Postoperative contrast enhancement in patients with brain tumor

Abstract

Contrast enhancement resulting from surgical trauma may mimic residual enhancing tumor, thereby complicating the interpretation of postoperative computed tomographic scans. We assessed the natural history of postoperative enhancement in 10 patients with brain tumor. Contrast enhancement distinguishable from residual enhancing tumor appeared along the operative margin following tumor resections but not lobectomies. Enhancement appeared as early as the fifth postoperative day, was most intense at two weeks, and persisted for several months. Prior to the fifth postoperative day, enhancement reflected residual tumor. Edema and artifacts were more prominent on the first and second postoperative days than on the third and fourth. We recommend that postoperative computed tomographic scans to assess residual enhancing tumor be performed on the third or fourth postoperative day. This timing avoids postoperative enhancement and minimizes interpretative difficulties caused by artifacts.

Current neurosurgical management and the impact of the extent of resection in the treatment of malignant gliomas of childhood: a report of the Children's Cancer Group Trial No. CCG-945

“…Further complicating any attempt to analyze the impact of residual tumor observed on radiographs was the interval between surgery and postoperative imaging; the average time from resection to CT scanning was 6 days in our study. Authors of both animal [24] and clinical reports [6,7,9] have recommended performing CT scans within 2 to 4 days of surgery, to avoid spurious enhancement from the development of reactive neovascularity and breakdown of the blood-brain barrier in the tumor bed. Even with early scans, enhancement may occur in biopsy-negative resection margins of pediatric brain tumors only to disappear on subsequent studies.…”

Early evaluation of tumour metabolic response using [18F]fluorodeoxyglucose and positron emission tomography:a pilot study following the phase II chemotherapy schedule for temozolomide in recurrent high-grade gliomas

“…Assessment of alterations in tumour extent with therapy using computerized tomography (CT) and magnetic resonance imaging (MRI) can be a problem for gliomas where the tumour can not be clearly delineated from post-operative enhancement (Cairncross et al, 1985) and radiation-induced necrosis and prognosis (Alavi et al, 1988 (Valk et al, 1988). It has been proposed that changes in […”

Computer Tomographic Scanning within 24 Hours of Craniotomy for a Tumor in Children

“…Enhancement of the dura mater was not seen before 2 weeks and was limited to the area beneath the craniotomy. In this and other studies, the enhance ment was interpreted as due to reactive vascular changes and neovascularity, based on the microscopic pathology and time delay in onset [5,8,9]. This led to the recom mendation for clinical postoperative scanning within 7 days of surgery to best define residual tumor [5,8], Cairncross et al [5] reported a series of patients undergoing serial scans after craniotomy for tumor resec tion.…”

“…Some treatment protocols mandate different treatment for patients with residual disease. Patients with residual disease may be subjected to more aggressive or more promptly instituted adjunctive therapies [5,6]. In fact, a measurable disparity between the incidence of true residual neoplasm and con trast enhancement on CT scans obtained within 3 days of craniotomy has been demonstrated [7], It had been sug gested that scanning patients even earlier than 72 h would further reduce the incidence of these artifacts [7].…”