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JCO Oncology Practice Jun 2024Expert commentary on the evolving role of proton therapy, discussing the current status and controversies of proton therapy in the modern era.
Expert commentary on the evolving role of proton therapy, discussing the current status and controversies of proton therapy in the modern era.
Topics: Proton Therapy; Humans; Neoplasms
PubMed: 38547434
DOI: 10.1200/OP.24.00132 -
JAMA Otolaryngology-- Head & Neck... Aug 2023
Topics: Humans; Proton Therapy; Osteoradionecrosis; Radiotherapy Dosage; Mandibular Diseases
PubMed: 37318798
DOI: 10.1001/jamaoto.2023.1301 -
JAMA Otolaryngology-- Head & Neck... Aug 2023
Topics: Humans; Proton Therapy; Osteoradionecrosis; Radiotherapy Dosage; Mandibular Diseases
PubMed: 37318819
DOI: 10.1001/jamaoto.2023.1302 -
Radiotherapy and Oncology : Journal of... Sep 2023Proton radiotherapy (PRT) offers potential benefits over other radiation modalities, including photon and electron radiotherapy. Increasing the rate at which proton...
BACKGROUND AND PURPOSE
Proton radiotherapy (PRT) offers potential benefits over other radiation modalities, including photon and electron radiotherapy. Increasing the rate at which proton radiation is delivered may provide a therapeutic advantage. Here, we compared the efficacy of conventional proton therapy (CONV) to ultrahigh dose-rate proton therapy, FLASH, in a mouse model of non-small cell lung cancers (NSCLC).
MATERIALS AND METHODS
Mice bearing orthotopic lung tumors received thoracic radiation therapy using CONV (<0.05 Gy/s) and FLASH (>60 Gy/s) dose rates.
RESULTS
Compared to CONV, FLASH was more effective in reducing tumor burden and decreasing tumor cell proliferation. Furthermore, FLASH was more efficient in increasing the infiltration of cytotoxic CD8 T-lymphocytes inside the tumor while simultaneously reducing the percentage of immunosuppressive regulatory T-cells (Tregs) among T-lymphocytes. Also, compared to CONV, FLASH was more effective in decreasing pro-tumorigenic M2-like macrophages in lung tumors, while increasing infiltration of anti-tumor M1-like macrophages. Finally, FLASH treatment reduced expression of checkpoint inhibitors in lung tumors, indicating reduced immune tolerance.
CONCLUSIONS
Our results suggest that FLASH dose-rate proton delivery modulates the immune system to improve tumor control and might thus be a promising new alternative to conventional dose rates for NSCLC treatment.
Topics: Animals; Mice; Protons; Radiotherapy Dosage; Lung Neoplasms; Proton Therapy; Carcinoma, Non-Small-Cell Lung
PubMed: 37315577
DOI: 10.1016/j.radonc.2023.109741 -
JAMA Network Open Aug 2023Radiotherapy plays an important role in the treatment of esophageal cancer. Proton therapy has unique physical properties and higher relative biological effectiveness.... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Radiotherapy plays an important role in the treatment of esophageal cancer. Proton therapy has unique physical properties and higher relative biological effectiveness. However, whether proton therapy has greater benefit than photon therapy is still unclear.
OBJECTIVE
To evaluate whether proton was associated with better efficacy and safety outcomes, including dosimetric, prognosis, and toxic effects outcomes, compared with photon therapy and to evaluate the efficacy and safety of proton therapy singly.
DATA SOURCES
A systematic search of PubMed, Embase, the Cochrane Library, Web of Science, SinoMed, and China National Knowledge Infrastructure databases was conducted for articles published through November 25, 2021, and updated to March 25, 2023.
STUDY SELECTION
For the comparison of proton and photon therapy, studies including dosimetric, prognosis, and associated toxic effects outcomes were included. The separate evaluation of proton therapy evaluated the same metrics.
DATA EXTRACTION AND SYNTHESIS
Data on study design, individual characteristics, and outcomes were extracted. If I2 was greater than 50%, the random-effects model was selected. This meta-analysis is reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.
MAIN OUTCOMES AND MEASURES
The main outcomes were organs at risk (OARs) dosimetric outcomes, prognosis (overall survival [OS], progression-free survival [PFS], and objective response rate [ORR]), and radiation-related toxic effects.
RESULTS
A total of 45 studies were included in the meta-analysis. For dosimetric analysis, proton therapy was associated with significantly reduced OARs dose. Meta-analysis showed that photon therapy was associated with poor OS (hazard ratio [HR], 1.31; 95% CI, 1.07-1.61; I2 = 11%), but no difference in PFS was observed. Subgroup analysis showed worse OS (HR, 1.42; 95% CI, 1.14-1.78; I2 = 34%) and PFS (HR, 1.48; 95% CI, 1.06-2.08; I2 = 7%) in the radical therapy group with photon therapy. The pathological complete response rate was similar between groups. Proton therapy was associated with significantly decreased grade 2 or higher radiation pneumonitis and pericardial effusion, and grade 4 or higher lymphocytopenia. Single-rate analysis of proton therapy found 89% OS and 65% PFS at 1 year, 71% OS and 56% PFS at 2 years, 63% OS and 48% PFS at 3 years, and 56% OS and 42% PFS at 5 years. The incidence of grade 2 or higher radiation esophagitis was 50%, grade 2 or higher radiation pneumonitis was 2%, grade 2 or higher pleural effusion was 4%, grade 2 or higher pericardial effusion was 3%, grade 3 or higher radiation esophagitis was 8%, and grade 4 or higher lymphocytopenia was 17%.
CONCLUSIONS AND RELEVANCE
In this meta-analysis, proton therapy was associated with reduced OARs doses and toxic effects and improved prognosis compared with photon therapy for esophageal cancer, but caution is warranted. In the future, these findings should be further validated in randomized clinical trials.
Topics: Humans; Proton Therapy; Protons; Pericardial Effusion; Radiation Pneumonitis; Esophageal Neoplasms
PubMed: 37581887
DOI: 10.1001/jamanetworkopen.2023.28136 -
Surgical Oncology Clinics of North... Jul 2023Esophageal cancer is the eighth most common cancer worldwide and is the sixth most common cause of cancer-related mortality. The paradigm has shifted to include a... (Review)
Review
Esophageal cancer is the eighth most common cancer worldwide and is the sixth most common cause of cancer-related mortality. The paradigm has shifted to include a multimodality approach with surgery, chemotherapy, targeted therapy (including immunotherapy), and radiation therapy. Advances in radiotherapy through techniques such as intensity modulated radiotherapy and proton beam therapy have allowed for the more dose homogeneity and improved organ sparing. In addition, recent studies of targeted therapies and predictive approaches in patients with locally advanced disease provide clinicians with new approaches to modify multimodality treatment to improve clinical outcomes.
Topics: Humans; Esophageal Neoplasms; Radiotherapy, Intensity-Modulated; Proton Therapy; Radiotherapy Dosage; Chemoradiotherapy
PubMed: 37182986
DOI: 10.1016/j.soc.2023.03.004 -
Annals of Palliative Medicine Nov 2023Given its sharp dose fall off and ability to spare healthy surrounding tissue, proton beam therapy (PBT) has traditionally been used to treat various types of... (Review)
Review
Given its sharp dose fall off and ability to spare healthy surrounding tissue, proton beam therapy (PBT) has traditionally been used to treat various types of malignancies in the definitive setting, with strong, empirical data supporting its utility and safety. In the palliative setting, however, photon therapy has generally remained the standard of care in radiation treatment delivery due to lower cost, and greater availability. However, recent data suggest that the use of PBT may provide benefit in terms of symptom management and disease control in patients with locally advanced or recurrent disease who do not qualify for definitive therapy or with metastatic disease. Additionally, due to its unique dosimetric properties, PBT may confer less overall toxicity, thus helping preserve or improve the quality of life in this patient population, especially for those who are nearing end of life. While there is a need for further study, initial data analyzed from both retrospective and prospective single-institution and multi-institution trials are promising. This review aims to explore the efficacy and safety of PBT in the palliative setting among adults and to summarize pertinent studies that support its usage. To the authors' knowledge, this is the first review of the literature pertaining to PBT used in the palliative setting across multiple disease sites.
Topics: Adult; Humans; Proton Therapy; Retrospective Studies; Quality of Life; Prospective Studies; Neoplasms
PubMed: 37574582
DOI: 10.21037/apm-23-230 -
Cancers Aug 2023Adolescent and young adult cancer patients are at high risk of developing radiation-associated side effects after treatment. Proton beam radiation therapy might reduce... (Review)
Review
BACKGROUND
Adolescent and young adult cancer patients are at high risk of developing radiation-associated side effects after treatment. Proton beam radiation therapy might reduce the risk of these side effects for this population without compromising treatment efficacy.
METHODS
We review the current literature describing the utility of proton beam radiation therapy in the treatment of central nervous system tumors, sarcomas, breast cancer and Hodgkin lymphoma for the adolescent and young adult cancer population.
RESULTS
Proton beam radiation therapy has utility for the treatment of certain cancers in the young adult population. Preliminary data suggest reduced radiation dose to normal tissues, which might reduce radiation-associated toxicities. Research is ongoing to further establish the role of proton therapy in this population.
CONCLUSION
This report highlights the potential utility of proton beam radiation for certain adolescent young adult cancers, especially with reducing radiation doses to organs at risk and thereby potentially lowering risks of certain treatment-associated toxicities.
PubMed: 37686545
DOI: 10.3390/cancers15174269 -
Ugeskrift For Laeger Jan 2024The general population is aging, which expectedly will lead to a future increase in older patients with cancer. This review summarises the recent advances in... (Review)
Review
The general population is aging, which expectedly will lead to a future increase in older patients with cancer. This review summarises the recent advances in radiotherapy. Technological advances have led radiotherapy to be an efficient and well-tolerated treatment option in older patient with cancer. Studies show no difference in toxicity and disease control rates compared with the ones in younger patients with cancer. MR-guided radiotherapy, proton therapy, and integration of artificial intelligence in treatment planning represent the latest advances in the field of radiotherapy and hold potential to further improve the treatment of older patients with cancer.
Topics: Humans; Aged; Artificial Intelligence; Neoplasms; Proton Therapy; Aging
PubMed: 38305322
DOI: 10.61409/V06230381 -
Clinical and Molecular Hepatology Oct 2023Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death, and external beam radiation therapy has emerged as a promising approach for managing HCC.... (Review)
Review
Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death, and external beam radiation therapy has emerged as a promising approach for managing HCC. Proton beam therapy (PBT) offers dosimetric advantages over X-ray therapy, with superior physical properties known as the Bragg peak. PBT holds promise for reducing hepatotoxicity and allowing safe dose-escalation to the tumor. It has been tried in various clinical conditions and has shown promising local tumor control and survival outcomes. A recent phase III trial demonstrated the non-inferiority of PBT in local tumor control compared to current standard radiofrequency ablation in early-stage HCC. PBT also tended to show more favorable outcomes compared to transarterial chemoembolization in the intermediate stage, and has proven effective in-field disease control and safe toxicity profiles in advanced HCC. In this review, we discuss the rationale, clinical studies, optimal indication, and future directions of PBT in HCC treatment.
Topics: Humans; Carcinoma, Hepatocellular; Proton Therapy; Liver Neoplasms; Chemoembolization, Therapeutic
PubMed: 37822213
DOI: 10.3350/cmh.2023.0274