A Rare Case of Thyroid Sarcoidosis.

ABSTRACT: Thyroid sarcoidosis is a rare manifestation of sarcoidosis, an inflammatory disease characterized by the formation of noncaseating granulomas in various organs. The diagnosis of thyroid sarcoidosis is challenging because of its nonspecific symptoms and the absence of specific biomarkers. Here, we report the case of a 43-year-old woman who presented with a 2-year history of neck swelling, dysphonia, and dysphagia, and suspected nodule in her left thyroid.

The systemic impact of different COVID-19 vaccines in 2-[18F] FDG-PET/CT.

Austria started its COVID-19-vaccination program in December 2020 with three different vaccines. As the vaccination program continues, we encountered increased 2-[18F] FDG-activity not only in axillary lymph nodes ipsilateral to the injection site but also in other organs. The aim of this retrospective study is to present results of the metabolic activity of ipsilateral axillary lymph nodes, liver, blood pool, spleen, and bone marrow after three different vaccines. To our knowledge, this is the first study to examine systemic response changes in relation to time after COVID-19 vaccination using three different vaccines. The collected data of 220 eligible vaccinated patients (127 with BioNTech/Pfizer BNT162b2, 61 with Moderna, and 32 with AstraZeneca) examined with 2-[18F] FDG-PET/CT were enrolled. The PET/CT examinations were evaluated from day 1 to day 135 (SD: 23.2, median: 26) after different vaccinations. Seventy-one out of these 220 patients underwent a pre-vaccination 2-[18F] FDG -PET/CT. SUVmax of axillary node(s), and blood pool, liver, spleen, and bone marrow as reference organs were calculated. The ratio of SUVmax activity of axillary lymph node to reference organs was also compared in all patients. The tracer activity dynamics were investigated in three different vaccines. After BioNTech/Pfizer vaccination 2-[18F] FDG activity in axillary lymph nodes shows a steady decrease in all patients. Ten days after vaccination the 2-[18F] FDG uptake was at its highest activity. Seventy days after vaccination, tracer activity is not different from the background activity of 2-[18F] FDG in the axillary region. This result also applies to other two vaccines; however, in the 4th week after Moderna vaccination SUVmax in lymph nodes showed the highest peak of tracer activity. With AstraZeneca the highest activity was at the earlier days. There was no significant statistical difference of SUVmax of lymph nodes or its ratios to other reference organs between three groups of vaccines. SUVmax in lymph nodes was statistically significant lower than SUVmax in the liver, spleen, and bone marrow with p-values of < 0.001, 0.044, and 0.001, respectively. In the group of 71 patients with a pre-vaccination PET/CT examination, the median SUVmax of lymph nodes increased significantly after vaccination from 0.82 (IQR 0.59-1.38) to 1.80 (IQR 1.07-3.89)(p < 0.001). In contrast median tracer activity in the liver decreased from 3.37 (IQR 2.83-3.91) to 3.11 (2.56-3.70) (p = 0.032). There was no significant change of tracer activity after vaccination in other reference regions (mediastinum, spleen, and bone marrow). In this group of 71 patients, there was also no significant difference in tracer activity in different types of vaccines. Local site and ipsilateral axillary lymph node activity in 2-[18F] FDG PET/CT after COVID19-vaccination is suggested in many studies. The main challenge is recognizing the changes in lymph nodes during time after vaccination to minimize false interpretation, foremost in patients with oncological diagnoses. Moreover, different vaccines cause different system metabolic changes. The knowledge of vaccine type, the time interval between vaccination and PET/CT scan is essential, especially in therapy evaluation.

Diagnostic value of two-time point [68Ga]Ga-PSMA-11 PET/CT in the primary staging of untreated prostate cancer.

The emerging PET tracer [68Ga]Ga-PSMA-11 has been established for staging in prostate cancer (PCa). Aim was to determine the value of early static imaging in two-phase PET/CT. 100 men with newly diagnosed histopathologically confirmed untreated PCa who underwent [68Ga]Ga-PSMA-11 PET/CT from January 2017 to October 2019 were included. The two-phase imaging protocol consisted of an early static scan of the pelvis (6 min p.i.) and a late total-body scan (60 min p.i). Associations of semi-quantitative parameters derived via volumes of interest (VOI) with Gleason grade group and PSA were investigated. In 94/100 patients (94%) the primary tumor was detected in both phases. In 29/100 patients (29%) metastases were detected at a median PSA level of 32.2 ng/ml (0.41-503 ng/ml). In 71/100 patients (71%) without metastasis a median PSA level of 10.1 ng/ml (0.57-103 ng/ml) was observed (p = < 0.001). Primary tumors demonstrated a median standard uptake value maximum (SUVmax) of 8.2 (3.1-45.3) in early phase versus 12.2 (3.1-73.4) in late phase and a median standard uptake value mean (SUVmean) of 4.2 (1.6-24.1) in early phase versus 5.8 (1.6-39.9) in late phase, significantly increasing over time (p = < 0.001). Higher SUVmax and SUVmean were associated with higher Gleason grade group (p = 0.004 and p = 0.003, respectively) and higher PSA levels (p = < 0.001). In 13/100 patients the semi-quantitative parameters including SUVmax were declining in the late phase compared to early phase. Two-phase [68Ga]Ga-PSMA-11 PET/CT demonstrates a high detection rate for primary tumor of untreated PCa of 94% and improves diagnostic accuracy. Higher PSA levels and Gleason grade group are associated with higher semi-quantitative parameters in the primary tumor. Early imaging provides additional information in a small sub-group with declining semi-quantitative parameters in the late phase.

F18-FDG PET/CT in a patient with Antisynthetase Syndrome.

More prevalent in women than men, Antisynthetase Syndrome is a rare and poorly defined autoimmune disease associated with interstitial lung disease, polymyositis, and dermatomyositis. In addition to various diagnostic tools, imaging modalities are needed in certain situations. A 42-year-old woman with Anti-Jo-1-positive Antisynthetase Syndrome presented with thoracic muscular pain. She underwent whole-body Fluorodeoxyglucose positron emission tomography/computed tomography (F18-FDG PET/CT) to evaluate the total extent of the muscles affected. Depicting symptomatic symmetric myositis of the intercostal muscles, F18-FDG PET/CT additionally revealed unusually extensive fasciitis of the lower extremities.

18F-FDG PET/CT in Primary Mesothelioma of the Liver.

ABSTRACT: Primary malignant mesothelioma is a rarity among malignant liver tumors. We present the case of a 48-year-old woman presenting with increasing upper abdominal discomfort and inappetence accompanied by a weight loss of approximately 10 kg. CT and MRI revealed a highly suspicious mass lesion in the liver. 18F-FDG PET/CT performed for staging showed a pathological 18F-FDG uptake of the known liver tumor. Histology and immunohistochemistry indicated mesothelioma of the liver. Herein we present a rare case of primary mesothelioma in the liver with CT, MRI, and 18F-FDG PET/CT.

Diagnostic value of F-18 FDG PET/CT in fever or inflammation of unknown origin in a large single-center retrospective study.

Cause determination is challenging in fever or inflammation of unknown origin (FUO/IUO) despite today's diagnostic modalities. We evaluated the value of F-18 FDG PET/CT in an unselected patient collective. This retrospective nonrandomized single-center study enrolled 300 male and female patients with FUO/IUO. PET/CT findings were compared with final clinical outcomes to determine the sensitivity, specificity, clinical significance, etiological distribution of final diagnoses, impact on treatment, role of white-blood cell count (WBC), and C-reactive protein (CRP). In 54.0% (162/300) PET/CT was the decisive exanimation for establishing the final diagnosis, in 13.3% (40/300) the findings were equivocal and indecisive, in 3.3% (10/300) PET/CT findings were false positive, while in 29.3% (88/300) a normal F-18 FDG pattern was present. Statistical analysis showed a sensitivity of 80.2% and a specificity of 89.8% for the contribution of PET/CT to the final diagnosis. CRP levels and WBC were not associated with PET/CT outcome. PET/CT let to new treatment in 24.0% (72/300), treatment change in 18.0% (54/300), no treatment change in 49.6% (149/300), and in 8.3% (25/300) no data was available. Our study demonstrates the utility of F-18 FDG PET/CT for source finding in FUO/IUO if other diagnostic tools fail.

Different Appearances of 3 Malignancies in 68Ga-PSMA-11 Versus 18F-FDG PET/CT.

ABSTRACT: Prostate-specific membrane antigen (PSMA) overexpression has been described in various malignancies. Hereby we present a case of a 69-year-old man simultaneously diagnosed with prostate cancer, esophageal adenocarcinoma, and HCC (hepatocellular carcinoma). 18F-FDG PET/CT showed pathological uptake in the esophageal adenocarcinoma and the primary prostate tumor, whereas 68Ga-PSMA-11 PET/CT performed for staging of the histopathologically confirmed prostate cancer revealed the primary tumor and significant uptake in the HCC. This finding is remarkable because the high physiological liver uptake of 68Ga-PSMA-11 may hamper the detection of small lesions.

18F-FDG PET/CT in the Hyperparathyroidism-Jaw-Tumor Syndrome.

ABSTRACT: Hyperparathyroidism-jaw-tumor syndrome (HPT-JTS) is a rare autosomal dominant disorder. A typical manifestation of HPT-JTS is the association of jaw-ossifying fibroma with primary hyperparathyroidism. Due to its rarity and diversity in its manifestations, it is a challenging diagnosis. A 33-year-old woman was referred due to painful swelling of the right maxilla suggestive of malignancy. The clinical presentations were not conclusive until she underwent F18-fluorodeoxyglucose positron emission tomography/computed tomography (F18-FDG PET/CT). F18-FDG PET/CT proved to be a useful tool to assist the clinicians in visualizing the "bigger picture" and, therefore all manifestation as pieces of "one puzzle."

Oligodendroglioma in 68Ga-PSMA-11 and 18F-Fluciclovine PET/CT.

ABSTRACT: Prostate cancer (PC) is one of the most common cancers affecting men worldwide, with a high recurrence rate after therapy. 68Ga-PSMA-11 and 18F-fluciclovine are PET imaging tracers for the detection of recurrence sites in PC patients. 68Ga-PSMA-11 is a membrane antigen overexpressed by tumor cells, whereas 18F-fluciclovine targets increased amino acid transporter in the membrane of cancer cells. We report a case of an 83-year-old man with known oligodendroglioma and biochemically recurrent PC who shows a high focal 68Ga-PSMA-11 and 18F-fluciclovine uptake in the brain.

Lymphoscintigraphy for Sentinel Lymph Node Biopsy in Breast Cancer: Do We Need a Delayed Image?

BACKGROUND: Sentinel lymph node biopsy has become a standard of care in the treatment of patients with early breast cancer, but clinical guidelines continue to be vague on details of the procedure. We were interested in the results of our 2-day protocol, which includes delayed lymphoscintigraphy at 18 h. METHODS: We reviewed the results of preoperative lymphoscintigrams in patients undergoing surgery for breast cancer. Lymphoscintigraphy was performed 2 h after periareolar injection of 4 × 37 MBq 99mTc nanocolloid (early lymphoscintigraphy) and 18 h following injection (delayed lymphoscintigraphy). The early results were compared with the late results. RESULTS: A total of 238 lymphoscintigraphies were performed in 232 patients (6 bilateral). At 2 h, ≥1 sentinel nodes were visualized in 154/238 (65%) cases; in 84 (35%), no sentinel node was visualized. Delayed lymphoscintigraphy visualized a sentinel node in 40 of 76 (53%) cases with no visualization at 2 h and failed to show a sentinel node in 36 (47%) of these cases (in 8 cases, no delayed lymphoscintigram was obtained). CONCLUSIONS: Delayed lymphoscintigraphy was useful in about 50% of the breast cancer patients in whom immediate scintigraphy failed to demonstrate a sentinel lymph node.

A Prospective Head-to-Head Comparison of 18F-Fluciclovine With 68Ga-PSMA-11 in Biochemical Recurrence of Prostate Cancer in PET/CT.

PURPOSE: One of the major challenges for all imaging modalities is accurate detection of prostate cancer (PCa) recurrence. Beyond the established Ga-PSMA, a novel promising PET tracer in PCa imaging is F-fluciclovine. For evaluating the advantages and disadvantages and the comparability, we conducted a prospective head-to-head comparison on F-fluciclovine and Ga-PSMA-11 in patients with biochemical recurrence of PCa. METHODS: 58 patients with biochemical recurrence of PCa after definitive primary therapy were included. Both scans were performed within a time window of mean 9.4 days. All scans were visually analyzed independently on a patient-, region- and lesion-based analysis. All the examinations were performed in the same medical department using identical scanners at any time. RESULTS: The overall detection rate for PCa recurrence was 79.3% in F-fluciclovine and 82.8% in Ga-PSMA-11 (P = 0.64). Local recurrence was detected in 37.9% on F-fluciclovine and in 27.6% on Ga-PSMA-11 (P = 0.03). Local pelvic lymph node recurrence was detected on F-fluciclovine versus Ga-PSMA-11 in 46.6% versus 50%, in extrapelvic lymph node metastases in 41.4% versus 51.7% and in bone metastases in 25.9% versus 36.2%. Lesion-based analysis showed identical findings in local pelvic lymph nodes in 39.7%, in extrapelvic lymph nodes in 22.4%, and in bone metastases in 13.8%. CONCLUSIONS: The advantage of F-fluciclovine is detecting curable localized disease in close anatomical relation to the urinary bladder, whereas Ga-PSMA-11 fails because of accumulation of activity in the urinary bladder. F-fluciclovine is almost equivalent to Ga-PSMA-11 in detecting distant metastases of PCa recurrence.

Diagnostic and prognostic value of additional SPECT/CT in sentinel lymph node mapping in breast cancer patients.

THE AIM: of the study was to demonstrate the diagnostic and prognostic value of SPECT/CT in sentinel lymph node mapping (SLNM) in patients with invasive breast cancer. METHODS: 114 patients with invasive breast cancer with clinically negative lymph nodes were included in this retrospective study as they were referred for SLNM with 99mTc-nanocolloid. Planar image acquisition was accomplished in a one-day or two-day protocol depending on the schedule of the surgical procedure. Low dose SPECT/CT was performed after the planar images. The sentinel lymph node biopsy (SLNB) was considered false negative if a primary recurrence developed within 12 months after SLNB in the axilla from which a tumor-free SLN had been removed. RESULTS: Between December 2009 and December 2011, 114 patients (pts.) underwent SLNM with additional SPECT/CT. Planar imaging identified in 109 pts. 139 SLNs, which were tumor-positive in 42 nodes (n = 41 pts.). SPECT/CT identified in 81 pts. 151 additional SLNs, of which 19 were tumor-positive and led to therapy change (axillary lymph node dissection) in 11 pts. (9.6 %). Of overall 61 tumor-positive SLNs (n = 52 pts.) SPECT/CT detected all, whereas planar imaging detected only 42 of 61 (P < 0.0001). No patient had lymph node metastasis within 12 months after SLNB in the axilla from which a tumor-free SLN had been removed resulting in a false-negative rate of 0 %. The local relapse rate was 1.8 % leading to a 4-year disease-free survival rate of 90 %. CONCLUSION: Among patients with breast cancer, the use of SPECT/CT-aided SLNM correlated due to a better anatomical localization and identification of planar not visible SLNs with a higher detection rate of SLNs. This led to therapeutic consequences and an excellent false-negative and 4-year disease-free survival rate.