CT-guided brain biopsy using a modified Pelorus Mark III Stereotactic System: Experience with 50 dogs

This report describes the results of CT-guided stereotactic brain biopsies performed on 50 consecutive dogs using a modified Pelorus Mark III Stereota ctic System. Based on available histopathologic samples (stereotactic biops y [n = 50], surgery [n = 17], necropsy [n = 9]) the patient population cons isted of 34 dogs with primary brain tumors, 2 with invasive nasal adenocarc inomas, and 13 with non-neoplastic brain lesions. Brain tissue was not obta ined from one dog. In 22 dogs a final diagnosis was made from tissue subseq uently obtained from surgical resection or at necropsy. The final diagnosis was in agreement with the stereotactic biopsy diagnosis in 20 of these 22 dogs. In 17 other dogs without follow-up, stereotactic biopsy provided a di agnosis of a specific primary brain tumor subtype. Postoperative complicati ons associated with the biopsy procedure were assessed in 41 dogs. The othe r 9 dogs either went directly to surgery (II = 7) or were killed (n = 2) im mediately after the biopsy procedure. Thirty-six dogs recovered without app arent clinical complications. Postoperative clinical complications in the r emaining 5 dogs included transient epistaxis (1 dog), transient exacerbatio n of cerebellar signs (1 dog), obtundation progressing to coma (1 dog), and medically uncontrollable seizures (2 dogs). The latter 3 dogs with severe neurologic complications all had large primary brain tumors and had been re ceiving high doses of phenobarbital and glucocorticoids to control seizures at the time of biopsy. These results suggest that this CT-guided biopsy pr ocedure can provide an accurate pathologic diagnosis of brain lesions detec ted by CT and MR neuroimaging. Further refinement of both technique and cas e selection is expected to reduce the rate of clinical complications and to improve the accuracy of the procedure.