Clinical Nuclear Medicine

A 78-year-old woman with diffuse large B-cell lymphoma was referred for an 18F-FDG PET/CT to evaluate therapy response after 6 cycles of R-mini-CHOP. A new 18F-FDG accumulation was noticed medial in the upper part of the right lower leg, spreading along the medial head of the gastrocnemius muscle. The shaft-bow-looking curvature, arch sign, of 18F-FDG revealed a fluid collection on CT. This typical pattern and its specific location are indicative of a ruptured Baker's cyst. It can manifest in 1 or both legs...

PURPOSE: Prostate-specific membrane antigen (PSMA)-targeting PET radiotracers reveal physiologic uptake in the urinary system, potentially misrepresenting activity in the prostatic urethra as an intraprostatic lesion. This study examined the correlation between midline 18F-DCFPyL activity in the prostate and hyperintensity on T2-weighted (T2W) MRI as an indication of retained urine in the prostatic urethra. PATIENTS AND METHODS: Eighty-five patients who underwent both 18F-DCFPyL PSMA PET/CT and prostate MRI between July 2017 and September 2023 were retrospectively analyzed for midline radiotracer activity and retained urine on postvoid T2W MRIs...

99mTc-3,3-diphosphono-1,2-propanedicarboxylic acid (DPD) scintigraphy and 99mTc-pyrophosphate (PYP) scintigraphy are highly sensitive modalities for imaging both myocardial and extracardiac amyloid transthyretin in patients with wild-type transthyretin (ATTRwt) amyloidosis. "Loss of bone signal" on planar imaging of 99mTc-DPD scintigraphy, in which the tracer uptake in bone is obscured by marked tracer uptake in the overlying skeletal muscles, is reported. However, this phenomenon has not yet been documented on 99mTc-PYP scintigraphy...

A 57-year-old woman who had persistent symptoms of transthyretin cardiac amyloidosis underwent 99mTc-pyrophosphate (99mTc-PYP) scintigraphy. The 99mTc-PYP planar and SPECT/CT fusion image showed diffuse myocardial uptake and multiple fractures of the sternum and ribs. These fractures interfered with semiquantitative scores of 99mTc-PYP uptake, leading to false positive in 99mTc-PYP imaging.

BACKGROUND: The aim of our study was to retrospectively analyze FDG PET/CT data in patients with facial nerve palsy (FNP) for the presence of the monocle sign. PATIENTS AND METHODS: A total of 85 patients with unilateral FNP were included into our study, thereof 73 with peripheral FNP and 12 with central FNP. FDG uptake (SUVmax, SUVmean, total lesion glycolysis) was measured in both orbicularis oculi muscles (OOMs). FDG uptake of paretic and nonparetic muscles was compared in patients with FNP (Wilcoxon test and Mann-Whitney U test) and was also compared with FDG uptake in 33 patients without FNP (Mann-Whitney U test)...

PURPOSE: This study was designed to assess the uptake heterogeneity in neuroendocrine tumor (NET) patients at initial diagnosis with dual-tracer PET imaging and the staging changes and prognostic value it brings to explore the indication of the use of dual-tracer PET. METHODS: Fifty-one newly diagnosed patients with pathologically confirmed NET who underwent 18F-FDG and 68Ga-DOTATATE PET imaging between January 2020 and September 2022 were enrolled. Dual-tracer uptake patterns were classified into 3 groups: A...

We report the findings of 68Ga-DOTATATE PET/CT in a 56-year-old woman with solitary pulmonary perivascular epithelioid cell tumor. 68Ga-DOTATATE PET/CT showed a lesion with intense uptake in the region of pancreatic head and a solitary nodule with moderate uptake in the left lung. Pancreatic neuroendocrine tumor with pulmonary metastasis was considered. The postoperative pathological results showed a benign perivascular epithelioid cell tumor of the lung. This case emphasizes the need to increase awareness of benign perivascular epithelioid cell tumors in the differential diagnosis of solitary pulmonary nodule with moderate DOTATATE activity...

A 69-year-old man diagnosed with progressive bone metastatic castration-resistant prostate adenocarcinoma and concurrent alcoholic cirrhosis with multiple hepatocellular carcinoma (HCC) nodules was referred to our nuclear medicine service for 177Lu-PSMA-617 therapy. The patient's pretreatment screening using 68Ga-PSMA-11 PET/CT revealed high prostate-specific membrane antigen expression in both prostatic and HCC lesions. The patient underwent 2 doses of 177Lu-PSMA-617. Subsequent imaging assessments with 68Ga-PSMA-11 PET/CT and hepatic MRI indicated progressive HCC nodules, while showing a partial response in prostatic bone metastases...

In preparation for 90Y radioembolization for hepatic malignancies, hepatic angiography is performed with intra-arterial delivery of 99mTc-macroaggregated albumin (MAA), known as premapping. This initial procedure allows for evaluation of standard/variant hepatic arterial anatomy using MAA as a surrogate marker for the delivery of 90Y to visualize the likely distribution of 90Y. Premapping allows for the assessment of at-risk extrahepatic targets and for the quantification of hepatopulmonary shunting. We present cases where MAA scintigraphic images reveal unusual perfusion patterns in hepatic cancers, treated with 90Y glass microspheres (Therasphere; Boston Scientific, Marlborough, MA)...

PATIENTS AND METHODS: The primary endpoints were objective response rate (ORR) and disease control rate (DCR). Secondary endpoints were duration of response, blood pressure control, safety, overall and progression-free survival rates, MIBG uptake, and correlations with genetic background. RESULTS: The study included 25 patients. Twenty-four patients had distant metastases, 17 (68%) had hormonally active tumors, and 13 (52%) had previously received antineoplastic treatment...

An 83-year-old woman with newly diagnosed multiple myeloma (MM) was enrolled in our 68Ga-pentixather and 68Ga-pentixafor PET/CT trial for evaluation of tumor burden. 68Ga-pentixather PET/CT detected more focal bone lesions, and the uptake levels of focal bone lesions on 68Ga-pentixather PET/CT were higher than those on 68Ga-pentixafor PET/CT. This suggests that 68Ga-pentixather PET/CT may be an alternative imaging modality and more sensitive in detecting MM lesions than 68Ga-pentixafor PET/CT.

PURPOSE OF THE REPORT: 18F-PBR06-PET targeting 18-kDa translocator protein can detect abnormal microglial activation (MA) in multiple sclerosis (MS). The objectives of this study are to develop individualized mapping of MA using 18F-PBR06, to determine the effect of disease-modifying treatment (DMT) efficacy on reducing MA, and to determine its clinical, radiological, and serological correlates in MS patients. PATIENTS AND METHODS: Thirty 18F-PBR06-PET scans were performed in 22 MS patients (mean age, 46 ± 13 years; 16 females) and 8 healthy controls (HCs)...

We report 18F-FDG PET/CT appearances of intracholecystic papillary neoplasm (ICPN) in the gallbladder neck and duct of a 74-year-old woman with a history of hepatitis B cirrhosis. The lesion presented with a large and sessile soft mass in the neck and duct of gallbladder with obvious glucose metabolism on PET/CT images, which was confirmed pathologically as ICPN (gastric foveolar type) with high-grade intraepithelial neoplasia. ICPN localized in the gallbladder neck and duct is extremely rare, and is easily misdiagnosed as gallbladder carcinoma...

A 78-year-old man underwent 68Ga-prostate-specific membrane antigen-11 (PSMA-11) PET/CT for biochemical recurrence of prostate adenocarcinoma following a simple prostatectomy. The scan showed PSMA-avid local recurrence within the prostatectomy bed and a suspicious right internal iliac nodal metastasis. In addition, there was a mildly avid subcutaneous lesion in the right flank, which revealed high-grade spindle cell sarcoma at histopathology. This case represents a potential pitfall for PSMA-11 PET imaging...

Cerebral amyloid angiopathy-related inflammation is a rare encephalopathy characterized by inflammation against amyloid protein accumulated in cerebral small vessels. A 50-year-old man was presented with a subacute consciousness disorder. Brain MRI revealed high intensity lesions in the white matter of the right parietal and occipital lobes on fluid-attenuated inversion recovery sequences and cerebral microbleeds in the right parietal and occipital lobes on T2*-weighted images. Pittsburgh compound B-PET demonstrated accumulation in the right temporoparietal lobe, confirming a potential diagnosis of probable cerebral amyloid angiopathy-related inflammation without brain biopsy...

PURPOSE: This article aims to describe the presentation of Plummer disease and its evolution after radioiodine treatment and determine factors that may influence treatment efficacy. PATIENTS AND METHODS: The sample included retrospective medical records of 165 adult patients with toxic nodular goiter treated with radioiodine between 1997 and 2017, followed up at a single thyroid center. RESULTS: The efficacy of treatment with a single dose of radioiodine was higher than 90%...

A 17-year-old man presented with dull pain in the left upper abdomen for 1 month. Initial CT and gastroscopy revealed a mass in the gastric fundas, protruding into the lumen. Based on findings of a fine-needle biopsy, an inflammatory myofibroblastic tumor was suspected. Subsequent PET/CT showed increased FDG uptake in the gastric fundas as well as hepatogastric ligament, para-aortic region. Eventually, he underwent surgical resection, and histopathologic findings confirmed the diagnosis of splenosis.

We report the successful application of radioembolization (SIRT) in a 77-year-old man with end-stage renal disease on hemodialysis and repeated episodes of macroscopic hematuria due to a large renal cell carcinoma of the right kidney extending to liver segment VI. A compassionate SIRT therapy was performed with resin microspheres through the upper pole renal artery and the feeding segmental artery of liver segment VI. Hematuria was resolved after treatment, and 4 months later, a follow-up CT scan revealed tumor size reduction and complete tumor necrosis (Response Evaluation Criteria in Solid Tumors criteria)...

A 56-year-old man with metastatic lung adenocarcinoma received combined 177Lu-FAP-2286 radiation therapy and targeted therapy. After 1 treatment cycle, improvement of symptoms and radiological remission was observed. Moreover, the patient did not report any adverse effects.

Progressive supranuclear palsy (PSP) is the most prevalent form of degenerative atypical parkinsonism. Clinical manifestations of PSP commonly encompass deficits in vertical gaze, postural stability, akinesia, and cognitive impairment. The characteristic metabolic pattern observed in PSP through FDG PET displays hypometabolism in the midbrain, striatum, thalamus, and frontal lobe. However, visual interpretation of midbrain hypometabolism poses challenges. In this report, we aim to elucidate a novel observation termed the "loss of Mickey Mouse ears' sign," which signifies midbrain hypometabolism as detected through visual assessment of FDG PET images...