DW-MRI Lights up Small Ovarian Lesions like Light Bulbs

By MedImaging International staff writers
Posted on 12 Mar 2024

Image: Diffusion-weighted MRI (DW-MRI) has been found to have value in ovarian cancer treatment planning (Photo courtesy of 123RF)

Radiologists face a significant challenge in identifying peritoneal disease on CT scans, which have a mere 11% sensitivity rate for lesions under 5 mm. However, MRI, particularly diffusion-weighted imaging (DW-MRI), shows these lesions much more clearly, illuminating them as if they were light bulbs. This suggests DW-MRI's potential value in the treatment planning of ovarian cancer. Researchers, including those from the Netherlands Cancer Institute (Amsterdam, Netherlands), engaged in the multicenter MISSION trial which focuses not only on the feasibility of achieving complete debulking surgery but also examines the cost-effectiveness of DW-MRI in the diagnostic process of advanced ovarian cancer. The prospective study was designed to follow a routine care pathway and also assess surgical outcomes, interobserver agreement, and MRI’s ability to detect small lesions not identified during initial surgical examination.

The study enrolled 220 patients with advanced-stage (FIGO III/IV) ovarian cancer, aged 65 to 67, scheduled for primary (27 patients) or interval (193 patients) debulking surgery between 2018 and 2023. Exclusions were made for those with debulking or MRI contraindications and any prior malignancy within the last five years. Significantly, surgeons were unaware of preoperative MRI findings and were only exposed to MRI results after completing a thorough abdominal inspection and estimating a Peritoneal Carcinomatosis Index (PCI) score. The study’s results demonstrated that MRI could predict complete primary and interval debulking surgeries with considerable accuracy (AUC 0.9 for primary and AUC 0.83 for interval). However, the researchers noted limitations in detecting lesions smaller than 4 mm.

Additionally, there was strong interobserver agreement, with a score of 0.81. Additionally, surgeons confirmed MRI findings that were initially overlooked during surgical inspection upon reviewing the DW-MRI data. The study also found that MRI was budget-neutral, offsetting the need for diagnostic laparoscopy in certain cases. Although diagnostic laparoscopy effectively predicts complete debulking, it is not an ideal method. The study’s significance lies in its contribution to managing patients with advanced ovarian cancer, who typically have a poor five-year prognosis due to late-stage detection at diagnosis.

Related Links:
Netherlands Cancer Institute