INSIDE in-beam positron emission tomography system for particle range monitoring in hadrontherapy

Abstract

The quality assurance of particle therapy treatment is a fundamental issue that can be addressed by developing reliable monitoring techniques and indicators of the treatment plan correctness. Among the available imaging techniques, positron emission tomography (PET) has long been investigated and then clinically applied to proton and carbon beams. In 2013, the Innovative Solutions for Dosimetry in Hadrontherapy (INSIDE) collaboration proposed an innovative bimodal imaging concept that combines an in-beam PET scanner with a tracking system for charged particle imaging. This paper presents the general architecture of the INSIDE project but focuses on the in-beam PET scanner that has been designed to reconstruct the particles range with millimetric resolution within a fraction of the dose delivered in a treatment of head and neck tumors. The in-beam PET scanner has been recently installed at the Italian National Center of Oncologic Hadrontherapy (CNAO) in Pavia, Italy, and the commissioning phase has just started. The results of the first beam test with clinical proton beams on phantoms clearly show the capability of the in-beam PET to operate during the irradiation delivery and to reconstruct on-line the beam-induced activity map. The accuracy in the activity distal fall-off determination is millimetric for therapeutic doses.

Use of short-lived positron emitters for in-beam and real-time β+ range monitoring in proton therapy

“…The left plot shows the number of decays integrated up to 240 s and the right plot a zoom on the first 10 s for a beam intensity of 1 proton per second. For integration times of a few minutes, the measurement is dominated by 15 O, followed by 11 C, 12 N and 10 C. Contributions of 8 B and 14 O are marginal. For integration times of a few seconds, the main isotope is 12 N followed by 15 O, 8 B, 10 C and 11 C. The contribution of 14 O is marginal.…”

“…Measured data from Dendooven et al and simulation results using the two different hadronic models (QGSP_BIC and QGSP_BIC_AllHP) for 55 MeV protons stopped in the target highlight the same + β emitters: 11 C, 15 O, 12 N, 10 C, 14 O and 8 B. Table (2) presents the measured and simulated production rates for these isotopes.…”

“…This system measures annihilation gamma rays of slow-decaying isotopes (mostly 10 C, 11 C, 15 O, 14 O and 13 O) generated from the irradiated volume in a patient body during proton therapy from the start of the irradiation to 200 s after the end of irradiation [12,13]. The INSIDE (INnovative Solution for In-beam Dosimetry in hadronthErapy) project was created with the goal of building a bi-modal system to perform online monitoring in hadrontherapy [14][15][16][17]. Assembly of the INSIDE in-beam PET scanner was completed in January 2016 and subsequently installed at the Centro Nazionale di Adroterapia Oncologica (CNAO) facility located in Pavia (Italy), a synchrotron-based facility treating patients since September 2011.…”

Scintillating Fiber Devices for Particle Therapy Applications

“…In PT, recently, a beam range monitor technique based on the detection of prompt photons has been tested on a patient using the knife-edge slit camera developed by IBA in collaboration with Politecnico di Milano with good results [14], [15]. At the end of 2016, the imaging system based on the in-beam detection of PET photons [16], developed within the Research and Development in Hadrontherapy (RDH)/Innovative Solution for In-Beam DosimEtry in Hadrontherapy (INSIDE) project [17], has been installed at Centro Nazionale di Adroterapia Oncologica (CNAO) in Pavia (Italy) and tested on a patient undergoing a proton therapy treatment with promising results. The beam range monitoring techniques based on the detection of PET photons and prompt photons, when applied to carbon ion beam treatments, do suffer from a large background, difficult to suppress, induced by the 12 C ion beam nuclear interactions with tissues.…”

Control Of The Dose Distribution In Charged Particle Therapy

“…The recombination of the emitted positrons with an electron of the surrounding tissue, results in two coincident gammas that can be observed with a positron emission tomography (PET) camera. Details of this technique can be found in references [24,30], but it is worth to mention that in-vivo PET range verification has, in some institutes, moved from a research tool to clinical implementation, such as the case of the OpenPET scanner [31] tested at HIMAC or the INFN-INSIDE project [32] which has been recently tested at CNAO. These systems represent a powerful tool toward a possible image guided particle therapy, which would strongly improve the quality of a particle therapy treatment.…”