scholarly journals Quality Assurance for Small-Field VMAT SRS and Conventional-Field IMRT Using the Exradin W1 Scintillator

2021 ◽  
Vol 20 ◽  
pp. 153303382110365
Author(s):  
Zike Huang ◽  
Jian Qiao ◽  
Cui Yang ◽  
Ming Liu ◽  
Jiazhou Wang ◽  
...  
Keyword(s):  
Low Dose ◽  
High Dose ◽  
Sensitive Volume ◽  
Small Field ◽  
Measuring Point ◽  
Small Field Dosimetry ◽  
Different Types ◽  
Comparable Performance ◽  
One Stop ◽  
Dose Measurements

Background: Plastic scintillator detector (PSD) Exradin W1 has shown promising performance in small field dosimetry due to its water equivalence and small sensitive volume. However, few studies reported its capability in measuring fields of conventional sizes. Therefore, the purpose of this study is to assess the performance of W1 in measuring point dose of both conventional IMRT plans and VMAT SRS plans. Methods: Forty-seven clinical plans (including 29 IMRT plans and 18 VMAT SRS plans with PTV volume less than 8 cm3) from our hospital were included in this study. W1 and Farmer-Type ionization chamber Exradin A19 were used in measuring IMRT plans, and W1 and microchamber Exradin A16 were used in measuring SRS plans. The agreement between the results of different types of detectors and TPS was evaluated. Results: For IMRT plans, the average differences between measurements and TPS in high-dose regions were 0.27% ± 1.66% and 0.90% ± 1.78% ( P = 0.056), and were −0.76% ± 1.47% and 0.37% ± 1.34% in low-dose regions ( P = 0.000), for W1 and A19, respectively. For VMAT SRS plans, the average differences between measurements and TPS were −0.19% ± 0.96% and −0.59% ± 1.49% for W1 and A16 with no statistical difference ( P = 0.231). Conclusion: W1 showed comparable performance with application-dedicated detectors in point dose measurements for both conventional IMRT and VMAT SRS techniques. It is a potential one-stop solution for general radiotherapy platforms that deliver both IMRT and SRS plans.

scholarly journals Major Depressive Disorder (MDD) and Antidepressant Medication Are Overrepresented in High-Dose Statin Treatment

2021 ◽  
Vol 8 ◽  
Author(s):  
Leutner Michael ◽  
Matzhold Caspar ◽  
Kautzky Alexander ◽  
Kaleta Michaela ◽  
Thurner Stefan ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Inpatient Care ◽  
Low Dose ◽  
Antidepressant Medication ◽  
Statin Treatment ◽  
High Dose ◽  
Major Depressive ◽  
Dependent Relationship ◽  
Different Types ◽  
Dose Dependent

Objective: To examine the dose-dependent relationship of different types of statins with the occurrence of major depressive disorder (MDD) and prescription of antidepressant medication.Methods: This cross-sectional study used medical claims data for the general Austrian population (n = 7,481,168) to identify all statin-treated patients. We analyzed all patients with MDD undergoing statin treatment and calculated the average defined daily dose for six different types of statins. In a sub-analysis conducted independently of inpatient care, we investigated all patients on antidepressant medication (statin-treated patients: n = 98,913; non-statin-treated patients: n = 789,683). Multivariate logistic regression analyses were conducted to calculate the risk of diagnosed MDD and prescription of antidepressant medication in patients treated with different types of statins and dosages compared to non-statin-treated patients.Results: In this study, there was an overrepresentation of MDD in statin-treated patients when compared to non-statin-treated patients (OR: 1.22, 95% CI: 1.20–1.25). However, there was a dose dependent relationship between statins and diagnosis of MDD. Compared to controls, the ORs of MDD were lower for low-dose statin-treated patients (simvastatin>0– < =10 mg:OR: 0.59, 95% CI: 0.54–0.64; atorvastatin>0– < =10 mg:OR:0.65, 95%CI: 0.59–0.70; rosuvastatin>0– < =10 mg:OR: 0.68, 95% CI: 0.53–0.85). In higher statin dosages there was an overrepresentation of MDD (simvastatin>40– < =60 mg:OR: 2.42, 95% CI: 2.18–2.70, >60–80 mg:OR: 5.27, 95% CI: 4.21–6.60; atorvastatin>40– < =60 mg:OR: 2.71, 95% CI: 1.98–3.72, >60– < =80 mg:OR: 3.73, 95% CI: 2.22–6.28; rosuvastatin>20– < =40 mg:OR: 2.09, 95% CI: 1.31–3.34). The results were confirmed in a sex-specific analysis and in a cohort of patients taking antidepressants, prescribed independently of inpatient care.Conclusions: This study shows that it is important to carefully re-investigate the relationship between statins and MDD. High-dose statin treatment was related to an overrepresentation, low-dose statin treatment to an underrepresentation of MDD.

Acetaminophen: Neonatal hepatotoxicity due to late pregnancy exposure

1987 ◽  
Vol 45 ◽  
pp. 718-719
Author(s):  
G.A. Miranda ◽  
M.A. Arroyo ◽  
C.A. Lucio ◽  
M. Mongeotti ◽  
S.S. Poolsawat
Keyword(s):  
Low Dose ◽  
Fetal Liver ◽  
Late Pregnancy ◽  
Toxic Chemicals ◽  
Control Group ◽  
High Dose ◽  
Over The Counter ◽  
Liver And Kidney ◽  
Neonatal Liver ◽  
Childbearing Women

Exposure to drugs and toxic chemicals, during late pregnancy, is a common occurrence in childbearing women. Some studies have reported that more than 90% of pregnant women use at least 1 prescription; of this, 60% used more than one. Another study indicated that 80% of the consumed drugs were not prescribed, and of this figure, 95% were “over-the-counter” drugs. Acetaminophen, the safest of all over-the-counter drugs, has been reported to induce fetal liver necrosis in man and animals and to have abortifacient and embryocidal action in mice. This study examines the degree to which acetaminophen affects the neonatal liver and kidney, when a fatty diet is simultaneously fed to the mother during late pregnancy.Timed Swiss Webster female mice were gavaged during late pregnancy (days 16-19) with fat suspended acetaminophen at a high dose, HD = 84.50 mg/kg, and a low dose, LD = 42.25 mg/kg; a control group received fat alone.

Evaluation of hippocampus in rhesus monkeys after chronic (1-year) inhalation exposure to marijuana: I. Electron microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 398-399
Author(s):  
A.M. Andrews ◽  
S.W. Wilson ◽  
A.C. Scallet ◽  
S.F. Ali ◽  
J. Bailey ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Rhesus Monkeys ◽  
Low Dose ◽  
Inhalation Exposure ◽  
Synaptic Cleft ◽  
High Dose ◽  
Withdrawal Time ◽  
Treatment Groups ◽  
Ultrastructural Evidence ◽  
Male Rhesus

Exposure of rhesus monkeys (Macaca mulatta) to marijuana via inhalation or to intravenous delta-9-tetrahydrocannabinol (THC), reportedly caused ultrastructural evidence of increased synaptic width. Chronic marijuana smoke in a single rhesus monkey examined after a six month withdrawal time caused ultrastructure changes in the septal, hippocampal and amygdala regions; the synaptic cleft was widened, electron opaque material was found in the cleft and in the pre- and postsynaptic regions, with some clumping of the synaptic vesicles. The objective of our study was to assess neuropathological alterations produced by chronic inhalation of marijuana smoke.Nineteen male rhesus monkeys, 3-5 years of age and weighing 3-8 kg, were divided into four treatment groups: a) sham control, b) placebo smoke (7 days/ week) c) low dose marijuana (2 times/week with 5 days/week sham) and d) high dose marijuana (7 times/week). A smoke exposure consisted of smoke from one cigarette (2.6% THC) burned down to 10 mm butt length. Smoke was administered via smoke generator (ADL II, Arthur D. Little, Inc. Cambridge, MA) and nose-mouth only masks (local production) equipped with one-way valves.

The Acute Effect of Alcohol on Various Memory Processes

2010 ◽  
Vol 24 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Márk Molnár ◽  
Roland Boha ◽  
Balázs Czigler ◽  
Zsófia Anna Gaál
Keyword(s):  
Low Dose ◽  
Short Term Memory ◽  
Acute Effect ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Processes ◽  
Different Types ◽  
The Brain ◽  
Legal Consequences

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.

Benefit/Risk Profile of Combined Antiplatelet Therapy with Ticlopidine and Aspirin

1991 ◽  
Vol 65 (05) ◽  
pp. 504-510 ◽  
Author(s):  
Raffaele De Caterina ◽  
Rosa Sicari ◽  
Walter Bernini ◽  
Guido Lazzerini ◽  
Giuliana Buti Strata ◽  
...  
Keyword(s):  
Platelet Function ◽  
Low Dose ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Stable Coronary Artery Disease ◽  
High Dose ◽  
Single Drug ◽  
Before And After ◽  
Serum Thromboxane ◽  
Artery Disease

SummaryTiclopidine (T) and aspirin (ASA) are two antiplatelet drugs both capable of prolonging bleeding time (BT), with a different mechanism of action. A synergism in BT prolongation has been reported and is currently considered an argument for not recommending their combination. However, a profound suppression of platelet function might be a desirable counterpart of a marked prolongation of BT, with a possible use in selected clinical situations. We therefore studied ex vivo platelet function (aggregation by ADP 0.5-1-2.5 μM; adrenaline 0.75-2.5 μM; collagen 1.5-150 μg/ml; arachidonic acid 1 mM; PAF 1 μM; adrenaline 0.17 μM + ADP 0.62 μM; serum thromboxane ([TX]B2 generation) and BT (Mielke) in 6 patients with stable coronary artery disease receiving such combination. Patients underwent sequential laboratory evaluations at baseline, after 7 days of T 250 mg b.i.d., before and after the intravenous administration of ASA 500 mg, respectively, and, finally, after a minimum of 7 days of sole ASA oral administration (50 mg/day). The experimental design, therefore, allowed a comparison of T and ASA effects (2nd and 4th evaluation), and an assessment of the combination effect (3rd evaluation). Platelet aggregation in response to all doses of ADP was depressed more by T than by ASA. Conversely, responses to adrenaline, and arachidonate were affected more by ASA than by T. For all other agents, differences were not significant. T + ASA combination was more effective (p <0.05) than either treatment alone in depressing responses to high-dose collagen (% over control, mean ± SEM: T: 95 ± 3; ASA: 96 ± 5; T + ASA: 89 ± 4). Serum TXB2 (basal, ng/ml: 380 ± 54) did not change with T (372 ± 36), dropped to <1 ng/ml on ASA injection and slightly re-increased to 9.1 ± 3.1 ng/ml on oral low-dose ASA. BT (basal 7.4 ± 0.6 min) was affected similarly by T (9.2 ± 0.8) or ASA (9.7 ± 0.9) alone, but increased to 15.0 ± 0.7 min on combination treatment (106% increase over control). Thus, the strong synergism in BT prolongation by ASA-T combination has a counterpart in the inhibition of platelet function in response to strong stimuli such as high-dose collagen, not otherwise affected significantly by single-drug treatment. This effect is a possible rationale for the clinical evaluation of T + ASA combination.

Intensive Initial Oral Anticoagulation and Shorter Heparin Treatment in Deep Vein Thrombosis

1984 ◽  
Vol 52 (03) ◽  
pp. 276-280 ◽  
Author(s):  
Sam Schulman ◽  
Dieter Lockner ◽  
Kurt Bergström ◽  
Margareta Blombäck
Keyword(s):  
Deep Vein Thrombosis ◽  
Oral Anticoagulation ◽  
Dose Group ◽  
Low Dose ◽  
Clinical Signs ◽  
Coagulation Factor ◽  
High Dose ◽  
Vein Thrombosis ◽  
Heparin Treatment ◽  
Deep Vein

SummaryIn order to investigate whether a more intensive initial oral anticoagulation still would be safe and effective, we performed a prospective randomized study in patients with deep vein thrombosis. They received either the conventional regimen of oral anticoagulation (“low-dose”) and heparin or a more intense oral anticoagulation (“high-dose”) with a shorter period of heparin treatment.In the first part of the study 129 patients were randomized. The “low-dose” group reached a stable therapeutic prothrombin complex (PT)-level after 4.3 and the “high-dose” group after 3.3 days. Heparin was discontinued after 6.0 and 5.0 days respectively. There was no difference in significant hemorrhage between the groups, and no clinical signs of progression of the thrombosis.In the second part of the study another 40 patients were randomized, followed with coagulation factor II, VII, IX and X and with repeated venograms. A stable therapeutic PT-level was achieved after 4.4 (“low-dose”) and 3.7 (“high-dose”) days, and heparin was discontinued after 5.4 and 4.4 days respectively. There were no clinical hemorrhages, the activity of the coagulation factors had dropped to the same level in both groups at the time when heparin was discontinued and no thromboembolic complications occurred.Our oral anticoagulation regimen with heparin treatment for an average of 4.4-5 days seems safe and reduces in-patient costs.

Effects of Aspirin and Sulfinpyrazone on Thromboxane and Prostacyclin Synthesis in Rabbits

1979 ◽  
Author(s):  
J McDonald ◽  
A Cerskus ◽  
M Ali
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Low Dose ◽  
High Dose ◽  
Prostacyclin Synthesis

Arachidonic acid (AA) or collagen were infused into rabbits causing intravascular platelet aggregation with thrombocytopenia, hypotension and death. Thromboxane and prostacyclin synthesis were measured by radioimmunoassay of plasma TXB2 and 6-keto-PGF1α. The effects of pretreatement with aspirin (ASA) or sulfinpyrazone(SPZ) were assessed.Death in drug-treated rabbits was always associated with elevations of plasma TXB2(1-40 ng/ml) and of 6-keto-PGF1α(1-20 ng/ml). Collagen produced only small elevations of plasma TXB2 compared to AA but protection by ASA correlated better with inhibition of TXB2 and 6-keto-PGF1α synthesis than with inhibition of aggregation. Low dose ASA produced less inhibition of prostacyclin synthesis than high dose ASA but was less effective in preventing thromboxane synthesis and death.

LOW-DOSE-RATE OR HIGH-DOSE-RATE BRACHYTHERAPY IN COMBINATION WITH EXTERNAL BEAM RADIOTHERAPY FOR INTERMEDIATE AND HIGH-RISK PROSTATE CANCER

2018 ◽  
Vol 64 (1) ◽  
pp. 79-83
Author(s):  
Vladimir Solodkiy ◽  
Andrey Pavlov ◽  
Aleksey Tsybulskiy ◽  
Anton Ivashin
Keyword(s):  
Prostate Cancer ◽  
High Risk ◽  
Dose Rate ◽  
Low Dose ◽  
External Beam Radiotherapy ◽  
Combined Treatment ◽  
High Dose ◽  
External Beam ◽  
Low Dose Rate ◽  
Risk Of Progression

Introduction. One of the main problems of modem on-courology is treatment for prostate cancer of intermediate and high risk of progression. Modern radiotherapy in this category of patients has an advantage over surgical methods of treatment. One way to improve the effectiveness of radiotherapy is to escalate the dose in the prostate gland. For this purpose a combination of brachytherapy and remote radiotherapy is used. This combination allows increasing the dose of radiation, thereby providing better local control, reducing complications from neighboring organs. Purpose of the study. To conduct a comparative analysis of efficacy and safety of radical treatment of patients with prostate cancer at medium and high risk of progression using a combination of high and low dose rate brachytherapy with external beam radiotherapy. Materials and methods. 107 patients with prostate cancer of the group of medium and high risk of progression combined treatment (brachytherapy with external beam radiotherapy) was conducted. 53 patients underwent combined treatment (HDR-brachytherapy and external beam radiotherapy). 54 patients underwent combined treatment (LDR-brachytherapy and external beam radiotherapy). The observation period was 5 years. Conclusion. In a comparative analysis in groups of combined radiotherapy with the use of high-dose and low-dose-rate brachytherapy, the same effectiveness of immediate and long-term results of treatment was demonstrated. A significant reduction in early and late toxic reactions in patients with high-power brachytherapy has been demonstrated.

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