Pre-operative radionuclide localization of intracerebral lesions: a five-year experience

Intracerebral lesions demonstrated by computerized tomography usually require histological confirmation to determine subsequent management. Tissue samples are generally obtained by craniotomy or burr hole biopsy; either procedure can prove negative if a lesion is small, deep, or very superficial. Pre-operative imaging and localization reduce biopsy failures. Before the introduction of this straight forward radionuclide technique, our biopsy success rate using conventional localization methods was 88%. In a 5-year period, 200 patients underwent pre-operative radionuclide localization, with an improvement in the overall biopsy success rate to 92.7% (95.5% for lesions which took up radionuclide). Patients have benefitted from reduced operating time and improved post-operative recovery rates. About 85% of all intracerebral lesions may be expected to accumulate radionuclide. However in our series, 93.2% were sufficiently well visualized for a siting marker to be placed with confidence. Within this group, low grade astrocytomas (Kernohan Grades I and II) showed a predictably low incidence of imaging (30.8%). For the majority of lesions which present difficulties in biopsy due to size or site, the radionuclide method is a simple procedure which increases the chance of obtaining positive tissue with the minimum of surgical intervention.