Unenhanced and gadolinium-DTPA-enhanced MR imaging in postoperative evaluation in pediatric brain tumors

Abstract

Gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) is a chelated paramagnetic contrast agent under clinical trial for use in magnetic resonance (MR) imaging. The increased signal intensity following the intravenous infusion of contrast medium may improve the ability of MR imaging to delineate tumors. The use of this method in 15 pediatric patients with suspected brain-tumor recurrence was analyzed. All 15 patients underwent postoperative Gd-DTPA-enhanced MR imaging, and residual tumor was demonstrated in nine of them. Based on the findings of the enhanced MR studies, four patients had additional surgery, two underwent radiation therapy, and one was given immunotherapy. Continued surveillance was recommended for the remaining eight patients. In all cases the enhanced MR imaging studies were superior to the unenhanced studies in regard to the qualitative and quantitative assessment of the residual tumor. Gadolinium-DTPA-enhanced MR imaging appears to be a safe and effective means of providing an accurate postoperative assessment of residual disease in pediatric brain-tumor patients. It is as effective as contrast-enhanced computerized tomography and has the sensitivity and anatomic resolution provided by MR imaging. The most useful role of this agent was in the postoperative period, in assessing the adequacy of surgical resection. This technique is recommended as the procedure of choice in the postoperative assessment and long-term surveillance of patients with brain tumors.

Early postoperative magnetic resonance imaging following nonneoplastic cortical resection

“…2 Because tumor response to adjuvant therapy is also assessed by CT and MR imaging, these modalities have become integral to the postoperative standard of care management of neurooncological disease. 5,10,13,34,35…”

“…For these reasons MR imaging has become the imaging study of choice for postoperative assessment and surveillance of patients with brain tumors. 13,33…”

“…adjuvant treatment is also assessed by computerized tomography (CT) and magnetic resonance (MR) imaging, these modalities have become increasingly important in the management of neurooncological disease. 5,10,13,33,35 Appropriate evaluation of postoperative neuroimaging necessitates an accurate understanding of the effects of neurosurgical intervention on all intracranial contents. These changes have not been clearly defined, [2][3][4]6,9,15,16,21,25,42 with only a few studies published that describe postoperative MR imaging.…”

“…These changes have not been clearly defined, [2][3][4]6,9,15,16,21,25,42 with only a few studies published that describe postoperative MR imaging. 1,2,6,13,24 Furthermore, early postoperative MR differentiation of residual tumor enhancement and enhancement of injured brain parenchyma is often difficult. 2,9,19,25 In this prospective clinical investigation, we obtained MR images in patients 1 postoperative day after they had undergone temporal lobectomies for epilepsy.…”

MR contrast agents: Physical and pharmacologic basics

“…In conclusion, while many studies have confirmed the "added value" of contrast-enhanced images for pediatric MRI (97)(98)(99)(100)(101)(102)(103)(104)(105)(106)(107)(108), the question is whether or not routine contrast administration in children is warranted. Given that there appears to be an identical safety profile in the pediatric and adult populations, it seems reasonable to administer Gd-based agents to children in the same basic situations considered for adults, particularly in the evaluation of neoplastic or inflammatory disease.…”