Metastasis Infiltration: An Investigation of the Post-Operative Brain-Tumor Interface
MJ Schniederjan, B Raore, DJ Brat, HK Shu, JJ Olson. Emory University School of Medicine, Atlanta, GA
Background: After surgical resection of metastatic brain tumors, stereotactic radiosurgery (SRS) is targeted at the resection cavity and surrounding tissue in order to treat potential residual invading tumor cells. The treatment area, or clinical target volume (CTV), includes normal tissue surrounding the surgical cavity. To date, no systematic investigation of the amounts of tumor cells in tissue surrounding resection cavities has been conducted. We biopsied surrounding tissue after gross total resection to evaluate the biological basis for treating with SRS beyond the cavity margin.
Design: Eleven surgical cavities were examined in ten patients. Intra-operatively after gross total resection, multiple needle-core biopsies of the margins were taken and oriented relative to the tumor (proximal-distal) to assess the amount and extent of peritumoral infiltration by residual cells. These biopsies were examined histologically and the findings recorded.
Results: Microscopic examination of multiple levels of each biopsy failed to disclose even a single residual tumor cell in any case. The only abnormal finding in the biopsies was reactive gliosis, mostly limited to the proximal/tumor end of the tissue.
Conclusions: Lack of evidence of metastatic tumor cell infiltration into surrounding brain may suggest the need to only target the resection cavity margins or gross tumor volume, in the case of metastatic solid tumors, in order to prevent treatment size dependent SRS complications.
Tuesday, March 23, 2010 2:15 PM
Platform Session: Section G, Tuesday Afternoon