Assessment of Capillary Permeability Using Radiolabeled Albumin and 3D CZT-ring Gamma Camera

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Immune checkpoint inhibitors (ICIs) like pembrolizumab are crucial in cancer therapy.
• Capillary leak syndrome (CLS) is a rare but serious adverse effect of ICIs.
• Early diagnosis of ICI-related CLS is vital for patient management.

Purpose of the Study:

• To evaluate the utility of dynamic scintigraphy in diagnosing immune checkpoint inhibitor-related capillary leak syndrome.
• To demonstrate the capability of 3D CZT SPECT imaging in assessing vascular permeability.

Main Methods:

• A patient receiving paclitaxel, carboplatin, and pembrolizumab for breast carcinoma presented with symptoms suggestive of CLS.
• Dynamic scintigraphy was performed using technetium-99m-labeled human serum albumin with induced venous stasis.
• 3D CZT SPECT imaging was utilized for volumetric leak assessment.

Main Results:

• Baseline imaging showed symmetrical vascular activity.
• Venous stasis induced progressive, unilateral tracer uptake, indicating albumin extravasation.
• Incomplete tracer washout was observed, confirming persistent capillary leakage.
• Volumetric leak imaging accurately localized the sites of capillary leakage.

Conclusions:

• Dynamic scintigraphy with technetium-99m-labeled albumin is effective in diagnosing ICI-related CLS.
• 3D CZT-ring cameras offer valuable functional assessment of vascular permeability.
• This technique aids in precise localization and characterization of capillary leakage.