What imaging is used for pituitary (adenoma) tumors?

From the Guidelines

Magnetic Resonance Imaging (MRI) with contrast is the preferred imaging modality for pituitary tumors, and a dedicated pituitary protocol MRI should include thin-slice T1-weighted images before and after gadolinium contrast administration, along with T2-weighted sequences in multiple planes. This recommendation is based on the most recent and highest quality study available, which suggests that MRI provides detailed visualization of the pituitary gland, adjacent structures, and any abnormal tissue 1. The use of contrast-enhanced MRI is essential for comprehensive evaluation, as it helps distinguish between cystic and solid components, assess vascularity, and determine the relationship to critical structures like the optic chiasm and cavernous sinuses.

Some key points to consider when using MRI for pituitary tumors include:

• The use of high-resolution pituitary protocols to reliably depict anatomy and pathologies involving the pituitary gland, infundibulum, optic chiasm, and vascular structures 1
• The importance of using contrast-enhanced MRI to characterize lesions of the sella, suprasellar cistern, and any cavernous sinus invasion 1
• The potential use of 3-Tesla MRI for surgical planning or intra-operative MRI, as it enhances anatomical definition and might improve completeness of resection without altering complication rates 1
• The consideration of molecular (functional) imaging, such as hybrid imaging techniques using ligands like 11C-methionine or 18F-fluoroethyltyrosine, in patients with suspected pituitary adenoma where MRI is negative or equivocal 1

Overall, the use of MRI with contrast is the preferred imaging modality for pituitary tumors, and a dedicated pituitary protocol MRI should be used to provide detailed visualization of the pituitary gland and adjacent structures.

From the FDA Drug Label

Gadoteridol was evaluated in two multicenter trials of 310 evaluable patients suspected of having neurological pathology. In another multicenter study of 49 evaluable adult patients with known intracranial tumor with high suspicion of having cerebral metastases, two doses of gadoteridol were administered. Gadoteridol was given in one single 0. 1 mmol/kg dose. Repeat dosing was not studied. The results of the non-contrast and gadoteridol MRI scans were compared. In this database, MRI enhancement was noted in approximately 60% of the scans and additional diagnostic information in 30 to 95% of the scans.

Imaging for Pituitary Tumor:

• MRI is used for imaging pituitary tumors.
• Gadoteridol can be used as a contrast agent to improve visualization of the tumor.
• The recommended dose of Gadoteridol is 0.1 mmol/kg IV.
• In some cases, a second dose of 0.2 mmol/kg may be administered to improve visualization and border definition of the tumor 2.

From the Research

Imaging Modalities for Pituitary Tumors

• Magnetic Resonance Imaging (MRI) is the primary imaging tool for evaluating pituitary gland pathology 3, 4, 5, 6, 7
• MRI plays a central role in treatment planning for most patients with pituitary tumors 3
• High-resolution MRI at 3T provides superior spatial resolution and signal intensity, leading to significant improvements in image quality 7
• Dynamic contrast-enhanced T1-weighted sequences are crucial for the diagnosis of microadenoma and specific enhancement characteristic of some other tumors 4

Molecular Imaging

• Molecular imaging is a potential game-changer for precise localization of sites of active disease and enabling safe and effective targeted intervention 3
• Positron Emission Tomography (PET) is the preferred modality for pituitary and parasellar imaging due to its superior spatial resolution and sensitivity compared with Single Photon Emission Computed Tomography (SPECT) 3
• PET radioligands targeting specific molecular pathways relevant to pituitary adenoma biology are increasingly preferred and are beginning to find application in routine clinical practice 3

Follow-up and Monitoring

• MRI is the examination of choice for diagnosing and monitoring pituitary adenoma, whether treated or not 5
• The optimal frequency for pituitary MRI monitoring depends on the type, size, and location of the pituitary tumor and the clinical situation in general 5
• Repeating MRI examinations too often can be costly and may lead to tissue accumulation of gadolinium atoms, highlighting the need for monitoring algorithms to guide clinicians 5