Quantitative measurements of medical images for pharmaceutical clinical trials: comparison between on-site and off-site assessments.

Objective: In pharmaceutical clinical trials, quantitative measurements on medical images are often conducted to confirm drug efficacy. This study aims to compare the quantitative image analysis performance of an off-site core laboratory with the performance of investigators from multiple clinical sites.

Materials And Methods: In a phase I clinical trial, 25 healthy subjects underwent dynamic brain single-photon emission computed tomography (SPECT) scintigraphy with 123I-Altropane, a cocaine analogue with high affinity and selectivity for dopamine transporter sites in the striatum. In 20 patients examined on-site and off-site, a total of 80 measurements were made to calculate the drug's binding potential. A trained technologist off-site at a central core laboratory and on-site investigators at different clinical sites performed the image analysis. These results were compared with measurements made by a subspecialty radiologist whose assessments were the reference standard. Statistical analysis was performed using multiple regression analysis.

Results: Measurements from the central core laboratory (off-site) highly correlated (r = 0.95) with measurements of the reference standard. Measurements from the clinical sites (on-site) grouped together had lower correlation (r = 0.84) with the reference standard. This difference was statistically significant (p < 0.05).

Conclusion: Training and experience in the specific type of image analysis are critical in obtaining consistent data. Quantitative analysis by dedicated personnel at a core laboratory provides highly reproducible results. The findings support off-site assessment of medical images in pharmaceutical clinical trials.