Reading the signs: Radiographic characterization of morphologic subtypes of high-grade serous ovarian cancer (141)

Abstract

<b>Objectives:</b> Discrete patterns of the gross tumor appearance are seen within the singular histologic diagnosis of high-grade serous ovarian cancer (HGSOC). We aimed to identify radiographic features unique to such morphologic subtypes. <b>Methods:</b> Patients with advanced-stage HGSOC underwent laparoscopy prior to treatment, and surgical videos were reviewed to classify gross tumor appearance as type I (an infiltrative disease that distorts surrounding anatomy) or type II (exophytic with well-defined borders) disease. Two radiologists independently reviewed preoperative CT images of 109 patients from this cohort. They categorized disease at eight anatomic sites and assessed for radiographic characteristics of interest, including large infiltrative plaques, mass-like metastases, enhancing peritoneal lining, architectural distortion, fat stranding, calcifications, and lymph node involvement. Radiographic data were described by frequencies and percentages and compared between type I and type II morphology using Chi-square and Fisher's exact tests. Kappa statistics were calculated to assess inter-rater agreement. <b>Results:</b> Fifty-six patients (51%) had type I disease either uniformly or predominantly across anatomic sites upon laparoscopic assessment; however, 38 (35%) patients had type II uniform or predominant morphology. Large infiltrative plaques were more commonly identified by CT in patients with type I disease (89% vs 71%, p=0.04). Mass-like metastases on imaging were correlated with type II morphology (49% vs 23%, p=0.01). Concordance between readers reporting the presence of these features ranged from 0.12-0.79, indicating slight to substantial agreement. Location of radiographically-identified disease did not portend morphologic type, with the exception of the falciform ligament. Falciform involvement on CT scans was more common in type I disease (35% vs 13%, p=0.02). Concordance between radiologists classifying disease at specified sites was fair (κ=0.21-0.41). <b>Conclusions:</b> We identified several radiographic markers for morphologic subtypes of HGSOC. As our understanding of the morphologic subtypes of high-grade serous ovarian cancer grows, knowledge of the radiographic appearance may aid in treatment planning for this population.Fig. 1