The changing role of stereotaxis in surgical neuro-oncology.

PURPOSE: Evaluate evolution and time course of stereotactic neurosurgery within surgical neuro-oncology.
METHODS: MEDLINE search 1966-2003 sub-stratified and analyzed for annual trends. AANS/CNS membership databases for Joint Sections. ACRC neuro-oncology program database 1998-2003.
RESULTS: Tumor stereotaxis emerged in 1980 and became the dominant stereotactic publication topic by 1984. Frame-based tumor stereotaxis led publications through 1994, when supplanted by stereotactic radiosurgery (SR). Brachytherapy led SR 1982-1987, but then fell behind, reducing to pre-1983 levels by 1996. SR publications currently comprise 65% of stereotactic tumor articles and publication rate continues to rise at a steady rate. Frameless stereotaxis (FS) publications began to increase in 1993 and growth is larger than the corresponding fall in frame-based volumetric resection publications. Data suggest increased utilization for cases that would have otherwise utilized ultrasound or gone without image guidance. Intraoperative MR developed predominantly as complimentary technology to FS. Tumor diagnostic needle biopsy publications continue to be mostly frame-based, while FS techniques are largely resection focused. This may change as >80% of our tumors biopsied with frame-based techniques would be candidates for FS biopsy based solely on lesion size, location, and technique accuracy considerations. CNS parenchymal delivery of experimental therapies continues to be predominantly frame-based.
CONCLUSION: The role of tumor stereotaxis in surgical neuro-oncology is important, but changing. SR is increasingly dominating the subspecialty. Stereotactic tumor resection has become a mainstream neurosurgical procedure due to FS, and this will likely occur with needle biopsy as well. Delivery of experimental therapies remains predominantly frame-based, but may need to transition to FS in order to gain wider mainstream acceptance and applicability once efficacy is demonstrated.