Single-isocenter stereotactic non-coplanar arc treatment of 200 patients with brain metastases: multileaf collimator size and setup uncertainties

Purpose The purpose of this study was to evaluate our 2 years’ experience with single-isocenter, non-coplanar, volumetric modulated arc therapy (VMAT) for brain metastasis (BM) stereotactic radiosurgery (SRS). Methods A total of 202 patients treated with the VMAT SRS solution were analyzed retrospectively. Plan quality was assessed for 5 mm (120) and 2.5 mm (high-definition, HD) central leaf width multileaf collimators (MLCs). For BMs at varying distances from the plan isocenter, the geometric offset from the ideal position for two image-guided radiotherapy workflows was calculated. In the workflow with ExacTrac (BrainLAB, München, Germany; W‑ET), patient positioning errors were corrected at each couch rotation. In the workflow without ExacTrac (W-noET), only the initial patient setup correction was considered. The dose variation due to rotational errors was simulated for multiple-BM plans with the HD-MLC. Results Plan conformity and quality assurance were equivalent for plans delivered with the two MLCs while the HD-MLC plans provided better healthy brain tissue (BmP) sparing. 95% of the BMs had residual intrafractional setup errors ≤ 2 mm for W‑ET and 68% for W‑noET. For small BM (≤1 cc) situated >3 cm from the plan isocenter, the dose received by 95% of the BM decreased in median (interquartile range) by 6.3% (2.8–8.8%) for a 1-degree rotational error. Conclusion This study indicates that the HD-MLC is advantageous compared to the 120-MLC for sparing healthy brain tissue. When a 2-mm margin is applied, W‑noET is sufficient to ensure coverage of BM situated ≤ 3 cm of the plan isocenter, while for BM further away, W‑ET is recommended.

A Plan Robustness Qualification Method of Volumetric Arc Radiotherapy (VMAT) of Set Up Uncertainty in Nasopharyngeal Carcinoma (NPC) Radiotherapy

Purpose: To evaluate the set-up sensitivity of VMAT plans for Nasopharyngeal carcinoma (NPC) treatment by proposing a plan robustness evaluation method. Methods: 10 patients were selected for this study. A 2-arc volumetric-modulated arc therapy (VMAT) plan was generated for each patient using Varian Eclipse (13.6 Version) treatment planning system (TPS). 5 uncertainty plans (U-plans) were calculated based on the first 5 times set-up errors acquired from cone beam comuter tomography (CBCT). The dose differences and plan robustness of all the PTVs, CTVs, GTVs, and organs at risk (OARs) were analyzed. Tumor control probability (TCP) and normal tissues complication probability (NTCP) were calculated for biological evaluation. Results: The mean dose differences of D98 and D95 (△D98 and△D95) of PTVnx were respectively 3.30 Gy and 2.02 Gy. The △D98 and△D95 of CTVnx were 1.12 Gy and 0.58 Gy. The △D98 and△D95 of GTVnx were 0.56 Gy and 0.33 Gy. The dose coverage of GTVnx and CTVnx was guaranteed with minor dose variation. GTVnd exhibited strong robustness with little variation of D98 (0.5%) and D95 (0.9%). The △D98 and△D95 of CTVnd were 1.39 Gy and 1.03 Gy, distinctively lower than those in PTVnd (2.8 Gy and 2.0 Gy). No marked mean dose variations of Dmean were seen. The mean reduction of TCP (△TCP) in GTVnx and CTVnx were respectively 0.4% and 0.3%. The mean △TCP of GTVnd and CTVnd were 0.92 % and 1.3 % respectively. The CTV exhibited the largest △TCP (2.2 %). In OARs, the optical nerve chiasma was the one with the highest change, with a mean dose variation of 8.81 Gy. The Dmean of bilateral parotids varied in a large range. The mean reduction of NTCP (△NTCP) in the left parotid gland was 13.30%, which sharply increased the risk of parotid gland dysfunction. Conclusion: VMAT plans had a strong sensitivity to set-up uncertainty in NPC radiotherapy, due to the high degree of modulation. We proposed an effective method to evaluate the plan robustness of VMAT plans. Plan robustness and complexity should be taken into account in photon radiotherapy.

Photocatalytic Detoxification of Antibiotic- and Bacteria-Contaminated Water using Cobalt-Doped Ni–Zn Ferrites Magnetic Separable Nanopowders

Here, metronidazole (MZ) antibiotic degradation and bactericidal efficacy of Co–Ni0.5Zn0.5Fe2O4 (Co–NZF) with and without photoactivation by UV light is reported as a viable cost-competitive water disinfection solution. Co–NZF has a total pore volume of 0.298 cm3 g− 1, a specific surface area of 70.2 m2 g− 1 and sufficiently high magnetic properties (80.35 emu g− 1). After 360 min of UV–assisted irradiation at pH 3, 10 mg Co–NZF, and 4 mM H2O2, the maximum MZ degradation was reached (92.8%). The adsorption result of 10 mg Co–NZF in the dark for 12 h resulted in 70.2% MZ removal, whereas MZ self-degradation was significantly minimal in a blank trial. In the presence of interfering anions and very high molecular weight tylosin antibiotic, Co–NZF maintained 51.7–75.4% degradation efficiency. The effect of the Co–NZF dosage on the viability of Staphylococcus aureus and Escherichia coli strains showed that 15 mg of the catalyst was sufficient to cause bactericidal activity after 180 min in the presence of UV light, while 25 mg is needed under dark conditions. In addition, when compared to Escherichia coli strains, Co–NZF showed higher inhibition against Staphylococcus aureus in time-kill experiments under dose variation.

A Comparison of the Distortion in the Same Field MRI and MR-Linac System With a 3D Printed Phantom

PurposeA 3D printed geometric phantom was developed that can be scanned with computed tomography (CT) and magnetic resonance imaging (MRI) to measure the geometric distortion and determine the relevant dose changes.Materials and MethodsA self-designed 3D printed photosensitive resin phantom was used, which adopts grid-like structures and has 822 1 cm2 squares. The scanning plan was delivered by three MRI scanners: the Elekta Unity MR-Linac 1.5T, GE Signa HDe 1.5T, and GE Discovery-sim 750 3.0T. The geometric distortion comparison was concentrated on two 1.5T MRI systems, whereas the 3.0T MRI was used as a supplemental experiment. The most central transverse images in each dataset were selected to demonstrate the plane distortion. Some mark points were selected to analyze the distortion in the 3D direction based on the plane geometric distortion. A treatment plan was created with the off-line Monaco system.ResultsThe distortion increases gradually from the center to the outside. The distortion range is 0.79 ± 0.40 mm for the Unity, 1.31 ± 0.56 mm for the GE Signa HDe, and 2.82 ± 1.48 mm for the GE Discovery-sim 750. Additionally, the geometric distortion slightly affects the actual planning dose of the radiotherapy.ConclusionGeometric distortion increases gradually from the center to the outside. The distortion values of the Unity were smaller than those of the GE Signa HDe, and the Unity has the smallest geometric distortion. Finally, the Unity’s dose variation best matched with the standard treatment plan.

effectiveness testing of l-carnitine on the quality of spermatozoa and testosterone hormone in white rats (Rattus norvegicus) feeding with high fat

This study aims to determine the increase in the quality of spermatozoa and testosterone after giving L-carnitine to white rats (Rattus norvegicus). This study was conducted by giving L-carnitine as a treatment for 42 days in white rats with a dose variation of 100 mg/kg bw, 150 mg/kg bw, and 200 mg/kg bw and user controls as a comparison. The variables observed in this study were the quality of spermatozoa, namely: morphology, motility, viability, membrane integrity, and seeing the levels of the hormone testosterone. The research data were processed using a computer statistical program (SPSS 22.0 for Windows) using the One Way Anova test. The results showed that giving high doses of L-carnitine supplements for a long time could cause decreased spermatozoa quality, namely: morphology, motility, viability, membrane integrity and decreased levels of the hormone testosterone.

Pemanfaatan Mikroalga dalam Penurunan Kadar Amonia dengan Variasi Penambahan Effective Microorganism

The existence of microalgae in water -provides many benefits especially for biological treatments of wastewater. Microalgae have many species and are chlorophyll microorganisms. Photosynthesis carried out by microalgae requires essential nutrients such as CO2. Carbon dioxide can be obtained by symbiosis from other microorganisms, such as EM4, which can be used to decompose complex organic compounds into simple compounds (CO2). The addition of EM4 must be appropriate to make the photosynthesis process in microalgae take place optimally. Therefore, this study aims to determine the optimal dose variation of EM4 in the microalgae in the reactor. With variations in the doses tested were 0 mL, 1 mL, and 2 mL. The research was conducted by making artificial wastewater from liquid NPK, diluting it with tap water with a ratio of 1: 300. The test was carried out using a batch system, with solar lighting and aeration for 24 hours. The result of the best dose variation is the addition of 1 mL of EM4. The largest decrease in ammonia levels is obtained which is then compared to the variation of the doses of 0 mL and 2 mL.

Quantitative UV-C dose validation with photochromic indicators for informed N95 emergency decontamination

With COVID-19 N95 shortages, frontline medical personnel are forced to reuse this disposable–but sophisticated–multilayer respirator. Widely used to decontaminate nonporous surfaces, UV-C light has demonstrated germicidal efficacy on porous, non-planar N95 respirators when all surfaces receive ≥1.0 J/cm2 dose. Of utmost importance across disciplines, translation of empirical evidence to implementation relies upon UV-C measurements frequently confounded by radiometer complexities. To enable rigorous on-respirator measurements, we introduce a photochromic indicator dose quantification technique for: (1) UV-C treatment design and (2) in-process UV-C dose validation. While addressing outstanding indicator limitations of qualitative readout and insufficient dynamic range, our methodology establishes that color-changing dosimetry can achieve the necessary accuracy (>90%), uncertainty (<10%), and UV-C specificity (>95%) required for UV-C dose measurements. In a measurement infeasible with radiometers, we observe a striking ~20× dose variation over N95s within one decontamination system. Furthermore, we adapt consumer electronics for accessible quantitative readout and use optical attenuators to extend indicator dynamic range >10× to quantify doses relevant for N95 decontamination. By transforming photochromic indicators into quantitative dosimeters, we illuminate critical considerations for both photochromic indicators themselves and UV-C decontamination processes.

High-dose Vitamin D Supplementation on type 1 Diabetes Mellitus Patients: is there an Improvement in Glycemic Control?

Background: Some authors evaluated the effect of VD on hyperglycemia in T1DM, but the results remain controversial. This study aims to analyze the effects of high-dose VD supplementation on T1DM patients’ glycemic levels, maintaining stable doses of insulin. Methods: Prospective, 12-week clinical trial including 67 T1DM patients, who were supplemented with high doses of cholecalciferol according to participants' VD value. Patients with VD levels below 30 ng/mL received 10,000 IU/day; those with levels between 30-60 ng/mL received 4,000 IU/day. Patients who had not achieved 25(OH)D levels > 30 ng/ml or presented insulin dose variation during the study were not analyzed. Results: Only 46 out of 67 patients accomplished the criteria at the end of the study. There was no general improvement in the glycemic control evaluated by HbA1c (9.4 ± 2.4 vs 9.4 ± 2.6, p=NS) after VD supplementation. However, a posthoc analysis, based on HbA1c variation, identified patients who had HbA1c reduced at least 0.6% (group 1, N = 13 (28%)). In addition, a correlation between 25(OH)D levels with HbA1c and total insulin dose at the end of the study was observed (r = -0.3, p<0.05; r=-0.4, p<0.05, respectively) and a regression model demonstrated that 25(OH)D was independent of BMI, duration of T1DM and final total insulin dose, being capable of determining 9.2% of HbA1c final levels (Unstandardized B coefficient = −0.033 (CI 95%: −0.064 to −0.002), r² = 0.1, p <0.05). Conclusion: Our data suggests that VD is not widely recommended for glycemic control. Nevertheless, specific patients might benefit from this approach.

Kulit Pisang Kepok (Muca Acuminate) Menurunkan Kadar Mangan (Mn) Pada Air Sumur Gali

This type of research is experimental in nature by conducting experiments with variations in the dose of banana skin kepok. The study design used was a pre test - post test control group. Data analysis uses one way Anova statistical test with α = 0.05. The population in this study was all dug well water in the working area of the Cempaka Banjarbaru Inpatient Health Center in 2020. The results of the analysis of Manganese (Mn) decreased after treatment in each dose variation, the dose of banana peel 5 mg can reduce levels of Manganese (Mn) by 6.1% while the variation of the 25 mg dose can reduce the levels of Manganese (Mn) by 83.1 %. Based on the Anova One Way statistical test results there was no significant decrease in the value of p value (0.761)> α value (0.05). It is recommended for the community to improve the quality of well water. For related agencies, it is expected to supervise well water containing Mang.