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Practical Radiation Oncology 2023
Topics: Humans; Proton Therapy
PubMed: 37391235
DOI: 10.1016/j.prro.2023.04.001 -
International Journal of Radiation... Jul 2023FLASH radiation therapy (FLASH-RT) is a promising radiation technique that uses ultrahigh doses of radiation to increase the therapeutic window of the treatment....
PURPOSE
FLASH radiation therapy (FLASH-RT) is a promising radiation technique that uses ultrahigh doses of radiation to increase the therapeutic window of the treatment. FLASH-RT has been observed to provide normal tissue sparing at high dose rates and similar tumor control compared with conventional RT, yet the biological processes governing these radiobiological effects are still unknown. In this study, we sought to investigate the potential immune response generated by FLASH-RT in a high dose of proton therapy in an orthotopic glioma rat model.
METHODS AND MATERIALS
We cranially irradiated rats with a single high dose (25 Gy) using FLASH dose rate proton irradiation (257 ± 2 Gy/s) or conventional dose rate proton irradiation (4 ± 0.02 Gy/s). We first assessed the protective FLASH effect that resulted in our setup through behavioral studies in naïve rats. This was followed by a comprehensive analysis of immune cells in blood, healthy tissue of the brain, and tumor microenvironment by flow cytometry.
RESULTS
Proton FLASH-RT spared memory impairment produced by conventional high-dose proton therapy and induced a similar tumor infiltrating lymphocyte recruitment. Additionally, a general neuroinflammation that was similar in both dose rates was observed.
CONCLUSIONS
Overall, this study demonstrated that FLASH proton therapy offers a neuro-protective effect even at high doses while mounting an effective lymphoid immune response in the tumor.
Topics: Rats; Animals; Proton Therapy; Protons; Glioma; Radiation, Ionizing; Brain; Radiotherapy Dosage; Tumor Microenvironment
PubMed: 36563907
DOI: 10.1016/j.ijrobp.2022.12.018 -
Cancer Radiotherapie : Journal de La... Sep 2023Rare central nervous system tumors are defined by an incidence rate of less than 6 cases per 100 000 individuals a year. It comprises a large panel of entities... (Review)
Review
Rare central nervous system tumors are defined by an incidence rate of less than 6 cases per 100 000 individuals a year. It comprises a large panel of entities including medulloblastoma, glioneuronal tumors, solitary fibrous tumors, rare pituitary tumors, ependymal or embryonal tumors. The management of these tumors is not clearly defined and radiotherapy indications should be discussed at a multidisciplinary board. Image-guided and intensity-modulated radiation therapy should be proposed and MRI has a fundamental place in the treatment preparation. To avoid the occurrence of side effects, proton therapy is playing an increasingly role for the treatment of these tumors.
Topics: Humans; Radiation Oncology; Proton Therapy; Radiotherapy, Intensity-Modulated; Pituitary Neoplasms; Cerebellar Neoplasms
PubMed: 37481341
DOI: 10.1016/j.canrad.2023.06.008 -
Seminars in Radiation Oncology Oct 2023Advances in proton therapy have garnered much attention and speculation in recent years as the indications for proton therapy have grown beyond pediatric, prostate,... (Review)
Review
Advances in proton therapy have garnered much attention and speculation in recent years as the indications for proton therapy have grown beyond pediatric, prostate, spine, and ocular tumors. To achieve and maintain consistent access to this cancer treatment and to ensure the future viability and availability of proton centers in the United States, a call for evidence has been heard and answered by proton radiation oncologists. Answers provided in this review include the evolution of proton therapy research, rationale for proton clinical trial design, challenges in and barriers to the conduct of proton therapy research, and other unique considerations for the study of proton therapy.
Topics: Child; Humans; Male; Pelvis; Prostate; Proton Therapy; Protons; Radiation Oncologists; Clinical Trials as Topic
PubMed: 37684070
DOI: 10.1016/j.semradonc.2023.06.006 -
Journal of Oral Pathology & Medicine :... Aug 2023Oral and/or oropharyngeal cancers account for approximately 2% of all malignancies, with variation across age groups, genders, and geographic locations. Treatments for... (Review)
Review
BACKGROUND
Oral and/or oropharyngeal cancers account for approximately 2% of all malignancies, with variation across age groups, genders, and geographic locations. Treatments for oral and/or oropharyngeal cancers usually consist of a combination of surgical excision most commonly followed by radiotherapy ± chemotherapy and/or immunotherapy/biotherapy depending on the nature of the malignancy. The significant morbidity caused by high-dose radiotherapy to the head and neck region is widely observed. Proton therapy is a promising treatment option that localises a proton beam to direct radiation at a specific target, with reduced irradiation to adjacent structures.
METHOD
The objective was to explore the toxicity associated with proton therapy for adults with oral and/or oropharyngeal cancer. Eligibility criteria included full-text articles, English articles, published between up till 7 January 2023. Databases included PubMed, Scopus, Web of Science, Embase, and Scopus.
RESULTS
The systematic search identified 345 studies and a total of 18 studies were included after two independent reviewers completed title, abstract, and full-text screening. Included studies were from four countries, and median participant age range was 53.3 to 66 years. The most commonly reported acute toxic effects included dysphagia, radiation dermatitis, oral mucositis, dysgeusia, and alopecia.
CONCLUSION
Proton therapy is an evolving cancer treatment technique that has diverse advantages over conventional radiotherapy and chemotherapy. This review provides evidence that supports that proton therapy has an improved acute toxicity profile compared to radiotherapy to treat oral and/or oropharyngeal cancer individuals.
Topics: Adult; Humans; Female; Male; Middle Aged; Aged; Proton Therapy; Oropharyngeal Neoplasms
PubMed: 36871197
DOI: 10.1111/jop.13426 -
Practical Radiation Oncology 2024This work aims at reviewing challenges and pitfalls in proton facility design related to equipment upgrade or replacement. Proton therapy was initially developed at... (Review)
Review
PURPOSE
This work aims at reviewing challenges and pitfalls in proton facility design related to equipment upgrade or replacement. Proton therapy was initially developed at research institutions in the 1950s which ushered in the use of hospital-based machines in 1990s. We are approaching an era where older commercial machines are reaching the end of their life and require replacement. The future widespread application of proton therapy depends on cost reduction; customized building design and installation are significant expenses.
METHODS AND MATERIALS
We take this opportunity to discuss how commercial proton machines have been installed and how buildings housing the equipment have been designed.
RESULTS
Data on dimensions and weights of the larger components of proton systems (cyclotron main magnet and gantries) are presented and innovative, non-gantry-based, patient positioning systems are discussed.
CONCLUSIONS
We argue that careful consideration of the building design to include larger elevators, hoistways from above, wide corridors and access slopes to below grade installations, generic vault and treatment room layouts to accommodate multiple vendor's equipment, and modular system design can provide specific benefits during planning, installation, maintenance, and replacement phases of the project. Room temperature magnet coils can be constructed in a more modular manner: a potential configuration is presented. There is scope for constructing gantries and magnet yokes from smaller modular sub-units. These considerations would allow a hospital to replace a commercial machine at its end of life in a manner similar to a linac.
Topics: Proton Therapy; Humans; Facility Design and Construction; Equipment Design
PubMed: 37967747
DOI: 10.1016/j.prro.2023.09.011 -
International Journal of Radiation... Nov 2023Adjuvant proton beam therapy (PBT) is increasingly available to patients with breast cancer. It achieves better planned dose distributions than standard photon radiation... (Meta-Analysis)
Meta-Analysis
PURPOSE
Adjuvant proton beam therapy (PBT) is increasingly available to patients with breast cancer. It achieves better planned dose distributions than standard photon radiation therapy and therefore may reduce the risks. However, clinical evidence is lacking.
METHODS AND MATERIALS
A systematic review of clinical outcomes from studies of adjuvant PBT for early breast cancer published in 2000 to 2022 was undertaken. Early breast cancer was defined as when all detected invasive cancer cells are in the breast or nearby lymph nodes and can be removed surgically. Adverse outcomes were summarized quantitatively, and the prevalence of the most common ones were estimated using meta-analysis.
RESULTS
Thirty-two studies (1452 patients) reported clinical outcomes after adjuvant PBT for early breast cancer. Median follow-up ranged from 2 to 59 months. There were no published randomized trials comparing PBT with photon radiation therapy. Scattering PBT was delivered in 7 studies (258 patients) starting 2003 to 2015 and scanning PBT in 22 studies (1041 patients) starting 2000 to 2019. Two studies (123 patients) starting 2011 used both PBT types. For 1 study (30 patients), PBT type was unspecified. Adverse events were less severe after scanning than after scattering PBT. They also varied by clinical target. For partial breast PBT, 498 adverse events were reported (8 studies, 358 patients). None were categorized as severe after scanning PBT. For whole breast or chest wall ± regional lymph nodes PBT, 1344 adverse events were reported (19 studies, 933 patients). After scanning PBT, 4% (44/1026) of events were severe. The most prevalent severe outcome after scanning PBT was dermatitis, which occurred in 5.7% (95% confidence interval, 4.2-7.6) of patients. Other severe adverse outcomes included infection, pain, and pneumonitis (each ≤1%). Of the 141 reconstruction events reported (13 studies, 459 patients), the most prevalent after scanning PBT was prosthetic implant removal (34/181, 19%).
CONCLUSIONS
This is a quantitative summary of all published clinical outcomes after adjuvant PBT for early breast cancer. Ongoing randomized trials will provide information on its longer-term safety compared with standard photon radiation therapy.
Topics: Humans; Female; Breast Neoplasms; Proton Therapy
PubMed: 36868521
DOI: 10.1016/j.ijrobp.2023.02.023 -
Critical Reviews in Oncogenesis 2024Given the radiobiological and physical properties of the proton, proton beam therapy has the potential to be advantageous for many patients compared with conventional... (Review)
Review
Given the radiobiological and physical properties of the proton, proton beam therapy has the potential to be advantageous for many patients compared with conventional radiotherapy by limiting toxicity and improving patient outcomes in specific breast cancer scenarios.
Topics: Humans; Breast Neoplasms; Proton Therapy; Female; Protons
PubMed: 38683154
DOI: 10.1615/CritRevOncog.2023050319 -
Surgical Oncology Clinics of North... Jul 2023Proton therapy (PBRT) is a form of external beam radiotherapy with several dosimetric advantages compared with conventional photon (x-ray) radiotherapy. Unlike x-rays,... (Review)
Review
Proton therapy (PBRT) is a form of external beam radiotherapy with several dosimetric advantages compared with conventional photon (x-ray) radiotherapy. Unlike x-rays, protons deposit most of their dose over a finite range, with no exit dose, in a pattern known as the Bragg peak. Clinically, this can be exploited to optimize dose to tumors while delivering a lower integral dose to normal tissues. However, the optimal role of PBRT is not as well-defined as advanced x-ray-based techniques such as intensity-modulated radiotherapy.
Topics: Humans; Proton Therapy; Head and Neck Neoplasms; Radiotherapy, Intensity-Modulated; Radiotherapy Planning, Computer-Assisted; Radiation Oncology
PubMed: 37182994
DOI: 10.1016/j.soc.2023.03.003 -
International Journal of Particle... 2023Equitable inclusion of racial and ethnic participation in clinical trials is crucial to improving disparities in health care, especially for historically marginalized... (Review)
Review
PURPOSE
Equitable inclusion of racial and ethnic participation in clinical trials is crucial to improving disparities in health care, especially for historically marginalized populations. Our study aims to describe the racial and ethnic demographics of patients enrolled in published phase 2 clinical trials involving proton therapy in the United States.
MATERIALS AND METHODS
Published manuscripts were identified in PubMed, Embase, World of Science, and Cochrane. Phase 2 trials evaluating proton therapy for US patients were included. For each article in the study, data were collected comprising authors, title, and publication year, and clinical trial numbers were verified. Additional data included tumor site, primary institution, sample size, reported race/ethnicity, and raw number/percentile of race/ethnicity. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used.
RESULTS
Overall, 970 titles were identified; 636 remained after duplicate screening, and 75 full-text articles were assessed. We identified 38 eligible manuscripts for inclusion comprising 2648 patients. Only 15 (39%) of the publications reported race/ethnicity. Of these, 8 (21%) and 10 (26%) documented Hispanic or Black trial participants, respectively; however, only 6 (16%) documented trial participation for both Hispanic and Black patients. Of the 1409 patients with a documented race/ethnicity, 89.0% (n = 1254) were non-Hispanic white, 5.3% (n = 75) were Black, and 2.2% (n = 31) were Hispanic. Other and unknown race/ethnicity comprised the remaining patients (3.5%; n = 49).
CONCLUSION
We identified underreporting of demographic data in published phase 2 proton therapy trials, which unfortunately mirrored underreporting for cancer drug clinical trials. We also noted dramatic Black and Hispanic patient underrepresentation across the trials in which race and ethnicity are reported. Findings highlight the urgent need to identify and address barriers to proton therapy trials for Black and Hispanic patients ensuring clinical trials in radiation oncology are representative of the patients seen in clinical practice.
PubMed: 37823018
DOI: 10.14338/IJPT-22-00042.1