining the machine and beams in the TPS, and fine-tuning parameters to match measured and computed dose distributions. Validation compared modeled and measured profiles, percent depth doses, and other dosimetric tests. The rotation provided an understanding of the nuances of TPS modeling.
This document discusses various types of clinical radiation generators used for radiation therapy. It describes kilovoltage units that generate x-rays up to 300 kV and various superficial therapies. It also discusses megavoltage therapy using linear accelerators, betatrons, and cobalt-60 units to treat deeper tumors. Various particle beams including neutrons, protons, and pions are also mentioned but noted to still be experimental with high costs.
Evolution of gynaecological brachytherapyRitam Joarder
This document provides a historical overview of brachytherapy and the evolution of radiation sources used. It discusses some of the early discoveries in x-rays and radioactivity in the 1890s. It then describes some of the early uses of radium to treat skin lesions and cervical cancer in the early 1900s. The document outlines several early brachytherapy systems developed between 1913-1953, including the Stockholm, Paris, Manchester, and Paterson-Parker systems. It also discusses the introduction of the Quimby system using radium needles. The document notes the evolution of brachytherapy sources over time from radium to cesium-137 to iridium-192 to improve dosimetry, specific activity,
The document summarizes interstitial brachytherapy, including indications, contraindications, isotopes used, and details of various planning systems like Paterson-Parker, Quimby, Paris, and computer-based systems. It discusses dose rates, types of implants, applicators, volume definition, and dosimetry parameters like reference isodose and uniformity criteria for different planning approaches.
A linear accelerator (LINAC) is a device that uses high-frequency electromagnetic waves to accelerate electrons to high energies in a linear path inside an accelerator waveguide. LINACs are commonly used for external beam radiation therapy to treat cancer. LINACs work by using microwave technology to accelerate electrons, which are then directed at a target to produce high-energy x-ray or electron beams. The beams exit the machine shaped to the tumor and can be delivered from any angle by rotating the gantry and moving the treatment couch. LINACs are used to plan and deliver targeted radiation treatments to destroy cancer cells while sparing surrounding healthy tissue.
1. The Manchester system was one of the first standardized methods for interstitial brachytherapy implantation using radium sources. It provided rules for determining the amount of radium needed, its distribution, and dose specification based on the treatment area, distance, and desired total dose.
2. The amount of radium was calculated using exposure rates and tables that specified milligram hours of radium per 1000 rads of exposure for different areas and distances. The distribution of radium sources followed the inverse square law to achieve uniform dosing within 10% across the target area.
3. The system defined geometric terms and provided specific rules for distributing radium sources in planar moulds that were circular, square,
This document discusses various techniques for arc therapy including tomotherapy, intensity modulated arc therapy (IMAT), and volumetric modulated arc therapy (VMAT). It provides details on:
- The history and basic concept of arc therapy which involves continuous radiation delivery from a rotating source.
- Techniques like tomotherapy which uses fan beams and helical delivery, and IMAT/VMAT which modulates dose rate and leaf speed during single or multiple full gantry rotations.
- The planning process for these techniques including inverse planning with direct aperture optimization to determine optimal leaf positions and weights to achieve conformal dose distributions while satisfying delivery constraints.
The document discusses stereotactic radiosurgery techniques like Gamma Knife and X-Knife. It describes stereotaxy as a minimally invasive procedure using 3D coordinates to locate and treat small targets in the body. Gamma Knife uses 201 Cobalt-60 sources converged on a target to deliver a high radiation dose while sparing surrounding tissue. Key components include collimators, helmets, and frames to precisely locate the target. Planning involves imaging, contouring, dose optimization and evaluation. Gamma Knife provides non-invasive brain tumor treatment in a single session with sub-millimeter accuracy.
Evolving Role of Radiation Therapy in Hodgkins DiseaseSantam Chakraborty
1) Recent advances in radiation therapy for Hodgkin's lymphoma include reducing radiation volumes and doses based on clinical trials.
2) For early stage favorable Hodgkin's lymphoma, the standard is 2 cycles of ABVD chemotherapy followed by 20Gy involved field radiation.
3) For early stage unfavorable or poor prognosis disease, 4 cycles of ABVD plus 30Gy involved field radiation is standard based on clinical trials.
This document discusses the history and development of radiotherapy machines. It describes early machines that used X-rays and radium to treat cancers from the late 19th century up to the 1950s. The development of cobalt-60 teletherapy units in the 1950s provided a more powerful and practical radiation source. The document focuses on describing the Theratron 780C cobalt-60 teletherapy machine, including its parts, radiation modes, source, controls, specifications and safety features. It also discusses concepts like isocenter, penumbra and the advantages cobalt-60 provided over earlier radiation sources.
The document discusses inversion recovery MRI sequences. Inversion recovery sequences initially aimed to produce heavy T1 weighting but are now mainly used with fast spin echo sequences to produce T2-weighted images. The sequence begins with an 180-degree inversion pulse to invert spins, followed by a 90-degree excitation pulse after time TI. This produces an echo that can be used to generate T1- or T2-weighted images depending on timing parameters. Variants like fast inversion recovery, STIR, and FLAIR combine inversion recovery with other pulses to suppress signals from fat, fluid, or blood.
Evaluation of radiotherapy treatment planningAmin Amin
This document discusses the evaluation of radiotherapy treatment planning through the use of various tools and indices. The goals of treatment planning are to ensure the prescription dose adequately covers and conforms to the target volume while minimizing doses to surrounding healthy tissues. Key evaluation tools discussed include isodose distributions, orthogonal planes, dose volume histograms, dose statistics, homogeneity indices, and conformity/coverage indices. These tools provide both qualitative and quantitative assessments of the dose distribution and how well it meets the goals of treatment planning.
The document provides details about the acceptance testing and commissioning of a new TrueBeam linear accelerator installed at the facility. Some key details include:
- The machine was installed in an existing bunker previously occupied by a Siemens Primus Plus with additional shielding added.
- Acceptance testing verifies a small subset of beam data based on manufacturer guidelines to check specifications, while commissioning involves comprehensive beam measurements and treatment planning system configuration.
- Beam data measurements included depth doses, profiles, output, symmetry, flatness, and other dosimetric parameters which were analyzed and entered into the treatment planning system.
- Electron and photon beam energies and characteristics were evaluated to ensure they met tolerance limits. Other
Isodose lines represent points of equal absorbed radiation dose on a dose distribution map. They are depicted as curves on isodose charts showing the volumetric and planar variations in absorbed dose. Factors influencing isodose curves include beam quality, field size, source-to-skin distance, beam modifiers like wedges or bolus, and depth. Isodose curves are used in radiation therapy treatment planning to evaluate dose distributions and ensure tumor coverage while sparing surrounding healthy tissues. They provide critical information about the radiation dose profile essential for safe and effective treatment.
A summary of recent innovations in radiation oncology focussing on the priniciples of different techniques and their application. An overview of clinical results has also been given
This document discusses brachytherapy dosimetry using the TG-43 formulation. It begins by introducing brachytherapy and the sources commonly used, such as iridium-192 and iodine-125. It then covers how sources are specified and calibrated, including using exposure rate constants, air kerma rate constants, and apparent activity. Methods for source calibration include air ionization chambers, well chambers, and solid phantoms. Dose distribution around sources is also discussed, including using the Sievert integral for line sources. The TG-43 formalism provides a standardized method for calculating dose around brachytherapy sources.
This document discusses radiotherapy and CT simulation procedures. It begins with an introduction to radiotherapy and how it uses radiation to destroy cancer cells. It then describes the linear accelerator machine commonly used to deliver targeted radiation treatments. Finally, it outlines the mould room procedure for creating customized thermoplastic masks to immobilize patients, ensuring accurate radiation delivery to the treatment site.
Actualités 2015 en radiothérapie des cancers des voies aéro-digestives supérieures. Revue subjective des congrès et publications. Présentation CRONOR 21/11/2015. Thèmes : radiochimiothérapie, modification du fractionnement, biothérapie,
A novel technique of radiation delivery with ultrahigh dose rate radiation therapy delivered in milisecond of time. Although, still in investigational phase
Beam modification devices are used in radiotherapy to modify the spatial distribution of radiation within the patient. The main types of beam modification are shielding to eliminate dose to some areas, compensation to allow for irregular surfaces and tissues, wedge filtration to modify isodose curves, and flattening filters to modify the natural beam profile. Beam modification devices can alter the dose distribution due to effects of primary radiation attenuation and scattering. Common beam modification devices include shielding blocks, compensators, wedges, and multileaf collimators.
This document summarizes the goals and process of modeling treatment beams in a treatment planning system (TPS) during a radiation oncology rotation. The goals were to model one photon beam, one electron beam, and wedges, and then validate the modeled beams. Modeling involved collecting beam data, defining the machine and beams in the TPS, and fine-tuning parameters to match measured and computed dose distributions. Validation compared modeled and measured profiles, percent depth doses, and other dosimetric tests. The rotation provided an understanding of the nuances of TPS modeling.
This document discusses various types of clinical radiation generators used for radiation therapy. It describes kilovoltage units that generate x-rays up to 300 kV and various superficial therapies. It also discusses megavoltage therapy using linear accelerators, betatrons, and cobalt-60 units to treat deeper tumors. Various particle beams including neutrons, protons, and pions are also mentioned but noted to still be experimental with high costs.
Evolution of gynaecological brachytherapyRitam Joarder
This document provides a historical overview of brachytherapy and the evolution of radiation sources used. It discusses some of the early discoveries in x-rays and radioactivity in the 1890s. It then describes some of the early uses of radium to treat skin lesions and cervical cancer in the early 1900s. The document outlines several early brachytherapy systems developed between 1913-1953, including the Stockholm, Paris, Manchester, and Paterson-Parker systems. It also discusses the introduction of the Quimby system using radium needles. The document notes the evolution of brachytherapy sources over time from radium to cesium-137 to iridium-192 to improve dosimetry, specific activity,
The document summarizes interstitial brachytherapy, including indications, contraindications, isotopes used, and details of various planning systems like Paterson-Parker, Quimby, Paris, and computer-based systems. It discusses dose rates, types of implants, applicators, volume definition, and dosimetry parameters like reference isodose and uniformity criteria for different planning approaches.
A linear accelerator (LINAC) is a device that uses high-frequency electromagnetic waves to accelerate electrons to high energies in a linear path inside an accelerator waveguide. LINACs are commonly used for external beam radiation therapy to treat cancer. LINACs work by using microwave technology to accelerate electrons, which are then directed at a target to produce high-energy x-ray or electron beams. The beams exit the machine shaped to the tumor and can be delivered from any angle by rotating the gantry and moving the treatment couch. LINACs are used to plan and deliver targeted radiation treatments to destroy cancer cells while sparing surrounding healthy tissue.
1. The Manchester system was one of the first standardized methods for interstitial brachytherapy implantation using radium sources. It provided rules for determining the amount of radium needed, its distribution, and dose specification based on the treatment area, distance, and desired total dose.
2. The amount of radium was calculated using exposure rates and tables that specified milligram hours of radium per 1000 rads of exposure for different areas and distances. The distribution of radium sources followed the inverse square law to achieve uniform dosing within 10% across the target area.
3. The system defined geometric terms and provided specific rules for distributing radium sources in planar moulds that were circular, square,
This document discusses various techniques for arc therapy including tomotherapy, intensity modulated arc therapy (IMAT), and volumetric modulated arc therapy (VMAT). It provides details on:
- The history and basic concept of arc therapy which involves continuous radiation delivery from a rotating source.
- Techniques like tomotherapy which uses fan beams and helical delivery, and IMAT/VMAT which modulates dose rate and leaf speed during single or multiple full gantry rotations.
- The planning process for these techniques including inverse planning with direct aperture optimization to determine optimal leaf positions and weights to achieve conformal dose distributions while satisfying delivery constraints.
The document discusses stereotactic radiosurgery techniques like Gamma Knife and X-Knife. It describes stereotaxy as a minimally invasive procedure using 3D coordinates to locate and treat small targets in the body. Gamma Knife uses 201 Cobalt-60 sources converged on a target to deliver a high radiation dose while sparing surrounding tissue. Key components include collimators, helmets, and frames to precisely locate the target. Planning involves imaging, contouring, dose optimization and evaluation. Gamma Knife provides non-invasive brain tumor treatment in a single session with sub-millimeter accuracy.
Evolving Role of Radiation Therapy in Hodgkins DiseaseSantam Chakraborty
1) Recent advances in radiation therapy for Hodgkin's lymphoma include reducing radiation volumes and doses based on clinical trials.
2) For early stage favorable Hodgkin's lymphoma, the standard is 2 cycles of ABVD chemotherapy followed by 20Gy involved field radiation.
3) For early stage unfavorable or poor prognosis disease, 4 cycles of ABVD plus 30Gy involved field radiation is standard based on clinical trials.
This document discusses the history and development of radiotherapy machines. It describes early machines that used X-rays and radium to treat cancers from the late 19th century up to the 1950s. The development of cobalt-60 teletherapy units in the 1950s provided a more powerful and practical radiation source. The document focuses on describing the Theratron 780C cobalt-60 teletherapy machine, including its parts, radiation modes, source, controls, specifications and safety features. It also discusses concepts like isocenter, penumbra and the advantages cobalt-60 provided over earlier radiation sources.
The document discusses inversion recovery MRI sequences. Inversion recovery sequences initially aimed to produce heavy T1 weighting but are now mainly used with fast spin echo sequences to produce T2-weighted images. The sequence begins with an 180-degree inversion pulse to invert spins, followed by a 90-degree excitation pulse after time TI. This produces an echo that can be used to generate T1- or T2-weighted images depending on timing parameters. Variants like fast inversion recovery, STIR, and FLAIR combine inversion recovery with other pulses to suppress signals from fat, fluid, or blood.
Evaluation of radiotherapy treatment planningAmin Amin
This document discusses the evaluation of radiotherapy treatment planning through the use of various tools and indices. The goals of treatment planning are to ensure the prescription dose adequately covers and conforms to the target volume while minimizing doses to surrounding healthy tissues. Key evaluation tools discussed include isodose distributions, orthogonal planes, dose volume histograms, dose statistics, homogeneity indices, and conformity/coverage indices. These tools provide both qualitative and quantitative assessments of the dose distribution and how well it meets the goals of treatment planning.
The document provides details about the acceptance testing and commissioning of a new TrueBeam linear accelerator installed at the facility. Some key details include:
- The machine was installed in an existing bunker previously occupied by a Siemens Primus Plus with additional shielding added.
- Acceptance testing verifies a small subset of beam data based on manufacturer guidelines to check specifications, while commissioning involves comprehensive beam measurements and treatment planning system configuration.
- Beam data measurements included depth doses, profiles, output, symmetry, flatness, and other dosimetric parameters which were analyzed and entered into the treatment planning system.
- Electron and photon beam energies and characteristics were evaluated to ensure they met tolerance limits. Other
Isodose lines represent points of equal absorbed radiation dose on a dose distribution map. They are depicted as curves on isodose charts showing the volumetric and planar variations in absorbed dose. Factors influencing isodose curves include beam quality, field size, source-to-skin distance, beam modifiers like wedges or bolus, and depth. Isodose curves are used in radiation therapy treatment planning to evaluate dose distributions and ensure tumor coverage while sparing surrounding healthy tissues. They provide critical information about the radiation dose profile essential for safe and effective treatment.
A summary of recent innovations in radiation oncology focussing on the priniciples of different techniques and their application. An overview of clinical results has also been given
This document discusses brachytherapy dosimetry using the TG-43 formulation. It begins by introducing brachytherapy and the sources commonly used, such as iridium-192 and iodine-125. It then covers how sources are specified and calibrated, including using exposure rate constants, air kerma rate constants, and apparent activity. Methods for source calibration include air ionization chambers, well chambers, and solid phantoms. Dose distribution around sources is also discussed, including using the Sievert integral for line sources. The TG-43 formalism provides a standardized method for calculating dose around brachytherapy sources.
This document discusses radiotherapy and CT simulation procedures. It begins with an introduction to radiotherapy and how it uses radiation to destroy cancer cells. It then describes the linear accelerator machine commonly used to deliver targeted radiation treatments. Finally, it outlines the mould room procedure for creating customized thermoplastic masks to immobilize patients, ensuring accurate radiation delivery to the treatment site.
Actualités 2015 en radiothérapie des cancers des voies aéro-digestives supérieures. Revue subjective des congrès et publications. Présentation CRONOR 21/11/2015. Thèmes : radiochimiothérapie, modification du fractionnement, biothérapie,
Clinical implementation of Surface Guided Radiotherapy (SGRT) for palliative ...SGRT Community
Jack Hannant
Senior Radiographer
The Christie at Oldham NHS Foundation Trust
UK
Helen Squibbs
Superintendent Radiographer
The Christie at Oldham NHS Foundation Trust
UK
Big data analysis for setup margin personalization derived from intra fractio...
SGRT implementation at IPC Unicancer, Marseille France
1. Vision RT : l’expérience de l’Institut
Paoli Calmettes – Marseille
Congrès SFRO
Paris 5/10/18
Dr Véronique FAVREL Radiothérapeute
Mme Océane ABRARD Manipulatrice
2. 1- Le département de radiothérapie
• Site de l’IPC - Marseille
- Equipements :
- 2 Synergy avec système de repositionnement
surfacique Align RT
- 1 Méridian en cours d’installation et 1 Versa HD
- 1 scanner de simulation dédié
- 1 salle de curiethérapie
- personnel :
- 7 ETP radiothérapeutes, 21 ETP MEM, 5 ETP
physiciens, 3,5 ETP dosimétristes, 1 MEM
Principale, 1 Cadre Sup
3. 1- Activité globale
Radiothérapie externe 2017 :
• 1730 patients 34130 séances
• 130 patients stéréo 730 séances
• 96 % techniques IRMT/Vmat
Radiothérapie cancers du sein :
• 2017 : 630 traitements seins, dont 318 Vmat
sur 1688 traitements
• 2018 (janvier à fin aout) : 421 seins dont 224
Vmat sur 1113 traitements
4. 2- Choix du système :
Objectif :
• Mettre en place un système de blocage
respiratoire ou gating pour la prise en charge
des cancers du sein pour épargner au mieux
poumons et cœur, notamment pour les
traitements du sein gauche avec radiothérapie
ganglionnaire
• Etude préalable de la littérature par l’équipe de
physique et l’équipe médicale pour comparer les
différents systèmes de gating
5. 2- Choix du système :
Avantages du repositionnement surfacique :
• Pour le gating sein : pas de lien physique entre le
système et la patiente (type spiromètre ou
capteurs infrarouges)
• Pour le repositionnement (avec ou sans gating) :
pas d’irradiation supplémentaire par rapport au
CBCT quotidien
• Repositionnement simple et rapide de la tête et du
bras qu’on ne visualise pas sur le CBCT
7. 2- Choix du système : précision du système
Etude de comparaison Align RT et lasers marques cutanées et IP :
Moyenne des déplacements sur les 50 patientes : 4.1 ± 2.6
mm (A/P), 2.7 ± 1.4 mm (S/I), and 2.6 ± 1.2 mm (D/G)
Clinical evaluation of interfractional variations for whole
breast radiotherapy using 3-dimensional surface imaging
Amish P. Shah et al
Practical Radiation Oncology (2013) 3,16-25
–
8. 2- Choix du système : doses au cœur
Pract Radiat Oncol.
2015 Nov-Dec;5(6):358-
65. Prospective
assessment of deep
inspiration breath-hold
using 3-dimensional
surface tracking for
irradiation of left-sided
breast cancer.
Tanguturi Sk et al
11. 3- Présentation du Système Align RT
• Dispositif définissant la radiothérapie guidée en
surface
• recalage surfacique tridimensionnel.
• Align RT permet d’effectuer, par une vidéo
tridimensionnelle, un suivi en temps réel de la
surface 3D du patient
• non irradiant et non invasif
• assure une surveillance continue
• Permet de réaliser un traitement en respiration
profonde bloquée (gating)
12. Align RT
Système constitué de 3 dispositifs montés
latéralement sur le plafond pour assurer une vision
complète du patient (environ 240°)
14. 4- Implémentation du système
• Formation d’utilisateurs référents à Londres
(1 physicien et 1 MEM)
• Formation sur site par les utilisateurs référents du
personnel et évaluation on line
• Formateur vison RT sur site avec première utilisation
clinique sur patientes choisies (seins traités en Vmat
avec aires ganglionnaires = 13 patientes)
• Création d’un groupe de travail pluridisciplinaire
15. 4- Activité AlignRT :
• Depuis février 2017, le système AlignRT° est
utilisé pour tous les traitements en Vmat des
cancers du sein conformément à la décision de
l’ensemble de l’équipe
• Base de données AlignRT : 578 patients (dont 41
patients traités pour d’autres localisations que le
sein : ORL, membres ..)
16. 4- Première étude :
Analyse des écarts de positionnement entre l’imagerie
CBCT et l’imagerie de positionnement surfacique pour
les patientes traitées en radiothérapie
(Mémoire de Master Justine Deborne) :
• 40 patientes
• Positionnement avec laser et points de tatouages
puis avec AlignRT
• Puis CBCT :
- si décalages < 0,4 cm pas de changement et
traitement
- si ≥ 0,4 cm application décalages et traitement
17. 4- Première étude :
• Résultats :
1- comparaison CBCT AlignRT pour le
positionnement initial
Valeurs min Valeurs max moyenne
vertical -0,034 0,437 0,195
longitudinal -0,416 0,197 -0,128
latéral -0,236 0,235 0,01
Valeurs comparables à celles de la littérature
18. 4- Première étude :
• Résultats :
En T/P et D/G les valeurs sont réparties autour de la
valeur zero, les valeurs en A/P sont déclées vers les
valeurs positives : en lien avec avec un affaissement
de la patiente en cours d’installation
19. 4- Première étude :
• Résultats :
2- Analyse des mouvements en cours de traitement
comparaison CBCT et AlignRT : pas d’impact sur le
monitoring AlignRT sauf en cas de respiration très
ample : affaissement possible en cours d’installation
mais retour aux zones de tolérance après
application des décalages
20. 4- Première étude :
• Affaissement visible pour une patiente donnée sur
CBCT et sur le monitoring AlignRT :
21. 4- Première étude :
Constat :
Certains traitements sont réalisés en coupant le
système RESPONSE car perte d’informations lors
du passage du bras devant la caméra.
Hypothèse : certains ROI isocentriques créés sont
plus pertinents que d’autres pour eviter ces pertes
d’information (coupures)
22. 4- Première étude :
Donc recherche de ROIs pertinents pour éviter
les sorties d’une ou plusieurs valeurs en dehors
des tolérances dues à la rotation du bras
passant devant le faisceau laser de surveillance
d’Align RT (coupures) :
• 1ere étape : essai de plusieurs ROIs sur un
volontaire
• 2eme étape : comparaison entre anciens ROIs
et ROIs élargis sur 2 séries de 30 patientes
23. 4- Deuxième étude :
• Recueils du nombre de coupures durant le
traitement dues à la rotation du bras passant
devant le faisceau laser de surveillance
d’AlignRT en fonction du choix des ROIs
(Franck Chabbert – Oceane Abrard)
Ancienne ROI sein
seul
Nouvelle ROI sein
plus hémi sein
controlat
24. 4- Deuxième étude :
• Résultats
61%
39%
ANCIENNE ROI
pas de
coupure
coupure
93%
7%
NOUVELLE ROI
pas de
coupure
coupure
25. 4- ROIs retenus
• Isocentrique : sein tté +
hémi-sein controlat
Centroïdes :
cou menton
et bras
26. 5- Elaboration d’un arbre décisionnel :
• Objectifs : que faire si discordances entre CBCT
et AlignRT rendant impossible l’utilisation du
repositionnement surfacique et du suivi en cours
de séances.
• Cause principale : modification significative de la
morphologie du sein entre le scan dosimétrique et
la 1ere séance ou après plusieurs séances (prise
ou perte de poids ; lymphocèle ; etc..)
• Implémentation le 3/07/18 pour la version finale
27. Positionner la patiente avec Align
RT en respectant < 1 mm et < 1°
Acquisition CBCT
décalage
s XVI ≥
4,00 mm
?
non
oui
Début de la
séance
Rentrer le tube RX et l’imageur
SÉANCES AVEC
IMAGERIE
Ne pas déplacer la table
Déplacement automatique de
table
28. Les
décalages
Align RT
basculent en
dehors des
tolérances
?
oui
Le
décalage est dû à
l’obstruction d’une
des caméras par
le bras de
l’accélérateur
?
ouinon
non
décalages
Align RT
hors-
tolérance ?
Appel Radiothérapeute
oui
non
Repositionner la patiente avec Align
RT
Démarrer l’irradiation
Vérification critères:
Bras, Rachis et
Respiration
(diaphragme)
Déconnecter le système
Response et terminer
l’irradiation
Fin de la délivrance des
faisceaux
29. • Appel Radiothérapeute
Scanner de simu
effectué en respiration
bloquée
Modification du sein ou
paroi
autre
Nombre
de
séances
restantes
≤ 5
Dosi
OK
oui non
oui
Resim
Décision médecin :
abandon Align RT ou
autre
+
Alerte physique par envoi
de tâche (problème Align
RT) par MEM
Nouvelle dosi et
reprise Align RT
Resim et recalcul des
anciens faisceaux sur
nouveau CT
Pas de resim
Abandon d’Align RT
CBCT quotidien
CBCT J1-J3 + calcul
moyenne + CBCT
hebdomadaire
no
n
Pas de changement et
abandon d’Align RT
30. 6- 3ème étude (O. Abrard, V.Favrel) :
Analyse a posteriori des discordances entre CBCT
et AlignRT entraînant l’arrêt de l’utilisation du
repositionnement surfacique et du suivi en cours de
séances, sur l’ensemble des patientes traitées pour
un cancer du sein depuis la mise en place du
système AlignRT en février 2017
31. 6- 3eme étude (O. Abrard, V.Favrel) :
• Nombre total de patients traités avec AlignRT :
• 546 patients ayant terminé leur traitement ; 32
actuellement en cours (traités avec 2 linacs)
• Sur les 546 patients, 505 cancers du sein tous
traités en Vmat :
• 495 patientes sein(s) et boost lit tumoral
• 10 boosts lit tumoral seul
• 41 patients traités pour des localisations autres
32. 6- 3ème étude (O. Abrard, V.Favrel) :
Résultats :
AlignRT tout le traitement Stop AlignRT
sein
497 (99,97%)
Sans resim Avec resim Sans
resim
Avec
resim
404 Pas de
nouvelle
dosi
Nouvelle
dosi
15 19 32 27
Lit T
10 (0,02%)
10 0 0 0 0
Sur 507 ptes 414 (82%) 34 59
447 (89%) 59 (11 %)
33. 6- 3ème étude : remarques complémentaires
• Arbre décisionnel : pas d’impact significatif sur la
réduction des arrêts de AlignRT pour le moment (4/44)
• 24 seins bilatéraux dans la population (0,04%) : tous
traités sans arrêter AlignRT ni resimulation
• Parmi les 58 patientes pour lesquelles AlignRT a été
arrêté, 35 l’ont été à moins de 10 séances, 23 au-delà
• Causes :
– arrêt précoce plutôt dû à des modifications anatomiques (lymphocèle), des
problèmes de position (douleurs) ou des évènements cliniques
intercurrents (abcès par ex)
– Arrêts plus tardifs : plutôt liés à des sorties de tolérances (affaissement de
la patiente ?)
34. - Membres et métastases osseuses : 19 patients
- Aires ganglionnaires cervicales et axillaires : 9
patients
- Tête et cou sans masque de contention : 5 patients
- Thorax, médiastin : 3 patients
- Lymphomes : 2 patient
- Œsophage : 1patient
- Canal anal : 1 patient
- Pelvis : 1 patient
Autres localisations dans la série :
35. Retour d’expérience :
• Système fiable
• Gain de temps pour les patientes
difficiles à positionner
36. Conclusion :
• Système fiable et simple d’utilisation
• Non irradiant
Prochaines étapes :
• Mise en place des traitements en respiration bloquée
pour les seins gauches notamment
• Points de tatouage ?
Autres localisations :
• Tête et cou avec masque ouverts
• Stéréotaxie crâne
• Gating pour les lymphomes de Hodgkin