Feasibility of whole-body diffusion-weighted MRI for detection of primary tumour, nodal and distant metastases in women with cancer during pregnancy: a pilot study

Objectives To evaluate the feasibility of whole-body diffusion-weighted MRI (WB-DWI/MRI) for detecting primary tumour, nodal and distant metastases in pregnant women with cancer. Methods Twenty pregnant patients underwent WB-DWI/MRI in additional to conventional imaging. Reproducibility of WB-DWI/MRI between two readers was evaluated using Cohen’s κ statistics and accuracy was compared to conventional imaging for assessing primary tumour site, nodal and visceral metastases. Results Both WB-DWI/MRI readers showed good–very good agreement for lesion detection (primary lesions: κ=1; lymph nodes: κ=0.89; distant metastases: κ=0.61). Eight (40 %) patients were upstaged after WB-DWI/MRI. For nodal metastases, WB-DWI/MRI showed 100 % (95 % CI: 83.2–100) sensitivity for both readers with specificity of 99.4 % (96.9–100) and 100 % (80.5–100) for readers 1 and 2, respectively. For distant metastases, WB-DWI/MRI showed 66.7 % (9.4–99.2) and 100 % (29.2–100) sensitivity and specificity of 94.1 % (71.3–99.9) and 100 % (80.5–100) for readers 1 and 2, respectively. Conventional imaging showed sensitivity of 50 % (27.2-72.8) and 33.3 % (0.8–90.6); specificity of 100 % (98–100) and 100 % (80.5–100), for nodal and distant metastases respectively. Conclusions WB-DWI/MRI is feasible for single-step non-invasive staging of cancer during pregnancy with additional value for conventional imaging procedures. Key points • In our study, WB-DWI/MRI was more accurate than conventional imaging during pregnancy. • WB-DWI/MRI improves diagnostic assessment of patients with cancer during pregnancy. • Accurate imaging and oncologic staging improves treatment and outcome.