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Journal of Chromatography. A Apr 2022Miniaturized liquid chromatography (LC) has been recognized as one of the most important analytical methods in several research fields. Reduced analytical work-scale... (Review)
Review
Miniaturized liquid chromatography (LC) has been recognized as one of the most important analytical methods in several research fields. Reduced analytical work-scale provides superior chromatographic resolution and decreases sample and organic solvent consumption. However, frequent clogging of tubing connections and use of small sample volumes are significant limitations when high throughput and sensitive analyses are required. Effective sample preparation could help to overcome these limitations. Online coupling of sample preparation techniques (such as column switching and in-tube solid-phase microextraction) with these miniaturized systems may result in more sensitive and reproducible analyses, improving analytical efficiency. This review describes the most common online miniaturized LC configurations, and the main applications of current online sample preparation techniques coupled to miniaturized LC systems in the bioanalytical, omics, and environmental areas. Relevant features, and challenges of these systems, and innovative sorbents, including restricted access materials, monoliths, and immunosorbents is also discussed.
Topics: Chromatography, Liquid; Immunosorbents; Solid Phase Microextraction; Solvents; Specimen Handling
PubMed: 35263675
DOI: 10.1016/j.chroma.2022.462925 -
Chinese Clinical Oncology Apr 2022Our objective was to identify contemporary management options for large brain metastases reported in literature, specifically evaluating local control and risk of... (Review)
Review
OBJECTIVE
Our objective was to identify contemporary management options for large brain metastases reported in literature, specifically evaluating local control and risk of toxicity.
BACKGROUND
Large brain metastases are typically defined as lesions >2 cm in diameter, and historically conferred poor outcomes due to the high rates of radiation necrosis and less local control in comparison to smaller brain metastases.
METHODS
A literature search examining modern management of large brain metastases was performed using ovid-MEDLINE. A total of 18 articles met criteria for review, evaluating single fraction radiosurgery [stereotactic radiosurgery (SRS)] and multi-fraction stereotactic radiation therapy (MFSRT) in both the definitive and post-operative cavity setting, as well as targeted therapies.
CONCLUSIONS
Multi-fractionated radiosurgery represents a modern and attractive treatment approach in the definitive management of patients with large brain metastases, with equivalent local control and reduced rates of radionecrosis less than 13% in comparison to single fraction SRS. In cases where surgery is indicated, fractionated cavity radiation should be considered for large tumor bed volumes. More research is needed for the optimal dose and fractionation regimen for optimal tumor control with reduced risk of radiation toxicity, but common regimens include 3-5 fractions while meeting appropriate biologically effective dose (BED) goals. Future areas of interest include targeted therapies in the initial management of brain metastases as well as pre-operative radiation therapy to reduce risk of leptomeningeal disease (LMD).
Topics: Brain Neoplasms; Dose Fractionation, Radiation; Humans; Meningeal Neoplasms; Radiation Injuries; Radiosurgery; Retrospective Studies; Treatment Outcome
PubMed: 35534794
DOI: 10.21037/cco-21-136 -
Analytical Chemistry Feb 2020Current methods for liquid-liquid extractions generally require microliter to milliliter volumes of solvents and sample, long equilibration times, and manual procedures....
Current methods for liquid-liquid extractions generally require microliter to milliliter volumes of solvents and sample, long equilibration times, and manual procedures. Extraction methods for samples in microfluidic systems have been limited as this tool is difficult to implement on the nanoliter or smaller scale. We have developed slug-flow nanoextraction (SFNE), a method based on droplet microfluidics that allows multiple liquid-liquid extractions to be performed simultaneously in a capillary tube, using only 5 nL of sample and extraction solvent per extraction. Each two-phase slug is segmented from the others by immiscible carrier fluid. We found rapid extractions (<5 s), partition coefficients matching those achieved at larger scale extractions, and potential to preconcentrate samples through volume manipulation. This method was used to accurately and rapidly determine octanol-water partition coefficients (), determining identical as the shake-flask method for acetaminophen, = 2.48 ± 0.02. The measurement, along with calibration and 12 replicates, was complete within 5 min, consuming under 150 nL of solvent and sample. The method was also applied to extract analytes from complex biological samples prior to electrospray ionization-tandem mass spectrometry (ESI-MS/MS) at a rate of 6 s per sample, allowing for simultaneous determination of five different drugs spiked into human plasma, synthetic urine (SU), and artificial cerebral spinal fluid (aCSF) using ethyl acetate as the extraction phase. The signal-to-noise (S/N) for analytes improved up to 19-fold compared to direct ESI-MS of single-phase droplets (aqueous plugs segmented by carrier fluid), with limits of detection down to 7 nM (35 amol).
Topics: Calibration; Humans; Limit of Detection; Liquid-Liquid Extraction; Pharmaceutical Preparations
PubMed: 31986881
DOI: 10.1021/acs.analchem.9b04915 -
Pathology Oncology Research : POR 2024The treatment of early stage non-small cell lung cancer (NSCLC) has improved enormously in the last two decades. Although surgery is not the only choice, lobectomy is... (Review)
Review
The treatment of early stage non-small cell lung cancer (NSCLC) has improved enormously in the last two decades. Although surgery is not the only choice, lobectomy is still the gold standard treatment type for operable patients. For inoperable patients stereotactic body radiotherapy (SBRT) should be offered, reaching very high local control and overall survival rates. With SBRT we can precisely irradiate small, well-defined lesions with high doses. To select the appropriate fractionation schedule it is important to determine the size, localization and extent of the lung tumor. The introduction of novel and further developed planning (contouring guidelines, diagnostic image application, planning systems) and delivery techniques (motion management, image guided radiotherapy) led to lower rates of side effects and more conformal target volume coverage. The purpose of this study is to summarize the current developments, randomised studies, guidelines about lung SBRT, with emphasis on the possibility of increasing local control and overall rates in "fit," operable patients as well, so SBRT would be eligible in place of surgery.
Topics: Humans; Lung Neoplasms; Carcinoma, Non-Small-Cell Lung; Radiosurgery; Lung; Dose Fractionation, Radiation; Small Cell Lung Carcinoma; Neoplasm Staging
PubMed: 38476352
DOI: 10.3389/pore.2024.1611709 -
Journal of Neuro-oncology Oct 2021The outcomes of five fraction stereotactic radiotherapy (hfSRT) following brain metastasectomy were evaluated and compared with published series. (Review)
Review
PURPOSE
The outcomes of five fraction stereotactic radiotherapy (hfSRT) following brain metastasectomy were evaluated and compared with published series.
METHODS
30 Gy in 5 fractions HfSRT prescribed to the surgical cavity was reduced to 25 Gy if the volume of 'brain-GTV' receiving 20 Gy exceeded 20 cm. Endpoints were local recurrence, nodular leptomeningeal recurrence, new brain metastases and radionecrosis. The literature was searched for reports of clinical and dosimetric outcomes following postoperative hfSRT in 3-5 fractions.
RESULTS
39 patients with 40 surgical cavities were analyzed. Cavity local control rate at 1 year was 33/40 (82.5%). 3 local failures followed 30 Gy/5 fractions and 4 with 25 Gy/5 fractions. The incidence of leptomeningeal disease (LMD) was 7/40 (17.5%). No grade 3-4 toxicities, particularly no radionecrosis, were reported. The incidence of distant brain metastases was 15/40 (37.5%). The median overall survival was 15 months. Across 13 published series, the weighted mean local control was 83.1% (adjusted for sample size), the mean incidence of LMD was 14.9% (7-34%) and the mean rate of radionecrosis was 10.3% (0-20.6%).
CONCLUSION
Postoperative hfSRT can be delivered with 25-30 Gy in 5 fractions with efficacy in excess of 82% and no significant toxicity when the dose to 'brain-GTV' does not exceed 20 cm.
Topics: Brain; Brain Neoplasms; Humans; Meningeal Neoplasms; Metastasectomy; Radiation Dose Hypofractionation; Radiation Injuries; Radiosurgery; Retrospective Studies; Treatment Outcome
PubMed: 34546498
DOI: 10.1007/s11060-021-03840-5 -
World Neurosurgery Oct 2023Stereotactic radiosurgery (SRS) is a well-established treatment for vestibular schwannomas (VS). Hearing loss remains a main morbidity of VS and its treatments,...
OBJECTIVE
Stereotactic radiosurgery (SRS) is a well-established treatment for vestibular schwannomas (VS). Hearing loss remains a main morbidity of VS and its treatments, including SRS. The effects of radiation parameters of SRS on hearing remain unknown. The goal of this study is to determine the effect of tumor volume, patient demographics, pretreatment hearing status, cochlear radiation dose, total tumor radiation dose, fractionation, and other radiotherapy parameters on hearing deterioration.
METHODS
Multicenter retrospective analysis of 611 patients who underwent SRS for VS from 1990-2020 and had pre- and post-treatment audiograms.
RESULTS
Pure tone averages (PTAs) increased and word recognition scores (WRSs) decreased in treated ears at 12-60 months while remaining stable in untreated ears. Higher baseline PTA, higher tumor radiation dose, higher maximum cochlear dose, and usage of single fraction resulted in higher post radiation PTA; WRS was only predicted by baseline WRS and age. Higher baseline PTA, single fraction treatment, higher tumor radiation dose, and higher maximum cochlear dose resulted in a faster deterioration in PTA. Below a maximum cochlear dose of 3 Gy, there were no statistically significant changes in PTA or WRS.
CONCLUSIONS
Decline of hearing at one year in VS patients after SRS is directly related to maximum cochlear dose, single versus 3-fraction treatment, total tumor radiation dose, and baseline hearing level. The maximum safe cochlear dose for hearingtbrowd preservation at one year is 3 Gy, and the use of 3 fractions instead of one fraction was better at preserving hearing.
Topics: Humans; Neuroma, Acoustic; Retrospective Studies; Radiosurgery; Follow-Up Studies; Hearing; Treatment Outcome
PubMed: 37268187
DOI: 10.1016/j.wneu.2023.05.098 -
Radiotherapy and Oncology : Journal of... Sep 2019The limited radiation tolerance of the small-bowel causes toxicity for patients receiving conventionally-fractionated radiotherapy for rectal cancer. Safe radiotherapy... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
The limited radiation tolerance of the small-bowel causes toxicity for patients receiving conventionally-fractionated radiotherapy for rectal cancer. Safe radiotherapy dose-escalation will require a better understanding of such toxicity. We conducted a systematic review and meta-analysis using published datasets of small bowel dose-volume and outcomes to analyse the relationship with acute toxicity.
MATERIALS AND METHODS
SCOPUS, EMBASE & MEDLINE were searched to identify twelve publications reporting small-bowel dose-volumes and toxicity data or analysis. Where suitable data were available (mean absolute volume with parametric error measures), fixed-effects inverse-variance meta-analysis was used to compare cohorts of patients according to Grade ≥3 toxicity. For other data, non-parametric examinations of irradiated small-bowel dose-volume and incidence of toxicity were conducted, and a univariate logistic regression model was fitted.
RESULTS
On fixed-effects meta-analysis of three studies (203 patients), each of the dose-volume measures V-V were significantly greater (p < 0.00001) for patients with Grade ≥3 toxicity than for those without. Absolute difference was largest for the lowest dose-volume parameter; however relative difference increases with increasing dose. On logistic regression multiple small-bowel DVH parameters were predictive of toxicity risk (V, V, V - V), with V the strongest (p = 0.004).
CONCLUSIONS
Analysis of published clinical cohort dose-volume data provides evidence for a significant dose-volume-toxicity response effect for a wide range of clinically-relevant doses in the treatment of rectal cancer. Both low dose and high dose are shown to predict toxicity risk, which has important implications for radiotherapy planning and consideration of dose escalation for these patients.
Topics: Dose Fractionation, Radiation; Humans; Intestine, Small; Radiotherapy; Radiotherapy Dosage; Rectal Neoplasms
PubMed: 31136961
DOI: 10.1016/j.radonc.2019.05.001 -
Cancer Radiotherapie : Journal de La... Oct 2019Head and neck cancers comprise a variety of tumours depending on the sub-site, for which target volumes and the prescribed doses need to be individualized according to... (Review)
Review
Head and neck cancers comprise a variety of tumours depending on the sub-site, for which target volumes and the prescribed doses need to be individualized according to each patient's history and presentation. This article aims at describing the main factors involved in decision-making regarding dose and volume, as well as ongoing research. Contouring and treatment guidelines, use of altered fractionation, major prognostic factors, the role of Human papillomavirus and of functional imaging will be presented and discussed.
Topics: Dose Fractionation, Radiation; Head and Neck Neoplasms; Humans; Oropharyngeal Neoplasms; Papillomaviridae; Positron-Emission Tomography; Practice Guidelines as Topic; Precision Medicine; Prognosis; Radiotherapy Dosage
PubMed: 31420129
DOI: 10.1016/j.canrad.2019.07.131 -
Journal of Environmental Radioactivity Apr 2022Achieving precise and accurate quantification of radium (Ra) and cesium (Cs) by inductively coupled plasma mass spectrometry (ICP-MS) is of particular interest in the... (Review)
Review
Achieving precise and accurate quantification of radium (Ra) and cesium (Cs) by inductively coupled plasma mass spectrometry (ICP-MS) is of particular interest in the field of radiological monitoring and more widely in environmental and biological sciences. However, the accuracy and sensitivity of the quantification depend on the analytical strategy implemented. Eliminating interferences during the sample handling step and/or during the analysis step is critical since presence of matrix elements can lead to spectral and non-spectral interferences in ICP-MS. Consequently, before the ICP-MS analysis, multiple sample preparation approaches have been applied to purify and/or pre-concentrate environmental and biological samples containing radium and cesium through years, such as (co)-precipitation, solid phase extraction (SPE) or dispersive SPE (dSPE). Separation steps using liquid chromatography and capillary electrophoresis can also be useful in complement with the abovementioned sample preparation techniques. The most attractive sample handling technique remains SPE but efficiency of the extraction procedures is currently limited by sorbent specificity. Indeed, with the recent advances in ICP-MS instrumentation, it becomes indispensable to eliminate residual interferences and improve sensitivity. It is in this direction that it will be possible to meet analytical challenges, e.g. analyzing radium and cesium at concentrations below the pg L range in complex matrices of small volumes, as they are found for instance in pore waters or in biological samples. Development of new innovative sorbents based for example on hybrid and nanostructured materials has been reported with the aim of enhancing sorbent specificity and/or capacity. In the present review, the performances of the different analytical approaches are discussed, followed by an overview of applications.
Topics: Cesium Radioisotopes; Mass Spectrometry; Radiation Monitoring; Solid Phase Extraction; Spectrum Analysis
PubMed: 35042022
DOI: 10.1016/j.jenvrad.2022.106812 -
In Vivo (Athens, Greece) 2022Stereotactic radiotherapy (SRT) for spine metastases with helical tomotherapy requires a long irradiation time due to the high dose per fraction. Since helical...
BACKGROUND/AIM
Stereotactic radiotherapy (SRT) for spine metastases with helical tomotherapy requires a long irradiation time due to the high dose per fraction. Since helical tomotherapy can neither confirm nor correct the position during irradiation, a plan with a long irradiation time cannot be used in actual clinical practice, given the intra-fractional motion error. To address this problem, we devised a method called REPEAT irradiation.
PATIENTS AND METHODS
REPEtitive pAinTing (REPEAT) irradiation is a method of dividing the irradiation for a given fraction per day into several sessions and performing the irradiation after position correction using mega-voltage computed tomography images for each session. In order to evaluate how REPEAT irradiation changes irradiation time and the dose-volume histogram (DVH), a planning study with helical tomotherapy was conducted using CT images of a patient with lumbar spine metastasis.
RESULTS
In this case, we found that dividing 3 irradiation fractions into 3 sessions per day (i.e., 9 fractions=9 sessions in 3 days) using REPEAT irradiation shortened the irradiation time per session and simultaneously improved dose-volume histogram parameters.
CONCLUSION
Although the optimal number of sessions may differ depending on the patient's condition, the fixing method, the irradiation site, and the calculation parameters, REPEAT irradiation does not require any special equipment and is a simple practical treatment method.
Topics: Dose Fractionation, Radiation; Humans; Radiosurgery; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated
PubMed: 34972730
DOI: 10.21873/invivo.12706