Dual-Energy CT in Breast Cancer: Current Applications and Future Outlooks

Abstract

Breast cancer is the most prevalent cancerous tumor in women, characterized by different subtypes and varying responses to treatment. The continued evolution of breast cancer diagnosis and management has resulted in a transition from a one-size-fits-all approach to a new era of personalized treatment plans. Therefore, it is essential to accurately identify the biological characteristics of breast tissue in order to minimize unnecessary biopsies of benign lesions and improve the overall clinical process, leading to reduced expenses and complications associated with invasive biopsy procedures. Challenges for future research include finding ways to predict the response of breast cancer patients to adjuvant systemic treatment. Dual-energy CT (DECT) is a new imaging technology integrating functional imaging and molecular imaging. Over the past decade, DECT has gained relevancy, especially in oncological radiology. This article proposed a literature review of the application and research status of DECT in breast cancer treatment strategy determination and prognosis prediction.

Keywords: Breast cancer; Clinical diagnosis; Dual‐energy CT; Prognosis prediction; Quantitative parameters.

FIGURE 1

CT and dual‐energy CT. Female, metastasis from colorectal cancer. A Mixed image. The enhancing arteries within the lesion (light blue arrowheads) have density similar to intralesional calcifications (red arrowhead). B Material labeling. The material decomposition evaluates the different attenuation curves of the basis materials, allowing for material labeling (iodine: blue map and arrowheads; calcium: red map and arrowheads).

FIGURE 2

Dual‐source CT. Male, gout. A Dual‐energy acquisition, 80/150 Sn kVp, mixed 0.5, coronal; arrowheads on hyperdense deposits on the right and left knees. Material decomposition allows for labeling of monosodium urate crystals in green on coronal (B) (arrowheads) with volumetric estimation.

FIGURE 3

Illustration of five different methods of dual‐energy CT data acquisition. 1 dual tubes with or without beam filtration,2 the fast kV switching of single tubes, 3 dual‐layer detector with single tube, 4 single tube with split filter, 5 single tube with sequential dual scans.

FIGURE 4

Example of a mono‐energetic reconstruction of a lung cancer patient. Various keV energy levels are reconstructed ranging from 40 keV to 180 keV. The bottom right panel shows the average Hounsfield Unit inside the region of interested together with an estimate of contrast‐to‐noise ratio, showing that 75 keV was optimal for this patient.

FIGURE 5

46‐year‐old female patient with recurrent invasive ductal breast cancer. Solid tumor with irregular margins and a mean density of 83.6 HU on the conventional CT‐image (a), an iodine‐uptake of 1.39 mg/ml in the iodine‐map (b), an elevated Zeffective value of 8.10 on the Zeffective‐map (c) and increasing mean densities in the virtual monoenergetic images from 57.9 HU at 100 keV (d), over 78.11 HU at 70 keV (e) to 161.8 HU at 40 keV (f).