Fig. 6

Genome maintenance and DNA damage control pathway. a Image showing the role of poly (ADP-ribose) polymerases (PARP) in DNA repair. PARP1 and PARP2 repair DNA single- or double-DNA strand breaks. In patients with BRCA loss-of-function mutations, PARP 1/2 inhibitors, such as niraparib, are particularly effective as BRCA contribute to DNA repair. b, c CT of the abdomen in 65-year-old woman with platinum resistant ovarian cancer on treatment with niraparib. a Baseline contrast-enhanced CT image before starting niraparib shows multiple hypodense large liver metastases. b Follow-up contrast-enhanced CT image performed two months after starting the treatment shows decreased enhancing component of the various lesions (arrows in c), with minimal interval increase in size in some of the lesions, representing atypical response to treatment