scholarly journals Deep Seated Tumour Treatments With Electrons of High Energy Delivered at FLASH Rates: The Example of Prostate Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Alessio Sarti ◽  
Patrizia De Maria ◽  
Giuseppe Battistoni ◽  
Micol De Simoni ◽  
Cinzia Di Felice ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Good Alternative ◽  
High Energy ◽  
Particle Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Surgical Removal ◽  
High Dose ◽  
Very High Energy ◽  
Technological Developments

Different therapies are adopted for the treatment of deep seated tumours in combination or as an alternative to surgical removal or chemotherapy: radiotherapy with photons (RT), particle therapy (PT) with protons or even heavier ions like 12C, are now available in clinical centres. In addition to these irradiation modalities, the use of Very High Energy Electron (VHEE) beams (100–200 MeV) has been suggested in the past, but the diffusion of that technique was delayed due to the needed space and budget, with respect to standard photon devices. These disadvantages were not paired by an increased therapeutic efficacy, at least when comparing to proton or carbon ion beams. In this contribution we investigate how recent developments in electron beam therapy could reshape the treatments of deep seated tumours. In this respect we carefully explored the application of VHEE beams to the prostate cancer, a well-known and studied example of deep seated tumour currently treated with high efficacy both using RT and PT. The VHEE Treatment Planning System was obtained by means of an accurate Monte Carlo (MC) simulation of the electrons interactions with the patient body. A simple model of the FLASH effect (healthy tissues sparing at ultra-high dose rates), has been introduced and the results have been compared with conventional RT. The study demonstrates that VHEE beams, even in absence of a significant FLASH effect and with a reduced energy range (70–130 MeV) with respect to implementations already explored in literature, could be a good alternative to standard RT, even in the framework of technological developments that are nowadays affordable.

scholarly journals Feasibility Study of a Prostate Cancer FLASH Therapy Treatment With Electrons of High Energy

2021 ◽  
Author(s):  
Alessio Sarti ◽  
Patrizia De Maria ◽  
Battistoni Giuseppe ◽  
Micol De Simoni ◽  
Cinzia Di Felice ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Technological Development ◽  
High Energy ◽  
Planning System ◽  
Treatment Planning System ◽  
High Dose ◽  
Dose Rates ◽  
Very High Energy ◽  
Almost All ◽  
Very High

Abstract Prostate cancer is among the most common cancers in men and one of the leading causes of death worldwide. Different therapies are adopted for its treatment and generally radiotherapy with photons (RT) is the preferred solution in almost all cases. Up to now, in addition to photons, only protons have been implemented as alternative radiotherapy. The use of Very High Energy Electron (VHEE) beams (100-200 MeV) has been suggested in literature but the needed accelerators are more demanding, as far as space and cost are concerned, with respect to standard photon devices, with only limited advantages when compared to protons or other heavy ions. In this contribution we investigate how recent developments in electron beam therapy could reshape the landscape of prostate treatments. The VHEE Treatment Planning System obtained combining an accurate Monte Carlo (MC) simulation with a simple modelling of the FLASH effect (healthy tissues sparing at very high dose rates) is compared with conventional RT. The results demonstrate that FLASH therapy with VHEE beams of 70-130 MeV could represent a valid alternative to standard RT allowing a better sparing of the healthy tissues surrounding the tumour, in the framework of an affordable technological development.

scholarly journals Dosimetric Studies of Mixed Energy Intensity Modulated Radiation Therapy for Prostate Cancer Treatments

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
K. Abdul Haneefa ◽  
K. K. Shakir ◽  
A. Siddhartha ◽  
T. Siji Cyriac ◽  
M. M. Musthafa ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Radiation Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
High Energy ◽  
Photon Beam ◽  
Planning System ◽  
Treatment Planning System ◽  
Intensity Modulated ◽  
Mixed Beam ◽  
Mixed Field

Dosimetric studies of mixed field photon beam intensity modulated radiation therapy (IMRT) for prostate cancer using pencil beam (PB) and collapsed cone convolution (CCC) algorithms using Oncentra MasterPlan treatment planning system (v. 4.3) are investigated in this study. Three different plans were generated using 6 MV, 15 MV, and mixed beam (both 6 and 15 MV). Fifteen patients with two sets of plans were generated: one by using PB and the other by using CCC for the same planning parameters and constraints except the beam energy. For each patient’s plan of high energy photons, one set of photoneutron measurements using solid state neutron track detector (SSNTD) was taken for this study. Mean percentage of V66 Gy in the rectum is 18.55±2.8, 14.58±2.1, and 16.77±4.7 for 6 MV, 15 MV, and mixed-energy plans, respectively. Mean percentage of V66 Gy in bladder is 16.54±2.1, 17.42±2.1, and 16.94±41.9 for 6 MV, 15 MV, and mixed-energy plans, respectively. Mixed fields neutron contribution at the beam entrance surface is 45.62% less than at 15 MV photon beam. Our result shows that, with negligible neutron contributions, mixed field IMRT has considerable dosimetric advantage.

scholarly journals Dosimetric comparison of MR-linac-based IMRT and conventional VMAT treatment plans for prostate cancer

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Vanessa Da Silva Mendes ◽  
Lukas Nierer ◽  
Minglun Li ◽  
Stefanie Corradini ◽  
Michael Reiner ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Target Coverage ◽  
Treatment Delivery ◽  
Ptv Margin ◽  
Delivery Times ◽  
Low Field ◽  
Treatment Plans

Abstract Background The aim of this study was to evaluate and compare the performance of intensity modulated radiation therapy (IMRT) plans, planned for low-field strength magnetic resonance (MR) guided linear accelerator (linac) delivery (labelled IMRT MRL plans), and clinical conventional volumetric modulated arc therapy (VMAT) plans, for the treatment of prostate cancer (PCa). Both plans used the original planning target volume (PTV) margins. Additionally, the potential dosimetric benefits of MR-guidance were estimated, by creating IMRT MRL plans using smaller PTV margins. Materials and methods 20 PCa patients previously treated with conventional VMAT were considered. For each patient, two different IMRT MRL plans using the low-field MR-linac treatment planning system were created: one with original (orig.) PTV margins and the other with reduced (red.) PTV margins. Dose indices related to target coverage, as well as dose-volume histogram (DVH) parameters for the target and organs at risk (OAR) were compared. Additionally, the estimated treatment delivery times and the number of monitor units (MU) of each plan were evaluated. Results The dose distribution in the high dose region and the target volume DVH parameters (D98%, D50%, D2% and V95%) were similar for all three types of treatment plans, with deviations below 1% in most cases. Both IMRT MRL plans (orig. and red. PTV margins) showed similar homogeneity indices (HI), however worse values for the conformity index (CI) were also found when compared to VMAT. The IMRT MRL plans showed similar OAR sparing when the orig. PTV margins were used but a significantly better sparing was feasible when red. PTV margins were applied. Higher number of MU and longer predicted treatment delivery times were seen for both IMRT MRL plans. Conclusions A comparable plan quality between VMAT and IMRT MRL plans was achieved, when applying the same PTV margin. However, online MR-guided adaptive radiotherapy allows for a reduction of PTV margins. With a red. PTV margin, better sparing of the surrounding tissues can be achieved, while maintaining adequate target coverage. Nonetheless, longer treatment delivery times, characteristic for the IMRT technique, have to be expected.

scholarly journals Back to the Future: Very High-Energy Electrons (VHEEs) and Their Potential Application in Radiation Therapy

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4942
Author(s):  
Maria Grazia Ronga ◽  
Marco Cavallone ◽  
Annalisa Patriarca ◽  
Amelia Maia Leite ◽  
Pierre Loap ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Current Knowledge ◽  
High Energy ◽  
High Dose Rate ◽  
Point Of View ◽  
High Dose ◽  
Dose Rates ◽  
High Energy Electrons ◽  
Very High Energy ◽  
Very High

The development of innovative approaches that would reduce the sensitivity of healthy tissues to irradiation while maintaining the efficacy of the treatment on the tumor is of crucial importance for the progress of the efficacy of radiotherapy. Recent methodological developments and innovations, such as scanned beams, ultra-high dose rates, and very high-energy electrons, which may be simultaneously available on new accelerators, would allow for possible radiobiological advantages of very short pulses of ultra-high dose rate (FLASH) therapy for radiation therapy to be considered. In particular, very high-energy electron (VHEE) radiotherapy, in the energy range of 100 to 250 MeV, first proposed in the 2000s, would be particularly interesting both from a ballistic and biological point of view for the establishment of this new type of irradiation technique. In this review, we examine and summarize the current knowledge on VHEE radiotherapy and provide a synthesis of the studies that have been published on various experimental and simulation works. We will also consider the potential for VHEE therapy to be translated into clinical contexts.

scholarly journals Differentiation of Using Flattening Filter Free Energy in Vmat Plans for Prostate Cancer

2018 ◽  
Vol 22 ◽  
pp. 01049 ◽  
Author(s):  
Yonca Yahşi Çelen ◽  
Atilla Evcin
Keyword(s):  
Prostate Cancer ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Dose Rates ◽  
Advantages And Disadvantages ◽  
Flattening Filter Free ◽  
Significant Difference ◽  
Treatment Plans ◽  
Flattening Filter

It is aimed to compare the values of conformity index (CI), homogeneity index (HI), monitor unit (MU) of volumetrically adjusted arthritis therapy (VMAT) plans using 10 prostate cancer patients with flattened filter (FF) and without flattening filter (FFF). In the study, treatment plans were prepared using 6 FF and 6 FFF in the Eclipse (ver.13.6) treatment planning system with Varian Trilogy Linear Accelerator. When planning was completed, CI averaged 0.87, HI averaged 0.44 and MU values were found to be 591 ± 26.8, 650 ± 33.06, respectively. When the PTV coverage, CI, HI and MU comparisons were made as a result of planning, there was no significant difference when comparing VMAT plans in FFF and FF energies. When we compare the MU values, the MU increase is seen when the straightening filter is removed. In both energy modes, good homogeneity in PTV was achieved with conventional francitation and close dose rates. No significant advantages and disadvantages of the unfiltered energy mode were observed in the assessment of plan quality in terms of CI, HI.

scholarly journals Toward an effective use of laser-driven very high energy electrons for radiotherapy: Feasibility assessment of multi-field and intensity modulation irradiation schemes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Luca Labate ◽  
Daniele Palla ◽  
Daniele Panetta ◽  
Federico Avella ◽  
Federica Baffigi ◽  
...  
Keyword(s):  
High Energy ◽  
High Dose Rate ◽  
High Dose ◽  
Feasibility Assessment ◽  
High Energy Electrons ◽  
Very High Energy ◽  
Effective Use ◽  
Dose Deposition ◽  
Therapeutic Doses ◽  
Very High

Abstract Radiotherapy with very high energy electrons has been investigated for a couple of decades as an effective approach to improve dose distribution compared to conventional photon-based radiotherapy, with the recent intriguing potential of high dose-rate irradiation. Its practical application to treatment has been hindered by the lack of hospital-scale accelerators. High-gradient laser-plasma accelerators (LPA) have been proposed as a possible platform, but no experiments so far have explored the feasibility of a clinical use of this concept. We show the results of an experimental study aimed at assessing dose deposition for deep seated tumours using advanced irradiation schemes with an existing LPA source. Measurements show control of localized dose deposition and modulation, suitable to target a volume at depths in the range from 5 to 10 cm with mm resolution. The dose delivered to the target was up to 1.6 Gy, delivered with few hundreds of shots, limited by secondary components of the LPA accelerator. Measurements suggest that therapeutic doses within localized volumes can already be obtained with existing LPA technology, calling for dedicated pre-clinical studies.

The effect of the carbon fibre insert for the Varian Exact™ couch on the attenuation and build-up of high energy photon beams

2010 ◽  
Vol 10 (2) ◽  
pp. 77-83 ◽  
Author(s):  
ML Wilson ◽  
WP Colley ◽  
AW Beavis
Keyword(s):  
Carbon Fibre ◽  
External Beam Radiotherapy ◽  
High Energy ◽  
Planning System ◽  
Treatment Planning System ◽  
Skin Dose ◽  
Angle Of Incidence ◽  
Photon Beams ◽  
Radiation Beam ◽  
Tolerance Dose

AbstractCarbon fibre couch inserts are widely used in external beam radiotherapy to provide rigid and lightweight patient support. Carbon fibre is often perceived to be essentially radiotranslucent implying that it does not interfere with the radiation beam. However, there is evidence in the literature which suggests that this perception may not be appropriate, particularly at oblique angles of incidence. Furthermore, there is evidence indicating that the use of carbon fibre significantly reduces the skin sparing effect. In this study, the radiation attenuation and surface dose enhancement characteristics of the carbon fibre insert for the Varian ExactTM couch have been investigated. It was found that attenuation increased significantly with increasing angle of incidence, resulting in in-phantom dose reductions of up to 6% at 6 MV and 4% at 15 MV. It has been shown that it is possible to model couch attenuation on a commercial treatment planning system (Elekta CMS XiO) by including the carbon fibre insert in the planning computed tomography (CT) dataset. Finally, the carbon fibre insert was found to significantly increase skin dose to the patient. The skin dose was approximately three times as large when the couch insert was added to 6 and 15 MV photon beams. However, even with this substantial increase it is highly unlikely that the skin tolerance dose will be exceeded.

Two Quality Control Procedures on Radiotherapy Beam Calibration and Treatment Planning System Implementation

1998 ◽  
Vol 84 (2) ◽  
pp. 150-154 ◽  
Author(s):  
Angelo Piermattei ◽  
Luigi Azario ◽  
Stefania delle Canne ◽  
Andrea Fidanzio ◽  
Giovanni Palazzoni
Keyword(s):  
Quality Control ◽  
Treatment Planning ◽  
High Energy ◽  
Planning System ◽  
Treatment Planning System ◽  
Silicon Detectors ◽  
X Ray ◽  
Silicon Diode ◽  
Output Factors ◽  
Control Procedures

New challenging dosimetric approaches, such as narrow beams and 3D algorithms, are being used in radiotherapy. In this paper two quality control (QC) procedures are reported. The first one concerns the QC of the dosimetry of small x-ray beams, generally carried out by using silicon detectors. The comparison of dose values obtained by a silicon diode, a diamond detector, and radiochromic films shows that for x-ray beams of high energy, the silicon diode can give an overestimation of the output factors in phantom, up to 4%. This is due to the higher than unit density silicon diode and the surrounding envelope that restore the lateral electron equilibrium. About the 3D algorithms for breast treatment planning, a quality control test has been adopted to verify the accuracy of the computed dosimetry when “loss of scatter” occurs. The results show a sensible agreement (within 1.5%) between computed and experimental data.

Ct Image Fusion as a Tool for Measuring in 3D the Setup Errors during Conformal Radiotherapy for Prostate Cancer

2006 ◽  
Vol 92 (2) ◽  
pp. 118-123 ◽  
Author(s):  
Raffaella Cambria ◽  
Federica Cattani ◽  
Mario Ciocca ◽  
Cristina Garibaldi ◽  
Giampiero Tosi ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Radiation Therapy ◽  
Image Fusion ◽  
The Body ◽  
Planning System ◽  
Treatment Planning System ◽  
Ct Image ◽  
Fusion Technique ◽  
Setup Accuracy ◽  
Image Fusion Technique

Aims and Background The importance of optimal daily patient positioning has been stressed in order to ensure treatment reproducibility and gain in accuracy and precision. We report our data on the 3D setup uncertainty during radiation therapy for prostate cancer using the CT image fusion technique. Methods Ten consecutive patients scheduled for radiation therapy for prostate cancer underwent 5 prone position CT scans using an individualized immobilization cast. These different setups were analyzed using the image fusion module of the ERGO 3D-Line Medical System (Milan, Italy) treatment planning system. The isocenter and the body marker displacements were measured. Results The 3D isocenter dislocations were quantified: systematic error was Σ3D = 3.9 mm, whereas random error was σ3D = 1 mm. The mean of the minimum displacements was 0.2 ± 1 mm showing that the immobilization device used allows an accurate setup to be obtained. Single direction errors were also measured showing systematic errors, ΣAP = 2.6 mm, ΣLL = 0.6 mm, ΣSI = 3 mm in the anterior-posterior, latero-lateral, superior-inferior direction, respectively. Related random errors were σAP = 1 mm, σLL = 0.6 mm, σSI = 1.2 mm. In terms of accuracy, our uncertainties are similar to those reported in the literature. Conclusions By applying the CT image fusion technique, a 3D study on setup accuracy was performed. We demonstrated that the use of an individualized immobilization system for prostate treatment is adequate to obtain good setup accuracy, as long as a high-quality positioning control method, such as the stereoscopic X-ray-based positioning system, is used.

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