Current Issue : October - December Volume : 2017 Issue Number : 4 Articles : 6 Articles
Background.Many studies have demonstrated that a higher radiotherapy dose is associated with improved outcomes in non-smallcell\nlung cancer (NSCLC). We performed a dosimetric planning study to assess the dosimetric feasibility of intensity-modulated\nradiation therapy (IMRT) with a simultaneous integrated boost (SIB) in locally advanced NSCLC. Methods. We enrolled twenty\npatients. Five different dose plans were generated for each patient. All plans were prescribed a dose of 60Gy to the planning tumor\nvolume (PTV). In the three SIB groups, the prescribed dose was 69Gy, 75Gy, and 81Gy in 30 fractions to the internal gross tumor\nvolume (iGTV). Results. The SIB-IMRT plans were associated with a significant increase in the iGTV dose (P < 0.05), without\nincreased normal tissue exposure or prolonged overall treatment time. Significant differences were not observed in the dose to the\nnormal lung in terms of the V5 and V20 among the four IMRT plans.The maximum dose (Dmax) in the esophagus moderately\nincreased along with the prescribed dose (P < 0.05). Conclusions. Our results indicated that escalating the dose by SIB-IMRT is\ndosimetrically feasible; however, systematic evaluations via clinical trials are still warranted. We have designed a further clinical\nstudy (which is registered with ClinicalTrials.gov, number NCT02841228)....
Background: Current pressurised metered dose asthma inhaler (pMDI) propellants are not inert pharmacologically\nas were previous chlorofluorocarbons, have smooth muscle relaxant� partial pressure effects in the lungs and inhaled\nhydrofluoroalkane 134a (norflurane) has anaesthetic effects. Volumes of propellant gas per actuation have never been\nmeasured.\nMethods: In-vitro studies measured gas volumes produced by pMDIs on air oxygen (O2) levels in valved holding\nchambers (VHC) and the falls in O2% following actuation into lung ventilator delivery devices.\nResults: Volumes of propellant gas hydrofluoroalkane (HFA) 134a and 227ea and redundant chlorofluorocarbons\n(CFC) varied from 7 ml per actuation from a small salbutamol HFA inhaler to 16 ml from the larger. Similar-sized CFC\npMDI volumes were 15.6 and 20.4 ml. Each HFA salbutamol inhaler has 220 full volume discharges; total volume of\ngas from a small 134a pMDI was 1640 ml, and large 3885 ml. Sensing the presence of liquid propellant by shaking\nwas felt at the 220th discharge in both large and small inhalers. Because of a partial pressure effect, VHC O2% in air\nwas reduced to 11% in the smallest 127 ml volume VHC following 10 actuations of a large 134a salbutamol inhaler.\nThe four ventilator delivery devices studied lowered 100% oxygen levels to a range of 93 to 81% after five actuations,\ndepending on the device and type of pMDI used.\nConclusion: Pressurised inhaler propellants require further study to assess smooth muscle relaxing properties....
Background: Asthma management may involve a step up in treatment when symptoms are not well controlled.\nWe examined whether budesonide/formoterol maintenance and reliever therapy (MRT) is as effective as higher,\nfixed-dose budesonide plus as-needed terbutaline in patients requiring step-up from Step 2 treatment (low-dose\ninhaled corticosteroids), stratified by baseline reliever use.\nMethods: A post-hoc analysis utilized data from three clinical trials of 6ââ?¬â??12 monthsââ?¬â?¢ duration. Patients aged ââ?°Â¥12 years\nwith symptomatic asthma uncontrolled despite Step 2 treatment were included. Severe exacerbation rate, lung function\nand reliever use were analysed, stratified by baseline reliever use (<1, 1ââ?¬â??2 and >2 occasions/day).\nResults: Overall, 1239 patients were included. Reductions in severe exacerbation rate with budesonide/formoterol MRT\nversus fixed-dose budesonide were similar across baseline reliever use levels, and were statistically significant in patients\nusing 1ââ?¬â??2 (42%, p = 0.01) and >2 (39%, p = 0.02) reliever occasions/day, but not <1 reliever occasion/day (35%, p = 0.11).\nBoth treatments significantly increased mean FEV1 from baseline; improvements were significantly greater for\nbudesonide/formoterol MRT in all reliever use groups. Reductions in reliever use from baseline were significantly greater\nwith budesonide/formoterol MRT versus fixed-dose budesonide in patients using 1ââ?¬â??2 and >2 reliever occasions/day\n(âË?â??0.33 and âË?â??0.74 occasions/day, respectively).\nConclusions: Treatment benefit with budesonide/formoterol MRT versus higher, fixed-dose budesonide plus short-acting\nÃ?²2-agonist was found in Step 2 patients with relatively low reliever use, supporting the proposal that budesonide/\nformoterol MRT may be useful when asthma is uncontrolled with low-dose inhaled corticosteroid....
Background: The decrease in peripheral blood lymphocytes induced by radiation lessens the antitumour effect of\nthe immune response, which might cause immunosuppression. We aimed to investigate the correlation between\nthe decrease in peripheral blood lymphocytes during radiotherapy (RT) and the spleen irradiation dose in patients\nwith hepatocellular carcinoma (HCC).\nMethods: The subjects were 59 patients with HCC who had received RT from 2005 to 2014. The Min ALC\n(minimum value of absolute counts for peripheral blood lymphocytes) was collected from the routine workup for\neach patient prior to RT and weekly during RT. Spleen dose-volume variables, including the percentage of the\norgan volume receiving �n Gy (Vn) and the mean spleen dose (MSD), were calculated using Eclipse treatment\nplanning. Potential associations between dosimetric variables and the Min ALC were assessed by multiple linear\nregression analysis.\nResults: Peripheral lymphocytes decreased during RT (P < 0.001). The Min ALC correlated with the MSD (P = 0.005),\nspleen V5 (P = 0.001), spleen V25 (P = 0.026) and spleen V30 (P = 0.018). Controlling for the Karnofsky performance\nstatus (KPS), sex, age, Child-Pugh grade, total dose and tumour stage, a multiple linear regression model with\nbootstrap analysis of 1000 replicates showed that only the spleen V5 was correlated with the decrease in the Min\nALC (P < 0.05). According to the receiver-operating characteristic (ROC) curve analysis, the predictive cutoff values of\nthe MSD, V5, V25 and V30 of the spleen for the Min ALC were 227.72 cGy, 17.84, 0.98 and 0.42%, respectively\n(P = 0.002, P = 0.004, P = 0.007 and P = 0.002, respectively). Furthermore, an MSD � 227.72 cGy (OR = 14.39; 95% CI,\n12.18 to 16.60) and V5 (OR = 7.99; 95% CI, 6.91 to 9.07) of the spleen significantly predicted the Min ALC.\nConclusions: Higher spleen irradiation doses were significantly correlated with lower Min ALC during RT for HCC.\nV5 should be limited in clinical practice. Maximum sparing for spleen irradiation during RT is recommended to\npreserve peripheral blood lymphocytes, which may decrease immunosuppression....
Background: The efficacy of corticosteroid use in acute respiratory distress syndrome (ARDS) remains controversial.\nGenerally, short-term high-dose corticosteroid therapy is considered to be ineffective in ARDS. On the other hand, lowdose,\nlong-term use of corticosteroids has been reported to be effective since they provide continued inhibition of the\nsystemic inflammatory response syndrome (SIRS) that accompanies ARDS. Thus far, no reports have been published on\nthe efficacy of initiating treatment with a high-dose corticosteroid regimen with tapering.\nMethods: We conducted a retrospective observational study involving 186 patients treated at a teaching\nhospital (68% had sepsis, pneumonia, or aspiration pneumonia). ARDS was diagnosed according to the Berlin\ndefinition. Patients were divided into a high-dose (n = 21) or low-dose corticosteroid group (n = 165) to compare the\neffectiveness of a down-titration regimen. The primary medical team chose which treatment a patient would receive.\nWe were careful to conduct a differential diagnosis of interstitial pneumonia (e.g., acute eosinophilic pneumonia) since\ncorticosteroid treatment has been proven effective in that patient population. The primary outcome was the 60-day\nmortality rate. The secondary outcome was the number of ventilator-free days (VFD).\nResults: Those started on a high-dose regimen had a significantly higher 60-day mortality rate (P = 0.031) with\nsignificantly fewer VFD (P = 0.021). Propensity scores were used to adjust patient backgrounds in a variable analysis that\nalso showed the high-dose regimen was a factor in decreasing VFD (OR, 95.63; 95% CI, 1.74ââ?¬â??5271.07; P = 0.026) and\nworsening the 60-day mortality rate (OR, 2.54; 95% CI, 0.92ââ?¬â??7.02; P = 0.072).\nConclusions: A tapering regimen after high-dose corticosteroids is likely to increase ventilator dependency and might\naggravate the prognosis of patients with ARDS diagnosed according to the Berlin definition....
Background: Lung cancer patients are often in poor physical condition, and a shorter treatment time would reduce\ntheir discomfort. Dynamic conformal arc therapy (DCAT) offers a shorter treatment time than conventional 3D\nconformal radiotherapy (3D CRT) and is usually available even in departments without inverse planning possibilities.\nWe examined its suitability as a treatment modality for lung cancer patients.\nMethods: On a cohort of 35 lung cancer patients, relevant dosimetric parameters were compared in respective DCAT\nand 3D CRT treatment plans. Radiochromic film dosimetry in an anthropomorphic phantom was used to compare\nboth DCAT and 3D CRT dose distributions against their planned counterparts.\nResults: In comparison with their 3D CRT counterparts, DCAT plans equal or exceed the agreement between the\ncalculated dose and the dose measured using film dosimetry. In dosimetric comparison, DCAT performed significantly\nbetter than 3D CRT in dose conformity to PTV and the number of monitor units used per plan, and significantly worse\nin dose homogeneity, mean lung dose and lung volume exposed to 5 Gy or more (V5Gy). No significant difference\nwas found in the V20Gy value to lung, dose to 1 cm3 of spinal cord, and the mean dose to oesophagus.\nImprovements in V20Gy and V5Gy were found to be negatively correlated. DCAT plans differ from 3D CRT by\nexhibiting a moderate negative correlation between target volume sphericity and dose homogeneity.\nConclusions: With respect to the agreement between the planned and the irradiated dose distribution, DCAT\nappears at least as reliable as 3D CRT. In specific conditions concerning the patient anatomy and treatment\nprescription, DCAT may yield more favourable dosimetric parameters. On average, however, conventional 3D CRT\nusually obtains better dosimetric parameters. We can thus only recommend DCAT as a complementary technique to\nthe conventional 3D CRT....
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