Assessment of the Prognostic Factors for a Local Recurrence of Rectal Cancer: the Utility of Preoperative MR Imaging

OBJECTIVE: To determine the utility of MR imaging in evaluating the prognostic factors for a local recurrence of rectal cancer following a curative resection. MATERIALS AND METHODS: The preoperative MR images obtained from 17 patients with a local recurrence and 54 patients without a local recurrence, who had undergone a curative resection, were independently evaluated by three radiologists. The following findings were analyzed: the direct invasion of the perirectal fat by the primary rectal carcinoma, involvement of the perirectal lymph nodes, perirectal spiculate nodules, perivascular encasement, and an enlargement of the pelvic wall lymph nodes. The clinical and surgical profiles were obtained from the patients' medical records. The association of a local recurrence with the MR findings and the clinicosurgical variables was statistically evaluated. RESULTS: Of the MR findings, the presence of perivascular encasement (p = 0.001) and perirectal spiculate nodules (p = 0.001) were found to be significant prognostic factors for a local recurrence. Of the clinicosurgical profiles, the presence of a microscopic vascular invasion (p = 0.005) and the involvement of the regional lymph nodes (p = 0.006) were associated with a local recurrence. Logistic regression analysis showed that the presence of perirectal spiculate nodules was an independent predictor of a local recurrence (odds ratio, 7.382; 95% confidence interval, 1.438, 37.889; p = 0.017). CONCLUSION: The presence of perirectal spiculate nodules and perivascular encasement on the preoperative MR images are significant predictors of a local recurrence after curative surgery for a rectal carcinoma. This suggests that preoperative MR imaging can provide useful information to help in the planning of preoperative adjuvant therapy.ope

A Recovery Method Supporting User-Interactive Undo in Database Management Systems

User-interactive undo is a kind of recovery facility that allows users to correct mistakes easily by canceling and reexecuting operations that have already been executed. Supporting user-interactive undo is essential for authoring processes in new database applications such as software engineering, hypermedia, and computer-aided design. A partial rollback using savepoints supported by commercial database management systems (DBMSs), which allows only cancellation of executed operations, is a restricted form of user-interactive undo. Although many applications use DBMSs, they have to provide user-interactive undo by themselves due to lack of support from the DBMSs. Since implementation of user-interactive undo is quite complex, it poses significant burden to application programmers. This paper proposes a new recovery method facilitating user-interactive undo in DBMSs. Such a facility relieves the programmers of implementing user-interactive undo themselves in developing DBMS applications..

A Recovery Method Supporting User-Interactive Undo in Database Management Systems

User-interactive undo is a kind of recovery facility that allows users to correct mistakes easily by canceling and reexecuting operations that have already been executed. Supporting userinteractive undo is essential for authoring processes in new database applications such as software engineering, hypermedia, and computer-aided design. A partial rollback using savepoints supported by commercial database management systems(DBMSs), which allows only cancellation of executed operations, is a restricted form of user-interactive undo. Although many applications use DBMSs, they have to provide user-interactive undo by themselves due to lack of support from the DBMSs. Since implementation of user-interactive undo is quite complex, it poses significant burden to application programmers. This paper proposes a new recovery method facilitating user-interactive undo in DBMSs. Such a facility relieves the programmers of implementing user-interactive undo themselves in developing DBMS applications. ..

Concise Papers __________________________________________________________________________________________ Spatial Join Processing Using Corner Transformation

AbstractÐSpatial join finds pairs of spatial objects having a specific spatial relationship in spatial database systems. Since spatial join is a fairly expensive operation, we need an efficient algorithm taking advantage of the characteristics of available spatial access methods. In this paper, we propose a spatial join algorithm using corner transformation and show its excellence through experiments. To the extent of authors ' knowledge, the spatial join processing using corner transformation is new. In corner transformation, two regions in one file joined with two adjacent regions in the other file share a large common area. The proposed algorithm utilizes this property in order to reduce the number of disk accesses for spatial join. Experimental results show that the performance of the algorithm is generally better than that of the R*-tree based algorithm proposed by Brinkhoff et al. This is a strong indication that corner transformation is a promising category of spatial access methods and that spatial operations can be performed better in the transform space than in the original space. This reverses the common belief that transformation will adversely effect the clustering. We also briefly mention that the join algorithm based on corner transformation has a nice property of being amenable to parallel processing. We believe that our result will provide a new insight towards transformation-based processing of spatial operations. Index TermsÐSpatial join, GIS, spatial databases, corner transformation.