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

68 Ga-PSMA PET/CT Found Lower Respiratory Tract Inflammation Due to Inhaler Use

ABSTRACT

Prostate-specific membrane antigen (PSMA) is a transmembrane protein physiologically expressed in nonprostatic tissues. Inflammation and infectious diseases could show false-positive PSMA uptake. Herein, we present a 55-year-old patient's findings of inflammation in the lower respiratory tract due to inhaler use in 68 Ga-PSMA PET/CT in a patient with prostate cancer.

Intense Diffuse Lung Uptake Due to Interstitial Pneumopathy Related to Polyangiitis Granulomata in 68 Ga-PSMA-11 PET/CT

ABSTRACT

We reported the case of a 73-year-old man for whom a prostatic adenocarcinoma with synchronous bone metastases was diagnosed. Because his disease was progressing despite several lines of chemotherapy and hormonotherapy, he was screened with a 68 Ga-PSMA PET/CT for a possible 177 Lu-PSMA-617 therapy. The examination demonstrated an intense diffuse bone uptake related to the known bone involvement. It also showed an unexpected diffuse and intense lung uptake, secondary to an active polyangiitis granulomata. This intense lung uptake prohibits the radioligand therapy.

Detection of COVID-19 Incidentally in 68Ga-PSMA PET/CT for Restaging of Prostate Cancer

BACKGROUND

A series of pneumonia cases with clinical presentations of viral pneumonia secondary to new coronavirus and subsequent global transmission arose in Wuhan, Hubei, China, in December 2019. Several cases of coronavirus disease 2019 (COVID-19) have been described incidentally in positron emission tomography-computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose (FDG) as a result of the pandemic. Herein, we describe the findings of a patient with unknown COVID-19 in PET/CT with the other radiopharmaceutical, ⁶⁸Ga-labeled prostatespecific membrane antigen (⁶⁸Ga-PSMA).

CASE REPORT

A 69-year-old man had previously undergone radical prostatectomy for adenocarcinoma. ⁶⁸Ga-PSMA PET/CT imaging was performed due to biochemical recurrence. ⁶⁸Ga-PSMA uptake in the prostate bed suggestive of local recurrence was detected in PET/CT images. Also, bilateral groundglass opacities with slightly increased ⁶⁸Ga-PSMA uptake were seen in the lungs, suspected of COVID-19. A reverse transcription-polymerase chain reaction test has confirmed the infection.

CONCLUSION

Even in asymptomatic patients, nuclear medicine departments must be aware of the possibility of COVID-19, take appropriate post-exposure procedures, and protect employees and other patients.

Oncology and cardiology positron emission tomography/computed tomography faced with COVID-19: A review of available literature data

The COVID-19 pandemic has forced people to significantly change their lifestyles and attitudes, and has greatly burdened healthcare delivery systems worldwide. The redistribution of the medical delivery system to maintain normal medical care while responding generously to COVID-19 is a continuing challenge that weighs heavily on medical institutions. Among imaging modalities, chest X-rays and computed tomography (CT) examinations have clearly made a large contribution to treatment of COVID-19. In contrast, it is difficult to express the standpoint of nuclear medicine examinations in a straightforward manner, as the greatest emphasis in this modality has been on how necessary medical care can continue to be provided. Many clinical reports of nuclear medicine examinations related to COVID-19 have been published, and knowledge continues to accumulate. This review provides a summary of the current state of oncology and cardiology positron emission tomography (PET) examinations related to COVID-19, and includes preparation of the nuclear medicine department, trends in PET examinations, specific imaging findings on 18F-fluorodeoxyglucose (FDG) PET/CT, imaging of complications of COVID-19, PET tracers other than FDG, and the effects of vaccines on PET imaging findings.

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.