PREOPERATIVE AND POSTOPERATIVE FOLLOW-UP IN HIGH-GRADE GLIOMAS - COMPARISON OF TRANSCRANIAL COLOR-CODED REAL-TIME SONOGRAPHY AND COMPUTED-TOMOGRAPHY FINDINGS

Twenty patients with high-grade gliomas were prospectively studied by pre- and postoperative transcranial color-coded real-time sonography ( TCCS) and CT, to determine the sensitivity of TCCS in the identificati on of residual tumor and tumor regrowth. Each patient was subjected to preoperative and early postoperative CT (postoperative day 1) and TCC S examinations (postoperative days 6 to 8) and subsequent CT and TCCS follow-up examinations within a time interval of 6 weeks to 3 months, In eight patients, a total of 15 biopsy specimens were intraoperativel y obtained from the wall of the resection cavity. Histological finding s of intraoperative biopsy specimens showed that hyperechogenic areas adjacent to the resection cavity always contained residual tumor tissu e. Early postoperative TCCS identified these hyperechogenic areas in 1 9 of 20 patients. In 12 patients, postoperative CT revealed contrast e nhancement at the resection margin, indicating residual tumor. In thes e patients the extension of these hyperechogenic areas on TCCS exceede d the contrast-enhancing areas on CT by a mean of 58%. In eight patien ts, postoperative CT displayed no contrast enhancement along the borde r of resection. TCCS and histological findings indicated residual tumo r in seven of these eight patients. The size of the hyperechogenic les ions identified by postoperative TCCS increased in time and follow-up examinations revealed that tumor regrowth arose from these hyperechoge nic areas in all patients. In four patients, tumor regrowth was identi fied, on average 0.7 months earlier by TCCS than by CT. From these dat a we conclude that the sensitivity of TCCS in detection of residual tu mor and tumor regrowth seems to be superior to CT. The value of TCCS r equires further clarification by comparative studies including histolo gy and MRI.