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Abstract: Pheochromocytomas (PHEOs) are neural crest-derived tumors originating from the chromaffin cells of the adrenal medulla and were recognized as one of the subtypes of paragangliomas by the World Health Organization in 2022. 68Ga-labeled somatostatin analog (68Ga-DOTA-NOC, 68Ga-DOTA-TOC, and 68Ga-DOTA-TATE) PET imaging has shown significant performance compared with 123MIBG scintigraphy in the diagnosis of paragangliomas. It is now known that fibroblast activation protein (FAP) is overexpressed by various cancer-associated fibroblasts, including PHEOs. We would like to present the findings of 68Ga-DOTA-FAPI-46 PET/CT and 68Ga-DOTA-TATE PET/CT imaging performed for restaging on a 42-year-old man diagnosed with metastatic PHEO., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Aim: This study aimed to compare the diagnostic capabilities of 18 F-FDG PET/CT and 68 Ga-FAPI-04 PET/CT imaging in staging gastric carcinoma, exploring the impact of 68 Ga-FAPI-04 PET/CT on treatment planning and its prognostic significance., Methods: The research included 31 patients undergoing staging for gastric cancer, who received both 18 F-FDG PET/CT and 68 Ga-FAPI-04 PET/CT scans. We compared the SUV max and SUV mean of the primary tumor and lymph nodes, the count of organ metastases, tumor-to-background ratios, and overall staging accuracy. Additionally, the study evaluated radiological progression-free survival and overall survival rates., Results: The 68 Ga-FAPI-04 PET/CT demonstrated superior efficacy in identifying the primary tumor compared with 18 F-FDG PET/CT, particularly in cases of poorly cohesive, signet-ring cell, and mucinous subtypes, with detection rates of 96.7% versus 77.4% ( P = 0.006 and P = 0.008, respectively). Analysis of lymph nodes showed a significantly higher detection of positive nodes with 68 Ga-FAPI-04 ( P = 0.026), although no significant differences were observed in SUV max and tumor-to-background ratio on a patient basis ( P > 0.05). SUV max and tumor-to-background ratios for peritoneal involvement were notably higher with 68 Ga-FAPI-04 PET/CT compared with 18 F-FDG PET/CT ( P = 0.04 for both). No significant differences were found in the detection of organ metastases and disease stage between the 2 imaging modalities ( P > 0.05). Primary tumor uptake did not significantly impact radiological progression-free survival or overall survival in either modality., Conclusions: 68 Ga-FAPI-04 PET/CT imaging surpasses 18 F-FDG PET/CT in detecting the primary tumor, especially in poorly cohesive and signet-ring cell gastric cancer types, and offers improved accuracy in disease staging. This indicates its potential to enhance treatment management and prognostic assessment in gastric cancer patients., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Rasmussen encephalitis is a rare condition characterized by chronic, progressive encephalitis. Typically, it involves one cerebral hemisphere and manifests through intractable epileptic seizures. Its occurrence in adults is notably infrequent. In this case, we presented the observations from an 18F-FDG PET/CT scan of a 70-year-old man diagnosed with Rasmussen encephalitis, where MRI displayed nonspecific findings., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 76-year-old woman was diagnosed breast carcinoma and treated with breast-conserving surgery and chemoradiotherapy. A year after the treatment completion, restaging 18 F-FDG PET/CT scan detected no any pathological finding. However, due to a lesion detected during physical examination on the right thoracic wall adjacent to the primary tumor bed, 18 F-FDG PET/CT imaging was performed 9 months later for restaging. Highly intense FDG uptake was detected in an approximately 1-cm nodular lesion, and metastasis was reported as suspicious, and histopathological confirmation was recommended. Excision was performed and pathological examination diagnosed benign cellular fibrous histiocytoma., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Metastatic insulinomas can cause recurrent hypoglycemia requiring continuous IV glucose infusion. Various medical and chemotherapeutic treatment options are used to reduce the patient's risk of death due to hypoglycemia. Treatment-resistant hepatic metastatic insulinomas may benefit clinically from 90Y transarterial radioembolization therapy. In this case, we present a case of liver metastatic insulinoma that achieved clinical improvement after 2 cycles of 90Y microspheres transarterial radioembolization, and the presence of active metastases was demonstrated with 68Ga-NODAGA-exendin-4 PET/CT imaging., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: An 84-year-old man with prostate adenocarcinoma underwent 68 Ga-PSMA PET/CT due to PSA recurrence. Foci of 68 Ga-PSMA uptake were observed in bilateral adrenal glands. Adrenal MRI showed metastasis only in the left adrenal gland. Metastatic 68 Ga-PSMA uptake was also observed in the mediastinum and bone. Enzalutamide treatment was started. Follow-up 68 Ga-PSMA PET/CT scan showed regression in both adrenal gland metastases and other metastases., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We present an 87-year-old man diagnosed with prostate cancer and neuroendocrine differentiation, posttherapy results to consecutive 177 Lu-prostate-specific membrane antigen and 177 Lu-DOTATATE. Despite hormonal therapy and chemoradiotherapy, the patient progressed rapidly, and multiple liver and bone metastases showed regression after 177 Lu-prostate-specific membrane antigen and 177 Lu-DOTATATE treatment. Prostate cancer with neuroendocrine differentiation is resistant to treatments; however, treatment with the combination of 177 Lu-DOTATATE therapy may be promising., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Prostate-specific membrane antigen (PSMA)-targeted PET/CT is a well-established imaging method in prostate cancer (PC) for both staging and restaging, and also for theranostic applications. An alternative imaging method is crucial for 15% PSMA-negative cases. We aimed to investigate the contribution of 68 Ga-DOTA-FAPI-04 PET/CT to PC imaging., Patients and Methods: Thirty-six patients diagnosed with PC were included. Patients underwent both 68 Ga-PSMA PET/CT and 68 Ga-DOTA-FAPI-04 PET/CT imaging within 1 week. In staging group, primary tumor uptake values were compared, and also correlations were done with histopathological findings, MRI findings, and total PSA levels. In biochemical recurrence group, the uptake values in prostatic region and metastases were evaluated to define the local recurrence or metastatic disease., Results: In staging group, PSMA PET showed increased uptake in the primary lesion area in 14/27 (52%) patients, whereas 20/27 (74%) patients were positive in FAPI-04 PET. FAPI-04 positivity was found to be quite high, such as 54%, in PSMA-negative patients. A significant difference was observed between ISUP grade 1-3 patients and ISUP grade 4-5 patients in FAPI-04 PET ( P = 0.03). Local recurrence was detected in 3 patients, pelvic lymph node metastasis in 1 patient, and sacrum metastasis in 1 patient in biochemical recurrence group, and all of the lesions had more intense uptake in PSMA PET than FAPI-04 PET., Conclusions: FAPI PET imaging seems to have a potential to contribute PSMA PET imaging with FAPI positivity in more than half of PSMA-negative cases. Also, FAPI-targeted radionuclide therapy may be a promising method in patients resistant to PSMA-targeted therapy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

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., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Medication-related osteonecrosis of the jaw (ONJ) is rare adverse effect of zoledronic acid. We present ONJ detected in a 65-year-old man with prostate cancer who underwent 18 F-FDG PET/CT for metabolic characterization and to exclude a second primary malignancy of the liver lesion observed in 68 Ga-PSMA PET/CT. ONJ has high metabolic activity on 18 F-FDG PET/CT and no PSMA receptor activation on the 68 Ga-PSMA PET/CT. In this case, we wanted to underline the importance of 18 F-FDG PET/CT imaging of medication-related ONJ in patients receiving zoledronic acid therapy and to emphasize that rapid and appropriate treatment can be provided., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We present a case of bilateral Phyllodes tumor located in both breasts in a 41-year-old woman who was detected with increased uptake on 68 Ga-FAPI-04 (fibroblast activation protein inhibitor) and 18 F-FDG PET/CT imaging. The tumor filling up the right breast was identified as borderline Phyllodes. The tumor with mild uptake in the left breast was reported as a benign Phyllodes tumor., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: In this prospective study, PET findings of 18 F-FDG PET/CT in breast cancer staging were compared with 68 Ga-FAP inhibitor (FAPI) 04 PET/CT findings in selected cases with relatively low 18 F-FDG uptake in the primary tumor or with suspected nodal or distant metastases., Patients and Methods: Twenty-four women with a median age of 45 years (range, 36-67 years) who underwent initial staging 18 F-FDG PET/CT for breast cancer underwent 68 Ga-FAPI-04 PET/CT imaging within the same week. SUV max and quantities of primary tumors and locoregional and distant metastatic lesions were recorded from both images, and these data were compared statistically., Results: The histological subtypes of primary tumors were 11 invasive lobular, 8 invasive ductal, and 5 mucinous subtypes. More intense 68 Ga-FAPI-04 uptake (mean, 17.1 ± 7.9; 7.4-38.5) was detected in all primary tumoral lesions compared with 18 F-FDG (mean, 6.3 ± 3.9; 1.5-20.5) ( P = <0.001, Z = 4.107). Additional lesions showing 68 Ga-FAPI-04 uptake in the breast were detected in 29.2% (n = 7) of patients. In 8.3% (n = 2) of the patients, the primary lesion showed only 68 Ga-FAPI-04 uptake. In 68 Ga-FAPI-04 PET/CT, 25% (n = 6) of the patients showed more lymph node involvement and more intense uptake in the ipsilateral axilla. In addition, infraclavicular (level 3) lymph nodes in 4 patients (16.7%), supraclavicular lymph nodes in 1 patient, and internal mammary lymph nodes in 1 patient were detected only on 68 Ga-FAPI-04 PET/CT. In a patient with lung and bone metastases, 68 Ga-FAPI-04 uptake was higher, and the lung nodule showed only 68 Ga-FAPI-04 uptake., Conclusions: In selected low-FDG-affinity breast cancer patients, 68 Ga-FAPI-04 PET/CT showed the primary tumor with higher sensitivity and higher SUV max values compared with 18 F-FDG PET/CT. In addition, it is believed that this method may contribute to the management of patients' treatment by increasing the nodal stage., Competing Interests: Conflicts of interest and sources of funding: This study was carried out with the support of the University of Health Sciences-Türkiye Scientific Research Project (2020/080). The authors have no conflicts of interest to report., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We presented a 69-year-old man with liver cirrhosis who underwent 68 Ga-fibroblast activation protein (FAPI)-04 PET/CT imaging for an ongoing study. In addition to the significant activity in liver cirrhosis on FAPI PET, a primary prostate tumor was incidentally detected with bone metastases. Further, FAPI-negative metastases were not observed on CT evaluation. In this context, we think that FAPI may be helpful with the potential theranostic aspect, especially in selected patients when current treatment options are not applicable or unresponsive. However, we should await the results of prospective studies investigating both prognostic and theranostic use of FAPI and demonstrating its effectiveness in cancer therapy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 79-year-old man with prostate cancer was evaluated with 68Ga-prostate-specific membrane antigen (PSMA), 68Ga-FAPI-04, and 18F-FDG PET/CT scans since a rise in prostate-specific antigen was seen at last control while receiving chemotherapy. Abnormal FDG uptakes were observed in the tumoral areas of the left half of the prostate and walls of the bladder, although PSMA and FAPI activity were absent or lower in the relevant tumoral areas. Restaging 68Ga-PSMA and 18F-FDG PET/CT scans were obtained on the patient whose progression continued after transurethral tumor resection. Herein, we present a case proving intraindividual tumor heterogeneity in prostate cancer underwent PET/CT imaging with 3 different radiopharmaceuticals., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 47-year-old woman had complaint of palpable swelling in the left breast for the last 3 weeks. 18F-FDG PET/CT for staging of concomitant invasive carcinoma in the right breast and 68Ga-labeled fibroblast activation protein inhibitor 04 PET/CT imaging in an ongoing study were performed. Increased radiopharmaceutical uptake was observed in both PET/CT imaging in complex fibroadenoma located in the left breast., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 57-year-old man with familial adenomatous polyposis (FAP) and newly diagnosed colonic adenocarcinoma was referred to 18 F-FDG PET/CT for staging and 68 Ga-FAPI-04 PET/CT for ongoing trial. 18 F-FDG PET/CT showed equal intense 18 F-FDG uptake in the tumor and multiple hypermetabolic polypoid lesions in the entire colorectum. 68 Ga-FAPI-04 PET/CT showed intense 68 Ga-FAPI-04 uptake only at the colonic tumor, without uptake at polypoid lesions., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 58-year-old man who underwent surgery for a well-differentiated neuroendocrine tumor of pancreatic origin was evaluated with 68Ga-DOTATATE PET/CT imaging in the follow-up period. After PET/CT findings consistent with disease remission, the patient was started on leflunomide treatment with the diagnosis of rheumatoid arthritis. The patient received leflunomide for 6 months. Then, 68Ga-DOTATATE PET/CT scan was repeated to evaluate the primary disease outcome. Besides the disease remission, we also observed alterations in DOTATATE uptakes of some tissues and organs. In this case, we present the changes in 68Ga-DOTATATE PET/CT scan findings after leflunomide use., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We present 2 patients mimicking malignancy with intense gastric 68 Ga-FAPI-04 uptake on PET/CT. Both patients showed low to moderate 18 F-FDG uptake. Histopathology revealed chronic active gastritis. Chronic gastritis may resemble gastric malignancies by showing false-positive 68 Ga-FAPI-04 uptake., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Most patients treated with epidermal growth factor receptor inhibitors develop cutaneous advance effects. The extent and severity of treatment-related skin rashes are associated with good treatment response and prognosis. Herein, we presented increased uptake of the 18F-FDG in skin rashes after treatment with epidermal growth factor receptor inhibitors in 2 patients diagnosed with metastatic colorectal cancer., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: The 68 Ga-PSMA PET/CT imaging modality is used to evaluate biochemical recurrence, response to treatment, and staging in prostate cancer. Prostate-specific membrane antigen (PSMA) receptor activation can be seen in benign and malignant diseases as well as in many physiological tissues. Many pitfalls and artifacts have been reported when reporting 68 Ga-PSMA PET/CT. In this case, diffuse moderate PSMA receptor activation in pancreatic tissue due to the previous pancreatitis is presented in 68 Ga-PSMA PET/CT imaging modality that was performed for restaging of prostate cancer., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Urethral metastasis of bladder cancer after surgery is rare. We present a 63-year-old man who had surgery for invasive bladder carcinoma and prostate adenocarcinoma 4 years ago and referred for urethral hemorrhage. 18 F-FDG PET/CT was performed for restaging and showed intense linear 18 F-FDG activity in the proximal urethra. The patient underwent urethrectomy, and histopathology determined urethral metastasis., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 71-year-old man with prostate adenocarcinoma underwent 68 Ga-prostate-specific membrane antigen (PSMA) PET/CT for staging. 68 Ga-PSMA PET/CT showed the primary lesion along with bladder, rectum, bilateral seminal vesicle invasion, and metastatic pelvic lymph nodes with intense 68 Ga-PSMA uptake. Also, PET/CT showed rarely seen bilateral vas deferens invasion and metastasis to the inguinal canal. These rare metastases may be indicative of poor biological behavior and prognosis., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Prostate cancer is the most common cancer in men. 68 Ga-PSMA PET/CT is frequently used in staging and restaging prostate cancer; it is important to keep in mind the causes of false-positives when evaluating imaging. We present findings of 68 Ga-PSMA PET/CT and histopathological features of a 68-year-old prostate cancer man with neurofibroma. 68 Ga-PSMA PET/CT showed intense 68 Ga-PSMA uptake in neurofibroma., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Herein, we present the results of 18F-FDG PET/CT and 68Ga-FAPI-4 PET/CT of a patient with metastatic Kaposi sarcoma. A 47-year-old man with suspected gastric cancer was referred to 18F-FDG PET/CT for diagnosis and staging. PET/CT detected increased 18F-FDG uptake in metastatic lymphadenopathies and liver lesions. 68Ga-FAPI-4 PET/CT was performed for ongoing clinical trial. Although 68Ga-FAPI-4 PET/CT may be a better alternative than 18F-FDG for the imaging of primary tumoral infiltrations in the stomach, 18F-FDG seems to be a more useful agent for the Kaposi sarcoma in determining the extent of the disease and the localization of metastatic lesions., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Gallbladder metastasis from renal cell carcinoma is a rare condition. To our knowledge, only 1 case has been reported with 18 F-FDG PET/CT findings. Herein, we report the case of a 53-year-old man with renal cell carcinoma, having gallbladder metastasis revealed with restaging 18 F-FDG PET/CT., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We report a case of tuberculosis peritonitis in a 26-year-old woman who presented with abdominal pain, fatigue, and weight loss for the last 4 months. Abdominal US and CT demonstrated intra-abdominal massive ascites, misty mesentery, and diffuse peritoneal thickening. In addition, 3 nodular lesions were detected in the right lung. 18 F-FDG PET/CT showed hypermetabolism in lung nodules, mesenteric area, peritoneal thickening, and ascites. 68 Ga-FAPI-04 (fibroblast activation protein-specific inhibitor) PET/CT imaging was also performed; high uptakes were detected in the same regions of 18 F-FDG PET/CT. Tuberculosis diagnosis was made after histopathological examination of wedge resection of the right lung., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 38-year-old woman presented with a 4-month history of left-sided otalgia and otorrhea. Otoscopy revealed a mass in the left external auditory canal causing obliteration. A biopsy was taken, and the diagnosis was consistent with a well-differentiated neuroendocrine tumor. The patient was referred to our department for staging with 68 Ga-DOTATATE PET/CT. Increased radiopharmaceutical uptake was observed in the primary tumor and metastatic lymph nodes., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Primary renal well-differentiated neuroendocrine tumors (WDNETs), also called renal carcinoids, are extremely rare. Since first described in 1966, approximately 100 cases have been reported in the literature. However, there have been no cases shown by PET/CT to date. We presented a patient with primary renal WDNET who had undergone both 68Ga-DOTATATE PET/CT and 18F-FDG PET/CT for diagnosis and staging. This case illustrated that 68Ga-DOTATATE PET/CT scanning could play a role in the diagnosis, staging, and follow-up of primary renal WDNETs., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 35-year-old HIV-positive man with abdominal pain was referred to 18F-FDG PET/CT for metabolic characterization of mass in pancreas. PET/CT images showed intense FDG uptake in head of the pancreas, as well as diffuse moderate uptake throughout body and tail of the pancreas. Histopathological results revealed Epstein-Barr virus (EBV) associated large B-cell lymphoma and pancreatitis caused by cytomegalovirus., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction and Aim: Cancer-associated fibroblasts, which are densely found in tumor tissue, express high levels of fibroblast activation protein (FAP), and FAP inhibitors (FAPIs) labeled with radionuclides can be used in the diagnosis and treatment of cancer. In this study, the role of 68Ga-DOTA-FAPI-04 PET/CT in imaging of primary, metastatic, and recurrent cancers was investigated., Patients and Methods: A total of 42 patients (16 females, 26 males; mean age, 58.5 years; range, 31-84 years) with 22 different types of malignant diseases were included in the study. 68Ga-DOTA-FAPI-04 PET/CT imaging was performed 1 to 7 days after 18F-FDG PET/CT. Pathological uptake levels in primary tumoral lesions, lymph nodes, skeletal system, liver, peritoneal surfaces, and other body parts were compared between 2 PET/CTs. In addition, physiological uptake levels of 18F-FDG and 68Ga-FAPI were defined measuring the liver, thoracic aorta, gluteal muscle activities, and uterus activity in female patients., Results: Of the 42 patients in the study group, 33 patients were included for staging, 8 patients for restaging, and 1 patient for evaluation of treatment response. 68Ga-DOTA-FAPI-04 PET/CT showed intense uptake in 94.2% of primary tumoral lesions. In patients with multiple myeloma, 18F-FDG uptake in the bone marrow was significantly higher than 68Ga-FAPI uptake, whereas in gastric signet ring cell tumors, 68Ga-FAPI uptake was found to be significantly higher than 18F-FDG uptake. It was observed that 68Ga-DOTA-FAPI-04 PET/CT detected bone, liver, and peritoneum metastases with higher sensitivity and accuracy compared 18F-FDG PET/CT., Conclusions: The preliminary findings of this study showed that 68Ga-DOTA-FAPI-04 PET/CT can contribute to the diagnostic process in solid tumors. Especially in malignancies with mild uptake on 18F-FDG PET/CT, it stands out in diagnosis, staging, and restaging. It is also predicted that FAPI molecules can be used for radionuclide therapy in patients with metastatic disease and unresponsive to other treatments showing intense uptake on 68Ga-DOTA-FAPI-04 PET/CT., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Diffuse sclerotic metastases of the bone as initial presentation at gastric carcinoma are very rare. We present a 48-year-old man who was examined for pancytopenia and diagnosed with gastric cancer. 18F-FDG PET/CT showed moderate uptake in the primary gastric tumor and mild uptake in diffuse sclerotic metastatic lesions in the bone matrix, whereas 68Ga-DOTA-FAPI-04 showed mild uptake in the gastric lesion and intense uptake at the whole skeleton., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We present the findings of 68Ga-FAPI-4 PET/CT and 18F-FDG PET/CT of a metastatic malignant melanoma patient with osteoarthritis. A 65-year-old woman with a history of metastatic uveal malignant melanoma was referred to 18F-FDG PET/CT for restaging after enucleation and chemotherapy. 18F-FDG PET/CT imaging showed high radiotracer uptake in liver metastases; additionally mild uptake due to osteoarthritis was observed in both knees. However, although 68Ga-FAPI-4 showed lower uptake in liver lesions, it showed a more prominent uptake in both knee joints compared with 18F-FDG., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Primary carcinoma of the sigmoid colon in an inguinal hernia is a rare condition. We present a 79-year-old man diagnosed with sigmoid colon carcinoma referred to 18F-FDG PET/CT for staging. PET/CT showed the primary lesion in the inguinal hernia into scrotum., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 68-year-old woman with a mass lesion in right hepatic lobe had an elevated α-fetoprotein level (>54,000 ng/mL). The lesion showed higher 68Ga-DOTA-FAPI-04 uptake than 18F-FDG uptake in consecutive PET/CT images. The histopathological examination revealed neuroendocrine carcinoma with Ki-67 proliferation index of 80%., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Bilateral adrenal metastases from bladder carcinoma have been reported rarely. We report an 86-year-old man with urothelial bladder carcinoma who had received chemotherapy and radiotherapy. Bilateral synchronous adrenal gland metastases were observed on 18F-FDG PET/CT., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Leptomeningeal metastasis is the metastatic spread of the disease to leptomeninges from solid tumors such as breast, lung cancer, and melanoma. Cauda equine syndrome is a neurological condition caused by compression of the cauda equine. The incidence of large cell neuroendocrine carcinoma in resected lung cancers appears to be 2.1% and 3.5%. The incidence of clinically diagnosed leptomeningeal metastasis in patients with solid tumors is approximately 5%. Here, we present cauda equine syndrome caused by the metastasis of large cell neuroendocrine carcinoma detected by 18F-FDG PET/CT and also 68Ga-DOTATATE PET/CT., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Hyalinizing cholecystitis is a rare type of chronic cholecystitis. Moderate patchy transmural especially perivascular lymphoplasmacytic inflammatory cell infiltration is observed in the gallbladder wall. We present the 18F-FDG PET/CT and MRI findings of this rare subtype of chronic cholecystitis. Hyalinizing cholecystitis should be kept in mind in the differential diagnosis of gallbladder wall thickening with intense 18F-FDG uptake., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 49-year-old woman was diagnosed with diffuse large B-cell lymphoma of the left ovary. Two months after the hysterectomy and bilateral salpingo-oophorectomy operation, the patient was referred to 18F-FDG PET/CT for staging. A mass lesion measuring 2.8 × 3 cm with intense 18F-FDG uptake was observed at right labium majus, which could be considered as a Bartholin's cyst or abscess. The lesion was excised, and non-Hodgkin lymphoma involvement of vulva was revealed by histopathology., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Triple negative breast cancer (TNBC) is characterized by poor prognosis and limited response to standard treatments. Although 18F-FDG PET/CT is frequently used in staging and restaging, in some cases, it may be insufficient considering tumor heterogeneity. Prostate-specific membrane antigen (PSMA) has been reported to be overexpressed in many types of cancer due to tumor-associated neovascularization. 68Ga-PSMA-11 PET/CT can be used to demonstrate radionuclide therapy option as well as detection of primary tumor and recurrence in TNBC. We present a 47-year-old woman with TNBC having recurrent brain metastasis with avid PSMA receptor activity versus low FDG uptake., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

A 64-year-old woman who had yellowish orange-colored, sharp-edged, and flat skin plaques and back pain for about a year was referred for F-FDG PET/CT imaging and her bone marrow biopsy revealed 10% to 20% atypical plasma cells suggestive of monoclonal gammopathy. PET/CT showed linear F-FDG uptake on the surface of the skin on the neck, axillary, chest, inframammary, and inguinal regions. Punch biopsy revealed numerous histiocyte infiltrates with large vacuoles, xanthomized cytoplasm in the dermis, and midsection, and there are several Touton-type giant cells supporting the preliminary diagnosis of xanthoma disseminatum.

A 77-year-old man with newly diagnosed prostate adenocarcinoma with a total prostate-specific antigen level of 6.4 ng/mL and Gleason score 7 (4 + 3) was referred to Ga-prostate-specific membrane antigen-11 (PSMA) PET/CT for initial staging. An intense focal PSMA uptake was shown in the right peripheral zone of the prostate gland consistent with the primary tumor. Additionally, PET/CT demonstrated a PSMA-avid soft tissue mass in the left cerebellopontine angle. The patient had a history of left-sided sensorineural hearing loss.

A 68-year-old woman with colon carcinoma was referred to F-FDG PET/CT imaging for staging. In addition to primary tumor involvement, PET/CT demonstrated focal FDG uptake in the right temporal lobe suggestive of primary brain tumor or metastasis. To delineate the lesion, a brain MRI scan showed sigmoid sinus thrombosis and vasogenic edema in the right temporal lobe. The patient presented a history of right-sided headache that began 1 week before the PET/CT. Neurological examination and MRI findings were concluded as subacute venous infarct due to sigmoid sinus thrombosis and that is a potential cause for false-positive FDG uptake on PET/CT.

Introduction: Prostate-specific membrane antigen (PSMA) ligand PET/CT is an emerging modality to detect the metastatic disease, especially in intermediate- and high-risk prostate cancer (PCa). In this study, we analyzed the contribution of Ga-PSMA-11 PET/CT in staging and therapy management of newly diagnosed PCa., Materials and Methods: A total of 78 patients with biopsy-proven PCa who were referred for Ga-PSMA-11 PET/CT for primary staging were retrospectively analyzed. The patients were divided into risk groups according to the D'Amico risk stratification criteria. All of the patients had undergone pelvic MRI, and 65 patients had bone scintigraphy also. The findings of Ga-PSMA-11 PET/CT were compared with these conventional imaging (CI) methods for staging of the disease. The relations between SUVmax of the primary tumors and Gleason scores (GSs), prostate-specific antigen (PSA) levels, and metastatic extent of the disease were analyzed., Results: Of 78 patients, 5 patients were in low-risk group, 18 patients were in intermediate-risk group, and 55 patients were in high-risk group. Metastatic disease was found in 40 (51.2%) of 78 patients in Ga-PSMA-11 PET/CT. Ten patients had regional lymph node metastases, and 30 patients had distant metastases. Ga-PSMA-11 PET/CT changed the staging in 44 (56.4%) of 78 patients compared with CI. There was significant difference between the SUVmax of the tumors with GSs of 6 and 7 compared with GSs of 8, 9, and 10 (P = 0.003). The SUVmax were significantly different between the patients with no metastasis (n = 38) and patients with regional lymph node metastases or distant metastases (n = 40; 16.1 ± 10.9, 28.7 ± 25.8, P = 0.003, respectively). There was significant difference between the SUVmax of patients with PSA level less than 10 ng/mL compared with patients with PSA level of 10 or greater and less than 20 ng/mL and PSA 20 ng/mL or greater (P = 0.009). A weak correlation between PSA and primary tumor SUVmax was also found (r = 0.21)., Conclusions: Ga-PSMA-11 PET/CT is an important imaging modality for primary evaluation of newly diagnosed PCa changing the disease stage substantially. Also the SUVmax of the primary tumor has a relation with GS, metastatic extent of disease, and PSA levels defining the prognosis.

A 67-year-old man with prostate adenocarcinoma underwent Ga-labeled prostate-specific membrane antigen (PSMA) ligand PET/CT for restaging due to a rising prostate-specific antigen level. Local recurrence in the prostatic region and a metastasis in the left iliac bone were detected showing high PSMA expression. A mass lesion was seen in the left orbitofrontal region with high Ga PSMA uptake. The successive MRI confirmed that the lesion was consistent with meningioma.