The impact of IV contrast enhanced 18F-FDG PET/CT on the staging of bladder cancer.

OBJECTIVE: The aim of this retrospective study was to compare the diagnostic accuracies of conventional radiological imaging (CI) methods magnetic resonance imaging or computed tomography (MRI or CT) and intra venous (IV) contrast enhanced (CE) fluorine-18-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) for the staging of bladder cancer (BC). MATERIALS AND METHODS: The 18F-FDG CE-PET/CT results of 35 consecutive patients with BC were analyzed. Diagnostic value of CE-PET/CT and CI are compared for their accuracy in revealing primary tumors, nodal-distant metastasis, and the final tumor staging. The imaging results were compared with the gold standard, including of histopathology and clinical follow-up. We also investigated the effect of maximum standardize uptake value (SUVmax) and lymph node metastasis on survival. RESULTS: The CE-PET/CT had a diagnostic accuracy of 89% (31/35), compared to 57% (19/35) for CI. The results of CE-PET/CT imaging lead to upstaging in 37% (13/35) patients compared to CI staging. For primary tumor detection, the sensitivity of CE-PET/CT was 97% (34/35). Contrast enhanced-PET/CT detected nodal metastases in 19 (54%) patients, whereas CI detected in 9 (26%) patients. Contrast enhanced-PET/CT detected distant metastases in 14 (40%) patients, while conventional methods showed distant metastases in 9 (26%) patients. Maximum SUV of primary tumor does not have a significant effect on survival, whereas the median survival time of patients without lymph node metastasis is longer than patients who have lymph node metastasis (P=0.038). CONCLUSION: These data suggest that 18F-FDG CE-PET/CT had good diagnostic performance compared to conventional imaging for detecting primary tumor, nodal and distant metastasis in BC. Upstaging by CE-PET/CT changed the management of patients.

68 Ga-PSMA PET/CT Found Lower Respiratory Tract Inflammation Due to Inhaler Use.

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.

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.

Detection of Rare Gallbladder Microperforation by 18F-FDG PET/CT in a Patient with Maxillary Sinus Cancer.

Gallbladder perforation is one of the most serious complications of cholecystitis and is rarely seen in 2-11% of cases. Pericholecystic abscesses secondary to gallbladder perforation are rare. Rapid diagnosis is important because of high morbidity and mortalityrates. A subcapsular abscess secondary to gallbladder microperforation is presented on 18F-fluorodeoxyglucose positron emission tomography/computed tomography performed for restaging in a patient with maxillary sinus cancer.

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.

Two Rare Benign Lesions on 18F-FDG PET/CT: Peliosis Hepatis and SANT.

Peliosis hepatis (PH) and sclerosing angiomatoid nodular transformation of the spleen are uncommon benign lesions. Diagnosis can be difficult in some patients. Herein, we present the case of a 28-year-old woman referred with abdominal pain who had spleen lesions. 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography revealed multiple non-FDG avid lesions in the liver and hypermetabolic lesions in the spleen. In addition, abdominal magnetic resonance imaging was performed. Histopathology revealed sclerosing angiomatoid nodular transformation in the spleen and PH in the liver.

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.

Radiation Therapy-Induced Fibrous Histiocytoma, Mimicking Local Recurrence and Detected by 18 F-FDG PET/CT in a Patient With Breast Cancer.

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.

Bilateral Adrenal Metastasis of Prostatic Adenocarcinoma on 68 Ga-PSMA PET/CT Imaging.

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.

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.

Chronic Gastritis Mimicking Malignancy on 68 Ga-FAPI-04 PET/CT.

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.

68 Ga-FAPI-04 PET/CT In Primary Signet Ring-Like Cell Carcinoma of Prostate With Bone Metastases.

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.

Effect of Leflunomide Use on 68Ga-DOTATATE Biodistribution in a Case With Neuroendocrine Tumor.

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.

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.

Role of 68 Ga-FAPI PET/CT in Screening Malignancy of Familial Adenomatous Polyposis.

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.

68Ga-PSMA and 68Ga-FAPI-04 PET/CT Findings With 18F-FDG PET/CT in a Patient With Recurrent Prostate Cancer.

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.

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.

68 Ga-DOTA-FAPI-04 Imaging of Bilateral Phyllodes Tumor.

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.

68Ga-FAPI-04 PET/CT Findings in Patients with Liver Cirrhosis.

Fibroblast activation protein (FAP) is expressed as a pro-inflammatory agent from fibrous tissue in liver cirrhosis and in the tumor microenvironment. Cirrhosis is the last stage of any chronic liver disease, and the natural course of cirrhosis is the progression from the asymptomatic phase to the symptomatic decompensated phase with the development of ascites. Although various clinical features suggest cirrhosis in patients with chronic liver disease, non-invasive methods should follow the clinical approach before a definitive diagnosis. Herein, we present three cases of liver cirrhosis with fibroblast activation protein inhibitor (FAPI) uptake to demonstrate the usefulness of 68Ga-FAPI-04 positron emission tomography/computed tomography (PET/CT) scan in cirrhosis.

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.