DSC-MRI in Measuring Relative Cerebral Blood Volume for Early Response to Bevacizumab in Patients with Recurrent Glioblastoma

Summary

Objectives

PRIMARY OBJECTIVE:
I. To determine whether binary changes (increase versus [vs.] decrease) in normalized rCBV within enhancing tumor from baseline scan (S0) to post-dose 1 treatment scan (S1) is associated with overall survival (OS) in recurrent glioblastoma (GBM) patients receiving bevacizumab or its biosimilars for the first time.

SECONDARY OBJECTIVES:
I. To determine whether the baseline S0 normalized rCBV measure alone is associated with OS.
II. To determine whether change in normalized rCBV within enhancing tumor as a continuous variable is associated with OS.
III. To determine whether change in normalized rCBV within enhancing tumor as a continuous variable is associated with OS when adjusting for change in enhancing tumor volume and other potential confounders.
IV. To determine whether baseline cerebral blood flow (CBF) or changes in CBF are associated with OS.
V. To determine the association between standardized rCBV and OS.
VI. To determine whether baseline normalized rCBV or change in normalized rCBV are associated with progression-free survival (PFS).
VII. To determine whether baseline CBF or change in CBF are associated with PFS.
VIII. To determine the association between standardized rCBV and PFS.

EXPLORATORY OBJECTIVE:
I. To measure the repeatability of normalized rCBV and standardized rCBV at baseline (pre-bevacizumab or biosimilar).

OUTLINE:
Patients undergo DSC-MRI within 3 days before bevacizumab initiation and in 12-25 days before their second bevacizumab infusion is given.

After completion of study intervention, patients are followed up every 3 months for 5 years.