Impact of computed tomographic and magnetic resonance imaging findings on surgical outcome in petroclival meningiomas

OBJECTIVE: The preoperative radiological findings of computed tomographic a nd magnetic resonance imaging scans of 70 patients with petroclival meningi oma were evaluated and statistically compared with the degree of surgical r esection and patients' outcomes to depict the most important radiological f indings that may influence surgical radicality and outcome. METHODS: The following parameters were evaluated: 1) tumor diameters; 2) tu mor extension toward the middle fossa, the internal auditory canal, the bra instem, and the foramen magnum; 3) bone changes; 4) peritumoral edema; 5) s igns of tumor infiltrative pattern; and 6) surgical radicality. Postoperati ve results were analyzed immediately after the surgery and in a long-term f ollow-up study. RESULTS: Larger tumors affected a younger population and presented a signif icantly shorter time until symptom onset. In the majority of cases (67%), t he tumor extended to the parasellar region. Tumor extension toward the jugu lar foramen was found in 24% of the patients and reached the level of the f oramen magnum in 18%. Irregular tumor margins were found in 67% of the tumo rs, and 50% of them presented peritumoral edema in addition. Interestingly, edema also was found in 20% of tumors with well-delineated margins. CONCLUSION: Tumor size, brainstem compression, and tumor extension laterall y to the internal auditory canal did not influence either the degree of sur gical resection or the long-term outcome (P > 0.05). Supratentorial tumor e xtension to the middle fossa and downward involving the caudal cranial nerv es displayed a significant importance in regard to the surgical radicality and the patient's outcome, respectively (P < 0.05). Radiological evidence o f infiltrative tumor pattern and peritumoral edema at the brainstem surface were important parameters regarding surgical radicality (P < 0.05). Howeve r, only peritumoral edema influenced the long-term results significantly.