INTERESTING IMAGE
Prostate-Specific Membrane Antigen PET/CT in Splenic Sarcoidosis Carsten Kobe, MD,* David Maintz, MD,† Thomas Fischer, PhD,* Alexander Drzezga, MD,* and De-Hua Chang, MD† Abstract: A 65-year-old man who had prostate cancer presented with slightly progressive prostate-specific antigen values. In this situation of biochemical relapse, prostate-specific membrane antigen (PSMA) PET/CT has proven to be superior to choline PET. The 68Ga-PSMA PET/CT of our patient revealed PSMA-positive tissue in the spleen. Although the localization was not typical for metastases, metastasis could not be excluded because of the intense focal tracer uptake. A supplementary MRI was performed but also failed to rule out a malignant origin. Finally, biopsy confirmed benign disease in the spleen in the form of granulomatous disease. Key Words: prostate cancer, PSMA PET/CT, MRI, spleen, sarcoidosis (Clin Nucl Med 2015;40: 897–898)
Received for publication February 25, 2015; revision accepted March 14, 2015. From the Departments of *Nuclear Medicine and †Radiology, University Hospital of Cologne, Cologne, Germany. Conflicts of interest and sources of funding: none declared. Correspondence to: Carsten Kobe, MD, Department of Nuclear Medicine, University Hospital of Cologne, Kerpener Straße 62, 50924 Cologne, Germany. E-mail: [email protected]. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0363-9762/15/4011–0897 DOI: 10.1097/RLU.0000000000000827
REFERENCES 1. Valicenti RK, Thompson I Jr, Albertsen P, et al. Adjuvant and salvage radiation therapy after prostatectomy: American Society for Radiation Oncology/American Urological Association guidelines. Int J Radiat Oncol Biol Phys. 2013;86:822–828. 2. Afshar-Oromieh A, Malcher A, Eder M, et al. PET imaging with a [(68)Ga]galliumlabelled PSMA ligand for the diagnosis of prostate cancer: biodistribution in humans and first evaluation of tumour lesions. Eur J Nucl Med Mol Imaging. 2013;40:486–495. 3. Afshar-Oromieh A, Avtzi E, Giesel FL, et al. The diagnostic value of PET/CT imaging with the (68)Ga-labelled PSMA ligand HBED-CC in the diagnosis of recurrent prostate cancer. Eur J Nucl Med Mol Imaging. 2015;42:197–209. 4. Afshar-Oromieh A, Zechmann CM, Malcher A, et al. Comparison of PET imaging with a (68)Ga-labelled PSMA ligand and (18)F-choline-based PET/CT for the diagnosis of recurrent prostate cancer. Eur J Nucl Med Mol Imaging. 2014;41:11–20. 5. Eiber M, Nekolla SG, Maurer T, et al. 68Ga-PSMA PET/MR with multimodality image analysis for primary prostate cancer. Abdom Imaging. 2014. doi: 10.1007/ s00261-014-0301-z. [Epub ahead of print]. 6. Krohn T, Verburg FA, Pufe T, et al. [(68)Ga]PSMA-HBED uptake mimicking lymph node metastasis in coeliac ganglia: an important pitfall in clinical practice. Eur J Nucl Med Mol Imaging. 2015;42:210–214. 7. Fong ZV, Wong J, Maley WR, et al. Sarcoid-reaction mimicking metastatic malignant hepatopancreatobiliary tumors: report of two cases and review of the literature. J Gastrointest Surg. 2012;16:1245–1250. 8. Ludwig V, Fordice S, Lamar R, et al. Unsuspected skeletal sarcoidosis mimicking metastatic disease on FDG positron emission tomography and bone scintigraphy. Clin Nucl Med. 2003;28:176–179.
Clinical Nuclear Medicine • Volume 40, Number 11, November 2015 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.nuclearmed.com
897
Kobe et al
Clinical Nuclear Medicine • Volume 40, Number 11, November 2015
FIGURE 1. A 65-year-old man who had prostate cancer was referred for further diagnostics during follow-up. Biochemical recurrence after surgery is defined as a detectable or rising prostate-specific antigen (PSA) value that is greater than or equal to 0.2 ng/mL.1 Our patient showed an increasing PSA value of 0.2 ng/mL, which led to suspicion of recurrence. Prostate-specific membrane antigen (PSMA) is a cell surface protein showing high expression in prostate cancer.2 68Ga-PSMA PET/CT detects recurrent prostate cancer in a high number of patients and is known to be highly specific.3 When compared with choline PET/CT, 68 Ga-PSMA PET/CT shows an improved contrast, especially at low PSA levels, which may present new opportunities not only in suspected relapse but primary prostate cancer.4,5 The 68Ga-PSMA PET/CT showed a PSMA-positive lesion in the spleen in the MIP (arrow, A) and in the transversal slice (arrow, B) (SUVmax, 18.4; 5 cm), which was not detectable in the corresponding low-dose CT (C). Although 68Ga-PSMA PET/CT is known for its excellent specificity, the localization of the PSMA-positive tissue appeared not typical for prostate cancer metastasis, and as pitfalls are known, further diagnostic imaging was considered.6 FIGURE 2. The axial T2-weighted MRI demonstrated a hypointense lesion in the spleen (A). The lesion's largest dimension in the transversal plane was 4.9 3.9 cm. The mass was slightly hypointense in the late contrast phase, axial T1-weighted fat saturated contrast-enhanced MRI (4 minutes postinjection) (B). No other pathological findings could be seen. The finding was not specific for a benign splenic lesion such as a hemangioma. A metastasis of prostate cancer, or any malignant disease such as lymphoma, could not be excluded in this case. The additional biopsy performed revealed granulomatous disease most consistent with sarcoidosis. Sarcoidosis is a chronic granulomatous multisystem disease, which predominantly involves the lungs and thoracal lymph nodes, although sarcoid reactions can be found in lymph nodes or in organs and mimic metastatic disease in patients with cancer.7,8 However, isolated involvement of the spleen is a rare finding. Here, we observed that sarcoidosis may show relevant PSMA positivity in PET/CT, mimicking metastasis from prostate cancer.
898
www.nuclearmed.com
© 2015 Wolters Kluwer Health, Inc. All rights reserved. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Prostate-Specific Membrane Antigen PET/CT in Splenic Sarcoidosis Carsten Kobe, MD,* David Maintz, MD,† Thomas Fischer, PhD,* Alexander Drzezga, MD,* and De-Hua Chang, MD† Abstract: A 65-year-old man who had prostate cancer presented with slightly progressive prostate-specific antigen values. In this situation of biochemical relapse, prostate-specific membrane antigen (PSMA) PET/CT has proven to be superior to choline PET. The 68Ga-PSMA PET/CT of our patient revealed PSMA-positive tissue in the spleen. Although the localization was not typical for metastases, metastasis could not be excluded because of the intense focal tracer uptake. A supplementary MRI was performed but also failed to rule out a malignant origin. Finally, biopsy confirmed benign disease in the spleen in the form of granulomatous disease. Key Words: prostate cancer, PSMA PET/CT, MRI, spleen, sarcoidosis (Clin Nucl Med 2015;40: 897–898)
Received for publication February 25, 2015; revision accepted March 14, 2015. From the Departments of *Nuclear Medicine and †Radiology, University Hospital of Cologne, Cologne, Germany. Conflicts of interest and sources of funding: none declared. Correspondence to: Carsten Kobe, MD, Department of Nuclear Medicine, University Hospital of Cologne, Kerpener Straße 62, 50924 Cologne, Germany. E-mail: [email protected]. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0363-9762/15/4011–0897 DOI: 10.1097/RLU.0000000000000827
REFERENCES 1. Valicenti RK, Thompson I Jr, Albertsen P, et al. Adjuvant and salvage radiation therapy after prostatectomy: American Society for Radiation Oncology/American Urological Association guidelines. Int J Radiat Oncol Biol Phys. 2013;86:822–828. 2. Afshar-Oromieh A, Malcher A, Eder M, et al. PET imaging with a [(68)Ga]galliumlabelled PSMA ligand for the diagnosis of prostate cancer: biodistribution in humans and first evaluation of tumour lesions. Eur J Nucl Med Mol Imaging. 2013;40:486–495. 3. Afshar-Oromieh A, Avtzi E, Giesel FL, et al. The diagnostic value of PET/CT imaging with the (68)Ga-labelled PSMA ligand HBED-CC in the diagnosis of recurrent prostate cancer. Eur J Nucl Med Mol Imaging. 2015;42:197–209. 4. Afshar-Oromieh A, Zechmann CM, Malcher A, et al. Comparison of PET imaging with a (68)Ga-labelled PSMA ligand and (18)F-choline-based PET/CT for the diagnosis of recurrent prostate cancer. Eur J Nucl Med Mol Imaging. 2014;41:11–20. 5. Eiber M, Nekolla SG, Maurer T, et al. 68Ga-PSMA PET/MR with multimodality image analysis for primary prostate cancer. Abdom Imaging. 2014. doi: 10.1007/ s00261-014-0301-z. [Epub ahead of print]. 6. Krohn T, Verburg FA, Pufe T, et al. [(68)Ga]PSMA-HBED uptake mimicking lymph node metastasis in coeliac ganglia: an important pitfall in clinical practice. Eur J Nucl Med Mol Imaging. 2015;42:210–214. 7. Fong ZV, Wong J, Maley WR, et al. Sarcoid-reaction mimicking metastatic malignant hepatopancreatobiliary tumors: report of two cases and review of the literature. J Gastrointest Surg. 2012;16:1245–1250. 8. Ludwig V, Fordice S, Lamar R, et al. Unsuspected skeletal sarcoidosis mimicking metastatic disease on FDG positron emission tomography and bone scintigraphy. Clin Nucl Med. 2003;28:176–179.
Clinical Nuclear Medicine • Volume 40, Number 11, November 2015 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.nuclearmed.com
897
Kobe et al
Clinical Nuclear Medicine • Volume 40, Number 11, November 2015
FIGURE 1. A 65-year-old man who had prostate cancer was referred for further diagnostics during follow-up. Biochemical recurrence after surgery is defined as a detectable or rising prostate-specific antigen (PSA) value that is greater than or equal to 0.2 ng/mL.1 Our patient showed an increasing PSA value of 0.2 ng/mL, which led to suspicion of recurrence. Prostate-specific membrane antigen (PSMA) is a cell surface protein showing high expression in prostate cancer.2 68Ga-PSMA PET/CT detects recurrent prostate cancer in a high number of patients and is known to be highly specific.3 When compared with choline PET/CT, 68 Ga-PSMA PET/CT shows an improved contrast, especially at low PSA levels, which may present new opportunities not only in suspected relapse but primary prostate cancer.4,5 The 68Ga-PSMA PET/CT showed a PSMA-positive lesion in the spleen in the MIP (arrow, A) and in the transversal slice (arrow, B) (SUVmax, 18.4; 5 cm), which was not detectable in the corresponding low-dose CT (C). Although 68Ga-PSMA PET/CT is known for its excellent specificity, the localization of the PSMA-positive tissue appeared not typical for prostate cancer metastasis, and as pitfalls are known, further diagnostic imaging was considered.6 FIGURE 2. The axial T2-weighted MRI demonstrated a hypointense lesion in the spleen (A). The lesion's largest dimension in the transversal plane was 4.9 3.9 cm. The mass was slightly hypointense in the late contrast phase, axial T1-weighted fat saturated contrast-enhanced MRI (4 minutes postinjection) (B). No other pathological findings could be seen. The finding was not specific for a benign splenic lesion such as a hemangioma. A metastasis of prostate cancer, or any malignant disease such as lymphoma, could not be excluded in this case. The additional biopsy performed revealed granulomatous disease most consistent with sarcoidosis. Sarcoidosis is a chronic granulomatous multisystem disease, which predominantly involves the lungs and thoracal lymph nodes, although sarcoid reactions can be found in lymph nodes or in organs and mimic metastatic disease in patients with cancer.7,8 However, isolated involvement of the spleen is a rare finding. Here, we observed that sarcoidosis may show relevant PSMA positivity in PET/CT, mimicking metastasis from prostate cancer.
898
www.nuclearmed.com
© 2015 Wolters Kluwer Health, Inc. All rights reserved. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
