⁶⁸Ga-PSMA-HBED-CC PET for Differential Diagnosis of Suggestive Lung Lesions in Patients with Prostate Cancer

Example PET/CT scans of patient with primary lung cancer (adenocarcinoma). (A) CT shows spiculated lesion in right upper lobe in PC patient after prostatectomy and suspected local recurrence; PSA was 4.09 ng/mL. (B) PSMA PET exhibits focal tracer enhancement in pulmonary lesion (SUV_max, 5.3) and in 2 mediastinal lymph nodes, which were histologically confirmed as primary lung cancer and associated lymph node metastases. This was the only case for which lymph node uptake was evaluated. (C) ¹⁸F-FDG PET as established imaging method of choice for lung cancer shows similar enhancement in primary tumor and 2 mediastinal lymph node metastases.

Distribution of SUV_max for different lesion classes. No significant difference was shown when comparing SUV_max distributions between groups: PC all (n = 76) consisting of PC-proven and PC highly probable vs. lung cancer–proven (n = 7) (P = 0.408) and PC-proven (n = 39) only vs. lung cancer–proven (P = 0.780).

Intraindividual variability of PSMA uptake in pulmonary PC metastases. Shown is distribution of SUV_max for proven or probable pulmonary PC metastases in patients exhibiting 3 or more lesions.

Autoradiography and PSMA immunohistochemistry of exemplary case of primary lung cancer and PSMA immunohistology of tuberculous lesion. (A) PSMA autoradiography of primary lung carcinoma from imaged cohort, which exhibited strong signal in PSMA PET (SUV_max, 5.2). (B) Hematoxylin and eosin stain showing tumor contours. (C) PSMA immunohistochemistry of same tumor, showing detail of tumor region with high cell density and high signal in autoradiography (red arrowhead in A), exhibiting no tumor cells with clear PSMA expression but PSMA in neovasculature (black arrowheads). (D) PSMA immunohistochemistry of case of active tuberculosis from our histologic database, showing PSMA-positive blood vessels (black arrowheads).