A Comparison of 18 F-FDG PET/CT and 68 Ga-PSMA PET/CT in Detecting Osteonecrosis of the Jaw in a Patient With Prostate Cancer.

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.

68Ga-DOTA-FAPI-46 PET/CT Imaging for Restaging in a Patient With Metastatic Pheochromocytoma: Comparison With 68Ga-DOTA-TATE PET/CT.

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.

Dual 177 Lu-Prostate-Specific Membrane Antigen and 177 Lu-DOTATATE Therapy in Metastatic Castration-Resistant Prostate Cancer With Neuroendocrine Differentiation.

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.

68Ga-NODAGA-Exendin-4 PET/CT Findings in a Case of Metastatic Insulinoma With Refractory Hypoglycemia Controlled by 90Y Transarterial Radioembolization.

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.

The Contribution of 68 Ga-FAPI-04 PET/CT to Staging and Prognosis in Gastric Cancer.

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.

Contribution of 68 Ga-DOTA-FAPI-04 PET/CT to Prostate Cancer Imaging : Complementary Role in PSMA-Negative Cases.

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.

Increased FDG Uptake in Skin Rashes Caused by EGFR Inhibitors.

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.

Findings of I-131 SPECT/CT, 18F-FDG, and 68Ga-FAPI-04 PET/CT Imaging in a Patient Treated with Radioiodine Therapy for Metastatic Papillary Thyroid Carcinoma.

A 50-year-old man undergone total thyroidectomy and histopathology revealed papillary thyroid carcinoma with a tumor size of 4.5 cm. The patient was referred to a nuclear medicine clinic for radioiodine therapy. Since the thyroglobulin level before the treatment was 495 ug/L, low-dose (185 MBq) I-131 scan was performed. In addition to multiple liver metastases, bone metastases were detected in the sacrum and right 7th rib in I-131 whole body scanning and single photon emission computed tomography/computed tomography (CT) imaging at the time of initial staging. We present a case of multiple metastatic papillary thyroid carcinoma whose radioiodine treatment response and clinical outcome were evaluated with 18F-fluorodeoxyglucose and Gallium-68 FAPI-04 positron emission tomography/CT.

Cutaneous Metastase of Rectal Neuroendocrine Carcinoma Revealed on 18F-FDG PET/CT.

Rectal neuroendocrine carcinomas constitute <1% of all neuroendocrine carcinomas and <1% of all gastrointestinal tract malignancies. Cutaneous metastases of rectal neuroendocrine carcinoma are rarer than visceral metastases. We represent a 71-year-old man who was diagnosed with neuroendocrine tumor grade 3 originating from the rectum 1 year ago. He was referred for 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography for restaging after 6 cycles of chemotherapy and radiotherapy. Intensely increased 18F-FDG uptake in the right cutaneous inguinal region was consistent with neuroendocrine carcinoma metastasis with biopsy from the same region.

The potential role of 68Ga-FAPI-04 PET/CT for screening malignancy in suspected colonic lesions.

AIM: Benign colonic lesions like tubular adenoma may show intense uptake on F-18-FDG PET/CT and can be mistaken for malignancy. In this study, we evaluated the role of 68Ga-FAPI-04 PET/CT for discriminating the benign and malignant colonic lesions. METHODS: Forty patients with diagnosis of colorectal cancer who had undergone 18F-FDG-PET/CT and 68Ga-FAPI-04 PET/CT for initial staging were retrospectively analyzed. The unexpected foci of uptake in colon on 18F-FDG PET/CT were compared with 68Ga-FAPI-04 PET/CT with lesion and background SUVmax. RESULTS: The primary colorectal lesion SUVmax on both PET/CTs was similar. A total of 9 incidental colon lesions in 7 patients were detected showing intense 18F-FDG uptake and no 68Ga-FAPI-04 uptake. All of the lesions were consistent with tubular adenoma histopathologically. CONCLUSION: 68Ga-FAPI PET/CT may have a crucial role for discrimination of benign and malignant colonic lesions and avoid the unnecessary interventions and extended surgeries in patients with colorectal cancer.

The roles of 68 Ga-PSMA PET/CT and 18 F-FDG PET/CT imaging in patients with triple-negative breast cancer and the association of tissue PSMA and claudin 1, 4, and 7 levels with PET findings.

AIM: Aim of study is to compare the results of Gallium-68-prostate-specific membrane antigen ( 68 Ga-PSMA) and 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography(PET)/computed tomography (CT), to evaluate the correlation between PET findings and the level of PSMA, Claudin (Clau) 1, 4, and 7 receptors obtained by immunohistochemical (IHC) analysis, and to determine potential predictive and prognostic values in TNBC. METHODS: Forty-seven lesions of 42 subjects diagnosed TNBC both underwent PET/CT scan for preoperative staging/restaging were prospectively included study. PSMA, Clau 1, 4, and 7 expressions were IHC evaluated from the biopsy samples of the primary tumor (PT). Maximum standardized uptake value(SUV max) of the PT, lymph node, and distant organ metastases (DOMs) on 18 F-FDG and 68 Ga-PSMA PET/CT were compared with PSMA, Clau 1, 4, and 7 receptor expressions. RESULTS: IHC analyses on 29 BC lesions to demonstrate Clau expression showed 86% (25/29) Clau 1, 86% (25/29) Clau 4, 45% (13/29) Clau 7, and 48% (14/29) PSMA-positive. The mean DOM (SUVmax) was 15.5 ± 11.6 for 18 F-FDG and 6.0 ± 2.9 for 68 Ga-PSMA. Axial diameter of BC PT had a significant positive correlation with 18 F-FDG SUVmax, 68 Ga-PSMA SUVmax, and PSMA scores. BC lesions 68 Ga-PSMA SUVmax had a significant negative correlation with the Ki-67 index. Axial diameter of the primary tumor had significant negative correlation with Clau 7 scores ( r = -0.409, P = 0.034). Absence of Clau 1 expression found to significantly increase the rate of DOM (100% vs. 28%) ( P = 0.014). All patients with axillary lymph node (ALN) metastases ( n = 17, 100%) exhibited Clau 4 positivity ( P = 0.021). The presence of PSMA expression observed to significantly increase the rate of ALN metastases (64.7% vs. 25%) ( P = 0.035). CONCLUSION: Confirming PSMA expression with PET imaging would be significant as PSMA, a theranostic agent, may be a considerable potential agent for radionuclide treatment strategies, in addition to its additional diagnostic contribution to FDG, especially in patients with metastatic TNBC, which is an aggressive, heterogeneous disease.

18F-FDG PET/CT Findings in HIV-Positive Patient With Primary Pancreas Lymphoma and CMV Pancreatitis.

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.

Peritoneal Tuberculosis Mimicking Peritoneal Carcinomatosis on 68 Ga-FAPI-04 and 18 F-FDG PET/CT.

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.

18F-FDG PET/CT and 68Ga-DOTATATE PET/CT Findings in a Patient With Primary Renal Well-Differentiated Neuroendocrine Tumor.

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.

68 Ga-DOTATATE Uptake in Well-Differentiated Neuroendocrine Tumor of the External Auditory Canal.

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.

Multiple Subcutaneous 18F-FDG-avid Granulomas Due to Enoxaparin Injection.

A 67-year-old female patient with metastatic gastric adenocarcinoma was referred to 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for restaging. PET/CT revealed liver metastasis and the patient received six-cycles of chemotherapy. On control 18F-FDG PET/CT the liver lesion disappeared but newly formed multiple foci of increased uptake in the subcutaneous adipose tissues of the abdominal wall were detected. The uptake was related to nodular lesions resulting from an idiosyncratic reaction to enoxaparin and from local trauma through repeated injections.

Two Cases of Acrometastasis from Lung Cancer Revealed on 18F-FDG PET/CT.

We present 2 cases of acrometastases that manifest as the first signs of underlying lung cancer. The first case is 37 year-old-man misdiagnosed and treated as having a traumatic fracture at the left thumb. The second case is a 77 year-old-man who received treatment for soft tissue infection at left hand for 4 weeks. In both cases 18fluorine-fluorodeoxyglucose positron emission tomography/computed tomography demonstrated primary malignant lesions in the lungs consistent with primary lung cancer with acrometastases.

Sigmoid Colon Carcinoma Presenting in Inguinoscrotal Hernia With FDG PET/CT.

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.

Detection of Cauda Equine Syndrome With 18F-FDG PET/CT and Leptomeningeal Metastasis by 68Ga-DOTATATE in the Same Patient With Large Cell Neuroendocrine Carcinoma of Lung.

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.