Image-based surgical risk factors for Wilms tumor

The standard treatment for Wilms tumor (WT) is primary resection. However, in cases with unresectable tumor or tumor spillage, which are considered to have high surgical risks, more intensive chemotherapy and radiotherapy are required. In the present study, we retrospectively analyzed preoperative image parameters to identify factors associated with surgical risks. Twenty-nine patients with WT were enrolled in this study. Data on various preoperative image parameters, such as tumor size, tumor volume, displacement of great vessels, and contralateral extension of the tumor were collected, and their relationship with surgical factors, including operative time, hemorrhage, tumor spillage, and unresectability were analyzed. Patients with unresectable tumor or with tumor spillage (surgical high-risk group) more frequently demonstrated displacement of great vessels and contralateral tumor extension. Operative time and blood loss were also significantly related to tumor size, area, volume, displacement of great vessels and contralateral extension. Besides tumor size, displacement of great vessels and contralateral extension were significantly associated with surgical risks. These factors are easily determined using CT images and are, therefore, useful to decide whether preoperative chemotherapy should be started instead of primary tumor resection for large localized WTs.