Predicting tumor response and outcome of second-look surgery with (18)F-FDG PET/CT: insights from the GINECO CHIVA phase II trial of neoadjuvant chemotherapy plus nintedanib in stage IIIc-IV FIGO ovarian cancer

BACKGROUND: This ancillary study aimed to evaluate (18)F-FDG PET parameter changes after one cycle of treatment compared to baseline in patients receiving first-line neoadjuvant anti-angiogenic nintedanib combined to paclitaxel-carboplatin chemotherapy or chemotherapy plus placebo and to evaluate the ability of (18)F-FDG PET parameters to predict progression-free survival (PFS), overall survival (OS), and success of second-look surgery. MATERIALS AND METHODS: Central review was performed by two readers blinded to the received treatment and to the patients’ outcome, in consensus, by computing percentage change in PET metrics within a volume of interest encompassing the entire tumor burden. EORTC and PERCIST criteria were applied to classify patients as responders (partial metabolic response and complete metabolic response) or non-responders (stable metabolic disease and progressive metabolic disease). Also analyzed was the percentage change in metabolic active tumor volume (MATV) and total lesion glycolysis (TLG). RESULTS: Twenty-four patients were included in this ancillary study: 10 received chemotherapy + placebo and 14 chemotherapy + nintedanib. PERCIST and EORTC criteria showed similar discriminative power in predicting PSF and OS. Variation in MATV/TLG did not predict PFS or OS, and no optimal threshold could be found for MATV/TLG for predicting survival. Complete cytoreductive surgery (no residual disease versus residual disease < 0.25 cm/0.25–2.5 cm/> 2.5 cm) was more frequent in responders versus non-responders (P = 0.002 for PERCIST and P = 0.02 for EORTC criteria). No correlation was observed between the variation of PET data and the variation of CA-125 blood level between baseline sample and that performed contemporary to the interim PET, but a statistically significant correlation was observed between ΔSUL(peak) and ΔCA-125 between baseline sample and that performed after the second cycle. CONCLUSION: (18)F-FDG PET using EORTC or PERCIST criteria appeared to be a useful tool in ovarian cancer trials to analyze early tumor response, and predict second-look surgery outcome and survival. An advantage of PERCIST is the correlation of ΔSUL(peak) and ΔCA-125, PET response preceding tumor markers response by 1 month. Neither MATV nor TLG was useful in predicting survival. TRIAL REGISTRATION: NCT01583322 ARCAGY/ GINECO GROUP GINECO-OV119, 24 April 2012 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00259-020-05092-3.