Selective internal radiation therapy is a very effective and well-tolerated regional treatment for colorectal liver metastases, which should be considered for those with liver-only metastatic disease.
BackgroundCancer treatments are complex and involve different actions, which include many times a surgical procedure. Medical imaging provides important information for surgical planning, and it usually demands a proper segmentation, i.e., the identification of meaningful objects, such as organs and lesions. This study proposes a methodology to segment the liver, its vessels and nodules from computer tomography images for surgical planning.MethodsThe proposed methodology consists of four steps executed sequentially: segmentation of liver, segmentation of vessels and nodules, identification of hepatic and portal veins, and segmentation of Couinaud anatomical segments. Firstly, the liver is segmented by a method based on a deformable model implemented through level sets, of which parameters are adjusted by using a supervised optimization procedure. Secondly, a mixture model is used to segment nodules and vessels through a region growing process. Then, the identification of hepatic and portal veins is performed using liver anatomical knowledge and a vein tracking algorithm. Finally, the Couinaud anatomical segments are identified according to the anatomical liver model proposed by Couinaud.ResultsExperiments were conducted using data and metrics brought from the liver segmentation competition held in the Sliver07 conference. A subset of five exams was used for estimation of segmentation parameter values, while 15 exams were used for evaluation. The method attained a good performance in 17 of the 20 exams, being ranked as the 6th best semi-automatic method when comparing to the methods described on the Sliver07 website (2008). It attained visual consistent results for nodules and veins segmentation, and we compiled the results, showing the best, worst, and mean results for all dataset.ConclusionsThe method for liver segmentation performed well, according to the results of the numerical evaluation implemented, and the segmentation of liver internal structures were consistent with the anatomy of the liver, as confirmed by a specialist. The analysis provided evidences that the method to segment the liver may be applied to segment other organs, especially to those whose distribution of voxel intensities is nearly Gaussian shaped.
This study suggests that early diagnosis and curative resection of retroperitoneal sarcomas can improve long-term survival. Adjacent organs with evidence of direct invasion must be removed en bloc; others should be spared.
High sensitivity associated with substantial agreement with histopathologic findings shows that IOU is an indispensable evaluation method for hepatic screening in patients with abdominal tumors who undergo laparotomy and should become a routine procedure wherever available.
BackgroundThe effectiveness of chemotherapy (CT) for select cases of metastatic colorectal cancer (MCRC) has been well established in the literature, however, it provides limited benefits and in many cases constitutes a treatment with high toxicity. The use of specific molecular biological treatments with monoclonal antibodies (MA) has been shown to be relevant, particularly for its potential for increasing the response rate of the host to the tumour, as these have molecular targets present in the cancerous cells and their microenvironment thereby blocking their development. The combination of MA and CT can bring a significant increase in the rate of resectability of metastases, the progression-free survival (PFS), and the global survival (GS) in MCRC patients.ObjectiveTo assess the effectiveness and safety of MA in the treatment of MCRC.MethodsA systematic review was carried out with a meta-analysis of randomised clinical trials comparing the use of cetuximab, bevacizumab, and panitumumab in the treatment of MCRC.ResultsSixteen randomised clinical trials were selected. The quality of the evidence on the question was considered moderate and data from eight randomised clinical trials were included in this meta-analysis. The GS and PFS were greater in the groups which received the MA associated with CT, however, the differences were not statistically significant between the groups (mean of 17.7 months versus 17.1 months; mean difference of 1.09 (CI: 0.10–2.07); p = 0.84; and 7.4 versus 6.9 months. mean difference of 0.76 (CI: 0.08–1.44); p = 0.14 respectively). The meta-analysis was not done for any of the secondary outcomes.ConclusionThe addition of MA to CT for patients with metastatic colorectal cancer does not prolong GS and PFS.
This chapter presents a method based on level sets to segment organs using computer tomography (CT) medical images. Initially, the organ boundary is manually set in one slice as an initial solution, and then the method automatically segments the organ in all other slices, sequentially. In each step of iteration it fits a Gaussian curve to the organ’s slice histogram to model the speed image in which the level sets propagate. The parameters of our method are estimated using genetic algorithms (GA) and a database of reference segmentations. The method was tested to segment the liver using 20 different exams and five different measures of performance, and the results obtained confirm the potential of the method. The cases in which the method presented a poor performance are also discussed in order to instigate further research.
Objective to evaluate the effectiveness of the 3D virtual anatomical table as a complementary resource to the learning of the hepatobiliary anatomy by undergraduate medical students. Method A randomized controlled study comparing the anatomical learning of hepatobiliary structures, supported by a real model versus a virtual model, both three-dimensional (3D), by undergraduate medical students. The students’ perception of the resources used to teach anatomy was also evaluated. The students were submitted to a pre-test and to two evaluations after the interventions were applied. Results Overall, both the 3D virtual anatomical table and the real liver increased students’ knowledge of the hepatobiliary anatomy in relation to their previous knowledge (p = 0.001 and p = 0.01, respectively for second and third evaluations). In the longitudinal comparison between the pre-test and the second evaluation (hepatobiliary anatomy and Couinaud’s segmentation), this increase was significantly higher in the group allocated to the real liver (p = 0.002); in the comparison of the pre-test with the third evaluation (inclusion of adjacent organs in the anatomical table or in the real liver), the increase in knowledge was significantly higher in the group allocated to the anatomical table (p = 0.04). The perception of participants’ satisfaction regarding the learning resources was considered very good, with a minimum percentage of satisfaction of 80%. Conclusion the 3D virtual anatomical table provided more hepatobiliary anatomy knowledge than a real liver for undergraduate medical students, in comparison to their previous knowledge about these structures. In the cross-sectional comparison of the post-instruction evaluations, there was no difference between the two interventions. Moreover, the 3D platform had a positive impact on the level of satisfaction of study participants. This study shows that the 3D virtual anatomical table has the potential to improve both medical students’ understanding and interest in anatomy. It is recommended, however, that future protocols such as this be carried out with larger samples and exploring other anatomical structures.
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