mahmoud ahmed

This study aims to use the Intensity Modulated Radiation Therapy (IMRT) technique for prostate cancer patients to evaluate the effectiveness of four different commercial Treatment Planning Systems (TPS): (Eclipse, Monaco, Ray plan, and Prowess). In terms of Conformality Index, Homogeneity Index, the dose distributions, the mean dose, the maximum dose, number of segments in each plan for each TPS, Monitor Units per fraction for each treatment plan for each TPS, coverage of the PTVs, and avoidance of Organs At Risk (OARs) for Simultaneous Integrated Boost (SIB) for cancer prostate treatment plans.
CT images and volumes structure of 10 patients were used to make IMRT plans. The target volume’s structure was contoured according to RTOG 0534 protocol. Fixed beam geometry and clinical goals were set for all individual patient plans. The results were analyzed in terms of dosimetric parameters, the number of segments, and monitor units per segment.
All TPSs achieve similar coverage, and dose distributions to the PTVs. For PTV60 Eclipse achieved the lowest coverage relative to other planning and the nearest mean dose to prescription dose and significant difference relative to other planning. For PTV 44: the Ray plan achieved the best coverage with a significant difference relative to other systems, but Eclipse achieved the nearest mean dose to the prescribed dose with a significant difference relative to the ray plan. Prowess achieved the lowest MU/fraction with a significant difference relative to Monaco the highest in Mus and the lowest possible number of segments.
The four planning systems achieve close dose distributions and confirmation numbers but there is a significant difference in total segments per fraction and total monitor units per fraction which affect the long life of the machine and the session treatment time.

Megaloporous controlled release tablets of diclofenac sodium (DS) were prepared with two kinds of granules. One of them is the restraining-phase matrix granule (RMG) and it controls the release rate of the drug. The other one is the soluble housing-phase matrix granule (HMG) and controls liquid penetration into the system. Carnauba wax and Eudragit L 100 polymers were used to constitute the restraining and housing matrix phases, respectively. The prepared tablets were evaluated for various parameters. In vitro drug release study was carried out in simulated gastric fluid (pH 1.2) for the first 2 h and in phosphate buffer (pH 7.2) for the next 10 h following USP 25 paddle method. Two independent model methods, AUC and Lin Ju and Liaw's difference factor (ƒ1) and similarity factor (ƒ2) were used to compare various dissolution profiles. The fabricated megaloporous matrix tablets released only 3 to 5% of DS in pH 1.2 depending on the proportion of carnauba wax used in the RMG. Increase in polymer content/hardness value of the tablet resulted in a significant decrease in AUC0-2 h and AUC2-12 h values . The f1and f2analysis also confirms the discrimination between corresponding dissolutionpairs. The dissolution profiles of an ideal matrix formulation containing 15.77% carnauba wax and 6.76% Eudragit L100 was found to be comparable with the reference product (Voveran® SR) and theoretical release profile. The drug release from all fabricated products and reference product followed better Higuchi model than the zero order and first order kinetic models. Ritger-Peppas model analysis indicated that the DS release followed non-Fickian transport mechanism. From the above analysis, it is evident that the release mechanism of DS from matrix tablet is influenced by both hardness and polymer contents. The stability profiles indicate that the physico-chemical properties of the tablets are not affected on storage at 45°C /75% RH up to 6 months.