168 research outputs found
High granularity tracker based on a Triple-GEM optically read by a CMOS-based camera
The detection of photons produced during the avalanche development in gas
chambers has been the subject of detailed studies in the past. The great
progresses achieved in last years in the performance of micro-pattern gas
detectors on one side and of photo-sensors on the other provide the possibility
of making high granularity and very sensitive particle trackers. In this paper,
the results obtained with a triple-GEM structure read-out by a CMOS based
sensor are described. The use of an He/CF (60/40) gas mixture and a
detailed optimization of the electric fields made possible to obtain and very
high GEM light yield. About 80 photons per primary electron were detected by
the sensor resulting in a very good capability of tracking both muons from
cosmic rays and electrons from natural radioactivity
Hippocampal and Amygdalar Volumes Changes in Drug Addicts: A Preliminary Study
Oral comunication for American Society of Neuroradiology 45th Annual Meeting. Chicago, June 9-14 200
Intraoperative β-Detecting probe for radio-guided surgery in tumour resection
The development of the β− based radio-guided surgery aims to extend the technique to those tumours where surgery is the only possible treatment and the assessment of the resection would most profit from the low background around the lesion, as for brain tumours. Feasibility studies on meningioma and gliomas already estimated the potentiality of this new treatment. To validate the technique, a prototype of the intraoperative probe detecting β− decays and specific phantoms simulating tumour remnant patterns embedded in healthy tissue have been realized. The response of the probe in this simulated environment is tested with dedicated procedures. This document discusses the innovative aspects of the method, the status of the developed intraoperative β− detecting probe and the results of the preclinical tests
An Intraoperative Detecting Probe For Radio-Guided Surgery in Tumour Resection
The development of the based radio-guided surgery aims to extend
the technique to those tumours where surgery is the only possible treatment and
the assessment of the resection would most profit from the low background
around the lesion, as for brain tumours. Feasibility studies on meningioma,
glioma, and neuroendocrine tumors already estimated the potentiality of this
new treatment. To validate the technique, prototypes of the intraoperative
probe required by the technique to detect radiation have been
developed. This paper discusses the design details of the device and the tests
performed in laboratory. In such tests particular care has to be taken to
reproduce the surgical field conditions. The innovative technique to produce
specific phantoms and the dedicated testing protocols is described in detail.Comment: 7 pages, 15 figure
Monitoring of hadrontherapy treatments by means of charged particle detection
The interaction of the incoming beam radiation with the patient body in hadrontherapy
treatments produces secondary charged and neutral particles, whose detection can be
used for monitoring purposes and to perform an on-line check of beam particle range. In
the context of ion-therapy with active scanning, charged particles are potentially attractive
since they can be easily tracked with a high efficiency, in presence of a relatively low
background contamination. In order to verify the possibility of exploiting this approach
for in-beam monitoring in ion-therapy, and to guide the design of specific detectors, both
simulations and experimental tests are being performed with ion beams impinging on
simple homogeneous tissue-like targets (PMMA). From these studies, a resolution of the
order of few millimeters on the single track has been proven to be sufficient to exploit
charged particle tracking for monitoring purposes, preserving the precision achievable
on longitudinal shape. The results obtained so far show that the measurement of charged
particles can be successfully implemented in a technology capable of monitoring both
the dose profile and the position of the Bragg peak inside the target and finally lead to
the design of a novel profile detector. Crucial aspects to be considered are the detector
positioning, to be optimized in order to maximize the available statistics, and the capability
of accounting for the multiple scattering interactions undergone by the charged
fragments along their exit path from the patient body. The experimental results collected
up to now are also valuable for the validation of Monte Carlo simulation software tools
and their implementation in Treatment Planning Software packages
Towards a Radio-guided Surgery with Decays: Uptake of a somatostatin analogue (DOTATOC) in Meningioma and High Grade Glioma
A novel radio guided surgery (RGS) technique for cerebral tumors using
radiation is being developed. Checking the availability of a
radio-tracer that can deliver a emitter to the tumor is a
fundamental step in the deployment of such technique. This paper reports a
study of the uptake of 90Y labeled (DOTATOC) in the meningioma and the high
grade glioma (HGG) and a feasibility study of the RGS technique in these cases.Comment: 21 pages, 5 figure
Charged particle's flux measurement from PMMA irradiated by 80 MeV/u carbon ion beam
Hadrontherapy is an emerging technique in cancer therapy that uses beams of
charged particles. To meet the improved capability of hadrontherapy in matching
the dose release with the cancer position, new dose monitoring techniques need
to be developed and introduced into clinical use. The measurement of the fluxes
of the secondary particles produced by the hadron beam is of fundamental
importance in the design of any dose monitoring device and is eagerly needed to
tune Monte Carlo simulations. We report the measurements done with charged
secondary particles produced from the interaction of a 80 MeV/u fully stripped
carbon ion beam at the INFN Laboratori Nazionali del Sud, Catania, with a
Poly-methyl methacrylate target. Charged secondary particles, produced at
90 with respect to the beam axis, have been tracked with a drift
chamber, while their energy and time of flight has been measured by means of a
LYSO scintillator. Secondary protons have been identified exploiting the energy
and time of flight information, and their emission region has been
reconstructed backtracking from the drift chamber to the target. Moreover a
position scan of the target indicates that the reconstructed emission region
follows the movement of the expected Bragg peak position. Exploting the
reconstruction of the emission region, an accuracy on the Bragg peak
determination in the submillimeter range has been obtained. The measured
differential production rate for protons produced with 83 MeV and emitted at 90 with respect to the beam line is: .Comment: 13 pages, 9 figure
Measurement of charged particle yields from therapeutic beams in view of the design of an innovative hadrontherapy dose monitor
Particle Therapy (PT) is an emerging technique, which makes use of charged particles to efficiently cure different kinds of solid tumors. The high precision in the hadrons dose deposition requires an accurate monitoring to prevent the risk of under-dosage of the cancer region or of over-dosage of healthy tissues. Monitoring techniques are currently being developed and are based on the detection of particles produced by the beam interaction into the target, in particular: charged particles, result of target and/or projectile fragmentation, prompt photons coming from nucleus de-excitation and back-to-back γ s, produced in the positron annihilation from β + emitters created in the beam interaction with the target. It has been showed that the hadron beam dose release peak can be spatially correlated with the emission pattern of these secondary particles. Here we report about secondary particles production (charged fragments and prompt γ s) performed at different beam and energies that have a particular relevance for PT applications: 12C beam of 80 MeV/u at LNS, 12C beam 220 MeV/u at GSI, and 12C, 4He, 16O beams with energy in the 50–300 MeV/u range at HIT. Finally, a project for a multimodal dose-monitor device exploiting the prompt photons and charged particles emission will be presented
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