Brain biopsies are often needed to guide further treatment and aid in diagnosis of intracranial lesions. Magnetic resonance spectroscopy (MRS) has been shown to improve the diagnostic accuracy of needle biopsies, but its clinical utility remains unknown. The study cohort consisted of 14 patients in whom a neoplastic brain tumor was suspected, and a navigated biopsy was planned. Preoperative magnetic resonance imaging (MRI) and MRS were retrospectively analyzed by three neurosurgeons individually. They were asked to make two different biopsy plans: first according to anatomical MRI only and next after MRS was presented. Influence of MRS on the decision making was evaluated. According to the results, the cases were divided into three groups: “significant added value”, “moderate added value”, and “no added value”. The usefulness of MRS was also rated by the evaluators on a scale from 0 to 10. MRS significantly affected the targeting in 7 out of 14 patients (50%), in three more cases it was still considered useful since it confirmed the targeting plan. Only in four cases (29 %) MRS was rated less valuable for current biopsy planning. MRS could be a helpful adjunct to MRI in planning biopsies in brain tumor patients especially if large T2 signal abnormality or contrast enhancing areas, or multiple different lesions are present. In certain cases, biopsy might be avoided based on MRS findings.
Piironen et al. (Fri,) studied this question.