Ye Young Seo

Effectiveness of Breast MRI and 18F-FDG PET/CT for the Preoperative Staging of Invasive Lobular Carcinoma versus Ductal Carcinoma

Purpose We 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). Methods The 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. Results Primary 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. Conclusion The 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.

FDG uptake in fat necrosis following transverse rectus abdominis myocutaneous (TRAM) flap reconstructed breasts: 3 cases.

Abstract: We describe 3 cases of fat necrosis with increased FDG uptake in patients with breast cancer who underwent mastectomy and then transverse rectus abdominis myocutaneous (TRAM) flap reconstruction. PET/CT performed for restaging showed focal FDG uptake in the reconstructed breast. The FDG uptake corresponded to irregular fibrotic nodular lesions containing fat density or calcification in accompanying CT images. Subsequent ultrasound examination demonstrated ill-defined echogenic lesions with internal hypoechoic components. Fat tissue rich flap used for breast reconstruction may be injured by surgical manipulation. Abnormal FDG uptake in this setting is most likely due to fat necrosis, rather than recurrent tumor.

Clinical Significance of F-18 FP-CIT Dual Time Point PET Imaging in Idiopathic Parkinson’s Disease

PurposeThe purpose of this study was to investigate the diagnostic value of dual time point F-18 FP-CIT PET imaging in idiopathic Parkinson’s disease (PD).Materials and MethodsTwenty-four patients with PD (mean age 69.6) and 18 healthy people (mean age 70.26) underwent two sequential PET/CT scans (dual time point imaging) at 90 and 210 min after F-18 FP-CIT injection. Tracer activity of region of interest was measured in the caudate, putamen and a reference region in the brain from both time points. The outcome parameter was the striatooccipital ratio (SOR). Normal SOR values were obtained in the control group. The percent change in tracer activity between 90- and 210-min images was calculated. The SOR values and the percent change in tracer activity were compared between the patients and healthy control group.ResultsThe SOR values for the caudate, anterior and posterior putamen at both 90- and 210-min images were significantly reduced in the patients with PD. The lowest P value was obtained for the anterior and posterior putamen (p < 0.001) at both time points. There were significant differences of the percent change in tracer activity for the anterior and posterior putamen in the two groups (p = 0.01).ConclusionsF-18 FP-CIT PET scans at 90 and 210 min after injection are both able to diagnose PD. Therefore, the 90-min image by itself is sufficient for diagnosing PD.