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

Abstract

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. 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. 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). 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.