Prevalence of interstitial pneumonia suggestive of COVID-19 at 18F-FDG PET/CT in oncological asymptomatic patients in a high prevalence country during pandemic period: a national multi-centric retrospective study.

PURPOSE: To assess the presence and pattern of incidental interstitial lung alterations suspicious of COVID-19 on fluorine-18-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) ([18F]FDG PET/CT) in asymptomatic oncological patients during the period of active COVID-19 in a country with high prevalence of the virus. METHODS: This is a multi-center retrospective observational study involving 59 Italian centers. We retrospectively reviewed the prevalence of interstitial pneumonia detected during the COVID period (between March 16 and 27, 2020) and compared to a pre-COVID period (January-February 2020) and a control time (in 2019). The diagnosis of interstitial pneumonia was done considering lung alterations of CT of PET. RESULTS: Overall, [18F]FDG PET/CT was performed on 4008 patients in the COVID period, 19,267 in the pre-COVID period, and 5513 in the control period. The rate of interstitial pneumonia suspicious for COVID-19 was significantly higher during the COVID period (7.1%) compared with that found in the pre-COVID (5.35%) and control periods (5.15%) (p < 0.001). Instead, no significant difference among pre-COVID and control periods was present. The prevalence of interstitial pneumonia detected at PET/CT was directly associated with geographic virus diffusion, with the higher rate in Northern Italy. Among 284 interstitial pneumonia detected during COVID period, 169 (59%) were FDG-avid (average SUVmax of 4.1). CONCLUSIONS: A significant increase of interstitial pneumonia incidentally detected with [18F]FDG PET/CT has been demonstrated during the COVID-19 pandemic. A majority of interstitial pneumonia were FDG-avid. Our results underlined the importance of paying attention to incidental CT findings of pneumonia detected at PET/CT, and these reports might help to recognize early COVID-19 cases guiding the subsequent management.

Scintimammography with a hybrid SPECT/CT imaging system.

BACKGROUND: Planar scintimammography is useful for characterizing breast lesions >10 mm. Our aim was to evaluate Tc-99m sestamibi scintimammography with a hybrid (SPECTICT) device for functional anatomical mapping (FAM). PATIENTS AND METHODS: Three planar images and a chest SPECT/CT were performed with a hybrid device in 53 patients with mammographically suspicious lesions. The final histopathological diagnosis was obtained after surgery. RESULTS: The planar images were positive in 27 out of 37 carcinomas (sensitivity 73%) and the SPECT/CT in 33 (sensitivity 89.2%). The sensitivity of planar imaging and SPECT/CT was 42.9% and 71.4% in cancers < or =10 mm, and 91.3%, and 100% in cancers >10 mm, respectively. The specificity was 93.8% for both planar and SPECT/CT imaging; accuracy was 79.2% for planar scans and 90.6% for SPECT/CT. FAM was useful in providing a precise anatomical localisation of the SPECT findings. CONCLUSION: SPECT/CT scintimammography using a hybrid device is able to detect breast cancer, showing a sensitivity higher than that of planar images, especially for small cancers.

High-resolution gamma-camera for molecular breast imaging: First clinical results.

Scintimair mography is a molecular breast imaging technique using tumour-seeking radiopharmaceuticals; with standard gamma-cameras, is proved of value especially when mammography is indeterminate and in women with dense breasts; nevertheless, this technique shows a high sensitivity only for cancers >1 cm. The issue of detecting small cancers is critical for the future development and clinical usefulness of breast imaging with radiopharmaceuticals, because other modalities are increasingly employed for early identification of small abnormalities. The use of high-resolution dedicated cameras for breast imaging is the best option to improve small cancers' detection: they allow greater flexibility in patient positioning, and the availability of projections similar to those of mammography. Moreover, the detector can be placed directly against the breast, and a mild compression is possible, with the results of reducing breast thickness, increasing the target-to-background ratio and the sensitivity. Our first clinical findings using the dedicased camera Lumagem 3200S (Gamma Medica, Inc., Northridge, USA) are very satisfactory. Till now, 29 patients with BI-RADS category III and IV lesions

Scintimammography for the detection of breast cancer.

Scintimammography is a functional imaging technique whereby radionuclide tracers in the patient's breasts are observed with a radiation-detection camera (gamma-camera). Tracers are designed to accumulate in tumors more than in healthy tissue; the most common tracers used to date are Tc-99m sestamibi and Tc-99m tetrofosmin. Scintimammography is useful in some clinical indications as an adjunct to mammography and to reduce the rates of negative biopsies, and it is recommended for lesions where additional information is required to reach a definitive diagnosis. Patients with equivocal mammograms may benefit from this test, as well as women with dense breasts and those with implants, since scintigraphy is not affected by breast density and the photons arising from the radiotracer are not overly attenuated by implants. Scintimammography is also of value in patients with locally advanced breast cancer, for monitoring and predicting the response to neoadjuvant chemotherapy. The near availability of high-resolution breast-dedicated cameras will allow the suboptimal sensitivity in detecting cancers of less than 1 cm to be improved; this is currently the main limitation of scintimammography. These new devices also have the potential to increase the number of breast scintigraphies performed and the role of nuclear medicine in breast cancer imaging.