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Physica Medica : PM : An International... Feb 2022Patient shielding during medical X-ray imaging has been increasingly criticized in the last years due to growing evidence that it often provides minimal benefit and may... (Review)
Review
PURPOSE
Patient shielding during medical X-ray imaging has been increasingly criticized in the last years due to growing evidence that it often provides minimal benefit and may even compromise image quality. In Europe, and as also shown in a short assessment in Switzerland, the use of patient shielding is inhomogeneous. The aim of this study was to systematically review recent literature in order to assess benefits and appraise disadvantages related to the routine use of patient shielding.
METHODS
To evaluate benefits and disadvantages related to the application of patient shielding in radiological procedures, a systematic literature review was performed for CT, radiography, mammography and fluoroscopy-guided medical X-ray imaging. In addition, reports from medical physics societies and authorities of different countries were considered in the evaluation.
RESULTS
The literature review revealed 479 papers and reports on the topic, from which 87 qualified for closer analysis. The review considered in- and out-of-plane patient shielding as well as shielding for pregnant and pediatric patients. Dose savings and other dose and non-dose related effects of patient shielding were considered in the evaluation.
CONCLUSIONS
Although patient shielding has been used in radiological practice for many years, its use is no longer undisputed. The evaluation of the systematic literature review of recent studies and reports shows that dose savings are rather minimal while significant dose- and non-dose-related detrimental effects are present. Consequently, the routine usage of patient protection shielding in medical X-ray imaging can be safely discontinued for all modalities and patient groups.
Topics: Child; Female; Fluoroscopy; Humans; Pregnancy; Radiation Dosage; Radiation Protection; Radiography; Radiology; X-Rays
PubMed: 35030383
DOI: 10.1016/j.ejmp.2021.12.016 -
Radiotherapy and Oncology : Journal of... Jun 2024This systematic review examines the role of dosimetric parameters in predicting temporal lobe necrosis (TLN) risk in nasopharyngeal carcinoma (NPC) patients treated with... (Meta-Analysis)
Meta-Analysis Review
This systematic review examines the role of dosimetric parameters in predicting temporal lobe necrosis (TLN) risk in nasopharyngeal carcinoma (NPC) patients treated with three-dimensional conformal RT (3D-CRT), intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). TLN is a serious late complication that can adversely affect the quality of life of NPC patients. Understanding the relationship between dosimetric parameters and TLN can guide treatment planning and minimize radiation-related complications. A comprehensive search identified relevant studies published up to July 2023. Studies reporting on dosimetric parameters and TLN in NPC patients undergoing 3D-CRT, IMRT, and VMAT were included. TLN incidence, follow-up duration, and correlation with dosimetric parameters of the temporal lobe were analyzed. The review included 30 studies with median follow-up durations ranging from 28 to 110 months. The crude incidence of TLN varied from 2.3 % to 47.3 % and the average crude incidence of TLN is approximately 14 %. Dmax and D1cc emerged as potential predictors of TLN in 3D-CRT and IMRT-treated NPC patients. Threshold values of >72 Gy for Dmax and >62 Gy for D1cc were associated with increased TLN risk. However, other factors should also be considered, including host characteristics, tumor-specific features and therapeutic factors. In conclusion, this systematic review highlights the significance of dosimetric parameters, particularly Dmax and D1cc, in predicting TLN risk in NPC patients undergoing 3D-CRT, IMRT, and VMAT. The findings provide valuable insights that can help in developing optimal treatment planning strategies and contribute to the development of clinical guidelines in this field.
Topics: Humans; Nasopharyngeal Carcinoma; Temporal Lobe; Necrosis; Radiation Injuries; Nasopharyngeal Neoplasms; Radiotherapy, Intensity-Modulated; Radiotherapy Dosage; Radiotherapy, Conformal
PubMed: 38537680
DOI: 10.1016/j.radonc.2024.110258 -
Radiotherapy and Oncology : Journal of... Aug 2021Linear Energy Transfer (LET) is widely used to express the radiation quality of ion beams, when characterizing the biological effectiveness. However, averaged LET may be... (Review)
Review
Linear Energy Transfer (LET) is widely used to express the radiation quality of ion beams, when characterizing the biological effectiveness. However, averaged LET may be defined in multiple ways, and the chosen definition may impact the resulting reported value. We review averaged LET definitions found in the literature, and quantify which impact using these various definitions have for different reference setups. We recorded the averaged LET definitions used in 354 publications quantifying the relative biological effectiveness (RBE) of hadronic beams, and investigated how these various definitions impact the reported averaged LET using a Monte Carlo particle transport code. We find that the kind of averaged LET being applied is, generally, poorly defined. Some definitions of averaged LET may influence the reported averaged LET values up to an order of magnitude. For publications involving protons, most applied dose averaged LET when reporting RBE. The absence of what target medium is used and what secondary particles are included further contributes to an ill-defined averaged LET. We also found evidence of inconsistent usage of averaged LET definitions when deriving LET-based RBE models. To conclude, due to commonly ill-defined averaged LET and to the inherent problems of LET-based RBE models, averaged LET may only be used as a coarse indicator of radiation quality. We propose a more rigorous way of reporting LET values, and suggest that ideally the entire particle fluence spectra should be recorded and provided for future RBE studies, from which any type of averaged LET (or other quantities) may be inferred.
Topics: Humans; Linear Energy Transfer; Monte Carlo Method; Proton Therapy; Protons; Radiobiology; Relative Biological Effectiveness
PubMed: 33894298
DOI: 10.1016/j.radonc.2021.04.007 -
Journal of Cancer Research and... 2020In recent times, research on the use of ultrahigh-dose rates delivered in super-fast times in cancer treatment has been garnering interest. This has brought about the...
In recent times, research on the use of ultrahigh-dose rates delivered in super-fast times in cancer treatment has been garnering interest. This has brought about the term "FLASH" radiotherapy (RT). Thus, in the present study, we systematically review these recent studies on FLASH RT with regard to its efficacy and safety. The reporting of this systematic review was done in line with the statement of Preferred Reporting Items for Systematic reviews and Meta-Analyses. Electronic search of the databases such as PubMed, Scopus, and Embase was conducted to retrieve relevant studies investigating the FLASH effect. From an initial search of 216 potential articles, 16 articles (in vivo, in vitro , and clinical studies) were finally included in this systematic review. Results showed that FLASH RT dose rates had protective effects on normal tissues in addition to antitumor effect. Although still in its early research stages, FLASH RT has the potential to rival present RT regimens in terms of safety and antitumor effect. However, further studies are needed to address the aspects such as optimal dose rate, effect on deep tumors, tumor recurrence, longer follow-up time, and mechanism of action.
Topics: Humans; Neoplasms; Organ Sparing Treatments; Radiation Oncology; Radiation Tolerance; Radiotherapy; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Treatment Outcome
PubMed: 33342774
DOI: 10.4103/jcrt.JCRT_180_20 -
BMC Gastroenterology May 2024There have been previous studies and earlier systematic review on the relationship between inflammatory bowel disease (IBD) and radiation exposure. With the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
There have been previous studies and earlier systematic review on the relationship between inflammatory bowel disease (IBD) and radiation exposure. With the diversification of current test methods, this study intended to conduct a meta-analysis to evaluate the IBD radiation exposure in recent years.
METHODS
Three databases (PUBMED, EMBASE, and MEDICINE) for relevant literature up to May 1, 2023 were searched. The statistical data meeting requirements were collated and extracted.
RESULTS
20 papers were enrolled. The overall high radiation exposure rate was 15% (95% CI = [12%, 19%]) for CD and 5% (95% CI = [3%, 7%]) for UC. The pooled result found that high radiation exposure rate was 3.44 times higher in CD than in UC (OR = 3.44, 95% CI = [2.35, 5.02]). Moreover, the average radiation exposure level in CD was 12.77 mSv higher than that in UC (WMD = 12.77, 95% CI = [9.93, 15.62] mSv). Furthermore, radiation exposure level of CD after 2012 was higher than those before 2012 (26.42 ± 39.61vs. 23.76 ± 38.46 mSv, P = 0.016), while UC did not show similar result (11.99 ± 27.66 vs. 10.01 ± 30.76 mSv, P = 0.1). Through subgroup analysis, it was found that disease duration (WMD = 2.75, 95% CI = [0.10, 5.40] mSv), complications (OR = 5.09, 95% CI = [1.50, 17.29]), and surgical history (OR = 5.46, 95% CI = [1.51, 19.69]) significantly increased the proportion of high radiation exposure.
CONCLUSION
This study found that radiation exposure level of IBD patients was high, which revealed the radiation risk in the process of diagnosis and treatment of IBD patients. In the future, longer follow-up and prospective studies are needed to reveal the relationship between high radiation exposure and solid tumorigenesis.
Topics: Humans; Radiation Exposure; Colitis, Ulcerative; Inflammatory Bowel Diseases; Crohn Disease; Radiation Dosage
PubMed: 38762503
DOI: 10.1186/s12876-024-03264-1 -
International Journal of Radiation... May 2024Women with locally advanced cervical cancer (LACC) undergoing primary platinum-based chemoradiotherapy and brachytherapy often experience toxicities. Normal-tissue... (Review)
Review
PURPOSE
Women with locally advanced cervical cancer (LACC) undergoing primary platinum-based chemoradiotherapy and brachytherapy often experience toxicities. Normal-tissue complication probability (NTCP) models quantify toxicity risk and aid in optimizing radiation therapy to minimize side effects. However, it is unclear which predictors to include in an NTCP model. The aim of this systematic review was to provide an overview of the identified predictors contributing to gastrointestinal (GI), genitourinary (GU), and vaginal toxicities and insufficiency fractures for LACC.
METHODS AND MATERIALS
A systematic search was performed and articles evaluating the relationship between predictors and toxicities in women with LACC treated with primary chemoradiation were included. The Quality In Prognosis Studies tool was used to assess risk of bias, with high-risk studies being excluded from further analysis. Relationships between dose-volume parameters, patient and treatment characteristics, and toxicity endpoints were analyzed.
RESULTS
Seventy-three studies were identified. Twenty-six had a low or moderate risk of bias and were therefore included. Brachytherapy-related dose-volume parameters of the GI tract, including rectum and bowel equivalent dose in 2 Gy fractions (EQD2) D2 cm, were frequently related to toxicities, unlike GU dose-volume parameters. Furthermore, (recto)vaginal point doses predicted toxicities. Few studies evaluated external beam radiation therapy dose-volume parameters and identified rectum EQD2 V30 Gy, V40 Gy, and V55 Gy, bowel and bladder EQD2 V40 Gy as toxicity predictors. Also, total reference air kerma and vaginal reference length were associated with toxicities. Relationships between patient characteristics and GI toxicity were inconsistent. The extent of vaginal involvement at diagnosis, baseline symptoms, and obesity predicted GU or vaginal toxicities. Only 1 study evaluated insufficiency fractures and demonstrated lower pretreatment bone densities to be associated.
CONCLUSIONS
This review detected multiple candidate predictors of toxicity. Larger studies should consider insufficiency fractures, assess dose levels from external beam radiation therapy, and quantify the relationship between the predictors and treatment-related toxicities in women with LACC to further facilitate NTCP model development for clinical use.
Topics: Humans; Female; Uterine Cervical Neoplasms; Fractures, Stress; Urinary Bladder; Chemoradiotherapy; Brachytherapy; Rectum; Vagina; Radiotherapy Dosage
PubMed: 37979708
DOI: 10.1016/j.ijrobp.2023.11.010 -
Technology in Cancer Research &... 2022The development of new techniques in radiotherapy (RT) provides a better planned target volume (PTV) dose distribution while further improving the protection of organs... (Review)
Review
The development of new techniques in radiotherapy (RT) provides a better planned target volume (PTV) dose distribution while further improving the protection of organs at risk (OARs). The study aims to present the dosimetric results of studies using hybrid techniques in whole-breast radiotherapy (WBRT). This systematic literature review was conducted by scanning the relevant literature in PubMed, Scopus, and Web of Science following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Among the parameters are dose values for PTV and OARs beam contribute ratios, the value of monitors, and treatment times for different RT techniques. Initially, 586 articles were identified; 196 duplicate articles were removed leaving 391 articles for screening. Three-hundred and thirty-seven irrelevant articles were excluded, leaving 54 studies assessed for eligibility. A total of 22 articles met the search criteria to evaluate dosimetric results of hybrid and other RT techniques in WBRT. According to the dosimetric data of the studies, hybrid intensity-modulated RT (H-IMRT) and hybrid volumetric-modulated arc therapy (H-VMAT) techniques give dosimetrically advantageous results in WBRT compared to other RT techniques. Hybrid techniques using appropriate beams contribute value and show great promise in improving dosimetric results in WBRT. However, there is a need for new studies showing the long-term clinical results of hybrid RT.
Topics: Humans; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated; Breast; Organs at Risk
PubMed: 36537067
DOI: 10.1177/15330338221143937 -
Clinical Neuroradiology Jun 2023The introduction of the first whole-body CT scanner in 1974 marked the beginning of cross-sectional spine imaging. In the last decades, the technological advancement,... (Review)
Review
The introduction of the first whole-body CT scanner in 1974 marked the beginning of cross-sectional spine imaging. In the last decades, the technological advancement, increasing availability and clinical success of CT led to a rapidly growing number of CT examinations, also of the spine. After initially being primarily used for trauma evaluation, new indications continued to emerge, such as assessment of vertebral fractures or degenerative spine disease, preoperative and postoperative evaluation, or CT-guided interventions at the spine; however, improvements in patient management and clinical outcomes come along with higher radiation exposure, which increases the risk for secondary malignancies. Therefore, technical developments in CT acquisition and reconstruction must always include efforts to reduce the radiation dose. But how exactly can the dose be reduced? What amount of dose reduction can be achieved without compromising the clinical value of spinal CT examinations and what can be expected from the rising stars in CT technology: artificial intelligence and photon counting CT? In this article, we try to answer these questions by systematically reviewing dose reduction techniques with respect to the major clinical indications of spinal CT. Furthermore, we take a concise look on the dose reduction potential of future developments in CT hardware and software.
Topics: Humans; Artificial Intelligence; Cross-Sectional Studies; Radiation Dosage; Tomography, X-Ray Computed; Spine
PubMed: 36416936
DOI: 10.1007/s00062-022-01227-1 -
BMC Cancer Feb 2021Radiotherapy is the mainstay of brain metastasis (BM) management. Radiation necrosis (RN) is a serious complication of radiotherapy. Bevacizumab (BV), an anti-vascular... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Radiotherapy is the mainstay of brain metastasis (BM) management. Radiation necrosis (RN) is a serious complication of radiotherapy. Bevacizumab (BV), an anti-vascular endothelial growth factor monoclonal antibody, has been increasingly used for RN treatment. We systematically reviewed the medical literature for studies reporting the efficacy and safety of bevacizumab for treatment of RN in BM patients.
MATERIALS AND METHODS
PubMed, Medline, EMBASE, and Cochrane library were searched with various search keywords such as "bevacizumab" OR "anti-VEGF monoclonal antibody" AND "radiation necrosis" OR "radiation-induced brain necrosis" OR "RN" OR "RBN" AND "Brain metastases" OR "BM" until 1st Aug 2020. Studies reporting the efficacy and safety of BV treatment for BM patients with RN were retrieved. Study selection and data extraction were carried out by independent investigators. Open Meta Analyst software was used as a random effects model for meta-analysis to obtain mean reduction rates.
RESULTS
Two prospective, seven retrospective, and three case report studies involving 89 patients with RN treated with BV were included in this systematic review and meta-analysis. In total, 83 (93%) patients had a recorded radiographic response to BV therapy, and six (6.7%) had experienced progressive disease. Seven studies (n = 73) reported mean volume reductions on gadolinium-enhanced T1 (mean: 47.03%, +/- 24.4) and T2-weighted fluid-attenuated inversion recovery (FLAIR) MRI images (mean: 61.9%, +/- 23.3). Pooling together the T1 and T2 MRI reduction rates by random effects model revealed a mean of 48.58 (95% CI: 38.32-58.85) for T1 reduction rate and 62.017 (95% CI: 52.235-71.799) for T2W imaging studies. Eighty-five patients presented with neurological symptoms. After BV treatment, nine (10%) had stable symptoms, 39 (48%) had improved, and 34 (40%) patients had complete resolution of their symptoms. Individual patient data was available for 54 patients. Dexamethasone discontinuation or reduction in dosage was observed in 30 (97%) of 31 patients who had recorded dosage before and after BV treatment. Side effects were mild.
CONCLUSIONS
Bevacizumab presents a promising treatment strategy for patients with RN and brain metastatic disease. Radiographic response and clinical improvement was observed without any serious adverse events. Further class I evidence would be required to establish a bevacizumab recommendation in this group of patients.
Topics: Antineoplastic Agents, Immunological; Bevacizumab; Brain Neoplasms; Humans; Necrosis; Prognosis; Radiation Injuries; Radiotherapy
PubMed: 33593308
DOI: 10.1186/s12885-021-07889-3 -
JPMA. the Journal of the Pakistan... Jan 2021To build evidence about the effectiveness of computerized tomography virtual hysterosalpingography (CT-VHSG) in the evaluation of female infertility and to assess the... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To build evidence about the effectiveness of computerized tomography virtual hysterosalpingography (CT-VHSG) in the evaluation of female infertility and to assess the estimated radiation dose imposed.
METHODS
A systematic review method was utilized to evaluate relevant diagnostic studies. Electronic database was searched from July to October 2017. Hand search was also conducted when applicable. Study quality was assessed according to standardised criteria. Heterogeneity was assessed using subjective and statistical measures. Meta-analysis was judged appropriate and conducted using Open met-analyst software utilizing the random effect model.
RESULTS
Based on the assessment of risk of bias of the eligible studies, five studies were included in the final review. Random effects models showed that CT-VHSG has high diagnostic performance (pooled sensitivity 0.992 and specificity 0.98, with negative and positive likelihood ratios of 14.671 and 0.04 respectively). CT-VHSG had comparatively lesser radiation dose than conventional HSG (pooled mean effective dose 4.14 mSV vs 6 mSV respectively).
CONCLUSIONS
CT-VHSG is a reliable procedure with high diagnostic performance in evaluation of the female reproductive tract. CT-VHSG can be regarded as generally safe imaging diagnostic technique in the infertility workup. In contrary to common belief, CT-VHSG has comparable or lower radiation dose than conventional HSG.
Topics: Female; Humans; Hysterosalpingography; Infertility, Female; Radiation Dosage; Sensitivity and Specificity; Tomography, X-Ray Computed
PubMed: 33484533
DOI: 10.47391/JPMA.537