Spectroscopy-supported frame-based image-guided stereotactic biopsy of parenchymal brain lesions: Comparative evaluation of diagnostic yield and diagnostic accuracy

Objective

Comparative evaluation of diagnostic efficacy of stereotactic brain biopsy performed with and without additional use of spectroscopic imaging (¹H-MRS) for target selection was done.

Methods

From 2002 to 2006, 30 patients with parenchymal brain lesions underwent ¹H-MRS-supported frame-based stereotactic biopsy, whereas in 39 others MRI-guided technique was used. Comparison of diagnostic yield of the procedure in these two groups was performed. Additionally, the diagnostic accuracy was evaluated in 37 lesions, which were surgically resected within 1 month thereafter.

Results

Stereotactic biopsy permitted establishment of a definitive histopathological diagnosis in 57 cases and diagnosis of low-grade glioma without specific tumor typing in 8 cases. In 4 cases tissue sampling was non-diagnostic. In 5 out of 8 cases with incomplete diagnosis and in all non-diagnostic cases target selection was performed without the use of ¹H-MRS (P = 0.2073). The diagnostic yields of ¹H-MRS-supported and MRI-guided procedures were 100% and 90%, respectively (P = 0.1268). Comparison of the histopathological diagnoses after stereotactic biopsy and surgical resection revealed complete diagnostic agreement in 13 cases, minor disagreement in 14 cases, and major disagreement in 10 cases. Among these last 10 cases, initial undergrading of non-enhancing WHO grade III gliomas was the most common (7 cases). The diagnostic accuracy of ¹H-MRS-supported and MRI-guided procedures was 67% and 79%, respectively (P = 0.4756).

Conclusion

While in the present study the diagnostic yield of ¹H-MRS-supported frame-based stereotactic brain biopsy was 100%, its statistically significant diagnostic advantages over MRI-guided technique were not proved. Optimal selection of the spectroscopic target for tissue sampling remains unclear.