Molecular imaging of HER2-positive breast cancer: a step toward an individualized 'image and treat' strategy

PURPOSE OF REVIEW: HER2 overexpression is correlated with aggressive tumor behavior and poor clinical outcome. Therefore, HER2 has become an important prognostic and predictive factor, as well as a target for molecular therapies. The article reviews recent advances in molecular imaging of HER2 that could facilitate individual approaches to targeted therapy of HER2-positive breast cancers. RECENT FINDINGS: Because of the heterogeneity of breast cancer and possible discordance in HER2 status between primary tumors and distant metastases, assessment of HER2 expression by non-invasive imaging may become an important complement to immunohistochemistry or fluorescence in situ hybridization analyses of biopsied tissue. Monoclonal antibodies such as trastuzumab and pertuzumab, or small scaffold proteins such as Affibody molecules are used as HER2-targeting agents. For imaging purposes, these agents are labelled with positron-, gamma-emitting radionuclides, optical dyes, or paramagnetic contrast molecules for PET, SPECT, optical, and magnetic resonance imaging, respectively. HER2-specific molecular probes combined with modern imaging techniques, providing information on HER2 expression not only in primary tumors but also in distant metastases not amenable to biopsy may reduce problems with false negative results and, thereby, influence patient management by selecting patients that would benefit from HER2-targeted therapies. SUMMARY: The new “Image and Treat” strategy, involving assessment of target presence and distribution in an individual patient followed by optimized, target-specific drug delivery, may potentially improve efficacy of cancer treatment while reducing side effects

'Image and treat': an individualized approach to urological tumors

PURPOSE OF REVIEW: The current treatment options for advanced urologic cancers demonstrate limited efficacy. To obtain optimal clinical results, there is a need for new, individualized, therapeutic strategies, which has only recently been applied to these malignancies. Nuclear medicine plays an increasing role in establishing imaging biomarkers necessary for personalized medicine. This review focuses on the current status of the “image and treat” approach combining molecular imaging with targeted radionuclide therapy of urological malignancies RECENT FINDINGS: Tumour-specific targets in uro-oncology are showing promising results for development of personalized therapy using positron emission tomography/computed tomography (PET/CT) molecular imaging and radioimmunotherapy (RIT). The antibody cG250, which binds to carbonic anhydrase IX (CAIX), is being evaluated as a radiolabelled imaging and therapeutic agent in clear cell renal cell carcinoma (ccRCC). (124)I -cG250 PET/CT has demonstrated excellent targeting of ccRCC. Prostate specific membrane antigen (PSMA) is a promising target for both PET/CT and RIT of prostate cancer. HER2 may be another potential target in bladder and prostate cancer. SUMMARY: Tumour-specific targets and biomarkers are being studied for PET/CT and RIT. This may lead to development of new therapeutic strategies. However, considerable investment in new research will be required for personalized medicine to be routinely used in uro-oncology

COVID-19-Associated Erythema Nodosum Detected on FDG PET/CT

We report the case of a 69-year-old woman who underwent 18F-FDG PET/CT due to prolonged fever. One month before, the patient was diagnosed with COVID-19 infection. The 18F-FDG PET/CT showed several subcutaneous nodules with 18F-FDG uptake on the thorax and upper extremities and bilateral lung infiltrates due to organizing pneumonitis. Clinical examination revealed multiple tender nodules on thorax, arms, and legs, consistent with erythema nodosum (EN) induced by COVID-19 infection. The woman was treated with prednisone with a good effect on EN. To our knowledge, this is the first report on EN secondary to COVID-19 infection diagnosed on 18F-FDG PET/CT

Prostate specific membrane antigen- a target for imaging and therapy with radionuclides

Prostate cancer continues to represent a major health problem, and yet there is no effective treatment available for advanced metastatic disease. Thus, there is an urgent need for the development of more effective treatment modalities that could improve the outcome. Because prostate specific membrane antigen (PSMA), a transmembrane protein, is expressed by virtually all prostate cancers, and its expression is further increased in poorly differentiated, metastatic, and hormone-refractory carcinomas, it is a very attractive target. Molecules targeting PSMA can be labelled with radionuclides to become both diagnostic and/or therapeutic agents. The use of PSMA binding agents, labelled with diagnostic and therapeutic radio-isotopes, opens up the potential for a new era of personalized management of metastatic prostate cancer

Positron emission tomography/computed tomography and radioimmunotherapy of prostate cancer

PURPOSE OF REVIEW: Traditional morphologically based imaging modalities are now being complemented by positron emission tomography (PET)/computerized tomography (CT) in prostate cancer. Metastatic prostate cancer is an attractive target for radioimmunotherapy (RIT) since no effective therapies are available. This review highlights the most important achievements within the last year in PET/CT and RIT of prostate cancer. RECENT FINDINGS: Conflicting results exist on the use of choline for detection of malignant disease in the prostate gland. The role of PET/CT in N-staging remains to be elucidated further. However, (18)F-choline and (11)C-choline PET/CT have been demonstrated to be useful for detection of recurrence. (18)F-choline and (18)F-fluoride PET/CT are useful for detection of bone metastases. Prostate tumor antigens may be used as targets for RIT. Prostate specific membrane antigen (PSMA) is currently under focus of a number of diagnostic and therapeutic strategies. J591, a monoclonal antibody, that targets the extracellular domain of PSMA, shows promising results. HER2 receptors may also have a potential as target for PET/CT imaging and RIT of advanced prostate cancer. SUMMARY: PET/CT in prostate cancer has proven to play a significant role, in particular for detection of prostate cancer recurrence and bone metastases. Radioimmunotherapy of metastatic prostate cancer warrant further investigations