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International Journal of Molecular... Sep 2020FLASH radiotherapy is the delivery of ultra-high dose rate radiation several orders of magnitude higher than what is currently used in conventional clinical... (Review)
Review
FLASH radiotherapy is the delivery of ultra-high dose rate radiation several orders of magnitude higher than what is currently used in conventional clinical radiotherapy, and has the potential to revolutionize the future of cancer treatment. FLASH radiotherapy induces a phenomenon known as the FLASH effect, whereby the ultra-high dose rate radiation reduces the normal tissue toxicities commonly associated with conventional radiotherapy, while still maintaining local tumor control. The underlying mechanism(s) responsible for the FLASH effect are yet to be fully elucidated, but a prominent role for oxygen tension and reactive oxygen species production is the most current valid hypothesis. The FLASH effect has been confirmed in many studies in recent years, both and , with even the first patient with T-cell cutaneous lymphoma being treated using FLASH radiotherapy. However, most of the studies into FLASH radiotherapy have used electron beams that have low tissue penetration, which presents a limitation for translation into clinical practice. A promising alternate FLASH delivery method is via proton beam therapy, as the dose can be deposited deeper within the tissue. However, studies into FLASH protons are currently sparse. This review will summarize FLASH radiotherapy research conducted to date and the current theories explaining the FLASH effect, with an emphasis on the future potential for FLASH proton beam therapy.
Topics: Humans; Neoplasms; Proton Therapy; Protons; Radiotherapy; Radiotherapy Dosage; Reactive Oxygen Species
PubMed: 32899466
DOI: 10.3390/ijms21186492 -
The British Journal of Radiology Mar 2022Localized prostate cancer can be treated with several radiotherapeutic approaches. Proton therapy (PT) can precisely target tumors, thus sparing normal tissues and... (Review)
Review
OBJECTIVE
Localized prostate cancer can be treated with several radiotherapeutic approaches. Proton therapy (PT) can precisely target tumors, thus sparing normal tissues and reducing side-effects without sacrificing cancer control. However, PT is a costly treatment compared with conventional photon radiotherapy, which may undermine its overall efficacy. In this review, we summarize current data on the dosimetric rationale, clinical benefits, and cost of PT for prostate cancer.
METHODS
An extensive literature review of PT for prostate cancer was performed with emphasis on studies investigating dosimetric advantage, clinical outcomes, cost-effective strategies, and novel technology trends.
RESULTS
PT is safe, and its efficacy is comparable to that of standard photon-based therapy or brachytherapy. Data on gastrointestinal, genitourinary, and sexual function toxicity profiles are conflicting; however, PT is associated with a low risk of second cancer and has no effects on testosterone levels. Regarding cost-effectiveness, PT is suboptimal, although evolving trends in radiation delivery and construction of PT centers may help reduce the cost.
CONCLUSION
PT has several advantages over conventional photon radiotherapy, and novel approaches may increase its efficacy and safety. Large prospective randomized trials comparing photon therapy with proton-based treatments are ongoing and may provide data on the differences in efficacy, toxicity profile, and quality of life between proton- and photon-based treatments for prostate cancer in the modern era.
ADVANCES IN KNOWLEDGE
PT provides excellent physical advantages and has a superior dose profile compared with X-ray radiotherapy. Further evidence from clinical trials and research studies will clarify the role of PT in the treatment of prostate cancer, and facilitate the implementation of PT in a more accessible, affordable, efficient, and safe way.
Topics: Cost-Benefit Analysis; Forecasting; Humans; Male; Prostatic Neoplasms; Proton Therapy; Radiotherapy Dosage
PubMed: 34558308
DOI: 10.1259/bjr.20210670 -
International Journal of Radiation... Oct 2021Radiation therapy plays an important role in the multidisciplinary management of breast cancer. Recent years have seen improvements in breast cancer survival and a... (Review)
Review
Radiation therapy plays an important role in the multidisciplinary management of breast cancer. Recent years have seen improvements in breast cancer survival and a greater appreciation of potential long-term morbidity associated with the dose and volume of irradiated organs. Proton therapy reduces the dose to nontarget structures while optimizing target coverage. However, there remain additional financial costs associated with proton therapy, despite reductions over time, and studies have yet to demonstrate that protons improve upon the treatment outcomes achieved with photon radiation therapy. There remains considerable heterogeneity in proton patient selection and techniques, and the rapid technological advances in the field have the potential to affect evidence evaluation, given the long latency period for breast cancer radiation therapy recurrence and late effects. In this consensus statement, we assess the data available to the radiation oncology community of proton therapy for breast cancer, provide expert consensus recommendations on indications and technique, and highlight ongoing trials' cost-effectiveness analyses and key areas for future research.
Topics: Breast; Breast Neoplasms; Consensus; Cost-Benefit Analysis; Female; Humans; Linear Energy Transfer; Neoplasm Recurrence, Local; Proton Therapy; Radiotherapy Planning, Computer-Assisted; Relative Biological Effectiveness
PubMed: 34048815
DOI: 10.1016/j.ijrobp.2021.05.110 -
Physics in Medicine and Biology Nov 2021Radiation therapy treatments are typically planned based on a single image set, assuming that the patient's anatomy and its position relative to the delivery system... (Review)
Review
Radiation therapy treatments are typically planned based on a single image set, assuming that the patient's anatomy and its position relative to the delivery system remains constant during the course of treatment. Similarly, the prescription dose assumes constant biological dose-response over the treatment course. However, variations can and do occur on multiple time scales. For treatment sites with significant intra-fractional motion, geometric changes happen over seconds or minutes, while biological considerations change over days or weeks. At an intermediate timescale, geometric changes occur between daily treatment fractions. Adaptive radiation therapy is applied to consider changes in patient anatomy during the course of fractionated treatment delivery. While traditionally adaptation has been done off-line with replanning based on new CT images, online treatment adaptation based on on-board imaging has gained momentum in recent years due to advanced imaging techniques combined with treatment delivery systems. Adaptation is particularly important in proton therapy where small changes in patient anatomy can lead to significant dose perturbations due to the dose conformality and finite range of proton beams. This review summarizes the current state-of-the-art of on-line adaptive proton therapy and identifies areas requiring further research.
Topics: Humans; Proton Therapy; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted
PubMed: 34710858
DOI: 10.1088/1361-6560/ac344f -
Ugeskrift For Laeger Oct 2019This review summarises the potential usage of proton therapy in Denmark. About one third of Danes are diagnosed with cancer, and half of these need radiotherapy in the... (Review)
Review
This review summarises the potential usage of proton therapy in Denmark. About one third of Danes are diagnosed with cancer, and half of these need radiotherapy in the course of treatment. Radiation dose cannot be adequately increased without giving rise to unacceptable, high risk of toxicity, but proton therapy is encouraging due to a unique depth dose distribution. In some cases, the benefit of proton therapy is obvious, but in most cases the gain is less obvious, and patients should only receive treatment within clinical trials. Clinical studies on proton therapy with focus on reduction of radiation-induced side effects and improvement of quality of life should be conducted.
Topics: Denmark; Humans; Proton Therapy; Quality of Life; Radiation Injuries; Radiotherapy Dosage
PubMed: 31610837
DOI: No ID Found -
Neuro-oncology Sep 2022
Topics: Brain Neoplasms; Brain Stem; Child; Humans; Proton Therapy; Protons; Radiometry
PubMed: 35512698
DOI: 10.1093/neuonc/noac121 -
Journal of Medical Radiation Sciences Mar 2021A transparent and equitable process for selecting patients who will benefit most from treatment at the Australian Bragg Centre for Proton Therapy as well as providing...
A transparent and equitable process for selecting patients who will benefit most from treatment at the Australian Bragg Centre for Proton Therapy as well as providing cost benefit for the investment made by government for this valuable resource, needs to be in place as soon as the Centre becomes operational, particularly for patients with more common cancers. Markov modelling is one method of patient selection and an example is provided in this issue of the Journal of Medical Radiation Sciences.
Topics: Cost-Benefit Analysis; Humans; Patient Selection; Proton Therapy
PubMed: 33259660
DOI: 10.1002/jmrs.454 -
The British Journal of Radiology Mar 2020
Topics: Humans; Neoplasms; Proton Therapy
PubMed: 32081045
DOI: 10.1259/bjr.20209004 -
Physics in Medicine and Biology Feb 2021The treatment of cancer with proton radiation therapy was first suggested in 1946 followed by the first treatments in the 1950s. As of 2020, almost 200 000 patients have... (Review)
Review
The treatment of cancer with proton radiation therapy was first suggested in 1946 followed by the first treatments in the 1950s. As of 2020, almost 200 000 patients have been treated with proton beams worldwide and the number of operating proton therapy (PT) facilities will soon reach one hundred. PT has long moved from research institutions into hospital-based facilities that are increasingly being utilized with workflows similar to conventional radiation therapy. While PT has become mainstream and has established itself as a treatment option for many cancers, it is still an area of active research for various reasons: the advanced dose shaping capabilities of PT cause susceptibility to uncertainties, the high degrees of freedom in dose delivery offer room for further improvements, the limited experience and understanding of optimizing pencil beam scanning, and the biological effect difference compared to photon radiation. In addition to these challenges and opportunities currently being investigated, there is an economic aspect because PT treatments are, on average, still more expensive compared to conventional photon based treatment options. This roadmap highlights the current state and future direction in PT categorized into four different themes, 'improving efficiency', 'improving planning and delivery', 'improving imaging', and 'improving patient selection'.
Topics: Biology; Humans; Neoplasms; Photons; Physics; Proton Therapy; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted
PubMed: 33227715
DOI: 10.1088/1361-6560/abcd16 -
Medical Physics Dec 2023LATTICE radiation therapy delivers 3D heterogenous dose of high peak-to-valley dose ratio (PVDR) to the tumor target, with peak dose at lattice vertices inside the...
BACKGROUND
LATTICE radiation therapy delivers 3D heterogenous dose of high peak-to-valley dose ratio (PVDR) to the tumor target, with peak dose at lattice vertices inside the target and valley dose for the rest of the target. Although the lattice vertex positions can impact PVDR inside the target and sparing of organs-at-risk (OAR), they are fixed as constants and not optimized during treatment planning in current clinical practice.
PURPOSE
This work proposes a new LATTICE plan optimization method that can optimize lattice vertex positions during LATTICE treatment planning, which is the first lattice position optimization study to the best of our knowledge.
METHODS
The new LATTICE treatment planning method optimizes lattice vertex positions as well as other plan variables (e.g., photon fluences or proton spot weights), with optimization objectives for target PVDR and OAR sparing. To satisfy mathematical differentiability, the lattice vertices are approximated in sigmoid functions. For geometric feasibility, proper geometry constraints are enforced onto lattice vertex positions. The lattice position optimization problem is solved by iterative convex relaxation (ICR) method and alternating direction method of multipliers (ADMM), and lattice vertex positions and photon/proton plan variables are jointly updated via the Quasi-Newton method.
RESULTS
Both photon and proton LATTICE RT were considered, and the optimal lattice vertex positions in terms of plan objectives were found by solving all possible combinations on given discrete positions via exhaustive searching based on standard IMRT/IMPT, which served as the ground truth for validating the new LATTICE method. The results show that the new method indeed provided the optimal lattice vertex positions with the smallest optimization objective, the largest target PVDR, and the best OAR sparing.
CONCLUSIONS
A new LATTICE treatment planning method is proposed and validated that can optimize lattice vertex positions as well as other photon or proton plan variables for improving target PVDR and OAR sparing.
Topics: Humans; Protons; Radiotherapy Planning, Computer-Assisted; Neoplasms; Radiotherapy Dosage; Radiotherapy, Intensity-Modulated; Proton Therapy
PubMed: 37357825
DOI: 10.1002/mp.16572