Treatment Of Abdominal Tumors Research Articles

Application of membrane anatomy in hepatopancreatobiliary and splenic surgery

Understanding of a variety of membranous structures throughout the body,such as the fascia,the serous membrane,is of great importance to surgeons. This is especially valuable in abdominal surgery. With the rise of membrane theory in recent years,membrane anatomy has been widely recognized in the treatment of abdominal tumors,especially of gastrointestinal tumors. In clinical practice. The appropriate choice of intramembranous or extramembranous anatomy is appropriate to achieve precision surgery. Based on the current research results,this article described the application of membrane anatomy in the field of hepatobiliary surgery,pancreatic surgery,and splenic surgery,with the aim of blazed the path from modest beginnings.

Abstract No. 505 Validating the registration accuracy of a multimodal registration device to enhance computed tomography–guided percutaneous biopsy and ablation procedures

CT-guided biopsy and ablation procedures are commonly performed for diagnosis and treatment of abdominal tumors. However, targeting soft tissue lesions using low-resolution CT-fluoroscopy can be technically challenging due to limited visualization. The purpose of this study is to assess the accuracy of IGTFusion, an FDA-cleared device capable of performing real-time, nonrigid, multimodal image registration for targeting assistance, in the registration of pre-procedural abdominal CT with intra-procedural CT-fluoroscopy scans.

Treatment of abdominal tumors using radiotherapy

Treatment of abdominal tumors using radiotherapy

Thérapies par ultrasons focalisés

Many techniques of thermotherapy have emerged over the last several years in the field of oncology using different types of physical agents, including ultrasound. Only ultrasound can target deep seated lesions non-invasively without need for percutaneous probe insertion. Depending on their utilization, it is possible to select either thermal effects, in a continuous mode, at low temperature (allowing thermo-induced biological effects) or at high temperature (allowing thermoablation), or mechanical effects, in a pulsed mode, at low energy level (allowing biological effects) or at high energy levels (histotripsy). Thermoablation by focused ultrasound is now developing fast for applications in many organs. It gained a well defined role for the treatment of prostatic cancer and uterine leiomyoma but needs to be better evaluated in other organs such as the breast. Treatment of abdominal tumors must still be considered as experimental as long as problems related to acoustic interfaces (produced by ribs and gas) and movement correction are not resolved. Biological applications of focused ultrasound are currently being explored and have a great long term potential.

High intensity focused ultrasound treatment of abdominal tumors

A phase II clinical trial for the treatment of isolated liver metastases is currently underway at the Royal Marsden Hospital. Tumors lying 4–12 cm below the skin surface are targeted in fully conscious patients. Treatment success is monitored using either radiological methods in conjunction with biochemical marker assays, or by histological examination. Factors determining pain or other sensations have been studied in order that exposures may be optimized. Laboratory investigations have been undertaken in parallel with these clinical studies, and these have been used to establish the effects of, for example, rib shadowing, timing of individual exposures, and in situ intensity on tissue ablation. Skin studies have allowed the determination of thresholds for a ‘‘burn’’ when multiple, overlapping exposures are used.

A generic genetic algorithm for generating beam weights.

A genetic algorithm for generating beam weights is described. The algorithm improves an objective measure of the dose distribution while respecting dose volume constraints placed on critical structures. The algorithm was used to select beam weights for treatment of abdominal tumors. Weights were selected for up to 36 beams. Dose volume limits were placed on normal organs and a dose inhomogeneity limit was placed on tumor. Volumes were represented as sets of several hundred discrete points. The algorithm searched for the beam weights that would make the minimum tumor dose as high as the constraints would allow. The results were checked using dose volume histograms with standard sized grids. Nineteen trials were created using six patient cases by changing the required field margin or allowed beam position in each case. The sampling of points was sufficiently dense to yield solutions that strictly satisfied the constraints when the prescribed dose was renormalized by a factor of less than 6%. The genetic algorithm supplied solutions in 49 min on average, and in a maximum time of 87 min. The randomized search does not guarantee optimality, but high tumor doses were obtained. An example is shown for which the solution of the genetic algorithm gave a minimum tumor dose 7 Gy higher than the solution given by a simulated annealing algorithm under the same set of constraints. The genetic algorithm can be generalized to admit nonlinear functions of the beam intensities in the objective or in the constraints. These can include tumor control and normal tissue complication probabilities. The genetic algorithm is an attractive procedure for assigning beam weights in multifield plans. It improves the dose distribution while respecting specified rules for tissue tolerance.

Comparison of simulated annealing algorithms for conformal therapy treatment planning

The efficiency of four fast simulated annealing algorithms for optimizing conformal radiation therapy treatment plans was studied and the resulting plans were compared with each other and to optimized conventional plans. Four algorithms were selected on the basis of their reported successes in solving other minimization problems: fast simulated annealing with a Cauchy generating function, fast simulated annealing with a Lorentzian generating function, variable step size generalized simulated annealing (VSGSA), and very fast simulated reannealing (VFSR). They were tested on six clinical cases using a multiple beam coplanar conformal treatment technique. Relative beam weights were computed that maximized the minimum tumor dose subject to dose-volume constraints on normal organ doses. Following some initial tuning of the annealing parameters, each algorithm was applied identically to each test case. Optimization tests were run using different random number sequences and different numbers of iterations. The VSGSA algorithm consistently produced the best results. Using long run times, it generated plans with the highest minimum tumor dose in five of the six cases. For the short run times, the VSGSA solutions averaged larger minimum tumor doses than those of the other algorithms for all six patients, with increases ranging from 0.4 to 5.9 Gy. For three of the patients, the conformal plan gave a clinically significant increase in the minimum tumor dose over the conventional plan, ranging from 8.2 to 13.0 Gy. In two other cases, there was little difference between the two treatment approaches. For one case, the optimized conventional plan was much better than the conformal plan because the conventional beam arrangement included wedges, which offset the multiple beam advantage of the conformal plans. For equal computing times of both long and short duration, the VSGSA algorithm consistently produced conformal plans that were superior to those produced by the other algorithms. The simple conformal technique used in this study showed a significant potential advantage in the treatment of abdominal tumors. In three of the cases, the conformal plans showed clinically important increases in tumor dose over optimized conventional plans.

Recent Literature Diagnosis and Surgical Treatment of Abdominal Tumors . By Sir Spencer Wells, Bart. Philadelphia: P. Blakiston, Son & Co. 1885.

Recent Literature Diagnosis and Surgical Treatment of Abdominal Tumors . By Sir Spencer Wells, Bart. Philadelphia: P. Blakiston, Son & Co. 1885.