Progress and Future Trends in PET/CT and PET/MRI Molecular Imaging Approaches for Breast Cancer

Abstract

Breast cancer is a major disease with high morbidity and mortality in women worldwide. Increased use of imaging biomarkers has been shown to add more information with clinical utility in the detection and evaluation of breast cancer. To date, numerous studies related to PET-based imaging in breast cancer have been published. Here, we review available studies on the clinical utility of different PET-based molecular imaging methods in breast cancer diagnosis, staging, distant-metastasis detection, therapeutic and prognostic prediction, and evaluation of therapeutic responses. For primary breast cancer, PET/MRI performed similarly to MRI but better than PET/CT. PET/CT and PET/MRI both have higher sensitivity than MRI in the detection of axillary and extra-axillary nodal metastases. For distant metastases, PET/CT has better performance in the detection of lung metastasis, while PET/MRI performs better in the liver and bone. Additionally, PET/CT is superior in terms of monitoring local recurrence. The progress in novel radiotracers and PET radiomics presents opportunities to reclassify tumors by combining their fine anatomical features with molecular characteristics and develop a beneficial pathway from bench to bedside to predict the treatment response and prognosis of breast cancer. However, further investigation is still needed before application of these modalities in clinical practice. In conclusion, PET-based imaging is not suitable for early-stage breast cancer, but it adds value in identifying regional nodal disease and distant metastases as an adjuvant to standard diagnostic imaging. Recent advances in imaging techniques would further widen the comprehensive and convergent applications of PET approaches in the clinical management of breast cancer.

Breast cancer: initial workup and staging with FDG PET/CT

“…Hybrid PET-MRI imaging has also shown interesting performances [ 21 ]. In a group of 36 patients, the 37 known index cancers were detected by PET and MRI [ 22 ].…”

“…Better performances are expected with high-resolution PEM imaging [ 20 ], as well as with PET/MRI imaging [ 21 , 22 ]. In a group of 36 patients, the 37 known index cancers were detected by PET and MRI; 47 satellite lesions were additionally detected on MRI, of which 23 were avid for FDG, with a multifocal/multicentric character in 21 (58%) patients [ 22 ].…”

Primitive neuroectodermal tumor of the pericardium: a case report and literature review

“…Solid and mixed cystic changes of the tumor were related to inadequate blood supply to the corresponding region in the tumor. PET-CT used in the first occurrence of this patient was due to the advantage of PET-CT/PET-MRI could detect the distant metastasis [ 11 ]. PET-CT is much better in detecting lung metastasis, and PET-MRI is much better in detecting liver as well as bone metastasis [ 11 ].…”

The Present and Future of Neoadjuvant Endocrine Therapy for Breast Cancer Treatment

“…Nevertheless, there are some limitations to this technique, as low-proliferation tumors (luminal A-like, lobular), which otherwise are the best candidates for NET, have a lower glucose metabolism [ 72 ] and this may affect the interpretation of the response. An interesting alternative would be to employ 18 F-fluoroestradiol ( 18 F-FES) as radionuclide [ 73 , 74 , 75 ]. 18 F-FES PET/CT can measure the in vivo binding of estrogens and thus can be used to assess the biological activity of ER.…”

“…Unfortunately, these novel radiotracers are still not available in most centers and remain at the research stage, although they look very promising as an option in the NET setting. The combination of techniques such as MR imaging and FDG PET-TC, which are available in only a few facilities, might offer advantages for primary breast cancer therapy response assessment [ 63 , 73 ], yet further investigation is required in this field.…”