Effectiveness of Breast MRI and¹⁸F-FDG PET/CT for the Preoperative Staging of Invasive Lobular Carcinoma versus Ductal Carcinoma

Abstract

PurposeWe evaluated the utility of magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for the preoperative staging of invasive lobular carcinoma (ILC) of the breast and compared the results with those of invasive ductal carcinoma (IDC).MethodsThe study included pathologically proven 32 ILCs and 73 IDCs. We compared clinical and histopathological characteristics and the diagnostic performances of MRI and 18F-FDG PET/CT for the primary mass, additional ipsilateral and/or contralateral lesion(s), and axillary lymph node metastasis between the ILC and IDC groups.ResultsPrimary ILCs were greater in size, but demonstrated lower maximum standardized uptake values than IDCs. All primary masses were detected on MRI. The detection rate for ILCs (75.0%) was lower than that for IDCs (83.6%) on 18F-FDG PET/CT, but the difference was not significant. For additional ipsilateral lesion(s), the sensitivities and specificities of MRI were 87.5% and 58.3% for ILC and 100.0% and 66.7% for IDC, respectively; whereas the sensitivities and specificities of 18F-FDG PET/CT were 0% and 91.7% for ILC and 37.5% and 94.7% for IDC, respectively. The sensitivity of 18F-FDG PET/CT for ipsilateral lesion(s) was significantly lower in the ILC group than the IDC group. The sensitivity for ipsilateral lesion(s) was significantly higher with MRI; however, specificity was higher with 18F-FDG PET/CT in both tumor groups. There was no significant difference in the diagnostic performance for additional contralateral lesion(s) or axillary lymph node metastasis on MRI or 18F-FDG PET/CT for ILC versus IDC.ConclusionThe MRI and 18F-FDG PET/CT detection rates for the primary cancer do not differ between the ILC and IDC groups. Although 18F-FDG PET/CT demonstrates lower sensitivity for primary and additional ipsilateral lesions, it shows higher specificity for additional ipsilateral lesions, and could play a complementary role in the staging of ILC as well as IDC.

PET/MRI in Breast Cancer

“…DCE breast MRI has a high sensitivity, reported at up to 100%, and a positive predictive value above 35% . PET/CT is not routinely performed for breast cancer detection because is it not adequately sensitive, especially for lobular cancers and for cancers less than 1 cm . Authors have investigated whether combining DCE MRI and PET data in the breast can improve the diagnostic accuracy for breast cancer, but have found that the addition of PET often decreases the sensitivity of DCE‐MRI.…”

“…Two additional studies demonstrated MRI to be more sensitive than PET/CT for the detection of multifocal breast cancer, while PET/CT demonstrated higher specificity. Jung et al compared the two modalities among 105 biopsy‐proven breast cancers. MRI detected all 105 primary tumors, while PET/CT identified 85/105 (81.0%) primary tumors.…”

Breast PET/MR Imaging

“…When comparing 18 FDG-PET/CT with breast MR imaging for the identification of breast cancers, MR imaging demonstrates increased sensitivity, 7,37,38 especially in subcentimeter lesions, 10,39,40 nonmass lesions, 10 and lobular cancers. 37 Moreover, DCE-MR imaging has been shown to be more sensitive alone than when combined with PET.…”

“…37 Moreover, DCE-MR imaging has been shown to be more sensitive alone than when combined with PET. 7,10,41 …”

“…MR imaging has been shown to be more sensitive but less specific than PET/CT 37,38,42 or PET alone for multifocality, 43 whereas PET/CT has generally been shown to have a higher sensitivity for axillary nodal metastases. 38,42,43 PET and MR imaging have demonstrated similar performance for the detection of internal mammary adenopathy.…”