Background: It is not clear if changes in lesion volume might represent a clinically relevant and statistically advantageous outcome parameter in early phase trials of novel drugs aimed at preventing bleeding in cerebral cavernous malformations (CCM). Methods: We analyzed the modified intention to treat cohort (33 patients receiving atorvastatin and 31 placebo) who contributed at least one paired imaging biomarker in the recently completed double-blinded randomized controlled AT CASH EPOC trial (clinicaltrials.gov NCT02603328). We examined prospective changes in CCM lesion volume and correlated these with symptomatic hemorrhage (SH) events. We contemporaneously assessed changes in lesional iron content by quantitative susceptibility mapping (QSM) on MRI, and objective (mRS) and subjective (EQ-VAS) functional status. We also simulated sample sizes needed to detect potential effects of a drug on lesion volume. Results: There was excellent correlation between independently assessed maximum lesion diameter and CCM lesion volume (R 2 = 0.68, P0.05), including in brainstem lesions analyzed separately. Sample size simulations indicate larger numbers of cases needed to demonstrate a drug effect on changes in lesion volume than those needed to detect an effect on QSM change with a=0.05 and b=0.8, and even larger samples to detect effects on the proportion of cases with increased or decreased lesion volume. Conclusion: Changes in lesion volume occur frequently in CCM lesions after recent SH, but do not correlate with measures of bleeding in the lesions, nor appear to reflect functional changes. And they are not statistically advantageous in comparison to QSM measures for detecting potential drug effects.
Alcazar et al. (Thu,) studied this question.