Characterisation of the secondary-neutron production in particle therapy treatments with the MONDO tracking detector

Particle Therapy (PT) is a non-invasive technique that exploits charged light ions for the irradiation of tumours that cannot be effectively treated with surgery or conventional radiotherapy. While the largest dose fraction is released to the tumour volume by the primary beam, a non-negligible amount of additional dose is due to the beam fragmentation that occurs along the path towards the target volume. In particular, the produced neutrons are particularly dangerous as they can release their energy far away from the treated area, increasing the risk of developing a radiogenic secondary malignant neoplasm after undergoing a treatment. A precise measurement of the neutron flux, energy spectrum and angular distributions is eagerly needed in order to improve the treatment planning system software, so as to predict the normal tissue toxicity in the target region and the risk of late complications in the whole body. The MONDO (MOnitor for Neutron Dose in hadrOntherapy) project is dedicated to the characterisation of the secondary ultra-fast neutrons ([20-400] MeV energy range) produced in PT. The neutron tracking system exploits the reconstruction of the recoil protons produced in two consecutive (n, p) elastic scattering interactions to measure simultaneously the neutron incoming direction and energy. The tracker active media is a matrix of thin squared scintillating fibers arranged in orthogonally oriented layers that are read out by a sensor (SBAM) based on SPAD (Single-Photon Avalanche Diode) detectors developed in collaboration with the Fondazione Bruno Kessler (FBK)

Characterisation of the secondary-neutron production in particle therapy treatments with the MONDO tracking detector

Particle Therapy (PT) is a non-invasive technique that exploits charged light ions for the irradiation of tumours that cannot be effectively treated with surgery or conventional radiotherapy. While the largest dose fraction is released to the tumour volume by the primary beam, a non-negligible amount of additional dose is due to the beam fragmentation that occurs along the path towards the target volume. In particular, the produced neutrons are particularly dangerous as they can release their energy far away from the treated area, increasing the risk of developing a radiogenic secondary malignant neoplasm after undergoing a treatment. A precise measurement of the neutron flux, energy spectrum and angular distributions is eagerly needed in order to improve the treatment planning system software, so as to predict the normal tissue toxicity in the target region and the risk of late complications in the whole body. The MONDO (MOnitor for Neutron Dose in hadrOntherapy) project is dedicated to the characterisation of the secondary ultrafast neutrons ([20–400]MeV energy range) produced in PT. The neutron tracking system exploits the reconstruction of the recoil protons produced in two consecutive (n,p) elastic scattering interactions to measure simultaneously the neutron incoming direction and energy. The tracker active media is a matrix of thin squared scintillating fibers arranged in orthogonally oriented layers that are read out by a sensor (SBAM) based on SPAD (Single-Photon Avalanche Diode) detectors developed in collaboration with the Fondazione Bruno Kessler (FBK)

Scintillating fiber devices for particle therapy applications

Particle Therapy (PT) is a radiation therapy technique in which solid tumors are treated with charged ions and exploits the achievable highly localized dose delivery, allowing to spare healthy tissues and organs at risk. The development of a range monitoring technique to be used on-line, during the treatment, capable to reach millimetric precision is considered one of the important steps towards an optimization of the PT efficacy and of the treatment quality. To this aim, charged secondary particles produced in the nuclear interactions between the beam particles and the patient tissues can be exploited. Besides charged secondaries, also neutrons are produced in nuclear interactions. The secondary neutron component might cause an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignant neoplasms that can develop even years after the treatment. An accurate neutron characterization (flux, energy and emission profile) is hence needed for a better evaluation of long-term complications. In this contribution two tracker detectors, both based on scintillating fibers, are presented. The first one, named Dose Profiler (DP), is planned to be used as a beam range monitor in PT treatments with heavy ion beams, exploiting the charged secondary fragments production. The DP is currently under development within the INSIDE (Innovative Solutions for In-beam DosimEtry in hadrontherapy) project. The second one is dedicated to the measurement of the fast and ultrafast neutron component produced in PT treatments, in the framework of the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project. Results of the first calibration tests performed at the Trento Protontherapy center and at CNAO (Italy) are reported, as well as simulation studies

!CHAOS: A cloud of controls

The paper is aimed to present the !CHAOS open source project aimed to develop a prototype of a national private Cloud Computing infrastructure, devoted to accelerator control systems and large experiments of High Energy Physics (HEP). The !CHAOS project has been financed by MIUR (Italian Ministry of Research and Education) and aims to develop a new concept of control system and data acquisition framework by providing, with a high level of abstraction, all the services needed for controlling and managing a large scientific, or non-scientific, infrastructure. A beta version of the !CHAOS infrastructure will be released at the end of December 2015 and will run on private Cloud infrastructures based on OpenStack

Preliminary test of the MONDO project secondary fast and ultrafast neutrons tracker response using protons and MIP particles

The risk of developing a second malignant cancer as a late time consequence of undergoing a treatment, is one of the main concerns in particle therapy (PT). Since neutrons can release a significant dose far away from the tumour region, a precise characterisation of their production point, kinetic energy and abundance is eagerly needed. The treatment planning system (TPS) software that predicts the normal tissue toxicity in the target region and the risk of late complications in the whole body is currently based on the poorly known production cross-sections and will greatly benefit from improved precision double differential measurements. The MONDO (MOnitor for Neutron Dose in hadrOntherapy) project aims to build an ultrafast neutron tracker that could be used to characterise the production of secondary neutrons with energies in the 20-400 MeV range. The neutron tracking will proceed via the detection of recoil protons produced in two consecutive (n, p) elastic scattering interactions. The MONDO detector consists of a 10 × 10 × 20 cm3matrix of thin scintillating fibres, arranged in orthogonally oriented layers. A compact read-out sensor with single photon detection capabilities employing the CMOS SPAD technology has been developed in collaboration with Fondazione Bruno Kessler (FBK). The detector will be completed by the end of 2018. A 4 × 4 × 4.8 cm3prototype has been built using 250 μ m thick scintillating fibres of squared section and was tested using a proton beam and minimum ionising particles. In this contribution we present the experimental results related to the prototype test performed with a proton beam at the Proton Therapy Centre of the Trento Hospital (PTC) in May 2017. The results are compared with the results of a Monte Carlo simulation performed with the FLUKA software

FRED: A fast Monte Carlo code on GPU for quality control in particle therapy

Charged Particle Therapy is a non-invasive technique for radio-resistant tumor treatment performed with protons or light ions, aiming to deliver a high precision treatment. Compared to conventional radiotherapy, ions allow for a higher dose deposition in the tumor region while sparing the surrounding healthy tissue. To really exploit the potential benefits of this technique, the highest possible accuracy in the calculation of dose and its spatial distribution is required in treatment planning. Commonly used Treatment Planning Software solutions adopt a simplified beam–body interaction model. An alternative is the use of Monte Carlo simulations which explicitly take into account the interaction of charged particles with actual human tissues hence providing highly accurate results. However, Monte Carlo simulations are used in a restricted number of cases due to substantial computational resources required. The code FRED has been developed to allow a fast optimization of the treatment plans in Charged Particle Therapy while profiting from the dose release accuracy of a Monte Carlo tool. Currently, the most refined module is the transport of proton beams in water. A comparison with measurements shows that the lateral dose tails are reproduced within 2% in the field size factor test up to 20 cm. Models for the interaction of ion with the matter are currently under development in the FRED code. The status of new developments and the performance of FRED will be presented

Charged particles and neutron trackers: applications to particle therapy

The use of C, He and O as beam particles in Particle Therapy (PT) treatments is getting more and more widespread as a consequence of the enhanced relative biological effectiveness and oxygen enhancement ratio of such projectiles with respect to protons. The advantages in the tumor control probability, related to the improved efficacy of ions, are calling for an online monitor of the dose release spatial distribution. Such technology is currently missing in PT treatments clinical routine. In this contribution the status of [Formula presented] ions PT treatments monitoring, exploiting the detection of either charged secondary particles or neutrons, is reviewed. While charged fragments can be used to provide an online feedback to the beam control system, by correlating their emission profile with the position of the Bragg peak, neutrons have to be monitored to improve the experimental description of the secondary radiation component that significantly contributes to an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignancies development after the treatment. Two tracker detectors, employing scintillating fibers, are presented: the Dose Profiler designed for charged secondary fragments measurements and the MONDO tracker dedicated to the characterisation of the secondary fast and ultrafast neutron component, within the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project

Characterisation of the MONDO detector response to neutrons by means of a FLUKA Monte Carlo simulation

Particle therapy is increasingly used for the treatment of solid tumours, especially when the tolerance of organs at risk for conventional radiotherapy becomes dose limiting. To take full advantage of the particle therapy potential, the beam range in tissues has to be precisely known and the secondary particles production during the treatment has to be accurately characterised, as it can lead to unwanted dose deposition far from the target volume. Secondary neutrons can release a remarkable dose, also far from the tumour, increasing the probability of secondary cancer late insurgence in the patient. Currently, the treatment planning system software used in clinical routine suffer from the lack of high precision data related to the secondary neutron production in particle therapy treatments. The aim of the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project is to develop a tracking detector for secondary neutrons in the energy range of 20−400 MeV. Neutrons flux, energy spectra and angular distribution will become experimentally available by tracking the recoil protons produced after two consecutive neutron elastic scattering interactions in a 10×10×20cm3 matrix of scintillating fibres. A Monte Carlo simulation based on the FLUKA code was developed to optimise the MONDO detector layout, define the tracker trigger logic, evaluate the background contamination and possible strategies for its reduction: preliminary results are reported in this manuscript. A 4×4×4.8cm3 detector prototype was tested with protons at the APSS Proton Therapy Centre in Trento (Italy), where calibration and efficiency measurements were performed. Experimental and simulated results were compared