I will give an overview of the instrumental developments for proton therapy at different research groups of Comunitat Valenciana.
One of the currant tasks of Working Group 9 (WG9: Radiation dosimetry in Radiotherapy) of EURADOS (The European Radiation Dosimetry Group) is to characterize the spectrum of the neutron parasitic field originated as a consequence of radiotherapy. This neutron field may affect patient organs outside the treatment volume, leading to unwanted doses which potentially produce unwanted radiation...
PET range verification in proton therapy relies in the comparison of the measured and expected b+ annihilation profiles following the patient irradiation with protons of up to 200 MeV. The very different half-lives of the b+ emitters produced by the beam allows to study the b+ profiles both online or offline, by detecting either short- or long-lived isotopes, respectively.
In order to...
Background and Aims
The discovery of the FLASH effect has spurred the development of clinical proton therapy (PT) facilities to include Ultra-High Dose Rate (UHDR) capabilities for in-vitro, pre-clinical, and clinical studies. Here, we present a cost-effective passive irradiation system for small samples that can be installed and commissioned within minutes in a clinical PT facility.
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Positron Emission Tomography (PET) scanners possess the capability to both delineate three-dimensional images of organs affected by different diseases and investigate the metabolic behavior of tumoral structures. This is accomplished by detecting the two 511 keV photons produced in positron annihilation emitted by a β+ radionuclide. On the other hand, Single Photon Emission Computed Tomography...
Proton therapy has become a promising technique for cancer treatment, specifically targeting tumors and minimizing the impact on surrounding healthy tissues. Despite its benefits, there is uncertainty in the verification of the proton range, which implies higher doses in adjacent healthy tissues, this leads to use of wide safety margins in the doses, limiting the total potential of the...
We present a RayStation script to aid medical dosimetrists in preventing collisions between proton gantry head and patient or couch during treatment planning. The script imports 3D models of the treatment machine elements in STL format. These are visualized in the Patient Modeling tab together with the contoured patient surface. A graphical dialog with sliders allows for the interactive...
Hadron Therapy has advantages over conventional radiotherapy due to the maximization of the dose at the Bragg peak. However, owing to different systematic uncertainty sources associated with the technique, quasi-real-time monitoring for ion-range verification is required to reduce safety margins and enhance its potential benefits. Two of the most promising methodologies for in-room real-time...
Proton therapy's precision in targeting tumors while minimizing damage to healthy tissues has become increasingly important in clinical settings. However, accurate in-vivo verification of proton beam range is essential due to planning and delivery uncertainties. Compton cameras (CCs) are a promising solution for this challenge.
The IRIS group at IFIC-Valencia has developed two CC prototypes:...
The HELium Imaging Oncology Scanner (HELIOS) is a novel project to develop helium radiography based on existing proton imaging technologies for mixed carbon and helium beams. Its primary purpose is to enable range-guided particle therapy (RGPT) for non-small-cell lung cancer (NSCLC). One of the challenges in treating NSCLC is dealing with motion-induced changes in patient anatomy that occur on...
Background and aims: In-beam PET offers rapid treatment feedback, yet faces challenges with high event rates. Clinical implementation requires on-the-fly integration of a fast dose reconstruction algorithm. In this work, we present on-the-fly dose reconstruction from clinical in-beam PET data, using a novel In-beam Dose Estimation tool (IDE-PET), capable of obtaining on-line dose and of...
Silicon Carbide (SiC) is a radiation hard wide bandgap semiconductor, which makes it an interesting alternative for radiation detection applications such as radiotherapy instrumentation. Reducing the amount of metal over the active can positively affect the accuracy of the measurement.
The first SiC diodes with epitaxial graphene contacts were produced at IMB-CNM for radiation detection....
Nine years ago, the milestone of first-in-human range verification of a proton therapy treatment using prompt gamma-rays was achieved using a collimated gamma-ray camera. Despite being developed by a major proton accelerator vendor, the widespread clinical application and commercial availability of this device is not yet in sight. It remains unsure whether its size and weight will allow their...
Neutrons, as a form of radiation, possess high penetrating capabilities, contributing significantly to
the total absorbed dose within the human body. Consequently, the monitoring of neutron dose rates
is paramount for assessing the potential risks to workers, patients, and the public. Typically,
commercial portable neutron detectors, known as ambient neutron dosimeters, fulfill this...
The PEPITES detector is an ultra-thin, radiation-resistant profiler capable of continuous operation on mid-energy (O(100 MeV)) charged particle accelerators. With a water equivalent thickness of 10 microns, it induces minimal beam disturbance and is highly resistant to radiation.
Secondary electron emission (SEE) is used for the signal because it only requires a small amount of material (10...
The ability to measure the effects of radiation on healthy and tumorous tissues at the microscale can highly contribute to describing the dose distribution and establish correlations with the effects observed at the cellular level. Developing instruments with this characteristic is essential for planning particle radiotherapy for cancer treatment. The RADART (Radiation Dosimetry to Advance...
Poly-Allyl-Diglicol-Carbonate (PADC) track detectors, most commonly known by the name of one of its commercial brands (CR39), are the basis of the neutron dosimeter developed by the Radiation Physics Group at Universitat Autònoma de Barcelona (UAB). These dosimeters allow measuring the neutron component in general mixed radiation fields, including those encountered in proton radiotherapy....
Proton therapy requires precise knowledge of the patient's anatomy to guarantee an accurate dose delivery [1]. X-ray computed tomography (CT) images are used nowadays to calculate the relative stopping power (RSP) needed for proton therapy treatment planning [2]. Recent studies indicate that tomographic imaging using protons has the potential to provide a more accurate and direct measurement...
Proton therapy is an important radiotherapy that achieves very high dose conformity around the target, allowing a better protection of the organs at risk (decreasing radiation side effect). However, the dose delivered to a tumor is still conditioned by the dose that can be tolerated by the surrounding normal tissues. An emerging approach called FLASH therapy [2,3] delivers a therapeutic dose...
ABSTRACT
Around 40$\%$ of people surviving cancer do so because of radiotherapy. However, to improve this statistic, treatments based on hadron radiotherapy (HT) are rapidly expanding worldwide [1]. HT achieves very high dose conformity around the tumor target, allowing better protection of the organs at risk. This is particularly critical for radioresistant tumors, for tumors localized...
Recently, the use of ultra-high dose rates (FLASH) in radiation treatments has emerged as a new promising modality, where a pulsated ultra-high dose rate (>40 Gy/s) is delivered in comparison to conventional radiation therapy (~0.05 Gy/s). FLASH radiotherapy has demonstrated an unprecedented ability to reduce healthy tissue toxicity while maintaining tumor control, as shown in several in vivo...
High-frequency hadron therapy linear accelerators (linacs) have undergone extensive research and development, becoming integral components of proton therapy centers. Linacs operating at frequencies of 200-400 Hz provide the advantage of dynamically adjusting the output energy pulse by pulse. This capability enables the precise deposition of the dose with continuous depth variation, rapidly...
Laser-plasma accelerators have attracted significant interest, particularly thanks to the extreme accelerating fields in the plasma, offering a cost-effective and compact alternative to traditional accelerators. Significant progress has been made in recent years in laser-driven ion acceleration, including acceleration of protons with unprecedented properties, such as ultra-short duration, low...
Within the framework of the Science Industry strategy of the Basque Country, LINAC7 is a project that pursues the generation of knowledge and qualification in the field of accelerator science and technology. With the design and construction of a compact low energy (7 MeV) proton accelerator, the project presents the ideal framework to develop efficient technological solutions and meet the...
Research at the Institute for Instrumentation in Molecular Imaging (i3M, Valencia) is related to the development of diagnostic systems and clinical or preclinical applications of nuclear physics techniques. We present two recent advances related to particle therapy. The necessity for online range measurement for the real-time determination of the position of the Bragg peak has been much...
Ionizing radiation is widely employed for medical purposes, encompassing both diagnostic and therapeutic applications. Radiation therapy, a well-established medical modality routinely employed in cancer treatment, has demonstrated efficacy in addressing extra-cranial amyloidosis. Current evidence suggests its potential as a promising treatment for amyloid-associated neurodegenerative...
Tumors located near the optic pathways pose a particular challenge due to the risk of optical toxicities. For this reason, they are often treated with proton therapy. Such patients with paraoptic tumors represented more than half the whole patient population, suggesting referral biases to proton therapy toward difficult to treat tumors.
The PIOTox study aims to conduct a voxel-scale analysis...
Despite the improvements in cancer treatment over the past decades, tumor recurrence and metastases are still the main concern for the therapy's success [1]. Tumors are composed by a heterogenous population of cells, among which the Circulating Cancer Stem Cells (CCSCs) are the real responsible for metastasis formation. These cells are radioresistant and express markers critical for migration...
Background & Aims: In this study, we propose a strategy for multi-beam FLASH-PT combined with IMPT, applied to a meningioma case. The objective is to leverage the benefits of FLASH Bragg Peak-in-target beams in conjunction with IMPT. For this work, we defined “the FLASH effect” to occur in healthy tissue if irradiated with a minimum dose of 5 Gy, with a dose modifying factor (DMF) of...
En entornos de irradiación experimental para protonterapia, como aceleradores de baja energía o usando el modo técnico de un acelerador clínico, donde no es posible usar el control automático de dosis mediante el planificador, se hace necesario implementar un sistema de dosimetría independiente para los experimentos. En este contexto, las películas radiocrómicas juegan un papel esencial debido...
Introduction:
In proton therapy, in addition to better targeting of the dose delivered to the tumor, we expect greater biological effectiveness (RBE) due to the microscopic characteristics of the dose deposit. Protons are considered to be charged particles with high linear energy transfer (LET), particularly in the Bragg peak region. In this case the energy deposits are very close to each...
Background and aims
Radiopharmaceutical therapy (RPT) is a novel modality of oncology treatments which uses radiolabeled agents affine to biomolecules overexpressed in tumor cell environments. Alpha particle emitters are key in RPT by precisely targeting cancer cells while minimizing impact on healthy tissue, thanks to their limited range and localized energy delivery. In addition, this kind...
Proton therapy is a radiation treatment that targets tumoural masses more precisely than conventional radiotherapy. Simulations of clinical proton radiotherapy treatment plans and dose verification methods using Monte Carlo (MC) codes have been proven to be a valuable tool for basic research and clinical studies.
TOPAS, a CPU-based, open-source software tool, can be considered a golden...
The Spanish Nuclear Safety Council (CSN) demands a Radiation Protection (RP) report for the commissioning of the Varian BEAMPRO250 cyclotron at Valdecilla Hospital (HUMV) to ensure compliance with legal requirements. In response, the Physics Institute of Cantabria (IFCA) has developed a Geant4-based simulation tool called BUNSHI. Given the machine's geometry and anticipated annual workload,...
Introduction
We present an advanced pulse irradiation model (PIM) utilizing gMicroMC’s step-by- step algorithm (SBS) with the newly incorporated periodic boundary condition (PBC), along the modeling of the homogeneous stage with numerical ordinary differential equations (NumODEs). Our goal is to study the pulse structure effects on radical production during CONV and FLASH in pure...
Ionization chambers are the devices most commonly used as dosimeters in radiotherapy. They show, however, some limitations compared to other systems based in semiconductors: large sizes, high voltage requirement for biasing, etc. Some current-mode semiconductor devices have been studied for the same purpose, such as photodiodes and phototransistors. For these devices, the absorbed dose is...
Clinical aspects and challenges in Protontherapy at CAL
