-
Ocular Oncology and Pathology Sep 2017To investigate whether lower radiation doses may yield similar outcome measures to those from the COMS trial. (Review)
Review
AIM
To investigate whether lower radiation doses may yield similar outcome measures to those from the COMS trial.
METHODS
A literature review of English language articles was performed using the PubMed database of the U.S. National Library of Medicine and the Cochrane Central Register of Controlled Trials using the following keywords: uveal melanoma, choroidal melanoma, primary uveal malignant melanoma, iodine-125 brachytherapy, local recurrence, local treatment failure, and local tumor control. The relationships between study local recurrence rate and median dosage were tested by linear regression, with each study weighted by the number of patients included.
RESULTS
Fifteen retrospective and prospective studies were selected for systematic review (2,662 patients). Ranges of reported mean or median radiation dose to tumor apex were 62.5-104.0 Gy. Local recurrence rates ranged from 0 to 24%. A 1.0-Gy increase in the average study dose was associated with a 0.14% decrease in local recurrence rate, which was not statistically significant ( value 0.336).
CONCLUSION
The gold standard empirically derived 85.0-Gy radiation dose for the treatment of uveal melanoma could be tested in a randomized study.
PubMed: 29071269
DOI: 10.1159/000455872 -
Journal of Clinical Medicine Research Apr 2017Radiation necrosis (RN) of brain tissue is a serious late complication of brain irradiation and recently bevacizumab has been suggested as treatment option of RN. There... (Review)
Review
Radiation necrosis (RN) of brain tissue is a serious late complication of brain irradiation and recently bevacizumab has been suggested as treatment option of RN. There is a lack of data in the literature regarding the effectiveness of bevacizumab for the treatment of RN. The purpose of this review was to perform a comprehensive analysis of all reported cases using bevacizumab for the treatment of brain RN. In September 2016, we performed a comprehensive literature search of the following electronic databases: PubMed, Web of Science, Scopus and Cochrane Library. The research for the review was conducted using a combination of the keywords "radiation necrosis", "radiotherapy" and "bevacizumab" alongside the fields comprising article title, abstract and keywords. Randomized trials, non-randomized trials, prospective studies, retrospective studies and single case reports were included in the review. Our research generated 21 studies and 125 cases where bevacizumab had been used for the treatment of RN. The median follow-up was 8 months and the most frequent bevacizumab dose used was 7.5 mg/kg for 2 weeks with a median of four cycles. Low-dose bevacizumab resulted in effectiveness with improvement in both clinical and radiographic response. The median decrease in T1 contrast enhancement and in T2/FLAIR signal abnormality was 64% and 60%, respectively. A reduction in steroidal therapy was observed in majority of patients treated. Based on the data of our review, bevacizumab appears to be a promising agent for the treatment of brain RN. Future prospective studies are required to evaluate the role of bevacizumab in RN and to define the optimal scheduling, dosage and duration of therapy.
PubMed: 28270886
DOI: 10.14740/jocmr2936e -
Health Physics Nov 2020A systematic review of relevant studies that determined the dose response relationship (DRR) for the hematopoietic (H) acute radiation syndrome (ARS) in the canine...
A systematic review of relevant studies that determined the dose response relationship (DRR) for the hematopoietic (H) acute radiation syndrome (ARS) in the canine relative to radiation quality of mixed neutron:gamma radiations, dose rate, and exposure uniformity relative to selected reference radiation exposure has not been performed. The datasets for rhesus macaques exposure to mixed neutron:gamma radiation are used herein as a species comparative reference to the canine database. The selection of data cohorts was made from the following sources: Ovid Medline (1957-present), PubMed (1954-present), AGRICOLA (1976-present), Web of Science (1954-present), and US HHS RePORT (2002-present). The total number of hits across all search sites was 3,077. Several referenced, unpublished, non-peer reviewed government reports were unavailable for review. Primary published studies using canines, beagles, and mongrels were evaluated to provide an informative and consistent review of mixed neutron:gamma radiation effects to establish the DRRs for the H-ARS. Secondary and tertiary studies provided additional information on the hematologic response or the effects on hematopoietic progenitor cells, radiation dosimetry, absorbed dose, and organ dose. The LD50/30 values varied with neutron quality, exposure aspect, and mixed neutron:gamma ratio. The reference radiation quality varied from 250 kVp or 1-2 MeV x radiation and Co gamma radiation. A summary of a published review of a data set describing the DRR in rhesus macaques for mixed neutron:gamma radiation exposure in the H-ARS is included for a comparative reference to the canine dataset. The available evidence provided a reliable and extensive database that characterized the DRR for the H-ARS in canines and young rhesus macaques exposed to mixed neutron:gamma radiations of variable energy relative to 250 kVp, 1-2 MeV x radiation and Co gamma, and uniform and non-uniform total-body irradiation without the benefit of medical management. The mixed neutron:gamma radiation showed an energy-dependent RBE of ~ 1.0 to 2.0 relative to reference radiation exposure within both species. A marginal database described the DRR for the gastrointestinal (GI)-ARS. Medical management showed benefit in both species relative to the mixed neutron:gamma as well as exposure to reference radiation. The DRR for the H-ARS was characterized by steep slopes and relative LD50/30 values that reflected the radiation quality, exposure aspect, and dose rate over a range in time from 1956-2012.
Topics: Acute Radiation Syndrome; Animals; Dogs; Dose-Response Relationship, Radiation; Gamma Rays; Hematopoietic Stem Cells; Neutrons; Primates; Radiation Exposure; Reference Standards
PubMed: 32947486
DOI: 10.1097/HP.0000000000001319 -
Clinical and Translational Radiation... Jul 2022Radiotherapy (RT) is a cornerstone treatment strategy for brain tumours. Besides cytotoxicity, RT can cause disruption of the blood-brain barrier (BBB), resulting in an... (Review)
Review
Radiotherapy (RT) is a cornerstone treatment strategy for brain tumours. Besides cytotoxicity, RT can cause disruption of the blood-brain barrier (BBB), resulting in an increased permeability into the surrounding brain parenchyma. Although this effect is generally acknowledged, it remains unclear how and to what extent different radiation schemes affect BBB integrity. The aim of this systematic review and meta-analysis is to investigate the effect of photon RT regimens on BBB permeability, including its reversibility, in clinical and preclinical studies. We systematically reviewed relevant clinical and preclinical literature in PubMed, Embase, and Cochrane search engines. A total of 69 included studies (20 clinical, 49 preclinical) were qualitatively and quantitatively analysed by meta-analysis and evaluated on key determinants of RT-induced BBB permeability in different disease types and RT protocols. Qualitative data synthesis showed that 35% of the included clinical studies reported BBB disruption following RT, whereas 30% were inconclusive. Interestingly, no compelling differences were observed between studies with different calculated biological effective doses based on the fractionation schemes and cumulative doses; however, increased BBB disruption was noted during patient follow-up after treatment. Qualitative analysis of preclinical studies showed RT BBB disruption in 78% of the included studies, which was significantly confirmed by meta-analysis (p < 0.01). Of note, a high risk of bias, publication bias and a high heterogeneity across the studies was observed. This systematic review and meta-analysis sheds light on the impact of RT protocols on BBB integrity and opens the discussion for integrating this factor in the decision-making process of future RT, with better study of its occurrence and influence on concomitant or adjuvant therapies.
PubMed: 35601799
DOI: 10.1016/j.ctro.2022.04.013 -
Lasers in Medical Science May 2016Lasers and light-emitting diodes are used for a range of biomedical applications with many studies reporting their beneficial effects. However, three main concerns exist... (Review)
Review
Lasers and light-emitting diodes are used for a range of biomedical applications with many studies reporting their beneficial effects. However, three main concerns exist regarding much of the low-level light therapy (LLLT) or photobiomodulation literature; (1) incomplete, inaccurate and unverified irradiation parameters, (2) miscalculation of 'dose,' and (3) the misuse of appropriate light property terminology. The aim of this systematic review was to assess where, and to what extent, these inadequacies exist and to provide an overview of 'best practice' in light measurement methods and importance of correct light measurement. A review of recent relevant literature was performed in PubMed using the terms LLLT and photobiomodulation (March 2014-March 2015) to investigate the contemporary information available in LLLT and photobiomodulation literature in terms of reporting light properties and irradiation parameters. A total of 74 articles formed the basis of this systematic review. Although most articles reported beneficial effects following LLLT, the majority contained no information in terms of how light was measured (73%) and relied on manufacturer-stated values. For all papers reviewed, missing information for specific light parameters included wavelength (3%), light source type (8%), power (41%), pulse frequency (52%), beam area (40%), irradiance (43%), exposure time (16%), radiant energy (74%) and fluence (16%). Frequent use of incorrect terminology was also observed within the reviewed literature. A poor understanding of photophysics is evident as a significant number of papers neglected to report or misreported important radiometric data. These errors affect repeatability and reliability of studies shared between scientists, manufacturers and clinicians and could degrade efficacy of patient treatments. Researchers need a physicist or appropriately skilled engineer on the team, and manuscript reviewers should reject papers that do not report beam measurement methods and all ten key parameters: wavelength, power, irradiation time, beam area (at the skin or culture surface; this is not necessarily the same size as the aperture), radiant energy, radiant exposure, pulse parameters, number of treatments, interval between treatments and anatomical location. Inclusion of these parameters will improve the information available to compare and contrast study outcomes and improve repeatability, reliability of studies.
Topics: Humans; Lasers, Semiconductor; Low-Level Light Therapy; Radiation Dosage; Radiometry; Reproducibility of Results; Skin
PubMed: 26964800
DOI: 10.1007/s10103-016-1914-y -
Current Pediatric Reviews 2014Survivors of childhood cancer are at risk for treatment-related musculoskeletal late effects. Early detection and orthopedic intervention can help ameliorate... (Meta-Analysis)
Meta-Analysis Review
Survivors of childhood cancer are at risk for treatment-related musculoskeletal late effects. Early detection and orthopedic intervention can help ameliorate musculoskeletal late effects and prevent subsequent complications. This systematic review summarizes the literature describing associations between cancer, its treatment, and musculoskeletal late effects. We searched PubMed and Web of Science for English language articles published between January 1970 and December 2012. The search was limited to investigations with at least 15 participants and conducted at least 2 years after completion of therapy for childhood, adolescent, or young adult cancer. Some late skeletal effects, including low bone mineral density, osteonecrosis, slipped capital femoral epiphyses, oncogenic rickets, and hormonerelated growth disturbances have been previously reviewed and were excluded, as were outcomes following amputation and limb-salvage procedures. Of 2347 references identified, 30 met inclusion criteria and were retained. An additional 54 studies that met inclusion criteria were found in reference lists of retained studies. Of 84 studies, 60 focused on associations between radiotherapy, six between chemotherapy, and 18 between surgery and musculoskeletal late effects. We found that younger age, higher radiation dosage, and asymmetric or partial bone radiation volume influences the effects of radiation on the musculoskeletal system. Methotrexate and vincristine are associated with long-term muscular strength and flexibility deficits. Laminectomy and chest wall resection are associated with spinal malalignment, and enucleation is associated with orbital deformities among survivors. Radiotherapy, chemotherapy, and surgery are associated with musculoskeletal late effects independently and additively. Associations are additionally influenced by host and treatment characteristics.
Topics: Adult; Bone and Bones; Child; Drug-Related Side Effects and Adverse Reactions; Humans; Muscle, Striated; Musculoskeletal System; Neoplasms; Radiotherapy; Radiotherapy Dosage; Survivors
PubMed: 25403639
DOI: 10.2174/1573400510666141114223827 -
Radiotherapy and Oncology : Journal of... Oct 2022Recently, a number of clinical studies have explored links between possible Relative Biological Effectiveness (RBE) elevations and patient toxicities and/or image... (Review)
Review
Recently, a number of clinical studies have explored links between possible Relative Biological Effectiveness (RBE) elevations and patient toxicities and/or image changes following proton therapy. Our objective was to perform a systematic review of such studies. We applied a "Problem [RBE], Intervention [Protons], Population [Patients], Outcome [Side effect]" search strategy to the PubMed database. From our search, we retrieved studies which: (a) performed novel voxel-wise analyses of patient effects versus physical dose and LET (n = 13), and (b) compared image changes between proton and photon cohorts with regard to proton RBE (n = 9). For each retrieved study, we extracted data regarding: primary tumour type; size of patient cohort; type of image change studied; image-registration method (deformable or rigid); LET calculation method, and statistical methodology. We compared and contrasted their methods in order to discuss the weight of clinical evidence for variable proton RBE. We concluded that clinical evidence for variable proton RBE remains statistically weak at present. Our principal recommendation is that proton centres and clinical trial teams collaborate to standardize follow-up protocols and statistical analysis methods, so that larger patient cohorts can ultimately be considered for RBE analyses.
Topics: Humans; Relative Biological Effectiveness; Proton Therapy; Protons; Linear Energy Transfer; Radiotherapy Planning, Computer-Assisted
PubMed: 35988776
DOI: 10.1016/j.radonc.2022.08.014 -
Clinical Neuroradiology Sep 2023In 1971, the first computed tomography (CT) scan was performed on a patient's brain. Clinical CT systems were introduced in 1974 and dedicated to head imaging only. New... (Review)
Review
In 1971, the first computed tomography (CT) scan was performed on a patient's brain. Clinical CT systems were introduced in 1974 and dedicated to head imaging only. New technological developments, broader availability, and the clinical success of CT led to a steady growth in examination numbers. Most frequent indications for non-contrast CT (NCCT) of the head include the assessment of ischemia and stroke, intracranial hemorrhage and trauma, while CT angiography (CTA) has become the standard for first-line cerebrovascular evaluation; however, resulting improvements in patient management and clinical outcomes come at the cost of radiation exposure, increasing the risk for secondary morbidity. Therefore, radiation dose optimization should always be part of technical advancements in CT imaging but how can the dose be optimized? What dose reduction can be achieved without compromising diagnostic value, and what is the potential of the upcoming technologies artificial intelligence and photon counting CT? In this article, we look for answers to these questions by reviewing dose reduction techniques with respect to the major clinical indications of NCCT and CTA of the head, including a brief perspective on what to expect from current and future developments in CT technology with respect to radiation dose optimization.
Topics: Humans; Artificial Intelligence; Radiation Dosage; Tomography, X-Ray Computed; Computed Tomography Angiography; Angiography; Radiographic Image Interpretation, Computer-Assisted
PubMed: 36862232
DOI: 10.1007/s00062-023-01271-5 -
The Cochrane Database of Systematic... Aug 2017Please see Appendix 4 for a glossary of terms.The outcome of patients with esophageal cancer is generally poor. Although multimodal therapy is standard, there is... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Please see Appendix 4 for a glossary of terms.The outcome of patients with esophageal cancer is generally poor. Although multimodal therapy is standard, there is conflicting evidence regarding the addition of esophagectomy to chemoradiotherapy.
OBJECTIVES
To compare the effectiveness and safety of chemoradiotherapy plus surgery with that of chemoradiotherapy alone in people with nonmetastatic esophageal carcinoma.
SEARCH METHODS
We performed a computerized search for relevant studies, up to Feburary 2017, on the CENTRAL, MEDLINE, and Embase databases using MeSH headings and keywords. We searched five online databases of clinical trials, handsearched conference proceedings, and screened reference lists of retrieved papers.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) comparing chemoradiotherapy plus esophagectomy with chemoradiotherapy alone for localized esophageal carcinoma. We excluded RCTs comparing chemotherapy or radiotherapy alone with esophagectomy.
DATA COLLECTION AND ANALYSIS
Two authors independently selected studies, extracted data, and assessed risk of bias and the quality of the evidence, using standardized Cochrane methodological procedures. The primary outcome was overall survival (OS), estimated with Hazard Ratio (HR). Secondary outcomes, estimated with risk ratio (RR), were local and distant progression-free survival (PFS), quality of life (QoL), treatment-related mortality and morbidity, and use of salvage procedures for dysphagia. Data were analyzed using a random effects model in Review Manager 5.3 software.
MAIN RESULTS
From 2667 references, we identified two randomized studies, in six reports, that included 431 participants. All participants were clinically staged to have at least T3 and/or node positive thoracic esophageal carcinoma, 93% of which was squamous cell histology. The risk of methodological bias of the included studies was low to moderate.High-quality evidence found the addition of esophagectomy had little or no difference on overall survival (HR 0.99, 95% CI 0.79 to 1.24; P = 0.92; I² = 0%; two trials). Neither study reported PFS, therefore, freedom from loco-regional relapse was used as a proxy. Moderate-quality evidence suggested that the addition of esophagectomy probably improved freedom from locoregional relapse (HR 0.55, 95% CI 0.39 to 0.76; P = 0.0004; I² = 0%; two trials), but low-quality evidence suggested it may increase the risk of treatment-related mortality (RR 5.11, 95% CI 1.74 to 15.02; P = 0.003; I² = 2%; two trials).The other pre-specified outcomes (quality of life, treatment-related toxicity, and use of salvage procedures for dysphagia) were reported by only one study, which found very low-quality evidence that use of esophagectomy was associated with reduced short-term QoL (MD 0.93, 95% CI 0.24 to 1.62), and low-quality evidence that it reduced use of salvage procedures for dysphagia (HR 0.52, 95% CI 0.36 to 0.75). Neither study compared treatment-related morbidity between treatment groups.
AUTHORS' CONCLUSIONS
Based on the available evidence, the addition of esophagectomy to chemoradiotherapy in locally advanced esophageal squamous cell carcinoma, provides little or no difference on overall survival, and may be associated with higher treatment-related mortality. The addition of esophagectomy probably delays locoregional relapse, however, this end point was not well defined in the included studies. It is undetermined whether these results can be applied to the treatment of adenocarcinomas, tumors involving the distal esophagus and gastro-esophageal junction, and to people with poor response to chemoradiation.
Topics: Carcinoma; Carcinoma, Squamous Cell; Chemoradiotherapy; Cisplatin; Combined Modality Therapy; Deglutition Disorders; Esophageal Neoplasms; Esophagectomy; Fluorouracil; Humans; Neoplasm Recurrence, Local; Quality of Life; Randomized Controlled Trials as Topic
PubMed: 28829911
DOI: 10.1002/14651858.CD010511.pub2 -
Radiation and Environmental Biophysics May 2010Although the link between high doses of ionizing radiation and damage to the heart and coronary arteries has been well established for some time, the association between... (Meta-Analysis)
Meta-Analysis Review
Although the link between high doses of ionizing radiation and damage to the heart and coronary arteries has been well established for some time, the association between lower-dose exposures and late occurring cardiovascular disease has only recently begun to emerge, and is still controversial. In this paper, we extend an earlier systematic review by Little et al. on the epidemiological evidence for associations between low and moderate doses of ionizing radiation exposure and late occurring blood circulatory system disease. Excess relative risks per unit dose in epidemiological studies vary over at least two orders of magnitude, possibly a result of confounding and effect modification by well-known (but unobserved) risk factors, and there is statistically significant (p < 0.00001) heterogeneity between the risks. This heterogeneity is reduced, but remains significant, if adjustments are made for the effects of fractionated delivery or if there is stratification by endpoint (cardiovascular disease vs. stroke, morbidity vs. mortality). One possible biological mechanism is damage to endothelial cells and subsequent induction of an inflammatory response, although it seems unlikely that this would extend to low-dose and low-dose-rate exposure. A recent paper of Little et al. proposed an arguably more plausible mechanism for fractionated low-dose effects, based on monocyte cell killing in the intima. Although the predictions of the model are consistent with the epidemiological data, the experimental predictions made have yet to be tested. Further epidemiological and biological evidence will allow a firmer conclusion to be drawn.
Topics: Animals; Blood Circulation; Humans; Radiation Dosage; Radiation Injuries; Risk; Survivors; Vascular Diseases
PubMed: 19862545
DOI: 10.1007/s00411-009-0250-z