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A novel analytical method based on ultra-fast liquid chromatography using fluorimetric detector was developed and validated for determination of non-steroidal anti-inflammatory drugs (NSAIDs) (ibuprofen (IBP), etodolac (ETD), dexketoprofen (DKP), sodium diclofenac (SDCF), and naproxen (NPX) in tap water, urine and pharmaceutical samples. Precolumn derivatisation of targeted NSAIDs was carried out with 4-bromomethyl-7-methoxy coumarin (BrMmC) using dibenzo-18-crown-6-ether as reaction catalyst leading to the formation of a fluorescent compound. The obtained fluorescent compound of NSAIDs were measured at excitation wavelength as 325 nm, and emission wavelength of 395 nm. Optimum analytical conditions were carefully studied and improved. C18 column, with the dimensions of 4.0 × 100 mm and 3 µm particle size, was used. Gradient elution with methanol: water 40:60; v/v (eluent A) and acetonitrile 100% (eluent B) were used as mobile phase and flow rate of 0.4 mL/min. The linearity range of the analytes were between 0.01–10.0 µg mL−1. Recovery values obtained from pharmaceutical preparations were found as 100.04%, 99.99%, 100.09%, 99.98% and 100.47% for IBP, ETO, DKP, SDCF, NPX, respectively. LOD values were found to vary between 0.00009 µg mL−1 and 0.00048 µg mL−1 in tap water, urine and pharmaceutical samples. The optimised technique was successfully applied for the determination of NSAIDs in tap water, urine, and pharmaceutical specimen. The specified NSAIDs were not found in real tap water samples. [ABSTRACT FROM AUTHOR]

Background/Aim: To compare implant sparing irradiation with conventional radiotherapy (RT) using helical (H) and TomoDirect (TD) techniques in breast cancer patients undergoing immediate breast reconstruction (IBR). Patients and Methods: The dosimetric parameters of 40 patients with retropectoral implants receiving 50.4 Gy delivered in 28 fractions were analyzed. Three plans were created: H plan using conventional planning target volume (PTV) that included the chest wall, skin, and implant; TD plan using conventional PTV; and Hs plan using implantsparing PTV. The H, TD, and Hs plans were compared for PTV doses, organ-at-risk (OAR) doses, and treatment times. Results: Dose distribution in the Hs plan was less homogeneous and uniform than that in the H and TD plans. The TD plan had lower lung, heart, contralateral breast, spinal cord, liver, and esophagus doses than the Hs plan. Compared to the Hs plan, the H plan had lower lung volume receiving 5Gy (V5) (39.1±3.9 vs. 41.2±3.9 Gy; p<0.001), higher V20 (12.3±1.3 vs. 11.5±2.6 Gy; p=0.02), and higher V30 (7.5±1.6 vs. 4.4±1.7 Gy; p<0.001). H plan outperformed Hs plan in heart dosimetric parameters except V20. The Hs plan had significantly lower mean implant doses (43.4±2.1 Gy) than the H plan (51.4±0.5 Gy; p<0.001) and the TD plan (51.9±0.6 Gy; p<0.001). Implementing an implant sparing technique for silicone dose reduction decreases lung doses. Conclusion: Conventional H and TD plans outperform the implant sparing helical plan dosimetrically. Because capsular contracture during RT is unpredictable, long-term clinical outcomes are required to determine whether silicon should be spared. [ABSTRACT FROM AUTHOR]

Background: We analyzed a dose escalation of 36.25 Gy to the entire prostate and a dose increment up to 40 Gy with 1.25 Gy increments to intraprostatic lesion (IPL) using simultaneous integrated boost (SIB) in five fractions. Materials and methods: Eighteen low- and intermediate-risk prostate cancer patients treated with 1.5T MR-Linac were retrospectively evaluated. The same planning computed tomography (CT) images generated four plans: no SIB, 37.5 Gy SIB, 38.75 Gy SIB, and 40 Gy SIB. In four plans, planning target volume (PTV) doses, organ at risk (OAR) doses, and PTV-SIB homogeneity index (HI), gradient index (GI) and conformity index (CI) were compared. Results: All plans met the criteria for PTV and PTV-SIB coverage. PTV 40 Gy plan has higher maximum PTV and PTV-SIB doses than other plans. The PTV HI was significantly higher in the SIB 40 Gy plan (0.135 ± 0.007) compared to SIB 38.75 Gy plan (0.099 ± 0.007; p = 0.001), SIB 37.5 Gy (0.067 ± 0.008; p < 0.001), and no SIB plan (0.049 ± 0.010; p < 0.001), while there were no significant differences in HI, GI and CI for PTV-SIB between three plans. Four rectum and bladder plans had similar dosimetric parameters. The urethra D5 was significantly higher in SIB 40 Gy plan compared to no SIB plan (37.7 ± 1.1 Gy vs. 37.0 ± 0.7 Gy; p = 0.009) and SIB 37.5 Gy plan (36.9 ± 0.8 Gy; p = 0.008). There was no significant difference in monitor units between the four consecutive plans. Conclusions: Ultra-hypofractionated dose escalation to IPL up to 40 Gy in 5 fractions with a 1.5-T MR-linac is dosimetrically feasible, potentially paving the way for clinical trials. [ABSTRACT FROM AUTHOR]

Background: We examined the effects of reducing the planning target volume (PTV) margin in MR‐guided radiotherapy (MRgRT) on the distribution of radiation dose to target volumes and organs‐at‐risk (OARs). Thus, we compared MR‐Linac (MRL) plans with and without reduced margin and intensity‐modulated radiotherapy (IMRT) plan with conventional linac for low‐risk prostate cancer patients receiving 36.25 Gy in five fractions of ultra‐hypofractionated radiation therapy. Materials and Methods: Twenty low‐risk prostate cancer patients treated with 1.5 T MR‐Linac were evaluated. The same planning CT images were used for four plans: the MRL‐R plan with reduced margin planning target volume (PTV‐R) and the MRL‐N plan with normal margin PTV (PTV‐N), which is also used for IMRT plan. In four plans, PTV doses, organs‐at‐risk (OARs) doses, the homogeneity index (HI), and monitor units were compared. Results: All plans met the criteria for PTV coverage and OARs dose constraints. The maximum and mean PTV doses were significantly higher in the MRL‐R and MRL‐N plans compared to the IMRT plan. The HI was lowest in the IMRT plan (0.040 ± 0.013) and highest in the MRL‐N plan (0.055 ± 0.012; p < 0.001). There was no significant difference in the PTV dosimetric parameters between the MRL‐R and the MRL‐N plans. The high doses in the rectum was significantly lower in the MRL‐R compared to other plans. The bladder V36.25 Gy was significantly lower in the MRL‐R plan (2.43 ± 1.87 Gy) compared to MRL‐N (4.50 ± 2.42 Gy; p < 0.001), and IMRT plans (4.76 ± 2.77 Gy; p < 0.001). There was no significant difference in the low‐dose volumes of the body, maximum femur doses, or monitor units across each plan. Conclusions: Ultra‐hypofractionated MR‐guided RT with 1.5 T MRL is dosimetrically feasible for patients with prostate cancer. The improved soft tissue contrast and the online adaptive plan for 1.5 T MR‐Linac allows for PTV margin reduction resulted in a significant dose reduction in OARs. [ABSTRACT FROM AUTHOR]