Recent studies on cancer stem cells revealed they are tumorigenic and able to recapitulate the characteristics of the tumour from which they derive, so that it was suggested that elimination of this population is essential to prevent recurrences after any treatment. However, there is evidence that cancer stem cells are inherently resistant to conventional (photon) radiotherapy. Since the use of proton beam therapy in cancer treatment is growing rapidly worldwide, mainly because of their excellent dosimetric properties, the possibility could be considered that they also have biological advantages through preferential elimination of cancer stem cells.Indeed, a review of preclinical data suggest that protons and photons differ in their biological effects on cancer stem cells, with protons offering potential advantages, although the heterogeneity of cancer stem cells and the different proton irradiation modalities make the comparison of the results not so easy. Further research to understand the mechanisms underlying such effects is important for their possible exploitation in clinics and to perform proton beam therapy optimization.
{"title":"Targeting cancer stem cells: protons versus photons.","authors":"V. Dini, M. Belli, M. Tabocchini","doi":"10.1259/bjr.20190225","DOIUrl":"https://doi.org/10.1259/bjr.20190225","url":null,"abstract":"Recent studies on cancer stem cells revealed they are tumorigenic and able to recapitulate the characteristics of the tumour from which they derive, so that it was suggested that elimination of this population is essential to prevent recurrences after any treatment. However, there is evidence that cancer stem cells are inherently resistant to conventional (photon) radiotherapy. Since the use of proton beam therapy in cancer treatment is growing rapidly worldwide, mainly because of their excellent dosimetric properties, the possibility could be considered that they also have biological advantages through preferential elimination of cancer stem cells.Indeed, a review of preclinical data suggest that protons and photons differ in their biological effects on cancer stem cells, with protons offering potential advantages, although the heterogeneity of cancer stem cells and the different proton irradiation modalities make the comparison of the results not so easy. Further research to understand the mechanisms underlying such effects is important for their possible exploitation in clinics and to perform proton beam therapy optimization.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126698330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hypofractionated radiotherapy is attractive concerning patient burden and therapy costs, but many aspects play a role when it comes to assess its safety. While exploited for conventional photon therapy and carbon ion therapy, hypofractionation with protons is only rarely applied. One reason for this is uncertainty in the described dose, mainly due to the relative biological effectiveness (RBE), which is small for protons, but not negligible. RBE is generally dose-dependent, and for higher doses as used in hypofractionation, a thorough RBE evaluation is needed. This review article focuses on the RBE variability in protons and associated issues or implications for hypofractionation.
{"title":"Proton RBE dependence on dose in the setting of hypofractionation.","authors":"T. Friedrich","doi":"10.1259/bjr.20190291","DOIUrl":"https://doi.org/10.1259/bjr.20190291","url":null,"abstract":"Hypofractionated radiotherapy is attractive concerning patient burden and therapy costs, but many aspects play a role when it comes to assess its safety. While exploited for conventional photon therapy and carbon ion therapy, hypofractionation with protons is only rarely applied. One reason for this is uncertainty in the described dose, mainly due to the relative biological effectiveness (RBE), which is small for protons, but not negligible. RBE is generally dose-dependent, and for higher doses as used in hypofractionation, a thorough RBE evaluation is needed. This review article focuses on the RBE variability in protons and associated issues or implications for hypofractionation.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125039274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Lawell, D. Indelicato, Arnold C Paulino, W. Hartsell, Nadia N. Laack, R. Ermoian, J. Perentesis, R. Vatner, S. Perkins, V. Mangona, C. Hill-Kayser, S. Wolden, Y. Kwok, John Han-Chih Chang, J. Ben Wilkinson, I. MacEwan, Andrew L. Chang, B. Eaton, M. Ladra, S. Gallotto, E. Weyman, B. Bajaj, S. Baliga, B. Yeap, A. Berrington de González, T. Yock
OBJECTIVE The Pediatric Proton/Photon Consortium Registry (PPCR) is a comprehensive data registry composed of pediatric patients treated with radiation. It was established to expedite outcomes-based research. The attributes which allow the PPCR to be a successful collaboration are reviewed. METHODS AND MATERIALS Current eligibility criteria are radiotherapy patients < 22 years treated at one of 15 United States (US) participating institutions. Detailed health and treatment data are collected about the disease presentation and treatment exposures, and annually thereafter, in REDCap. DICOM imaging and radiation plans are collected through MIM/MIMcloud. An optional patient-reported quality-of-life (PedsQL) study is administered at 10 sites. RESULTS Accrual started October 2012 with 2,775 participants enrolled as of 25 July 2019. Most patients, 62.0%, were treated for central nervous system (CNS) tumors, the most common of which are medulloblastoma (n = 349), ependymoma (n = 309), and glial/astrocytoma tumors (n = 279). The most common non-CNS diagnoses are rhabdomyosarcoma (n = 284), Ewing's sarcoma (n = 153), and neuroblastoma (n = 130). While the majority of participants are US residents, 18.7% come from 36 other countries. Over 685 patients participate in the PedsQL study. CONCLUSIONS The PPCR is a valuable research platform capable of answering countless research questions that will ultimately improve patient care. Centers outside of the US are invited to participate directly or may engage with the PPCR to align data collection strategies to facilitate larger-scale international research. ADVANCES IN KNOWLEDGE For investigators looking to carry out research in a large pediatric oncology cohort or interested in registry work, this paper provides an updated overview of the PPCR.
{"title":"An open invitation to join the pediatric proton/photon consortium registry to standardize data collection in pediatric radiation oncology.","authors":"M. Lawell, D. Indelicato, Arnold C Paulino, W. Hartsell, Nadia N. Laack, R. Ermoian, J. Perentesis, R. Vatner, S. Perkins, V. Mangona, C. Hill-Kayser, S. Wolden, Y. Kwok, John Han-Chih Chang, J. Ben Wilkinson, I. MacEwan, Andrew L. Chang, B. Eaton, M. Ladra, S. Gallotto, E. Weyman, B. Bajaj, S. Baliga, B. Yeap, A. Berrington de González, T. Yock","doi":"10.1259/bjr.20190673","DOIUrl":"https://doi.org/10.1259/bjr.20190673","url":null,"abstract":"OBJECTIVE\u0000The Pediatric Proton/Photon Consortium Registry (PPCR) is a comprehensive data registry composed of pediatric patients treated with radiation. It was established to expedite outcomes-based research. The attributes which allow the PPCR to be a successful collaboration are reviewed.\u0000\u0000\u0000METHODS AND MATERIALS\u0000Current eligibility criteria are radiotherapy patients < 22 years treated at one of 15 United States (US) participating institutions. Detailed health and treatment data are collected about the disease presentation and treatment exposures, and annually thereafter, in REDCap. DICOM imaging and radiation plans are collected through MIM/MIMcloud. An optional patient-reported quality-of-life (PedsQL) study is administered at 10 sites.\u0000\u0000\u0000RESULTS\u0000Accrual started October 2012 with 2,775 participants enrolled as of 25 July 2019. Most patients, 62.0%, were treated for central nervous system (CNS) tumors, the most common of which are medulloblastoma (n = 349), ependymoma (n = 309), and glial/astrocytoma tumors (n = 279). The most common non-CNS diagnoses are rhabdomyosarcoma (n = 284), Ewing's sarcoma (n = 153), and neuroblastoma (n = 130). While the majority of participants are US residents, 18.7% come from 36 other countries. Over 685 patients participate in the PedsQL study.\u0000\u0000\u0000CONCLUSIONS\u0000The PPCR is a valuable research platform capable of answering countless research questions that will ultimately improve patient care. Centers outside of the US are invited to participate directly or may engage with the PPCR to align data collection strategies to facilitate larger-scale international research.\u0000\u0000\u0000ADVANCES IN KNOWLEDGE\u0000For investigators looking to carry out research in a large pediatric oncology cohort or interested in registry work, this paper provides an updated overview of the PPCR.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"259 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123012204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proton radiation therapy has been used clinically since 1952, and major advancements in the last 10 years have helped establish protons as a major clinical modality in the cancer-fighting arsenal. Technologies will always evolve, but enough major breakthroughs have been accomplished over the past 10 years to allow for a major revolution in proton therapy. This paper summarizes the major technology advancements with respect to beam delivery that are now ready for mass implementation in the proton therapy space and encourages vendors to bring these to market to benefit the cancer population worldwide. We state why these technologies are essential and ready for implementation, and we discuss how future systems should be designed to accommodate their required features.
{"title":"Proton therapy delivery: What is needed in the next ten years?","authors":"A. Schreuder, J. Shamblin","doi":"10.1259/bjr.20190359","DOIUrl":"https://doi.org/10.1259/bjr.20190359","url":null,"abstract":"Proton radiation therapy has been used clinically since 1952, and major advancements in the last 10 years have helped establish protons as a major clinical modality in the cancer-fighting arsenal. Technologies will always evolve, but enough major breakthroughs have been accomplished over the past 10 years to allow for a major revolution in proton therapy. This paper summarizes the major technology advancements with respect to beam delivery that are now ready for mass implementation in the proton therapy space and encourages vendors to bring these to market to benefit the cancer population worldwide. We state why these technologies are essential and ready for implementation, and we discuss how future systems should be designed to accommodate their required features.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131154483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Ricotti, A. Pella, B. Tagaste, G. Elisei, G. Fontana, M. Bonora, M. Ciocca, F. Valvo, R. Orecchia, G. Baroni
OBJECTIVES Accurate patient positioning is crucial in particle therapy due to the geometrical selectivity of particles. We report and discuss the XXX experience in positioning accuracy and stability achieved with solid thermoplastic masks fixed on index base plates and assessed by daily orthogonal X-ray imaging. METHODS Positioning data were retrospectively collected (between 2012 and 2018) and grouped according to the treated anatomical site. 1,9696 fractions of 1325 patients were evaluated.The study was designed to assess:(i) the number of fractions in which a single correction vector was applied (SCV);(ii) the number of fractions in which further setup verification was performed (SV);(iii) the number of fractions in which SV lead to an additional correction within (MCV<5min) or after (MCV>5min) 5 minutes from the first setup correction;(iv) the systematic (Σ) and random (σ) error components of the correction vectors applied. RESULTS A SCV was applied in 71.5% of fractions, otherwise SV was required. In 30.6% of fractions with SV, n patient position was not revised. In the remaining fractions, MCV<5min and MCV>5min was applied mainly in extracranial and cranial sites respectively.Inter-fraction Σ was ≤ 1.7mm/0.7° and σ was ≤ 1.2mm/0.6° in cranial sites while in extracranial sites Σ was ≤5.5mm/≤0.9° and σ was ≤4.4mm/≤0.9°. Setup residuals were sub-millimetric in all sites. In cranial patients, maximum intra-fractional Σ was 0.8mm/0.4° in cranial patients. CONCLUSIONS This report extensively quantifies inter- and intra- fraction setup accuracy on an Institutional basis and image guidance is fundamental to benefit from the geometrical selectivity of particles. ADVANCES IN KNOWLEDGE The reported analysis provides a board institutional dataset on the immobilisation and bony anatomy alignment for several particle therapy clinical indications.
{"title":"Long-time clinical experience in patient setup for several particle therapy clinical indications: management of patient positioning and evaluation of setup reproducibility and stability patient positioning evaluation in image-guided particle therapy.","authors":"R. Ricotti, A. Pella, B. Tagaste, G. Elisei, G. Fontana, M. Bonora, M. Ciocca, F. Valvo, R. Orecchia, G. Baroni","doi":"10.1259/bjr.20190595","DOIUrl":"https://doi.org/10.1259/bjr.20190595","url":null,"abstract":"OBJECTIVES\u0000Accurate patient positioning is crucial in particle therapy due to the geometrical selectivity of particles. We report and discuss the XXX experience in positioning accuracy and stability achieved with solid thermoplastic masks fixed on index base plates and assessed by daily orthogonal X-ray imaging.\u0000\u0000\u0000METHODS\u0000Positioning data were retrospectively collected (between 2012 and 2018) and grouped according to the treated anatomical site. 1,9696 fractions of 1325 patients were evaluated.The study was designed to assess:(i) the number of fractions in which a single correction vector was applied (SCV);(ii) the number of fractions in which further setup verification was performed (SV);(iii) the number of fractions in which SV lead to an additional correction within (MCV<5min) or after (MCV>5min) 5 minutes from the first setup correction;(iv) the systematic (Σ) and random (σ) error components of the correction vectors applied.\u0000\u0000\u0000RESULTS\u0000A SCV was applied in 71.5% of fractions, otherwise SV was required. In 30.6% of fractions with SV, n patient position was not revised. In the remaining fractions, MCV<5min and MCV>5min was applied mainly in extracranial and cranial sites respectively.Inter-fraction Σ was ≤ 1.7mm/0.7° and σ was ≤ 1.2mm/0.6° in cranial sites while in extracranial sites Σ was ≤5.5mm/≤0.9° and σ was ≤4.4mm/≤0.9°. Setup residuals were sub-millimetric in all sites. In cranial patients, maximum intra-fractional Σ was 0.8mm/0.4° in cranial patients.\u0000\u0000\u0000CONCLUSIONS\u0000This report extensively quantifies inter- and intra- fraction setup accuracy on an Institutional basis and image guidance is fundamental to benefit from the geometrical selectivity of particles.\u0000\u0000\u0000ADVANCES IN KNOWLEDGE\u0000The reported analysis provides a board institutional dataset on the immobilisation and bony anatomy alignment for several particle therapy clinical indications.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115772658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proton and ion beam therapy has been introduced in the Lawrence Berkeley National Laboratory in the mid-1950s, when protons and helium ions have been used for the first time to treat patients. Starting in 1972, the scientists at Berkeley also were the first to use heavier ions (carbon, oxygen, neon, silicon and argon ions). The first clinical ion beam facility opened in 1994 in Japan and since then, the interest in radiotherapy with light ion beams has been increasing slowly but steadily, with 13 centers in clinical operation in 2019. All these centers are using carbon ions for clinical application.The article outlines the differences in physical properties of various light ions as compared to protons in view of the application in radiotherapy. These include the energy loss and depth dose properties, multiple scattering, range straggling and nuclear fragmentation. In addition, the paper discusses differences arising from energy loss and linear energy transfer with respect to their biological effects.Moreover, the paper reviews briefly the existing clinical data comparing protons and ions and outlines the future perspectives for the clinical use of ions like oxygen and helium.
{"title":"Physical advantages of particles: protons and light ions.","authors":"Oliver Jaekel","doi":"10.1259/bjr.20190428","DOIUrl":"https://doi.org/10.1259/bjr.20190428","url":null,"abstract":"Proton and ion beam therapy has been introduced in the Lawrence Berkeley National Laboratory in the mid-1950s, when protons and helium ions have been used for the first time to treat patients. Starting in 1972, the scientists at Berkeley also were the first to use heavier ions (carbon, oxygen, neon, silicon and argon ions). The first clinical ion beam facility opened in 1994 in Japan and since then, the interest in radiotherapy with light ion beams has been increasing slowly but steadily, with 13 centers in clinical operation in 2019. All these centers are using carbon ions for clinical application.The article outlines the differences in physical properties of various light ions as compared to protons in view of the application in radiotherapy. These include the energy loss and depth dose properties, multiple scattering, range straggling and nuclear fragmentation. In addition, the paper discusses differences arising from energy loss and linear energy transfer with respect to their biological effects.Moreover, the paper reviews briefly the existing clinical data comparing protons and ions and outlines the future perspectives for the clinical use of ions like oxygen and helium.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"27 33","pages":"20190428"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141226606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Treatment planning is the process where the prescription of the radiation oncologist is translated into a deliverable treatment. With the complexity of contemporary radiotherapy, treatment planning cannot be performed without a computerised Treatment Planning System. Proton Therapy enables highly conformal treatment plans with a minimum of dose to tissues outside the target volume, but to obtain the most optimal plan for the treatment, there are a multitude of parameters that need to be addressed. In this review areas of ongoing improvements and research in the field of PT treatment planning are identified and discussed. The main focus is on issues of immediate clinical and practical relevance to the PT community highlighting the needs for the near future but also in a longer perspective. We anticipate that the manual tasks performed by treatment planners in the future will involve a high degree of computational thinking, as many issues can be solved much better by e.g. scripting. More accurate and faster dose calculation algorithms are needed, automation for contouring and planning is required and practical tools to handle the variable biological efficiency in PT is urgently demanded just to mention a few of the expected improvements over the coming 10 years.
{"title":"Treatment planning for Proton therapy: What is needed in the next 10 years?","authors":"H. Nystrom, M. F. Jensen, P. W. Nyström","doi":"10.1259/bjr.20190304","DOIUrl":"https://doi.org/10.1259/bjr.20190304","url":null,"abstract":"Treatment planning is the process where the prescription of the radiation oncologist is translated into a deliverable treatment. With the complexity of contemporary radiotherapy, treatment planning cannot be performed without a computerised Treatment Planning System. Proton Therapy enables highly conformal treatment plans with a minimum of dose to tissues outside the target volume, but to obtain the most optimal plan for the treatment, there are a multitude of parameters that need to be addressed. In this review areas of ongoing improvements and research in the field of PT treatment planning are identified and discussed. The main focus is on issues of immediate clinical and practical relevance to the PT community highlighting the needs for the near future but also in a longer perspective. We anticipate that the manual tasks performed by treatment planners in the future will involve a high degree of computational thinking, as many issues can be solved much better by e.g. scripting. More accurate and faster dose calculation algorithms are needed, automation for contouring and planning is required and practical tools to handle the variable biological efficiency in PT is urgently demanded just to mention a few of the expected improvements over the coming 10 years.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129948691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kountouri, A. Pica, M. Walser, F. Albertini, A. Bolsi, U. Kliebsch, B. Bachtiary, C. Combescure, A. Lomax, R. Schneider, D. Weber
OBJECTIVES To assess the radiation-induced optic neuropathy (RION) prevalence, following high dose pencil beam scanning proton therapy (PBS PT) to skull base and head and neck (H&N) tumours. METHODS Between 1999 and Between , 2014 and Between , 216 adult patients, median age 47 years (range, 18-77), were treated with PBS PT for skull base or H&N malignancies, delivering ≥45 GyRBE to the optic nerve(s) (ON) and/or optic chiasma (OC). The median administered dose to the planning target volume (PTV) was 74.0 GyRBE (range, 54.0-77.4). The median follow-up was 5.3 years (range, 0.8-15.9). RESULTS RION was observed in 14 (6.5%) patients at a median time of 13.2 months (range, 4.8-42.6) following PBS PT. Most (92.9%) of RION were symptomatic. Most affected patients (11/14; 79%) developed unilateral toxicity. Grade 4, 3, 2 and 1 toxicity was observed in 10, 2, 1 and 1 patients, respectively. On univariate analyses, age (<70 vs.≥70 years; p < 0.0001), hypertension (p = 0.0007) and tumour abutting the optic apparatus (p = 0.012) were associated with RION. OC's V60 GyRBE was of border line significance (p = 0.06). None of the other evaluated OC-ON dose/volume metrics (Dmax, Dmean, V40-60) were significantly associated with this complication. CONCLUSION This data suggests that high-dose PBS PT for skull base and H&N tumours is associated with a low prevalence of RION. Caution should be however exercised when treating elderly/hypertensive patients with tumours abutting the optic apparatus. ADVANCES IN KNOWLEDGE This is the first study reporting the risk of developing RION following proton therapy with PBS technique, demonstrating the safety of this treatment.
{"title":"Radiation induced optic neuropathy after pencil beam scanning proton therapy for skull-base and head and neck tumours.","authors":"M. Kountouri, A. Pica, M. Walser, F. Albertini, A. Bolsi, U. Kliebsch, B. Bachtiary, C. Combescure, A. Lomax, R. Schneider, D. Weber","doi":"10.1259/bjr.20190028","DOIUrl":"https://doi.org/10.1259/bjr.20190028","url":null,"abstract":"OBJECTIVES\u0000To assess the radiation-induced optic neuropathy (RION) prevalence, following high dose pencil beam scanning proton therapy (PBS PT) to skull base and head and neck (H&N) tumours.\u0000\u0000\u0000METHODS\u0000Between 1999 and Between , 2014 and Between , 216 adult patients, median age 47 years (range, 18-77), were treated with PBS PT for skull base or H&N malignancies, delivering ≥45 GyRBE to the optic nerve(s) (ON) and/or optic chiasma (OC). The median administered dose to the planning target volume (PTV) was 74.0 GyRBE (range, 54.0-77.4). The median follow-up was 5.3 years (range, 0.8-15.9).\u0000\u0000\u0000RESULTS\u0000RION was observed in 14 (6.5%) patients at a median time of 13.2 months (range, 4.8-42.6) following PBS PT. Most (92.9%) of RION were symptomatic. Most affected patients (11/14; 79%) developed unilateral toxicity. Grade 4, 3, 2 and 1 toxicity was observed in 10, 2, 1 and 1 patients, respectively. On univariate analyses, age (<70 vs.≥70 years; p < 0.0001), hypertension (p = 0.0007) and tumour abutting the optic apparatus (p = 0.012) were associated with RION. OC's V60 GyRBE was of border line significance (p = 0.06). None of the other evaluated OC-ON dose/volume metrics (Dmax, Dmean, V40-60) were significantly associated with this complication.\u0000\u0000\u0000CONCLUSION\u0000This data suggests that high-dose PBS PT for skull base and H&N tumours is associated with a low prevalence of RION. Caution should be however exercised when treating elderly/hypertensive patients with tumours abutting the optic apparatus.\u0000\u0000\u0000ADVANCES IN KNOWLEDGE\u0000This is the first study reporting the risk of developing RION following proton therapy with PBS technique, demonstrating the safety of this treatment.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121745004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Majid Mohiuddin, Connor Lynch, Mingcheng Gao, William Hartsell
OBJECTIVES Approximately 70 patients with large and bulky tumors refractory to prior treatments were treated with photon spatially fractionated GRID radiation (SFGRT). We identified 10 additional patients who clinically needed GRID but could not be treated with photons due to adjacent critical organs. We developed a proton SFGRT technique, and we report treatment of these 10 patients. METHODS Subject data were reviewed for clinical results and dosimetric data. 50% of the patients were metastatic at the time of treatment and five had previous photon radiation to the local site but not via GRID. They were treated with 15-20 cobalt Gray equivalent (CGE) using a single proton GRID field with an average beamlet count of 22.6 (range 7-51). 80% received an average adjuvant radiation dose to the GRID region of 40.8Gy (range 13.7-63.8Gy). Four received subsequent systemic therapy. RESULTS The median follow up time was 5.9 months (1.1-18.9). At last follow up, seven patients were alive and three had died. Two patients who had died from metastatic disease had local shrinkage of tumor. Of those alive, four had complete or partial response, two had partial response but later progressed, and one had no response. For all patients, the tumor regression/local symptom improvement rate was 80%. 50% had acute side-effects of grade1/2 only and all were well-tolerated. CONCLUSIONS In circumstances where patients cannot receive photon GRID, proton SFGRT is clinically feasible and effective, with a similar side-effect profile. ADVANCES IN KNOWLEDGE Proton GRID should be considered as a treatment option earlier in the disease course for patients who cannot be treated by photon GRID.
{"title":"Early clinical results of proton spatially fractionated GRID radiation therapy (SFGRT).","authors":"Majid Mohiuddin, Connor Lynch, Mingcheng Gao, William Hartsell","doi":"10.1259/bjr.20190572","DOIUrl":"https://doi.org/10.1259/bjr.20190572","url":null,"abstract":"OBJECTIVES\u0000Approximately 70 patients with large and bulky tumors refractory to prior treatments were treated with photon spatially fractionated GRID radiation (SFGRT). We identified 10 additional patients who clinically needed GRID but could not be treated with photons due to adjacent critical organs. We developed a proton SFGRT technique, and we report treatment of these 10 patients.\u0000\u0000\u0000METHODS\u0000Subject data were reviewed for clinical results and dosimetric data. 50% of the patients were metastatic at the time of treatment and five had previous photon radiation to the local site but not via GRID. They were treated with 15-20 cobalt Gray equivalent (CGE) using a single proton GRID field with an average beamlet count of 22.6 (range 7-51). 80% received an average adjuvant radiation dose to the GRID region of 40.8Gy (range 13.7-63.8Gy). Four received subsequent systemic therapy.\u0000\u0000\u0000RESULTS\u0000The median follow up time was 5.9 months (1.1-18.9). At last follow up, seven patients were alive and three had died. Two patients who had died from metastatic disease had local shrinkage of tumor. Of those alive, four had complete or partial response, two had partial response but later progressed, and one had no response. For all patients, the tumor regression/local symptom improvement rate was 80%. 50% had acute side-effects of grade1/2 only and all were well-tolerated.\u0000\u0000\u0000CONCLUSIONS\u0000In circumstances where patients cannot receive photon GRID, proton SFGRT is clinically feasible and effective, with a similar side-effect profile.\u0000\u0000\u0000ADVANCES IN KNOWLEDGE\u0000Proton GRID should be considered as a treatment option earlier in the disease course for patients who cannot be treated by photon GRID.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"81 6","pages":"20190572"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141226086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proton radiotherapy has clear dosimetric advantages over photon radiotherapy. In contrast to photons, which are absorbed exponentially, protons have a finite range dependent on the initial proton energy. Protons therefore do not deposit dose beyond the tumor, resulting in great conformality, and offers the promise of dose escalation to increase tumor control while minimizing toxicity. In this review, we discuss the rationale for using proton radiotherapy in the treatment of upper abdominal tumors-- hepatocellular carcinomas, cholangiocarcinomas and pancreatic cancers. We also review the clinical outcomes and technical challenges of using proton radiotherapy for the treatment of these malignancies. Finally, we discuss the ongoing clinical trials implementing proton radiotherapy for the treatment of primary liver and pancreatic tumors.
{"title":"Proton beam therapy for tumors of the upper abdomen.","authors":"A. Raldow, J. Lamb, T. Hong","doi":"10.1259/bjr.20190226","DOIUrl":"https://doi.org/10.1259/bjr.20190226","url":null,"abstract":"Proton radiotherapy has clear dosimetric advantages over photon radiotherapy. In contrast to photons, which are absorbed exponentially, protons have a finite range dependent on the initial proton energy. Protons therefore do not deposit dose beyond the tumor, resulting in great conformality, and offers the promise of dose escalation to increase tumor control while minimizing toxicity. In this review, we discuss the rationale for using proton radiotherapy in the treatment of upper abdominal tumors-- hepatocellular carcinomas, cholangiocarcinomas and pancreatic cancers. We also review the clinical outcomes and technical challenges of using proton radiotherapy for the treatment of these malignancies. Finally, we discuss the ongoing clinical trials implementing proton radiotherapy for the treatment of primary liver and pancreatic tumors.","PeriodicalId":226783,"journal":{"name":"The British journal of radiology","volume":"285 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116119874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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