Asia Oceania Journal of Nuclear Medicine and Biology最新文献

Vaccination against coronavirus disease 2019 (COVID-19) started in early December 2020 worldwide, and healthcare workers in Japan were vaccinated in February 2021. We encountered three patients who underwent ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for cancer screening at our institution, showing FDG uptakes in the axillary lymph nodes, which seemed to be reactive changes. Two of them were males in their 40s and one was a female in her 50s; all of them were healthcare workers. The medical history revealed that they received the Pfizer-BioNTech COVID-19 vaccination twice at their left shoulders before the FDG PET/CT examination. The degree of FDG uptakes were maximum standardized uptake value (SUV_max)=3.2-9.9, SUV_max=5.9-10.3, and SUV_max=2.8-7.9, respectively. They were diagnosed with reactive lymph nodes because of vaccination owing to the absence of abnormal FDG PET/CT findings at other sites. As COVID-19 vaccination becomes more widespread in Japan, radiologists should be aware of these findings to avoid misdiagnosis of FDG uptakes in pathological lymph nodes and to prevent unnecessary additional examinations. Recently, similar FDG PET/CT findings have been reported after receiving the COVID-19 vaccination, and we will report it with a literature review.

Objectives: We investigated the detectability of somatostatin receptor scintigraphy (SRS) for neuroendocrine neoplasms (NEN).

Methods: From January 2016 to October 2020, 125 SRS examinations using indium-111 pentetreotide performed for patients with NEN lesions were retrospectively evaluated. The detection rate of NEN lesions was determined according to histopathological classification by primary site and by organ.

Results: At least one NEN lesion was detected in 73% (91/125) with a positive Krenning score of ≥2 in SRS. The detection of abdominal NENs (gastrointestinal tract, 38; pancreas, 62; and others, 14) was 89% (49/55) for neuroendocrine tumor (NET)-grade (G) 1, 78% (32/41) for NET-G2, 66% (2/3) for NET-G3, 31% (4/13) for neuroendocrine carcinoma (NEC), 100% (1/1) for mixed neuroendocrine-non-neuroendocrine neoplasm, and 0% (0/1) for non-classified NEN. That of thoracic NENs was 33% (2/6) for typical carcinoid tumor and 40% (2/5) for atypical carcinoid tumor. For a total of 226 organ lesions, hepatic lesions were 76% (58/76); pancreatic lesions, 61% (31/51); lymph node lesions, 77% (27/35); bone lesions, 83% (20/24); duodenal lesions, 82% (9/11); and other lesions, 41% (11/27).

Conclusion: The detectability of SRS for NEN in Japan was verified at a center, and its usefulness was confirmed.

Objectives: Non-cutaneous malignant melanomas (NCM) are rare malignancies. Due to their nonspecific symptoms, they present later in life. The value of FDG PET/CT in this group of patients is not clear. The aim of this study is to assess the role of FDG PET/CT in the management of NCM and its prognostic implication.

Methods: We retrospectively selected twenty-three patients with a diagnosis of NCM evaluated with FDG PET/CT in Shariati hospital between 2019 and 2021. The PET/CT data were reviewed and compared with available conventional imaging findings. Five patients died within five months. The surviving patients were followed within a time interval of 7 to 27.5 months after their PET/CT study, regarding their disease status.

Results: Among 23 patients (8 ocular, 5 sinonasal, 3 pharyngeal, 2 anorectal, 2 vulvovaginal, and 3 unknown primaries), PET/CT was able to detect residual primary disease, assess treatment response, and reveal or exclude metastases. Additional lesions compared to conventional imaging were found in five, while in one with brain metastases PET/CT was unable to detect lesions on MRI. Thirteen patients had negative PET/CT finding of which 11 (85%) did not have remarkable finding on follow-up. Metastatic disease was recognized in eight. Patients with extensive metastases on FDG PET/CT had a poorer outcome.

Conclusion: Similar to cutaneous melanoma, PET/CT is valuable in the management of NCM patients and is superior to conventional imaging modalities, with the exception of brain metastases. Patients with negative PET/CT findings have a better outcome as opposed to patients with significant positive PET/CT findings.

Hypersensitivity pneumonitis (HP) is an interstitial lung disease resulting from an immune-mediated response in susceptible and sensitized individuals to various inhaled antigens in the environment. Imaging diagnosis is usually based on high-resolution CT findings. Here, we present a 49-year-old man with a history of diffuse large B-cell lymphoma presented with fever and occasional cough. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) revealed diffuse FDG uptake in the bilateral lungs. Expiratory low-dose CT simultaneously performed in PET scanning revealed centrilobular nodules and air trapping in ground glass opacities (GGO). Our imaging diagnosis was acute hypersensitivity pneumonitis (HP). Based on the results of his clinical course, blood laboratory tests, and bronchoscopy, he was diagnosed with acute HP. Diffuse pulmonary FDG uptake can be seen in the patients with acute HP. In addition, expiratory low-dose CT findings of centrilobular nodules and air trapping in GGO may be helpful for accurate diagnosis of acute HP.

Objectives: To illustrate incidental ¹⁸F-FDG PET-CT findings and related CT alterations of suspicious pulmonary interstitial involvement in asymptomatic oncologic patients during the first COVID-19 outbreak in the core of Italian peak.

Methods: We retrospectively evaluated the ¹⁸F-FDG PET-CT follow-up examinations performed during the first Italian COVID-19 outbreak (March 3rd-April 15th, 2020) in 10 asymptomatic oncologic patients with a highly suspicious interstitial pulmonary involvement on CT. Six cases were confirmed SARS-CoV-2 by molecular tests. The following parameters were assessed: 1) lung involvement on co-registration CT as extension (laterality, number of lobes), pattern (ground-glass opacities/GGO, consolidations, mixed) and stage (early, progressive, peak, and absorption); 2) the maximum standardized uptake value (SUV_max) of lung lesions on ¹⁸F-FDG PET.

Results: The involved lobes were 5 in 5 cases (3 confirmed SARS-CoV-2), 2-4 in 4 cases and 1 in 1 case. GGO were found in all patients; 3 cases also showed a combination of GGO and peripheral consolidations (mixed). Five cases were suggestive for an early stage of interstitial pneumonia, 4 for progressive and 1 for peak. All the lung lesions showed increased FDG uptake. In early stages SUV_max ranged from 1.5 to 11, in progressive from 3.3 to 6.8, in peak from 2.4 to 7.7. SUV_max ranged 1.5-11 in patients with only GGO and 2.8-7.7 in those with mixed pattern.

Conclusions: ¹⁸F-FDG PET-CT findings in suspected COVID-19 pulmonary involvement of asymptomatic oncologic patients showed an increase in FDG uptake of GGO and consolidations, but with a wide and apparently nonspecific range of SUV_max values.

This series involves a quiz pertaining to the identification of key anatomical landmarks and normal structures present at a given level on the computed tomography (CT) image. The current quiz demonstrates examples of normal and abnormal axial CT images at the level of origin of the coeliac artery. The representative image is subsequently followed by further images demonstrating various commonly encountered pathologies found at this level in clinical practice. In each image, readers are expected to identify highlighted anatomical structures and appreciate how given pathologies can alter the appearance of normal structures. This series aims to advance understanding of sectional anatomy and aid nuclear physicians in the interpretation of the CT component of single photon emission computed tomography (SPECT) and positron emission tomography (PET) studies.

Celiac disease is an immune-mediated disorder triggered by hypersensitivity to gluten occurring in genetically susceptible individuals. A high-index of suspicion is needed for diagnosis as patients can be asymptomatic or present with atypical symptoms or extra-intestinal manifestations. Typical ¹⁸F-Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET)/Computed Tomography (CT) gastrointestinal manifestations of celiac disease include increased multifocal or diffuse jejunal and ileal uptake; focal duodenal uptake is less common. Splenomegaly with increased splenic FDG uptake is also uncommon in celiac disease in the absence of portal hypertension; small-sized spleen and functional hyposplenism are more typical. We report a case of celiac disease diagnosed after PET/CT showed FDG uptake in the duodenum and enlarged spleen. Follow-up after gluten-free diet showed complete metabolic resolution and regression of splenomegaly. The combination of focal bowel and splenic uptake is unusual in celiac disease and may be mistaken for a lymphoproliferative disorder. Awareness of this entity may avoid misdiagnosis and guide appropriate management.

We present a case of metastatic prostate cancer with rare metastases involving the brain and orbit, in addition to liver, skeletal and nodal metastases. The patient had undergone prior hormonal therapy and chemotherapy and had disease progression despite 2 cycles of ¹⁷⁷Lu-Prostate specific membrane antigen (¹⁷⁷Lu-PSMA) based radioligand therapy. He had a partial response after 2 cycles of ²²⁵Ac-PSMA based targeted alpha therapy, as demonstrated on the ⁶⁸Ga-PSMA PET/CT study. However, the patient had disease progression at the end of 4 cycles of ²²⁵Ac-PSMA therapy, evident by rising prostate specific antigen levels and imaging findings. The end of treatment ⁶⁸Ga-PSMA PET/CT showed additional sites of metastases in the orbit and brain apart from overall disease progression. These are rare sites of distant spread in prostate cancer and require urgent evaluation and local treatment to prevent potential complications. The importance of detection of metastatic sites in closed cavities is because of the requirement for urgent intervention to avoid compression related complications.

A 73-year-old man with lung cancer underwent bone scintigraphy for disease staging. Diffuse myocardial technetium hydroxymethylene diphosphonate (^99mTc-HMDP) uptake was incidentally found. A diagnosis of amyloid transthyretin (ATTR) cardiac amyloidosis was suspected, although the patient had no symptoms at this time. Single-photon emission computed tomography (SPECT) showed particularly strong uptake in the ventricular septum. Cardiac magnetic resonance imaging (CMR) showed widespread subendocardial and partly transmural enhancement of the left ventricular myocardium on delayed postcontrast T1-weighted images. These findings were consistent with ATTR cardiac amyloidosis. ¹⁸F-FDG uptake in the left ventricle wall was observed on PET/CT. He was finally diagnosed with ATTR by endomyocardial biopsy. There are two major subtypes of cardiac amyloidosis: ATTR amyloidosis and amyloid light-chain (AL) amyloidosis. Endomyocardial biopsy is the gold standard for diagnosis. Recently, however, several reports have shown that bone scintigraphy using a ^99mTc-labelled bone-seeking agent can detect ATTR cardiac amyloidosis and differentiate it from AL amyloidosis. Bone scintigraphy may play an important role in the detection and differentiation of ATTR cardiac amyloidosis.

The stormy clouds of the coronavirus disease 2019 outbreak caused a rapidly spreading epidemic still hanging over the sphere. Any steps to transition toward a new normal should be guided by health authorities, together with economic and societal considerations. There are various items mainly falling into three classifications, including patient worry, clinical demand, and economic recession. Social distancing, lay-offs, and decreased number of patients with health insurance may lead to a prolonged period to retrieve normalcy. To return to a new normal, an individualized management model should be developed for each laboratory based on staff, instruments, services, crowding, physical space, hospital base unit, or outpatient clinic. Continuous training of different occupational staffs is among the key parameters in maintaining this readiness. The proposed response model should have internal and systemic integrity as well as coherence among the included items in two intra- and inter-unit management categories, namely thinking globally and acting locally.