Intraoperative magnetic resonance imaging during transsphenoidal surgery

Area of Science:

• Neurosurgery
• Radiology
• Oncology

Background:

• Transsphenoidal microsurgery is a common approach for pituitary macroadenomas.
• Assessing complete tumor resection traditionally requires postoperative imaging weeks later.
• Non-hormone-secreting pituitary macroadenomas present unique challenges in surgical resection assessment.

Purpose of the Study:

• To evaluate the efficacy of intraoperative magnetic resonance (MR) imaging in transsphenoidal microsurgery.
• To determine if intraoperative MR imaging improves the assessment of tumor resection for pituitary macroadenomas.
• To assess the impact on complete tumor removal rates and subsequent treatment planning.

Main Methods:

• Utilized a 0.2-tesla intraoperative MR imager in a specialized operating room.
• Performed microsurgery with MR-compatible instruments and acquired coronal/sagittal T1-weighted images.
• Compared intraoperative findings with postoperative 1.5-tesla MR images obtained 2-3 months post-surgery.

Main Results:

• Intraoperative MR imaging enabled ultra-early evaluation of tumor resection in 73% of 44 patients with large pituitary macroadenomas.
• A second intraoperative examination in 24 patients led to additional resection in 15 (34%) for suspected tumor remnants.
• Confirmed reliability of intraoperative assessment compared to conventional postoperative imaging.

Conclusions:

• Intraoperative MR imaging provides a crucial "second look" during surgery for incomplete tumor resection.
• This capability significantly improves the rate of complete tumor removal in pituitary macroadenoma surgeries.
• Facilitates early planning of additional treatments for patients with residual tumor, optimizing patient management.