protontherapy

We present the update of the recommendations of the French society of radiation oncology on soft tissue sarcomas. Currently, the initial management of sarcomas is very important as it may impact on patients' quality of life, especially in limb soft tissue sarcomas, and on overall survival in trunk sarcomas. Radiotherapy has to be discussed within a multidisciplinary board meeting with results of biopsy, eventually reexamined by a dedicated sarcoma pathologist. The role of radiotherapy varies according to localization of soft tissue sarcoma...

BACKGROUND: To assess the outcome after meningioma surgery and protontherapy (PT). METHODS: We processed the French Système National des Données de Santé database to retrieve appropriate cases of meningiomas operated and irradiated between 2008 and 2017. Survival methods were implemented. RESULTS: One hundred ninety-three patients who received PT after meningioma surgery over a 10-year period were identified. Of the 193 patients, 75.6% were female...

Because of the physical properties of proton beam radiation therapy (PT), which allows energy to be deposited at a specific depth with a rapid energy fall-off beyond that depth, PT has several theoretical advantages over photon radiation therapy for esophageal cancer (EC). Protons have the potential to reduce the dose to healthy tissue and to more safely allow treatment of tumors near critical organs, dose escalation, trimodal treatment, and re-irradiation. In recent years, larger multicenter retrospective studies have been published showing excellent survival rates, lower than expected toxicities and even better outcomes with PT than with photon radiotherapy even using IMRT or VMAT techniques...

PURPOSE: Management of optic nerve sheath meningiomas (ONSM) remains challenging. Photon radiation therapy (PhRT) is the most common treatment for sight-threatening ONSM. Proton beam therapy (PBT) is less commonly used because it is more expensive and because there are questions about its efficacy specifically in relation to ONSM. PBT has the theoretical advantage of reducing radiation exposure to adjacent structures. We report the visual outcome of patients with primary ONSM managed at the Fondation Ophtalmologique Adolphe de Rothschild, Paris, France, and treated with PBT at the Centre de Protonthérapie, Institut Curie, Orsay, France...

PURPOSE: Brainstem radionecrosis is an important issue during the irradiation of tumors of the posterior fossa. The aim of the present study is to analyze postsurgical geometrical variations of tumor bed (TB) and brainstem (BS) and their impact on dosimetry. METHODS: Retrospective collection of data from pediatric patients treated at a single institution. Availability of presurgical magnetic resonance imaging (MRI) was verified; availability of at least two postsurgical MRIs was considered a further inclusion criterion...

Reirradiation and irradiation of sarcoma is often difficult due to the frequent need for a high dose of radiation in order to increase tumor control. This can result in a greater risk of toxicity which can be mitigated with the use of proton therapy. The present review aims to summarize the role of proton therapy in these 2 clinical contexts.

PURPOSE: Protontherapy for mediastinal Hodgkin lymphoma reduces cardiac, lung and breast exposure, which may limit radiation-induced adverse events. While this technique is already widely implemented in the United-States, clinical experience is still limited in France. This study analyses the practice of mediastinal Hodgkin lymphoma protontherapy at the Institut Curie to implement this technique at a larger scale. MATERIALS AND METHODS: Data from all mediastinal Hodgkin lymphoma patients from the hematology department of the Institut Curie who were subsequently evaluated at the Protontherapy Center of Orsay (CPO) of Institut Curie for adjuvant protontherapy were retrieved...

Following major advances of the best of photon-techniques such as intensity-modulated radiotherapy (IMRT), stereotactic body radiotherapy (SBRT) and, to arrive soon, magnetic resonance (MR)-linac radiotherapy, there are still substantial opportunities in the treatment of head and neck cancers to further reduce the toxicity burden. Proton therapy represents another attractive option in this high-quality and highly competitive precision radiotherapy landscape. Proton therapy holds promises to reduce toxicities and to escalate the dose in radioresistant cases or cases where dose distribution is not satisfactory with photons...

In the current spectrum of cancer treatments, despite high costs, a lack of robust evidence based on clinical outcomes or technical and radiobiological uncertainties, particle therapy and in particular proton therapy (PT) is rapidly growing. Despite proton therapy being more than fifty years old (first proposed by Wilson in 1946) and more than 220,000 patients having been treated with in 2020, many technological challenges remain and numerous new technical developments that must be integrated into existing systems...

Protontherapy is a rapidly expanding radiotherapy modality where accelerated proton beams are used to precisely deliver the dose to the tumor target but is generally considered ineffective against radioresistant tumors. Proton-Boron Capture Therapy (PBCT) is a novel approach aimed at enhancing proton biological effectiveness. PBCT exploits a nuclear fusion reaction between low-energy protons and 11 B atoms, i.e. p+11 B→ 3α (p-B), which is supposed to produce highly-DNA damaging α-particles exclusively across the tumor-conformed Spread-Out Bragg Peak (SOBP), without harming healthy tissues in the beam entrance channel...

The quality of the initial management of sarcomas is fundamental because it conditions the patient's quality of life and his overall survival. Radiotherapy should be discussed in a multidisciplinary consultation meeting within the framework of the Netsarc+network. The place of radiotherapy in patients with soft tissue or bone sarcoma depends on the histology and tumour location, knowing that it is most often associated with surgery which remains the main treatment. It is part of the standard treatment for grade II and III deep limb sarcomas of 5cm or greater in size and Ewing's sarcomas...

Considering intracranial tumours, only few indications of protontherapy, such as chordoma, chondrosarcoma or uveal melanoma, are uniformly approved in the world. Other indications, excluding paediatric pathologies, are still debated. The aim of this article is to describe the rationale for the use of protonbeam irradiation for meningioma, pituitary adenoma, craniopharyngioma, paraganglioma, glioma, and schwannoma, and to inform the radiation oncologists if prospective studies or randomized studies are opened for inclusions...

We propose a novel Prompt-Gamma (PG) imaging modality for real-time monitoring in proton therapy: PG Time Imaging (PGTI). By measuring the Time-Of-Flight (TOF) between a beam monitor and a PG detector, our goal is to reconstruct the PG vertex distribution in 3D. In this paper, a dedicated, non-iterative reconstruction strategy is proposed (PGTI reconstruction). Here, it was resolved under a 1D approximation to measure a proton range shift along the beam direction. In order to show the potential of PGTI in the transverse plane, a second method, based on the calculation of the Centre-Of-Gravity (COG) of the TIARA pixel detectors' counts was also explored...

Passive dosimetry with radiochromic films is widely used in proton radiotherapy, both in clinical and scientific environments, thanks to its simplicity, high spatial resolution and dose-rate independence. However, film under-response for low-energy protons, the so-called linear-energy transfer (LET) quenching, must be accounted and corrected for. We perform a meta-analysis on existing film under-response data with EBT, EBT2 and EBT3 GAFchromic™ films and provide a common framework to integrate it, based on the calculation of dose-averaged LET in the active layer of the films...

PURPOSE: Breast protontherapy efficiently limits cardiac, lung and contralateral breast exposure, which may clinically translate into better late tolerance profile compared with classic photon techniques. While breast protontherapy is already implemented in the United States and in some European countries, clinical experience of breast cancer protontherapy is currently limited in France. The aim of this study is to evaluate the clinical practice of breast cancer protontherapy at the Institut Curie in order to implement this technique at a larger scale...

After years of lethargy, studies on two non-conventional microstructures in time and space of the beams used in radiation therapy are enjoying a huge revival.The first effect called 'FLASH" is based on very high dose-rate irradiation (pulse amplitude ≥106 Gy/s), short beam-on times (≤100 ms) and large single doses (≥10 Gy) as experimental parameters established so far to give biological and potential clinical effects. The second effect relies on the use of arrays of Minibeams ( e.g., 0.5-1 mm, spaced 1-3...

Although chemically synthesized ferro/ferrimagnetic nanoparticles have attracted great attention in cancer theranostics, they lack radio-enhancement efficacy due to low targeting and internalization ability. Herein, we investigated the potential of RGD-tagged magnetosomes, bacterial biogenic magnetic nanoparticles naturally coated with a biological membrane and genetically engineered to express an RGD peptide, as tumor radioenhancers for conventional radiotherapy and protontherapy. Although native and RGD-magnetosomes similarly enhanced radiation-induced damage to plasmid DNA, RGD-magnetoprobes were able to boost the efficacy of radiotherapy to a much larger extent than native magnetosomes both on cancer cells and in tumors...

The purpose of this work was reducing treatment-related toxicity for Hodgkin lymphomas using practical procedure inspired by the ILROG guidelines. Reporting the first case of localized Hodgkin lymphoma treated with protontherapy in France. A 24-year-old female with mediastinal, bulky, localized, mixed-cellularity, classic Hodgkin lymphoma required an involved-site radiation therapy after complete response following polychemotherapy. Three-dimensional conformal radiation therapy was not acceptable due to high doses to breasts, heart and lungs...

Protontherapy has emerged as more effective in the treatment of certain tumors than photon based therapies. However, significant capital and operational costs make protontherapy less accessible. This has stimulated interest in alternative proton delivery approaches, and in this context the use of laser-based technologies for the generation of ultra-high dose rate ion beams has been proposed as a prospective route. A better understanding of the radiobiological effects at ultra-high dose-rates is important for any future clinical adoption of this technology...

In proton therapy, Monte Carlo simulations are desirable to accurately predict the delivered dose. This paper introduces and benchmarks pGPUMCD, a GPU-based Monte Carlo code implementing the physical processes required for protontherapy applications. In pGPUMCD, the proton transport is carried out in a voxelized geometry with a class II condensed history scheme. For this purpose, the equivalent restricted stopping power formalism (L<sub>eq</sub> formalism), the Fermi-Eyges scattering theory and the discrete electromagnetic/nuclear interactions were considered...