Incidental COVID-19 Pneumonia on 18F-Fluorocholine PET/CT

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.

COVID-19 Pneumonia was Incidentally Detected on 18F-Fluorocholine PET/CT in a Work-up for Prostate Cancer

This is a presentation of the case of a patient who underwent ¹⁸F-fluorocholine positron emission/computed tomography to stage a prostate cancer with incidentally found bilateral pneumonia. A high prevalence of incidental pneumonia is very probable under the current circumstance of coronavirus disease-2019 (COVID-19) pandemic, and oncological patients are at increased risk of COVID-19 with poorer outcome. The lung inflammatory burden in the case of COVID-19 infection can be demonstrated by ¹⁸F-fluorocholine.

COVID-19 vaccination simulating lymph node progression in a patient with prostate cancer

Several cases of cancer patients with 18-fluorodeoxyglucose (¹⁸FDG) Positron Emission Tomography/Computed Tomography (PET/CT) evidence of metabolically active axillary lymph nodes after COVID-19 vaccination have been described, creating a diagnostic dilemma and sometimes leading to further unnecessary examinations. A 62-year-old male, diagnosed with prostate cancer, treated with hormone-therapy and radiotherapy of the prostate 2 years before, underwent fluorine-18 choline (F-FCH) PET/CT for restaging purpose, less than 3 weeks after he had received the second dose of the Pfizer BioNTech-BNT162b2 mRNA COVID-19 vaccine. This exam showed an increased F-FCH uptake and an enlargement of the left axillary, paratracheal, para-aortic, subcarinal, and hilar bilateral lymph nodes. Fourteen weeks later, the patient underwent a new F-FCH PET-CT scan, displaying an almost complete regularization of the FCH uptake in all the previously involved regions. The patient was not treated after the first PET-CT scan, thus, the aforementioned PET/CT findings represented inflammatory vaccine-related lymph nodes. This case highlights the significance of knowing vaccination history to correctly interpret imaging findings and to avoid false-positive reports.

99mTc-Vitamin C SPECT/CT imaging in SARS-CoV-2 associated pneumonia

We present the first 99mTc-Vitamin C single-photon emission computed tomography/computed tomography (SPECT/CT) images obtained in patients with SARS-CoV-2 (COVID-19) infection. The CT portion of SPECT/CT images showed mostly peripheral patchy and ground-glass opacities in both lungs, which are consistent with a diagnosis of SARS-CoV-2-associated pneumonia in both patients. 99mTc-Vitamin C SPECT images showed increased tracer uptake corresponding to abnormal lung findings seen on CT in patient 1 who was newly diagnosed and treatment naïve. However, no abnormal uptake corresponding to lung CT findings was seen in patient 2 who received anti-SARS-CoV-2 treatment.

COVID-19-Related Lung Parenchymal Uptake on 18F-PSMA-1007 PET/CT

ABSTRACT

A 70-year-old man with newly diagnosed prostate cancer underwent 18F-PSMA-1007 PET/CT for staging. PSMA-avid primary prostatic malignancy was identified. Incidental intense patchy peripheral lung uptake was also noted. The patient tested positive for COVID-19 infection.

Late PET/CT Findings of COVID-19 Pneumonia With 2 Different Radiopharmaceuticals in a Patient: PSMA Avidity Higher Than FDGs

ABSTRACT

We present the 68Ga-PSMA and 18F-FDG PET/CT findings comparatively of a 67-year-old prostate cancer and malignant melanoma patient who had COVID-19 pneumonia 3 months ago. In 68Ga-PSMA PET/CT, ground-glass opacities showing markedly increased PSMA uptake were observed in the patient's lungs. It was learned that the patient had COVID-19 pneumonia 3 months ago and was treated in the intensive care unit for 13 days. In 18F-FDG PET/CT, FDG uptake was minimal in the same areas. In the midterm period after COVID-19 pneumonia, lung PSMA uptake is more intense than FDG, which may help better understand the disease's healing phase.

A comprehensive review of imaging findings in COVID-19 - status in early 2021

Medical imaging methods are assuming a greater role in the workup of patients with COVID-19, mainly in relation to the primary manifestation of pulmonary disease and the tissue distribution of the angiotensin-converting-enzyme 2 (ACE 2) receptor. However, the field is so new that no consensus view has emerged guiding clinical decisions to employ imaging procedures such as radiography, computer tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, and in what measure the risk of exposure of staff to possible infection could be justified by the knowledge gained. The insensitivity of current RT-PCR methods for positive diagnosis is part of the rationale for resorting to imaging procedures. While CT is more sensitive than genetic testing in hospitalized patients, positive findings of ground glass opacities depend on the disease stage. There is sparse reporting on PET/CT with [18F]-FDG in COVID-19, but available results are congruent with the earlier literature on viral pneumonias. There is a high incidence of cerebral findings in COVID-19, and likewise evidence of gastrointestinal involvement. Artificial intelligence, notably machine learning is emerging as an effective method for diagnostic image analysis, with performance in the discriminative diagnosis of diagnosis of COVID-19 pneumonia comparable to that of human practitioners.

68Ga-DOTANOC PET/CT With Lung Involvement in the Era of COVID-19 Pandemic

ABSTRACT

Patient was a 55-year-old man with history of pancreas neuroendocrine tumor grade 2, Ki-67 index 10%. He was treated with surgical resection. 68Ga-DOTANOC PET/CT was performed as part of follow-up of known disease. The images showed opacities in both lungs' parenchyma with moderate uptake of radiotracer and mediastinal lymph nodes with high uptake suggestive of infection. Two weeks before a high-resolution CT was performed, these findings in the lungs were not present. The patient was asymptomatic and was referred to the emergency department for reverse transcriptase-polymerase chain reaction COVID-19 test, and the result was positive.

State of the art of 18F-FDG PET/CT application in inflammation and infection: a guide for image acquisition and interpretation

AIM

The diagnosis, severity and extent of a sterile inflammation or a septic infection could be challenging since there is not one single test able to achieve an accurate diagnosis. The clinical use of 18F-fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) imaging in the assessment of inflammation and infection is increasing worldwide. The purpose of this paper is to achieve an Italian consensus document on [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases, such as osteomyelitis (OM), prosthetic joint infections (PJI), infective endocarditis (IE), prosthetic valve endocarditis (PVE), cardiac implantable electronic device infections (CIEDI), systemic and cardiac sarcoidosis (SS/CS), diabetic foot (DF), fungal infections (FI), tuberculosis (TBC), fever and inflammation of unknown origin (FUO/IUO), pediatric infections (PI), inflammatory bowel diseases (IBD), spine infections (SI), vascular graft infections (VGI), large vessel vasculitis (LVV), retroperitoneal fibrosis (RF) and COVID-19 infections.

METHODS

In September 2020, the inflammatory and infectious diseases focus group (IIFG) of the Italian Association of Nuclear Medicine (AIMN) proposed to realize a procedural paper about the clinical applications of [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases. The project was carried out thanks to the collaboration of 13 Italian nuclear medicine centers, with a consolidate experience in this field. With the endorsement of AIMN, IIFG contacted each center, and the pediatric diseases focus group (PDFC). IIFG provided for each team involved, a draft with essential information regarding the execution of [¹⁸F]FDG PET/CT or PET/MRI scan (i.e., indications, patient preparation, standard or specific acquisition modalities, interpretation criteria, reporting methods, pitfalls and artifacts), by limiting the literature research to the last 20 years. Moreover, some clinical cases were required from each center, to underline the teaching points. Time for the collection of each report was from October to December 2020.

RESULTS

Overall, we summarized 291 scientific papers and guidelines published between 1998 and 2021. Papers were divided in several sub-topics and summarized in the following paragraphs: clinical indications, image interpretation criteria, future perspectivess and new trends (for each single disease), while patient preparation, image acquisition, possible pitfalls and reporting modalities were described afterwards. Moreover, a specific section was dedicated to pediatric and PET/MRI indications. A collection of images was described for each indication.

CONCLUSIONS

Currently, [¹⁸F]FDG PET/CT in oncology is globally accepted and standardized in main diagnostic algorithms for neoplasms. In recent years, the ever-closer collaboration among different European associations has tried to overcome the absence of a standardization also in the field of inflammation and infections. The collaboration of several nuclear medicine centers with a long experience in this field, as well as among different AIMN focus groups represents a further attempt in this direction. We hope that this document will be the basis for a "common nuclear physicians' language" throughout all the country.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40336-021-00445-w.

Role of 2-[18F]FDG as a Radiopharmaceutical for PET/CT in Patients with COVID-19: A Systematic Review

Some recent studies evaluated the role of fluorine-18 fluorodeoxyglucose (2-[¹⁸F]FDG) as a radiopharmaceutical for positron emission tomography/computed tomography (PET/CT) imaging in patients with Coronavirus Disease (COVID-19). This article aims to perform a systematic review in this setting. A comprehensive computer literature search in PubMed/MEDLINE and Cochrane library databases regarding the role of 2-[¹⁸F]FDG PET/CT in patients with COVID-19 was carried out. This combination of key words was used: (A) “PET” OR “positron emission tomography” AND (B) “COVID” OR “SARS”. Only pertinent original articles were selected; case reports and very small case series were excluded. We have selected 11 original studies of 2-[¹⁸F]FDG PET/CT in patients with COVID-19. Evidence-based data showed first preliminary applications of this diagnostic tool in this clinical setting, with particular regard to the incidental detection of interstitial pneumonia suspected for COVID-19. To date, according to evidence-based data, 2-[¹⁸F]FDG PET/CT cannot substitute or integrate high-resolution CT to diagnose suspicious COVID-19 or for disease monitoring, but it can only be useful to incidentally detect suspicious COVID-19 lesions in patients performing this imaging method for standard oncological and non-oncological indications. Published data about the possible role of 2-[¹⁸F]FDG PET/CT in patients with COVID-19 are increasing, but larger studies are warranted.

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.