Ahmed Adel - Academia.edu (original) (raw)

Papers by Ahmed Adel

International Journal of …, 2003

Background. To address the prognosis and the role of surgery in the management of patients with m... more Background. To address the prognosis and the role of surgery in the management of patients with malignant fibrous histiocytoma (MFH), strict definition and accurate evaluation of local recurrence is mandated, together with adequate gross and microscopic evaluation of the achieved surgical margins. Methods. One hundred and twenty-three patients with MFH were retrospectively analyzed regarding prognostic factors of the disease, which included the following: (1) primary or recurrent, (2) histological grade, (3) adjuvant chemotherapy, (4) size, (5) local recurrence after primary surgery done at the authors' institute, (6) adjuvant radiotherapy, and (7) surgical margin. Initially, all patients were metastasis-free (M0N0). Results. Local recurrence after primary surgery done at the authors' institute was the most significant prognostic factor, where 20 of 123 patients developed local recurrence (P Ͻ 0.0001). The cause of local recurrence were insufficient surgical margin in 16 patients, while in 4, local recurrences were related to lymph node metastasis, skip metastasis, and tumor embolism. The local recurrence rate for each surgical procedure was 75% for intralesional, 44.4% for marginal, 30.8% for inadequate wide, 12.3% for adequate wide, and 5% for curative procedures. In patients with a history of recurrent tumor or infiltrative pattern, local recurrence was not observed after a curative procedure, but occurred even after an adequate wide procedure.

Skeletal radiology, 2003

Objective: Local malignant bone tumor excision followed by pasteurization and subsequent reimplan... more Objective: Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. Design and patients: The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Results and conclusions: Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors.

Computer Communications, 2008

Wireless sensor network (WSN) is a wireless ad hoc network that consists of very large number of ... more Wireless sensor network (WSN) is a wireless ad hoc network that consists of very large number of tiny sensor nodes communicating with each other with limited power and memory constrain. WSN demands real-time forwarding which means messages in the network are delivered according to their end-to-end deadlines (packet lifetime). This paper proposes a novel real-time routing protocol with load distribution (RTLD) that ensures high packet throughput with minimized packet overhead and prolongs the lifetime of WSN. The routing depends on optimal forwarding decision that takes into account of the link quality, packet delay time and the remaining power of next hop sensor nodes. The proposed mechanism has been successfully studied and verified through simulation and real test bed implementation.

Journal of orthopaedic …, 2003

Positron-emission tomography (PET) can provide an in vivo method for evaluating metabolism and ph... more Positron-emission tomography (PET) can provide an in vivo method for evaluating metabolism and physiology in normal and diseased tissues. Clinical trials with [(18)F]2-deoxy-2-fluoro- d-glucose (FDG), the most commonly used radiolabeled tracer for PET imaging, have demonstrated increased accumulation of FDG in several cancer tissues. In this article, we introduce the basic principles of FDG-PET and review current knowledge about FDG-PET for evaluating musculoskeletal tumors. Recent reports and our own experience suggest that FDG-PET cannot be a screening method for differential diagnosis between benign and malignant musculoskeletal lesions, including many neoplasms originating from different tissues altogether. FDG-PET might not accurately reflect the malignant potential of musculoskeletal tumors, but rather might implicate cellular components included in the lesions. A high accumulation of FDG can be observed in histiocytic, fibroblastic, and some neurogenic lesions, regardless of whether they are benign or malignant. More specific uses of FDG-PET, such as grading, staging, and monitoring of musculoskeletal sarcomas, should be considered for each tumor of a different histologic subtype.

Management Research News, 2003

Accountants and the accounting profession have always been users of infor-mation technology and t... more Accountants and the accounting profession have always been users of infor-mation technology and the claim for enlarging levels of Information Tech-nology/Information Systems (IT/IS) skills/knowledge in practitioners and accounting graduates is more powerful than ever. ...

European journal of …, 2000

Fluorine-18 labelled α-methyltyrosine (FMT) was developed for positron emission tomography (PET) ... more Fluorine-18 labelled α-methyltyrosine (FMT) was developed for positron emission tomography (PET) imaging, and its potential for clinical application in patients with brain tumours has been demonstrated. This is the first trial to compare FMT with 18 F-fluoro-2-deoxy-D-glucose (FDG) for the evaluation of musculoskeletal tumours. Seventy-five patients were examined with both FMT-and FDG-PET within a 2-week period. Imaging findings were visually inspected in conjunction with computed tomography and/or magnetic resonance imaging, and standardized uptake values (SUVs) for both FMT and FDG in lesions were also generated and compared with histological findings. A significant correlation between FMT and FDG SUVs was found for all lesions (r=0.769, P<0.0001), and mean values for malignant tumours were significantly higher than those for benign lesions in both FMT-and FDG-PET. The diagnostic sensitivities and specificities for malignancy were 72.7% and 84.9%, respectively, using FMT with a cut-off SUV of 1.2, and 72.7% and 66.0%, respectively, using FDG with a cut-off SUV of 1.9. The resultant accuracy with FMT was 81.3%, higher than that for FDG (68.0%), and the difference with respect to specificity was significant (χ 2 cal=5.0625, P<0.05). On the other hand, while a significant correlation was found between malignant tumour grade and SUV with both FMT-(ρ=0.656) and FDG-PET (ρ=0.815), only the latter demonstrated significant differences among grades I, II and III. FMT and FDG for PET appear equally effective at detecting musculoskeletal tumours. In evaluating musculoskeletal tumours, FMT may be superior to FDG in the differentiation between benign and malignant tumours, while FDG may be the better choice for non-invasive malignancy grading.

… and related research, 2004

To clarify the safety margin in excision of bone and soft tissue sarcomas, a new evaluation metho... more To clarify the safety margin in excision of bone and soft tissue sarcomas, a new evaluation method for surgical margins was drafted by the Bone and Soft Tissue Committee of the Japanese Orthopaedic Association in 1989. This new evaluation system was applied to 1329 patients with bone and soft tissue sarcomas, of whom 492 were excluded because of insufficient details, leaving 837 patients (901 surgeries) for the current study. Based on the results derived from analyzing these registered surgical margins, predictable safety margins under different conditions could be determined. When preoperative treatment is not done or is ineffective in high-grade sarcoma, a margin greater than 3 cm wide is necessary. When the preoperative modality is effective, a 2-cm wide margin is permissible. However, for recurrent sarcoma, whether low-grade or high-grade, a curative procedure is necessary. For low-grade sarcoma, obtaining an adequate wide margin is essential but partial marginal margins are acceptable at sites where barriers exist. When the margin is insufficient, radiotherapy should be used regardless of the tumor grade. Making a safety margin definitive through this system, an optimum treatment can be obtained and unnecessary adjunctive modalities can be avoided.

Journal of computer …, 2003

Recently, a new positron emission tomography (PET) tracer, carbon-11 choline, has been introduced... more Recently, a new positron emission tomography (PET) tracer, carbon-11 choline, has been introduced in oncology investigations, but the role of choline PET in musculoskeletal tumor evaluation has not been previously examined. This is the first trial to investigate the utility of choline PET in evaluating musculoskeletal tumors in comparison with fluorine-18 fluoro-2-deoxy-D-glucose (FDG) PET. Thirty-three patients were examined with both choline PET and FDG PET, of which standardized uptake values (SUVs) were used for evaluation of the lesions. To decide the appropriate cutoff value and compare the two PET studies, receiver operating characteristic curve analysis was used. The binomial test was used for comparison of sensitivities between choline PET and FDG PET. A significant correlation (r = 0.537, P = 0.0013) between choline and FDG SUVs was noted for all lesions (n = 33). Mean SUVs for malignant tumors were significantly higher than those for benign lesions in both choline PET and FDG PET. Using a cutoff value of 2.7 for choline SUVs, the sensitivity for correctly diagnosing malignancy was 92.3% (12/13) with a specificity of 90.0% (18/20), resulting in an accuracy rate of 90.9%. With use of a cutoff value of 3.3 for SUVs in FDG PET, the sensitivity was 84.6% (11/13) with a specificity of 80.0% (16/20), resulting in an accuracy rate of 81.8%. The receiver operating characteristic curves of two analyses showed that the mean area under the curve value of choline PET (0.9577 +/- 0.041) was significantly greater (P = 0.0488) than that of FDG PET (0.8192 +/- 0.0806). There was no significant difference in sensitivity and specificity between choline PET and FDG PET analysis using either the binomial test (P = 0.4531) or McNemar test (P = 0.371). Choline PET analysis may not be inferior to FDG PET analysis for differentiating malignant from benign musculoskeletal tumors. The advantages of choline PET were shorter examination time and little retention in the bladder; therefore, this modality may be useful for preoperative planning for musculoskeletal tumors, especially for lesions around the hip joints.

Graph Drawing, 2006

This paper describes the GEOMI system, a visual analysis tool for the visualisation and analysis ... more This paper describes the GEOMI system, a visual analysis tool for the visualisation and analysis of large and complex networks. GEOMI provides a collection of network analysis methods, graph layout algorithms and several graph navigation and interaction methods. GEOMI is part of a new generation of visual analysis tools combining graph visualisation techniques with network analysis methods. GEOMI is available from