Radioimmunoscintigraphy of Colorectal Carcinoma: Patient Guidelines and Technical Considerations

Abstract

Objective: The purpose of this study was to determine optimum acquisition parameters for ¹¹¹In-monoclonal antibodies.

Methods: More than 100 patients were injected with 3–5 mCi ¹¹¹In-monoclonal antibodies and imaged using a large field of view gamma camera with a medium-energy collimator. Planar and SPECT images were obtained on Days 4 and 6.

Results: Planar images obtained on Days 4 and 6 allow for clearance of blood pool activity and increase the tumor-to-background ratio. Liver and pelvic SPECT images processed with the Butterworth filter and the cutoff of 0.35 and order of 5 produced better images with regard to smoothness, noise and edge definition.

Conclusion: The optimal imaging time was on Days 4 and 6. Planar images should be acquired for time and the use of digital images is important. SPECT images offer additional information on all patients.