CT Perfusion as an Early Biomarker of Treatment Efficacy in Advanced Ovarian Cancer: An ACRIN and GOG Study

Purpose: ACRIN 6695 was a feasibility study investigating whether CT perfusion (CTP) biomarkers are associated with progression-free survival (PFS) at 6 months (PFS-6) in patients with advanced ovarian cancer who were treated with carboplatin and either dose-dense (weekly) or conventional (3-weekly) paclitaxel, with optional bevacizumab in the prospective phase III GOG-0262 trial.Experimental Design: ACRIN 6695 recruited participants with residual disease after primary cytoreductive surgery or planned interval cytoreduction following neoadjuvant therapy, to undergo CTP studies before (T0), 3 weeks (T1), and 4 weeks (T2) after chemotherapy initiation. Tumor blood flow (BF) and blood volume (BV) were derived with commercial software. Fisher exact tests assessed the associations of CTP biomarkers changes from T0 to T2 dichotomized at zero with PFS-6 and overall radiographic response rate, while Cox regression assessed the associations between CTP biomarker changes and PFS and overall survival (OS). Bonferroni correction was used to account for multiple comparisons.Results: Seventy-six of 120 enrolled patients from 19 centers were evaluable with a median age of 61 years. BV increase was significantly associated with lower chance of PFS-6 (P = 0.028), while BF achieves borderline significance (P = 0.053). In addition, BF increase was associated with shorter PFS (HR 2.9, 95% CI, 1.3-6.4, P = 0.008) and remained significant after adjusting for age, change in tumor volume, and surgery status (P = 0.007). Neither BF nor BV changes were significantly associated with treatment response rate or OS.Conclusions: Early CTP biomarkers measurement may provide early prognostic information for PFS in newly diagnosed ovarian cancer. Clin Cancer Res; 23(14); 3684-91. ©2017 AACR.