Application of 68Ga-PSMA-11 PET/CT in the Diagnosis of Prostate Cancer Clinical Relapse.

BACKGROUND: This work aims to present a nuclear medicine imaging service's data regarding applying positron emission-computing tomography (PET/CT) scans with the radiopharmaceutical 68Ga-PSMA-HBED-CC (68Ga-PSMA-11) to diagnose prostate cancer clinical relapse. METHODS: Eighty patients with a mean age of 68.26 years and an average prostatic-specific antigen blood level of 7.49 ng/ml (lower concentration = 0.17 ng/ml) received 68Ga-PSMA-11 intravenously, and full-body images of PET-CT scan were obtained. Of the total of patients admitted to the imaging service, 87.5% were examined for disease's biochemical recurrence and clinical relapse, and 70.0% had a previous radical prostatectomy (RP). RESULTS: Of the patients without RP, 95.8% were detected with intra-glandular disease. The 68Ga- PSMA-11 PET/CT imaging results revealed small lesions, even in patients with low blood levels of prostatic-specific antigen, mainly in metastatic cancer cases in lymph nodes and bones. CONCLUSION: The 68Ga-PSMA-11 PET/CT imaging was essential in detecting prostate cancer, with significantly high sensitivity in detecting recurrent cases. Due to its inherent reliability and sensitivity, PET/CT scanning with 68Ga-PSMA-11 received an increasing number of medical requests throughout the present follow-up study, confirming the augmented demand for this clinical imaging procedure in the regional medical community.

Vaccine-Related Lymph Nodes: The Emerging Pitfalls of 18F-Fluorocholine and 68Ga-PSMA-11 PET/CT in the Era of COVID-19 Vaccination.

PURPOSE: Vaccination against coronavirus disease 2019 (COVID-19) is currently under worldwide deployment. The consequences of this vaccination can be seen in radiology and nuclear medicine explorations with visualization of axillary lymph nodes (LNs), as observed on ultrasonography, MRI, or 18F-FDG PET/CT.We aimed to evaluate on PET/CT the incidence of vaccine-related LNs and their characteristics after COVID-19 vaccination, using several radiopharmaceuticals different from 18F-FDG. PATIENTS AND METHODS: Between February and July 2021, all consecutive patients undergoing a whole-body PET/CT for any indication using a different radiopharmaceutical from 18F-FDG were eligible for inclusion if they had received at least 1 dose of the COVID-19 vaccine. The radiopharmaceutical administered and vaccine type were recorded for each patient. The incidence of positive vaccine-related axillary and supraclavicular LNs on PET/CT was our primary finding, along with the nodes characteristics. Statistical analyses were performed for patients with prostate cancer (PCa) to determine certain interaction factors that were associated with the detection of vaccine-related LNs. RESULTS: Of the 226 patients in our cohort study, 120 patients underwent an 18F-fluorocholine PET/CT, 79 a 68Ga-PSMA-11 PET/CT, 6 an 18F-FDOPA PET/CT, and 21 a 68Ga-DOTATOC PET/CT. A total of 67.3% of patients (152/226) received BNT162b2mRNA (Pfizer-BioNTech), 26.5% (60/226) ChAdOx1-S (AstraZeneca), 4.9% (11/226) mRNA-1273 (Moderna), and 1.3% (3/226) Ad26.COV2.S (Janssen). The incidence of positive vaccine-related axillary and supraclavicular LNs was 42.5% (51/120 patients) on PET/CT using 18F-fluorocholine and 12.7% (10/79 patients) with 68Ga-PSMA-11. None of our patients undergoing 18F-FDOPA or 68Ga-DOTATOC PET/CT presented any vaccine-related lymphadenopathy. Vaccine-related LNs were statistically associated with the nature of the radiopharmaceutical (P < 10-4), with the number of vaccine doses received (P = 0.041), with a short delay between vaccination and PET/CT realization (P < 10-5), and with a higher prostate-specific antigen level for patients with PCa (P = 0.032), but not with age or vaccine type. The vaccine-related nodes appeared in 85% of the cases, in the 30 days after vaccine injection, were limited in size and uptake, and were most often limited to the axilla level 1 area. CONCLUSIONS: Detecting positive LNs after COVID-19 vaccination is not an exclusive 18F-FDG PET/CT pattern but is common on 18F-fluorocholine and possible on 68Ga-PSMA-11 PET/CT. Confronting PET/CT findings with clinical data (such as date and site of injection) seems essential in the current pandemic context, just as it does for the radiopharmaceuticals used in PCa to avoid PET/CT misinterpretation and incorrect patient treatment. For 18F-FDOPA or 68Ga-DOTATOC PET/CT, this seems to have a lesser impact.

COVID-19 Lung Findings Detected by 68Ga-PSMA PET/CT for Staging Purposes in Patients With Prostate Cancer.

ABSTRACT: We report 3 patients with COVID-19 findings in 68Ga-PSMA PET/CT taken for staging. The first patient, A 64-year-old man with prostate cancer, who had COVID-19 in November 2020 and whose treatment was completed, was observed to continue with COVID-19 findings in 68Ga-PSMA PET/CT in December 2020 before surgery. Other patients were asymptomatic for the disease. It was determined that a PSMA uptake in the lungs corresponding to the CT findings of COVID-19 had increased in 68Ga-PSMA PET/CT.

68Ga-PSMA PET/CT With Incidental Finding of COVID-19 in an Asymptomatic Patient.

A 70-year-old man with prostate adenocarcinoma was diagnosed by transrectal biopsy, with Gleason of 4 + 5 and initial PSA of 225 ng/mL since March 2020. Ga-PSMA PET/CT was performed as part of initial staging. The images showed an enlarged prostate with focal PSMA uptake in both lobes. Retroperitoneal and pelvic lymph nodes with moderate uptake of PSMA were shown. Another finding was a moderate PSMA uptake in the both lung parenchymas associated with opacities in CT. The patient denied any symptoms of coronavirus disease and was referred to the emergency department for RT-PCR COVID-19, and the result was positive.

Unknown SARS-CoV-2 pneumonia detected by PET/CT in patients with cancer.

INTRODUCTION: In January 2020, the coronavirus disease 2019 (COVID-19) outbreak in Italy necessitated rigorous application of more restrictive safety procedures in the management and treatment of patients with cancer to ensure patient and staff protection. Identification of respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was a challenge during the pandemic owing to a large number of asymptomatic or mildly symptomatic patients. METHODS: We report 5 patients with unknown SARS-CoV-2 infection undergoing positron emission tomography (PET)/computed tomography (CT) with radiopharmaceuticals targeting different tumor processes: 18F-FDG, 18F-choline (FCH), and 68Ga-PSMA. RESULTS: In all patients, PET/CT showed increased tracer uptake in the lungs corresponding to CT findings of SARS-CoV-2 pneumonia. Quantitative assessment of tracer uptake showed more elevated values for the glucose analogue 18F-FDG (mean SUVmax 5.4) than for the other tracers (mean SUVmax 3.5). CONCLUSIONS: Our findings suggest that PET/CT is a sensitive modality to hypothesize SARS-CoV-2 pneumonia in patients with cancer, even when asymptomatic. More data are needed to verify the correlation among immune response to SARS-CoV-2 infection, clinical evolution, and PET results. Under the strict safety measures implemented at the PET center, the number of potentially SARS-CoV-2-positive patients undergoing PET/CT was very low (1.6%), and no staff member has been diagnosed with infection as of April 30, 2020.