Fewer beams and segments result in a shorter delivery time and a better quality intensity-modulated radiotherapy plan in gastric cancer

Background: This study evaluated whether IMRT using fewer beams and segments could reduce delivery time without compromising plan quality in gastric cancer adjuvant radiotherapy

Materials and Methods: Fifteen patients with advanced gastric cancer who underwent D2, R0 surgery were included in this study. IMRT plans for each patient were designed as 7 equal beams with 40 segments, 5 beams with 25 segments and 4 beams with 20 segments. The dosimetric parameters were compared for the planned target volume [PTV]. The dose of normal organs at risk [OARs] was also assessed. The monitor units and treatment times of the different IMRT plans were calculated

Results: The 20-segment IMRT plan significantly reduced the PTV maximum dose compared to the 40-segment IMRT plan. The 20-segment IMRT plan improved left kidney and liver dose sparing in V20 and V30 as well as the 40-segment IMRT plan did and provided be4er protection for the V20 [13.86+/-7.78] of the right kidney, the V30 [9.25+/-4.04] of the le kidney, the D mean [19.68+/-2.47] of liver and D max [38.79+/-3.57] of the spinal cord. Irradiation times in the 20-segment and 25-segment plans decreased by 2.5 and 1.9 min, respectively, compared to the 40-segment IMRT plan

Conclusion: IMRT using fewer beams and segments reduced delivery time without compromising plan quality in gastric cancer adjuvant radiotherapy. Fewer segments IMRT plans lowered the monitor units and the treatment time

Response to hepatitis B virus vaccination in haemodialysis patients with and without hepatitis C infection

The aim of this study was to determine the efficacy of hepatitis B virus [HBV] vaccination and the response to vaccine in individuals on haemodialysis with and without HCV infection. From April 2000 to September 2003 all haemodialysis patients referred to the haemodialysis department in a Babol hospital received 4 microg vaccine intramuscularly at 0, 1, and 6 months. All were negative for HBV infection markers [HBcAb, HBsAg and HBsAb]. Of 62 patients, 53 [85.5%] responded to vaccination and 26 [49.1%] were high responders. All individuals with HCV infection responded to vaccination. Duration of haemodialysis had no effect on response to vaccination

Comparison of the solubility of conventional glass ionomer and modified cements: an in vitro study

Solubility of restorative materials leads to loss of marginal intergrity, surface properties and aesthetics. Thus, the solubility of these materials is of considerable importance. The aim of this in vitro study was to measure the solubility of two types of conventional and resin-modified restorative glass-ionomer cements [GIC]. Two conventional GICs [Ionocid F and Fuji II] and two resin-modified GICs [Iono Gem LC, Fuji II LC] were employed in the present study. A Perspex mould, 7mm in diameter and 2mm thick was used to fabricate five specimens from each material. Samples were suspended in 50 cc distilled water during the study period. To measure solubility, all specimens were dried and weighed at different time intervals, up to one month. Solubility was expressed as the mean weight loss percentage. The results were analyzed using ANOVA with repeated measurements on one factor and Scheffe and t-paired tests [P<005]. Ionocid F and Fuji II LC demonstrated the highest [24.09% +/- 0.87%] and lowest [1.05% +/- 0.74%] solubility values, respectively. The solubility of Iono Gem LC [7.34% +/- 2.20%] and Fuji II [9.01% +/- 1.33%] were intermediate between the other two cements, An increase in solubility was observed during the test period for all studied materials. The solubility of Iranian GICs was significantly higher than Fuji II and Fuji II LC cements

Permeability of the round window membrane of guinea pigs in acute suppurative otitis media

Acute suppurative otitis media of guinea pigs had been induced by inoculation of Staphylococcus aureus in the bulla. The permeability of the round window membrane to endotoxin was investigated by detecting endotoxin of the perilymph, applied to the round window using limulus amebocyte lysate test. It was found that endotoxin could pass through round window membranes of animals. With inflammation of middle ear, the permeability of the round window membrane to endotoxin was increased. These results suggest that bacterial toxins and the consequential migration of chemical inflammatory mediators might act as promoting factors of round window membrane permeability