Methods and Advanced Equipment for Simulation and Treatment in Radiation Oncology

  • Haas, Olivier (Principal Investigator)
  • Burnham, Keith, (Co-Investigator)
  • Skworcow, Piotr, (Research Assistant)
  • Sahih, Abdelhamid, (Research Assistant)

Project: Research

Description

https://cordis.europa.eu/project/rcn/75531/reporting/en
Final Report Summary - MAESTRO (Methods and advanced equipment for simulation and treatment in radio-oncology)
The major challenge in the field of radiotherapy (RT) is to improve the conformation of dose delivered to the target (tumour and nearby tissues) whatever its shape, in order to treat the tumour more efficiently while sparing the surrounding healthy tissues. In this framework, the aim of MAESTRO was to optimise the application of conventional radiation therapy and allow emerging technologies like intensity-modulated radiation therapy (IMRT), image-guided radiotherapy (IGRT), and proton therapy to grow in providing them with more precise tools, quicker calculation means and appropriate quality assurance devices and procedures. At the same time partners expected to increase European competitiveness in this field.

A new model predictive control system was combined with a video tracker and a Kalman filter motion predictor to detect surrogate motion and move the PSS to compensate for the detected motion taking into account the software delays as well as the PSS dynamics. The Control Theory Applications Centre (CTAC) and UHCW (Coventry, UK) developed a "breathing" thorax phantom to facilitate the clinical validation of the "breathing couch" developed. The phantoms as well as other simpler electromechanical devices were positioned onto the PSS. Their motion was computer controlled to replicate realistic external as well as internal organ motion. The motion detection was performed using external markers monitored by video cameras or infrared tracking systems (e.g. Polaris). The control algorithms exploited the measured and predicted position to calculate the control action required to move the PSS in real time to enable it to compensate for target movements in such a way that the markers remain as motionless with respect to the room coordinate system and the treatment beam (i.e. the target did not move with respect to the beam).

Kalman filter-based predictors were compared to neural networks, polynomial and bilinear filters. The effect of motion prediction was assessed and a typical prediction horizon of 0.3s selected as the most appropriate to perform motion compensation with a standard Elekta PSS. The effect of motion prediction was experimentally demonstrated and it was shown to clearly improve the overall motion compensation.

Various image tracking algorithms were developed by CTAC, the University of East Anglia (UEA) (Norwich, UK), Universidad de Castilla-La Mancha (UCLM) (Ciudad Real , Spain). The UEA and UCLM focused on shape and volume tracking whereas CTAC focused on surrogate tracking (i.e. points in space). The method developed by UCLM was based on geometrical active contours and prediction. Several clinical tests with different image data including video showed good results in responding to different changes of the topology and contrast regions. ROC analysis was carried out for the different tests, obtaining an average of 97 % sensibility and 99 % specificity.

Irrespective of the topics dealt with in the course of MAESTRO project, at least the following fields were considered to be subject to specific appeal from the medical world and hence to future research programmes:
1. control of RT equipment: improvement in the robotic devices used to deliver radiation treatment were becoming increasingly topical with several manufacturers outside the EU preparing new commercial products for image-guided and adaptive radiation therapy. On the other hand, the increasing complexity of RT devices required new control/management software, in particular for patient and treatment follow-up, fault detection, preventive maintenance. 2.
imaging: improvement of imaging equipment and software remained a topical question, not only for diagnostic and treatment planning, but also for image-guided RT (IGRT), including imaging for intra-fraction motion compensation. In the future, efficiency of treatments may benefit more from improvement of imaging technologies than from linac.
3. small beams: whether delivered thanks to conventional linacs equipped with micro-MLC or devices like "Cyberknife", beams featuring a few cm, and even as narrow as less than 1 cm, were spreading for treatment of cancerous and non-cancerous disorders. One major concern was the relevant dosimetry: primary references, adapted dosimeters featuring small active volumes, dose calculations.
4. "in vivo" dosimetry: although not always applicable, the assessment of the actual dose delivered to the tumour (and possibly to organ at risk) thanks to dose measurements during one or several fractions, was a quality assurance task of interest, which had become compulsory in some countries, including France. There was demand for convenient devices.
5. hadrontherapy: the implementation of proton and carbon beams were considered to remain the source of intensive research. Hadron beams were clearly more conformational and advantageous than conventional treatments (as well as IMRT), at least for certain tumour locations. Prof. J. Bourhis, head of the RT department at IGR, and scientific coordinator of the hadrontherapy project "Archade" in Caen, reported that from published and accepted clinical studies, it is believed that 10 % of all RT treatments would benefit from proton treatments, and 10 % of these (hence 1 % of the total RT) would give even better outcomes with carbon ion beams.
6. dose modulation: while most of present expected deliveries are homogeneous doses to the cancerous volume (even with modulated beams), RT was expected to adapt in the future to more and more numerous prescriptions of modulated doses to the tumour.
7. biology: taking into account individual patient biological data and assessing individual organ sensitivity to the type of radiation delivered, would help to optimize the RT treatment parameters. Then the target of a radiation therapy would have to shift from a "physical" dose delivery (Gy) to an actual biological effect delivery. In addition, targeted RT, based on injected medicine, has already been subject to studies.
8. long-term adverse effects of RT: current RT devices aimed at minimising the short- and medium-term adverse side effects of RT treatments. The risk of secondary radiation-induced cancer or long-term non-cancerous diseases (like heart ischaemia for instance) had been already addressed by several research teams, but this had not yet been taken into account in routine to possibly influence treatment choice. A lot of work remained to be performed.

Furthermore the follow-up of all doses received by patient during their life, either by treatment or diagnostic devices, would certainly be of interest.

Layman's description

The WP 1 demonstrated the ability to detect the surrogate motion and to compensate for its motion in real time using a standard Elekta patient support system (PSS). A new model predictive control system was combined with a video tracker and a Kalman filter motion predictor to detect surrogate motion and move the PSS to compensate for the detected motion taking into account the software delays as well as the PSS dynamics.
CTAC and UHCW (Coventry, UK) developed a “breathing” thorax phantom to facilitate the clinical validation of the ‘breathing couch’ developed. The phantoms as well as other simpler electromechanical devices were positioned onto the PSS. Their motion was computer controlled to replicate realistic external as well as internal organ motion. The motion detection was performed using external markers monitored by video cameras or infrared tracking systems (e.g. Polaris). The control algorithms exploited the measured and predicted position to calculate the control action required to move the PSS in real time to enable it to compensate for target movements in such a way that the markers remain as motionless with respect to the room coordinate system and the treatment beam (i.e. the target does not move with respect to the beam).
Kalman filter based predictors were compared to neural networks, polynomial and bilinear filters. The effect of motion prediction was assessed and a typical prediction horizon of 0.3s selected as the most appropriate to perform motion compensation with a standard Elekta PSS. The effect of motion prediction was experimentally demonstrated and it was shown to clearly improve the overall motion compensation.
Various image tracking algorithms were developed by CTAC, UEA (Norwich, UK), UCLM (Ciudad Real , Spain). UEA and UCLM focused on shape and volume tracking whereas CTAC focused on surrogate tracking (i.e. points in space). The method developed by UCLM is based on geometrical active contours and prediction. Several clinical tests with different image data including video shown good results responding to different changes of the topology and contrast regions. ROC analysis was done for the different tests obtaining an average of 97% sensibility and 99% specificity.

Key findings

Work package lead for patient motion compensation using robotic couch for adaptive radiotherapy. €7M MAESTRO EU project involving 25 partners from 9 countries including 5 companies, 8 clinics and 12 research centres Co authored the proposal, managed work package 1 (3 Universities: 2 UK, 1 Sp; 1 hospital UK), led all research work and director of studies of all research students. Organised placement students from EU to support the project delivery. Resulted in Coventry being recognised as leader in motion management and first use (in the world) of model predictive control on a patient support system. The WP 1 demonstrated the ability to detect the surrogate motion and to compensate for its motion in real time using a standard Elekta patient support system (PSS). A new model predictive control system was combined with a video tracker and a Kalman filter motion predictor to detect surrogate motion and move the PSS to compensate for the detected motion taking into account the software delays as well as the PSS dynamics. CTAC and UHCW (Coventry, UK) developed a “breathing” thorax phantom to facilitate the clinical validation of the ‘breathing couch’ developed. The phantoms as well as other simpler electromechanical devices were positioned onto the PSS. Their motion was computer controlled to replicate realistic external as well as internal organ motion. The motion detection was performed using external markers monitored by video cameras or infrared tracking systems (e.g. Polaris). The control algorithms exploited the measured and predicted position to calculate the control action required to move the PSS in real time to enable it to compensate for target movements in such a way that the markers remain as motionless with respect to the room coordinate system and the treatment beam (i.e. the target does not move with respect to the beam). Kalman filter based predictors were compared to neural networks, polynomial and bilinear filters. The effect of motion prediction was assessed and a typical prediction horizon of 0.3s selected as the most appropriate to perform motion compensation with a standard Elekta PSS. The effect of motion prediction was experimentally demonstrated and it was shown to clearly improve the overall motion compensation. Various image tracking algorithms were developed by CTAC, UEA (Norwich, UK), UCLM (Ciudad Real , Spain). UEA and UCLM focused on shape and volume tracking whereas CTAC focused on surrogate tracking (i.e. points in space). The method developed by UCLM is based on geometrical active contours and prediction. Several clinical tests with different image data including video shown good results responding to different changes of the topology and contrast regions. ROC analysis was done for the different tests obtaining an average of 97% sensibility and 99% specificity. As far as protontherapy is concerned (WP 1.4), the challenge for IBA (Louvain-la-Neuve, Belgium) was to shift from the passive scattered beams mode to the active modalities, which allows better treatment accuracy (dose control and conformation) while sparing more efficiently the healthy tissues and strongly decreasing neutron production. In a first phase, IBA developed the Uniform Scanning (US) mode which is intermediate between the scattered mode and the Pencil Beam Scanning. The FDA clearance for US mode was obtained in March 2006 and after the system calibration and the clinical commissioning phases, the first patient was treated in January 2009. The studies related to the PBS mode (spot scanning), which requires much more sophisticated control and adapted equipment, were launched from the beginning of the project. In a first phase IBA developed the PBS in their “universal nozzle”, the part of the equipment closest to the patient, which now supports all treatment modalities with reduced time for the mechanical shift from one mode to another. The PBS modality received the FDA clearance on 12th December 2008, while the first patient was treated on 22nd December 2008. Following customer requests for enhanced performances, IBA lauched the design of a dedicated PBS nozzle in the middle of the project. This nozzle, optimized and more compact (and simple) from the mechanical standpoint, was completed and tested in the course of 2009. The WP 2 was dedicated to multimodality patient image registration and Atlas-Based Automatic Segmentation (ABAS), to help radiation oncologists to save time when contouring organs, and to Monte Carlo (MC) based calculation of dose with the aim of providing accurate calculated dose in all configurations (sharp dose gradients, tissue inhomogeneities). The image processing algorithms were developed by INRIA (Sophia-Antipolis, France) while the MC algorithms were developed by UCB (Barcelona, Spain) using its Penelope code and developing specific modules dedicated to RT in quadratic volumes for the linac head simulation and pixelized volume for the patient simulation. The relevant modules are intended for the commercial TPS “ISOgrayTM” proposed by Dosisoft (Cachan, France). The present version of ISOgrayTM includes the ABAS of brain and head-and-neck regions, as well as the MC calculation of the dose distribution in the patient for electron beams. Automatic contouring of pelvis or thorax organs are under development, as well as the integration of MC calculations for photon beams. IGR (Villejuif, France) performed extensive tests of the WP 2 modules during the periods 2 to 5 of the project, demonstrating their suitability to routine use, while hospitals UHCW, CFB (Caen, France) contributed to a lesser extent. UCL (Brussels, Belgium) contributed to studies in the specific field of contouring of head-and-neck organs and also provided INRIA with data to build the H&N atlas. In the framework of WP 3, eight different technologies of dosimeters were investigated with the aim to develop operational tools for pre-treatment verification, in vivo dosimetry and equipment quality assurance. They underwent tests in clinical environment to check for the characteristics defined in “Requirements” (see WP 4) : - The studies about point diamond detectors involved several partners in France (CEA Saclay, IGR), Italy (ISS, Rome, DFC, Florence), Poland (IFJ and COOK, Krakow), IBA-Dosimetry (Uppsala & Schwarzenbrück). CEA focused on CVD growing of synthetic diamond, passing in the course of the project, from poly-crystal to single-crystal. Tests of natural or HPHT diamonds (not produced within Maestro), poly-crystal and synthetic single-crystal diamonds showed that synthetic single-crystal diamond would be the only one able to meet the severe requirements of the clinical routine. The CVD synthetic single-crystal millimetric prototypes are really promising, and are well suited to small beams (stereotactic surgery, IMRT …). Collaboration with IBA-Dosimetry may result in the industrialization of the diamond dosimeter by this company. - A multi-point OSL (optically stimulated luminescence) prototype was developed at CEA and tested at IGR. The millimetric detectors (alumina) are located at the end of optical fibres, which transmit radioluminescence (during treatment) or OSL signal (after treatment), connected to the instrumentation case through a 16-channel mechanical switch. This device allows in vivo near-real-time multi-point control (up to 15). Its advantages are no dose-rate dependence, low energy dependence, low angular dependence, low fading, electromagnetic immunity, radiation hardness, radiation transparency. The non-linearity with dose is compensated for by calibration for doses smaller than 5 Gy in high energy photon / electron beams. - DFC developed 2D silicon dosimeter demonstrators. The design of the final detector has a modular structure. The basic module, 6.3 cm x 6.3 cm is constituted of 21 x 21 diodes (= 441) engraved in a single-crystal silicon plate with a pitch of 3 mm. The first prototype (1 module) used discrete electronics. The second one (1 module) was based on ASIC “Tera06” chips, developed by INFN Torino and industrialized by IBA/SCX, allowing parallel reading of all the pixels at the same time. The last prototype foresees 9 such modules, providing a 19 x 19 cm2 2D dosimeter with 4000 diodes. Due to the lack of Tera06, only the central module and a lateral one were mounted. This version of the detector was tested in hospital. It shows interesting properties, it was specially optimized to withstand 10 kGy without re-calibration, and the housing was carefully designed. DFC has a collaboration agreement with IBA-Dosimetry which may industrialize a version of the silicon detector. - TUD (Delft, The Netherlands) used GEM (Gas Electron Multipliers) detectors (from CERN) in a box to develop 2D dosimeters. The demonstrators include an out-of-field CCD camera which collects the light emitted by the GEMs and generates a 2D dose map of the beam with sub-millimetre resolution. The limitation in sensitivity with photon beams entailed the lab head to focus the studies on proton and carbon beams for which the detector features better characteristics than other technologies, especially for the Bragg peak region (lower dependence to LET – linear energy transmission- than with other technologies). - INFN developed a Pixel Ionization Chamber (PIC), a 2D network of cylindrical air ionisation chambers, as well as an ASIC chip “Terachip” in VLSI technology, able to perform the reading and integration of the signals issued from 64 pixels in parallel. IBA-Dosimetry, after having signed an agreement with INFN, industrialized and commercialized detectors based on the PIC technology : - The “ImRT MatriXX”, including a network of 32 x 32 ionisation chambers which a pitch of 7.62 mm (active area : 24.4 x 24.4 cm2), linked to the “OmniPro” software, is devoted to pre-treatment verification of IMRT beams. - The “StarTrack”, including 453 ionisation chambers laid on preferential axes (active area : 27 x 27 cm2), linked to the “OmniPro Advance” software, is devoted to the quality assurance of the beam (profile, symmetry, flatness, penumbra, dose output, MLC and wedge check …). - The “Compass”, based on the same technology, but not industrialized within Maestro, is dedicated to on line monitoring of the treatment. These detectors are very successful, 660 MatriXX and 120 StarTrack were sold by IBA-Dosimetry by the end of September 2009. - IFJ developed 2D thermoluminescent (TL) dosimetry systems consisting of 2D TL foils and planar TL readers. One, the “lab demonstrator”, is suited for circular foils, 6 cm in diameter, the other one, the stand-alone “clinical” demonstrator for 20 cm x 20 cm TL sheets. The first TL material tested was LiF, the second one was CaSO4, allowing much better sensitivity, hence better performances and lower detection limit. Each reader includes a heater and a CCD camera for the reading of irradiated foils. Homogeneity of the TL foils was a major issue. The goal of this promising technology is to replace the films by reusable dosimeters while featuring better resolution than numerical dosimeters do. - ISS studied the Fricke-agarose-Xylenol Orange gel dosimetry based on the use of (3D) tomographic optical reading, easier to manage than MRI (Magnetic Resonance Imaging). Readout of the sample OD (optical density) before and after irradiation shows a change in optical density proportional to dose. The rotation of the cylindrical sample (180 images) allows 3D tomographic reconstruction of the dose distribution, up to some Gy, with a resolution of 1 mm. The lab focused its effort 1°) on the tuning of the gel composition, obtaining a stable gel with negligible diffusion within 1 hour after irradiation, 2°) on the reader which includes a planar light source and a quick CCD camera, 3°) on the reconstruction software. Reading and processing takes now less than 10 min. The reader prototype allows for sample size up to 6 cm in diameter. - A 25 x 25 cm2 plastic scintillator was developed by the joint research lab LPC (Caen, France, Maestro partner : IN2P3,), with the aim of providing 2D profiles of the beam, 2D depth dose profiles, according to the orientation of the beam, or possibly 3D dose distributions thanks to the linear motion of the device. The company ELDIM (Caen, France) built a prototype, “DOSIMAP”, based on this technology, in which the plastic scintillator is sandwiched between polystyrene cubes and the light collected by an out-of-field lead-encased CCD camera packaged in a lead case. A dedicated filter and signal analysis allow discrimination of the Cerenkov light. DOSIMAP shows good physical properties (tissue equivalence, radiation hardness …), a resolution of 2 mm, its calibration requires very few correction factors. The WP 4 gathered the applications in clinical situation, it was coordinated by IGR with the help of DFC and UHCW. Its missions were : - Set up of “Requirements”, defining the expected characteristics of the devices developed within Maestro. As far as the dosimeters are concerned, suitable requirement lists were written for point, 2D and 3D devices. - Design of the protocols and procedures for the tests. - Assessment of the technical developments within Maestro and advices. Several “clinical meetings” were organized from this perspective. - Coordination of the tests in clinical environment, which are a major part of the clinical activities. No patients were involved in the tests in clinical environment. The Maestro clinics performed mainly the following tests : - IGR for the WP 2, and on diamond and OSL detectors (WP 3). - DFC on diamond, 2D silicon detectors, and 2D TL detector (WP 3). - UHCW for the WP 1, and some tests of the contouring module (WP 2). - COOK (cancer clinic in Krakow) on the 2D TL detector (WP 3). - CFB mainly on the plastic scintillator (WP 3) and also on ISOgrayTM (WP 2, contouring module). - UCL (University hospital, Brussels) specifically on the contouring of head-and-neck organs (WP 2). - UDE (Essen, Germany) on ISOgrayTM (WP 2). - INFN (Catania, Italy), houses a clinical proton treatment facility, and performed tests on diamond, 2D TL, 2D silicon detectors (WP 3). - IFJ also houses a proton facility and performed tests on the 2D TL detector (WP 3). It must be mentioned that a lot of clinical partners working outside Maestro were also entrusted tests by Maestro members, of which they are generally usual partners. We thank these clinical partners for their selfless participation. The WP 4 appeared to be a real integrating factor of the project. The post-treatment consequences were studies by the WP 4.3, dedicated to the calculation on numerical anthropomorphic phantoms of the out-of-field dose, with the future aim to assess the risk of radiation-induced secondary cancer. In a first phase TUD applied realistic treatment plans (provided by a clinic) to calculate whole-body doses in well-known numerical phantoms like “Adam” or “Eva” (developed by GSF, not Maestro partner) using the Monte Carlo code “Orange” developed by NRG (company located in Petten, The Netherlands). For example, a fatal second cancer probability for adults undergoing prostate treatment were assessed to be in the range 2 – 4 %, but the choice of the relation dose – risk (taken from the literature) remains subjective. In a second phase, IGR performed the tuning of deformable whole body phantoms, initially developed by the French institute INSERM (U605, not Maestro partner) for integration into the TPS ISOgrayTM. The principle relies on the choice, among a library, of the most suited available phantom. Then its shape is adapted to that of the actual patient to be treated, by registration with the region of interest of the patient. A classical calculation algorithm (Clarkson) is used to calculate the dose delivered to several out-of-field organs. The study showed the feasibility of routine out-of-field dose calculation, while Dosisoft improved the TPS interfaces. A French “industrialization project” following Maestro will optimize the commercial version. - In the framework of WP 5 (dissemination), were organized common contributions to national or (and mainly) international conferences and workshops. The dissemination programme was lauched by COOK and NPL (Teddington, UK). In agreement with the organizers, Maestro sessions, consisting of various scientific / technical presentations by Maestro partners, were integrated into the programme of international conferences : - ICSE, at CTAC, Coventry (UK), Sept 2006. - Biocare, organized along with the ESTRO conference, Leipzig (Germany), Oct. 2006. - IAEA – QANTRM, Vienna (Austria), Nov. 2006. - MCNEG 2007, at NPL, Teddington (UK), March 2007. - DEGRO, Hannover (Germany), June 2007. - EURADOS, Paris (France), January 2008. - ESTRO, Göteborg (Sweden), Sept. 2008. - LUMDETR, Krakow (Poland), July 2009. Also a stand presenting Maestro and its outputs was part of the technical exhibition of ESTRO conferences held in Göteborg in 2008 and in Maastricht in 2009. Maestro partners also organized Maestro workshops dedicated to specific topics of the project, with the participation of Maestro and external speakers : - 2-day Course on Monte Carlo codes, by INFN-Catania (Italy), Oct. 2006. - 1-day workshop on Multimodality Imaging, by IGR (France), Jan. 2007. - 2-day workshop on dosimetry, by DFC, Florence (Italy), March 2008. - 1-day workshop on Monte Carlo calculations, by IGR (France), April 2008. - 1-day training workshop on contouring of head-and-neck organ, by UCL and Dosisoft, in Paris (France), April 2009. - 1-day training workshop on contouring of head-and-neck organ, by UCL and Dosisoft, in Maastricht (The Netherlands, along with the ESTRO conference), August 2009. - 1-day workshop on organ motion management, by CTAC & UHCW, in Coventry (UK), Sept. 2009. - 2-day training workshop on Monte Carlo codes, by UCB, at Dosisoft, Cachan (France), Oct. 2009. The WP 6 was dedicated to the coordination / management of the project. Among the various tasks, the cohesion of the project was maintained thanks to plenary meetings, which took place every 6 months successively at CEA, INFN-Catania, IFJ, DFC, IBA, UCLM, INFN-Torino, UCB, ISS, UDE, CFB, IFJ (final meeting), and meetings of the Executive Committee every 3 months. The coordinator specially thanks those partners who housed the meetings. Conclusions and future The WP's of the project show various stages of progress, the outcome extending from the stage of feasibility demonstration to commercial success (exceeding the expected goals), according to the WP concerned. It is clear that MAESTRO met the global goal of the European Commission / Direction Research, say increase the European competitiveness, through 2 ways : 1°) bring technological breakthroughs, 2°) increase integration of members from various countries and various cultures. A factor affecting a lot of the WP's in the second half of the project, driven by the demand from the clinical field, was the application of Maestro-developed techniques to : 1°) treatment fields of small dimensions delivered by linacs or specific devices in the frame of new treatment techniques (IMRT, stereotactic radiosurgery, tomotherapy,….), 2°) proton- / carbon-therapy (most of dosimeters were evaluated with proton beams), 3°) “in vivo” dosimetry during treatment. Irrespective of the topics dealt with in the course of Maestro project, at least the following fields will be (or will remain) subject to specific appeal from the medical world, hence to future research programmes : - Control of RT equipment : Improvement in the robotic devices used to deliver radiation treatment are becoming increasingly topical with several manufacturer outside the EU preparing new commercial products for image guided and adaptive radiation therapy. On the other hand, the increasing complexity of RT devices requires new control / management software, in particular for patient and treatment follow up, fault detection, preventive maintenance. - Imaging : Improvement of imaging equipment and software will still remain a topical question, not only for diagnostic and treatment planning, but also for IGRT (Image Guided RT), including imaging for intra-fraction motion compensation. In the future, efficiency of treatments may more benefit from improvement of imaging technologies than of linac. - Small beams : whether delivered thanks to conventional linacs equipped with micro-MLC or devices like “Cyberknife”, beams featuring a few cm, and even as narrow as less than 1 cm, are spreading for treatment of cancerous and non-cancerous disorders. One major concern is the relevant dosimetry : primary references, adapted dosimeters featuring small active volumes, dose calculations. - “In vivo” dosimetry : although not always applicable, the assessment of the actual dose delivered to the tumour (and possibly to organ at risk) thanks to dose measurements during one or several fractions, is a quality assurance task of interest, which has become compulsory in some countries, including France. There is demand for convenient devices. - Hadrontherapy : the implementation of proton and carbon beams will certainly remain the source of intensive research. Hadron beams are clearly more conformational and advantageous than conventional treatments (as well as IMRT), at least for certain tumour locations. Pr. J. Bourhis, head of the RT department at IGR, and scientific coordinator of the hadrontherapy project “Archade” in Caen, reported that from published and accepted clinical studies, it is believed that 10 % of the whole RT treatments would benefit from proton treatments, and 10 % of these (hence 1 % of the total RT) would give even better outcome with carbon ion beams. - Dose modulation : While most of present expected deliveries are homogeneous doses to the cancerous volume (even with modulated beams), RT will certainly have to adapt in the future to more and more numerous prescriptions of modulated doses to the tumour. - Biology : taking into account individual patient biological data and assessing individual organ sensitivity to the type of radiation delivered, would help to optimize the RT treatment parameters. Then the target of a radiation therapy would have to shift from a “physical” dose delivery (Gy) to an actual biological effect delivery. In addition, targeted RT, based on injected medicine, has already been subject to studies. - Long term adverse effects of RT : Present RT devices aim at minimizing the short and medium term adverse side effects of RT treatments. The risk of secondary radiation-induced cancer or long-term non-cancerous diseases (like heart ischaemia for instance) has been already addressed by several research teams for a long time, but is not yet taken into account in routine to possibly influence treatment choice. A lot of work remains to be performed. Furthermore the follow-up of all doses received by patient during their life, either by treatment or diagnostic devices would certainly be of interest.
Short titleMAESTRO
AcronymMAESTRO
StatusFinished
Effective start/end date1/05/0430/04/09

Keywords

  • MAESTRO
  • IGRT
  • ART
  • radiotherapy
  • phantom
  • motion managment