Pharmacokinetic analysis of 6-O-[18F]FEE for PET imaging of EGFR mutation.

6-O-[18F]Fluoroethylerlotinib (6-O-[18F]FEE), with a suitable half-life for commercial distribution, may be a good replacement for [11C]erlotinib to identify epidermal growth factor receptor (EGFR) positive tumors with activating mutations to tyrosine kinase inhibitors therapy. In this study, we explored the fully automated synthesis of 6-O-[18F]FEE and investigated its pharmacokinetics in tumor-bearing mice. 6-O-[18F]FEE with high specific activity (28-100 GBq/µmol) and radiochemistry purity (over 99 %) was obtained by two-step reaction and Radio-HPLC separation in PET-MF-2 V-IT-1 automated synthesizer. PET imaging of 6-O-[18F]FEE in HCC827, A431, and U87 tumor-bearing mice with different EGFR expression and mutation was performed. Uptake and blocking of PET imaging indicated that the probe specifically targeted exon 19 deleted EGFR (the quantitative analysis of tumor-to-mouse ratio for HCC827, HCC827 blocking, U87, A431 was 2.58 ± 0.24, 1.20 ± 0.15, 1.18 ± 0.19, and 1.05 ± 0.13 respectively). Dynamic imaging was used to study the pharmacokinetics of the probe in tumor-bearing mice. Logan plot graphical analysis demonstrated late linearity and a high fitting correlation coefficient (0.998), supporting reversible kinetics. According to the Akaike Information Criterion (AIC) rule, the 2-compartment reversible model was more consistent with the metabolic properties of 6-O-[18F]FEE. The automated radiosynthesis and pharmacokinetic analysis will promote clinically transformation of 6-O-[18F]FEE.

Comparison of 68Ga-FAPI and 18F-FDG PET/CT in the Evaluation of Advanced Lung Cancer.

Background Gallium 68 (68Ga)-labeled fibroblast-activation protein inhibitor (FAPI) has recently been introduced as a promising tumor imaging agent. Purpose To compare 68Ga-FAPI PET/CT with fluorine 18 (18F)-labeled fluorodeoxyglucose (FDG) PET/CT in evaluating lung cancer. Materials and Methods In this prospective study conducted from September 2020 to February 2021, images from participants with lung cancer who underwent both 68Ga-FAPI and 18F-FDG PET/CT examinations were analyzed. The tracer uptakes, quantified by maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR), were compared for paired positive lesions between both modalities using the paired t test or Wilcoxon signed-rank test. Results Thirty-four participants (median age, 64 years [interquartile range: 46-80 years]; 20 men) were evaluated. From visual evaluation, 68Ga-FAPI PET/CT and 18F-FDG PET/CT showed similar performance in the delineation of primary tumors and detection of suspected metastases in the lungs, liver, and adrenal glands. The metabolic tumor volume in primary and recurrent lung tumors showed no difference between modalities (mean: 11.6 vs 10.8, respectively; P = .68). However, compared with 18F-FDG PET/CT, 68Ga-FAPI PET/CT depicted more suspected metastases in lymph nodes (356 vs 320), brain (23 vs 10), bone (109 vs 91), and pleura (66 vs 35). From semiquantitative evaluation, the SUVmax and TBR of primary or recurrent tumors, positive lymph nodes, bone lesions, and pleural lesions at 68Ga-FAPI PET/CT were all higher than those at 18F-FDG PET/CT (all P < .01). Although SUVmax of 68Ga-FAPI and 18F-FDG in brain metastases were not different (mean SUVmax: 9.0 vs 7.4, P = .32), TBR was higher with 68Ga-FAPI than with 18F-FDG (mean: 314.4 vs 1.0, P = .02). Conclusion Gallium 68-labeled fibroblast-activation protein inhibitor PET/CT may outperform fluorine 18-labeled fluorodeoxyglucose PET/CT in staging lung cancer, particularly in the detection of metastasis to the brain, lymph nodes, bone, and pleura. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Jacobson and Van den Abbeele in this issue.

Expression of fibroblast activation protein in lung cancer and its correlation with tumor glucose metabolism and histopathology.

PURPOSE: To explore the expression of fibroblast activation protein (FAP) in lung cancer (LC) and its correlation with tumor glucose metabolism and histopathology. METHODS: From June 2018 to November 2020, 73 patients with newly diagnosed LC were included. Immunohistochemical staining was used to quantify FAP expression in tumors. The histopathological type and tumor grade were determined via histopathological examination. The tumor glucose metabolism parameters and tumor maximal diameter were measured via [18F] F-FDG PET/CT. Univariate and multivariate analysis were performed to study the correlation of FAP expression levels with glucose metabolism variables and tumor histopathology. RESULTS: Positive FAP expression was observed in 97.3% (71/73) LC lesions, which was significantly higher than 87.7% (64/73) of [18F] F-FDG positivity observed on PET/CT (χ2 = 4.818, P = 0.028). In 12 early adenocarcinomas (ADCs), only three lesions (25%) were positive for [18F] F-FDG on PET/CT; however, 10 lesions (83.3%) were positive for FAP. When FAP expression was classified into low level (scores ≤ 3) and high level (scores > 4), high FAP level was found in 80.8% tumors and low FAP level in the other 19.2% tumors. High FAP level was identified in 100.0% of squamous cell carcinomas (SCCs), 85.7% of ADCs, 66.7% (4/6) of large cell neuroendocrine carcinomas (LCNCs), and 40.0% (4/10) of small cell lung cancers (SCLCs) (P < 0.05). In non-mucinous ADC lesions, on univariate analysis, FAP expression level showed a close relationship with tumor metabolism parameters (maximal standard uptake value (SUVmax), mean standard uptake value (SUVmean), and total lesion glycolysis (TLG)), tumor diameter, tumor grade, and lesion attenuation (P < 0.05). CONCLUSION: The present study demonstrates that FAP is widely expressed in LC and shows great variation in different histopathological types. A high positive rate of FAP expression implies that FAP-targeted imaging may be a sensitive modality for diagnosing LC, especially in early ADCs. Further validation with such probes is warranted.

Superiority of [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT to [18F]FDG PET/CT in delineating the primary tumor and peritoneal metastasis in initial gastric cancer.

OBJECTIVE: This study aimed to compare [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT with [18F]FDG PET/CT in the evaluation of initial gastric cancer. METHODS: We retrospectively compared [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT with [18F]FDG PET/CT in patients with initial gastric cancer from September 2020 to March 2021. Lesion detectability and the uptake of lesions quantified by the maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR) were compared between the two modalities using the Wilcoxon signed-rank test, Mann-Whitney U test, and McNemar's chi-square test. RESULTS: A total of 61 patients (37 males, aged 23-81 years) were included, of which 22 underwent radical gastrectomy. For primary lesions, higher uptake of [68Ga]Ga-FAPI-04/[18F]FAPI-42 was observed compared to [18F]FDG (median SUVmax, 14.60 vs 4.35, p < 0.001), resulting in higher positive detection using [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT than [18F]FDG PET/CT (95.1% vs 73.8%, p < 0.001), particularly for tumors with signet-ring cell carcinoma (SRCC) (96.4% vs 57.1%, p < 0.001). [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT detected more positive lymph nodes than [18F]FDG PET/CT (637 vs 407). However, both modalities underestimated N staging compared to pathological N staging. [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT showed a higher sensitivity (92.3% vs 53.8%, p = 0.002) and peritoneal cancer index score (18 vs 3, p < 0.001) in peritoneum metastasis and other suspect metastases compared to [18F]FDG PET/CT. CONCLUSION: Our findings indicate that [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT outperformed [18F]FDG PET/CT in the evaluation of primary tumors with SRCC and peritoneum metastasis in initial gastric cancer. However, no clinically useful improvement was seen in N staging. KEY POINTS: • The uptake of [68Ga]Ga-FAPI-04/[18F]FAPI-42 in primary tumor and metastasis was intensely higher than that of [18F]FDG (p < 0.001) in 61 patients with initial gastric cancer. • [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT had a higher sensitivity detection in primary tumors (95.1% vs 73.8%, p < 0.001) and peritoneal metastases (92.3% vs 53.8%, p = 0.002) than [18F]FDG PET/CT. • [68Ga]Ga-FAPI-04/[18F]FAPI-42 PET/CT depicted more positive lymph nodes than [18F]FDG PET/CT (637 vs 407); however, both underestimated N staging compared to pathological N staging.

Automatic radiosynthesis and preclinical evaluation of 18F-AlF-PSMA-NF as a potential PET probe for prostate cancer imaging.

Facile automatic production is important for the application of prostate-specific membrane antigen (PSMA) tracers in clinical practice. We developed a new 18F-AlF-labelled PSMA probe-18F-AlF-PSMA-NF-and explore its automated production method and potential value in clinical settings. 18F-AlF-PSMA-NF was prepared using an automated method with dimethylformamide (DMF) as the solvent in a positron emission tomography (PET)-MF-2 V-IT-I synthesizer. Tracer characteristics were examined both in vitro and in vivo. Micro-PET/computed tomography (CT) was performed to investigate the utility of 18F-AlF-PSMA-NF for imaging PSMA-positive tumours in vivo. 18F-AlF-PSMA-NF was prepared automatically within 35 min with a non-attenuation correction yield of 37.9 ± 11.2%. The tracer was hydrophilic, had a high affinity for PSMA (Kd = 2.58 ± 0.81 nM), and showed stability in both in vitro and in vivo conditions. In the cellular experiments, 18F-AlF-PSMA-NF uptake in PSMA-positive LNCaP cells was significantly higher than that in PSMA-negative PC-3 cells (P < 0.001), and could be blocked by excess ZJ-43-a PSMA inhibitor (P < 0.001). LNCaP tumours were clearly visualized by 18F-AlF-PSMA-NF on micro-PET/CT, with a high level of uptake (13.72 ± 2.01 percent injected dose per gram of tissue [%ID/g]) and high tumour/muscle ratio (close to 50:1). The PSMA-positive LNCaP tumours had a significantly higher uptake than PSMA-negative PC-3 tumours (13.72 ± 2.01%ID/g vs. 1.07 ± 0.48%ID/g, t = 10.382, P < 0.001), and could be blocked by ZJ-43 (13.72 ± 2.01%ID/g vs. 2.77 ± 1.44%ID/g, t = 8.14, P < 0.001). A new 18F-AlF-labelled PSMA probe-18F-AlF-PSMA-NF-was successfully developed and can be prepared automatically. It has the biological characteristics resembling that of a PSMA-based probe and can potentially be used in clinical settings.

Benefits of 18F-FDG PET/CT for the preoperative characterisation or staging of disease in the ampullary and duodenal papillary.

OBJECTIVES: Diagnosing ampullary and duodenal papillary carcinomas (ADPCs) is challenging. In the present study, we investigated the application value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the preoperative evaluation of these tumours. METHODS: 18F-FDG PET/CT images of 58 patients with ADPC and 28 patients with benign disease were retrospectively analysed. Preoperative 18F-FDG PET/CT was compared to contrast-enhanced (CE) CT and magnetic resonance imaging (MRI) in terms of diagnostic efficacy, certainty, staging and impact on treatment decisions. RESULTS: 18F-FDG PET/CT showed a high sensitivity (93.1%) and a medium specificity (78.6%) for diagnosing ADPC. Compared to CE CT/MRI, 18F-FDG PET/CT had a higher diagnostic specificity (78.6 vs. 35.7%, p = 0.001) but a similar sensitivity (93.1 vs. 89.6%, p = 0.508). 18F-FDG PET/CT provided a much higher diagnostic certainty than CE CT/MRI (definite reports, 88.4 vs. 50.0%, χ2 = 29.698, p < 0.001), especially for small tumours ≤ 1.5 cm, and found distant metastases in five patients. The 18F-FDG PET/CT findings affected the treatment plans of 11 patients and improved the confidence in the diagnoses of 28 patients. CONCLUSIONS: The present study demonstrated that 18F-FDG PET/CT can supplement CE CT/MRI to provide a more accurate diagnosis for ADPC, and thus, plays an important role in the decision-making process before complicated pancreaticoduodenectomy procedures. KEY POINTS: • It is a challenge for CT and MRI to diagnose ampullary carcinoma, especially at their early stage. • Our study demonstrated that the benefit of PET/CT was improving the diagnostic confidence for ampullary and duodenal papillary carcinomas. • 18F-FDG PET/CT can change the treatment decision for ampullary and duodenal papillary carcinomas.

Radiosynthesis and preclinical evaluation of [18F]FEM as a potential novel PET probe for tumor imaging.

In the 21st century, the incidence and mortality of cancer, one of the most challenging diseases in the world, have rapidly increased. The purpose of this study was to develop 2-(2-[18F]fluoroethoxy)ethyl 4-methylbenzenesulfonate ([18F]FEM) as a positron emission tomography (PET) agent for tumor imaging. In this study, [18F]FEM was synthesized with a good radiochemical yield (45.4 ± 5.8%), high specific radioactivity (over 25 GBq/µmol), and commendable radiochemical purity (over 99%). The octanol/water partition coefficient of [18F]FEM was 1.44 ± 0.04. The probe demonstrated good stability in vitro (phosphate-buffered saline (PBS) and mouse serum (MS)), and binding specificity to five different tumor cell lines (A549, PC-3, HCC827, U87, and MDA-MB-231). PET imaging of tumor-bearing mice showed that [18F]FEM specifically accumulated at the tumor site of the five different tumor cell lines. The average tumor-to-muscle (T/M) ratio was over 2, and the maximum T/M values reached about 3.5. The biodistribution and dynamic PET imaging showed that most probes were metabolized by the liver, whereas a small part was metabolized by the kidney. Moreover, dynamic brain images and quantitative data showed [18F]FEM can quickly cross the blood brain barrier (BBB) and quickly fade out, thereby suggesting it may be a promising candidate probe for the imaging of brain tumors. The presented results demonstrated that [18F]FEM is a promising probe for tumor PET imaging.

Imaging the expression of glypican-3 in hepatocellular carcinoma by PET.

The glypican-3 (GPC3) receptor is overexpressed in hepatocellular carcinoma (HCC) and is a potential diagnostic and therapeutic target. GPC3-targeted molecular imaging will be helpful to differentiate diagnosis and guide therapy. In the present study, we will develop a novel PET probe for imaging the expression of GPC-3. L5 (sequence: RLNVGGTYFLTTRQ), a GPC3 targeting peptide, was labeled with 5-carboxyfluorescein (FAM) and 18F-fluoride. Cell binding tests were performed to identify the binding specificity of FAM-L5 and 18F radiolabeled peptide. MicroPET/CT imaging was used to determine the potential of a novel PET tracer for visualizing HCC tumors with a high expression of GPC3. In vitro binding tests showed that the uptake of FAM-L5 in HepG2 cells (high expression of GPC3) was significantly higher than that of HL-7702 cells (negative expression of GPC3) (mean fluorescent intensity: 14,094 ± 797 vs. 2765 ± 314 events, t = 32.363, P = 0.000). Confocal fluorescent imaging identified that FAM-L5 accumulated where the GPC3 receptor was located. A novel PET tracer (18F-AlF-NODA-MP-6-Aoc-L5) was successfully labeled by chelation chemistry. In vitro cell uptake studies showed that 18F-AlF-NODA-MP-6-Aoc-L5 can bind to HepG2 tumor cells and was stable in PBS and mouse serum stability tests. MicroPET/CT showed that HepG2 tumors could be clearly visualized with a tumor/muscle ratio of 2.46 ± 0.53. However, the tumor/liver ratio was low (0.93 ± 0.16) due to the high physiological uptake in the liver. This study demonstrates that FAM and the 18F-labeled L5 peptide can selectively target HCC with a high expression of GPC3 in vitro and in vivo. 18F-AlF-NODA-MP-C6-L5 has the potential to be a GPC3 target tracer but requires some chemical modifications to achieve a high enough tumor/liver ratio for detection of the tumor in the liver.

18F-FDG PET/CT in differentiating malignant from benign origins of obstructive jaundice.

BACKGROUND: The various origins of obstructive jaundice make the diagnosis of the disease difficult. This study was undertaken to evaluate the role of 18F-FDG PET/CT in differentiating malignant from benign origins of obstructive jaundice and to quantify the added value of 18F-FDG PET/CT over conventional imaging (enhanced CT and/or MRI). METHODS: Eighty-five patients with obstructive jaundice who underwent 18F-FDG PET/CT within 2 weeks after enhanced CT and/or MRI were reviewed retrospectively. All 18F-FDG PET/CT images were independently evaluated by 2 nuclear medicine physicians who were unaware of other imaging data; differences were resolved by consensus of the physicians. All conventional imaging interpretations, according to the medical records, were reviewed by 2 radiologists to determine the potential value. Final diagnoses were based on histological or surgical findings. RESULTS: Sixty-six patients were diagnosed with malignancies, and 19 patients with benign lesions. The maximum standardized uptake values for malignant and benign lesions causing biliary obstruction were 8.2+/-4.4 and 4.0+/-5.0, respectively (P<0.05). The sensitivity, specificity, and overall accuracy for differentiating malignant from benign origins with 18F-FDG PET/CT were 86.4% (57/66), 73.7% (14/19), and 83.5% (71/85), respectively. 18F-FDG PET/CT in conjunction with conventional imaging changed the sensitivity, specificity, and overall accuracy of conventional imaging alone from 75.8% (50/66) to 95.5% (63/66) (P<0.05), 68.4% (13/19) to 57.9% (11/19) (P>0.05), and 74.1% (63/85) to 87.1% (74/85) (P<0.05), respectively. CONCLUSIONS: 18F-FDG PET/CT is of great value in differentiating malignant from benign origins of obstructive jaundice and is a useful adjuvant to conventional imaging. 18F-FDG PET/CT should be recommended for further etiological clarification.

Superiority of 18F-FAPI-42 PET/CT in the detection of primary tumor and management of appendiceal neoplasm to 18F-FDG PET/CT and CE-CT.

BACKGROUND: In the present study, we investigated the value of 18F-fibroblast-activation protein inhibitor (FAPI) positron emission tomography/computed tomography (18F-FAPI-42 PET/CT) to preoperative evaluations of appendiceal neoplasms and management for patients. METHODS: This single-center retrospective clinical study, including 16 untreated and 6 treated patients, was performed from January 2022 to May 2023 at Southern Medical University Nanfang Hospital. Histopathologic examination and imaging follow-up served as the reference standard. 18F-FAPI-42 PET/CT was compared to 18F-fluorodeoxyglucose (18F-FDG) PET/CT and contrast-enhanced CT (CE-CT) in terms of maximal standardized uptake value (SUVmax), diagnostic efficacy and impact on treatment decisions. RESULTS: The accurate detection of primary tumors and peritoneal metastases were improved from 28.6% (4/14) and 50% (8/16) for CE-CT, and 43.8% (7/16) and 85.0% (17/20) for 18F-FDG PET/CT, to 87.5% (14/16) and 100% (20/20) for 18F-FAPI-42 PET/CT. Compared to 18F-FDG PET/CT, 18F-FAPI-42 PET/CT detected more regions infiltrated by peritoneal metastases (108 vs. 43), thus produced a higher peritoneal cancer index (PCI) score (median PCI: 12 vs. 5, P < 0.01). 18F-FAPI-42 PET/CT changed the intended treatment plans in 35.7% (5/14) of patients compared to CE-CT and 25% (4/16) of patients compared to 18F-FDG PET/CT but did not improve the management of patients with recurrent tumors. CONCLUSIONS: The present study revealed that 18F-FAPI-42 PET/CT can supplement CE-CT and 18F-FDG PET/CT to provide a more accurate detection of appendiceal neoplasms and improved treatment decision making for patients.

18 F-FDG PET/CT characteristics of IASLC grade 3 invasive adenocarcinoma and the value of 18 F-FDG PET/CT for preoperative prediction: a new prognostication model.

OBJECTIVE: This study is performed to investigate the imaging characteristics of the International Association for the Study of Lung Cancer grade 3 invasive adenocarcinoma (IAC) on PET/CT and the value of PET/CT for preoperative predicting this tumor. MATERIALS AND METHODS: We retrospectively enrolled patients with IAC from August 2015 to September 2022. The clinical characteristics, serum tumor markers, and PET/CT features were analyzed. T test, Mann-Whitney U test, χ 2 test, Logistic regression analysis, and receiver operating characteristic analysis were used to predict grade 3 tumor and evaluate the prediction effectiveness. RESULTS: Grade 3 tumors had a significantly higher maximum standardized uptake value (SUV max ) and consolidation-tumor-ratio (CTR) ( P  < 0.001), while Grade 1 - 2 tumors were prone to present with air bronchogram sign or vacuole sign ( P  < 0.001). A stepwise logistic regression analysis revealed that smoking history, CEA, SUV max , air bronchogram sign or vacuole sign and CTR were useful predictors for Grade 3 tumors. The established prediction model based on the above 5 parameters generated a high AUC (0.869) and negative predictive value (0.919), respectively. CONCLUSION: Our study demonstrates that grade 3 IAC has a unique PET/CT imaging feature. The prognostication model established with smoking history, CEA, SUV max , air bronchogram sign or vacuole sign and CTR can effectively predict grade 3 tumors before the operation.

Unexpected Origin of Lung Metastases: Rare Colon Leiomyosarcoma Detected by 18 F-FDG PET/CT.

ABSTRACT: A 49-year-old woman was referred to our hospital due to suspected lung metastases for 1 month. She had a history of thyroid micropapillary carcinoma and uterine leiomyomas. An 18 F-FDG PET/CT scan, which was performed to search the source of the presumed metastasis of the disease, showed multiple lung metastases and 2 18 F-FDG-avid foci in the thyroid and colon. Biopsy of lung and resection of colon lesions were then performed, and the disease was finally identified to be rare primary colon leiomyosarcoma with multiple lung metastases.

PET/CT imaging fibroblast activation protein in initial colorectal cancer: compared to 18 F-FDG PET/CT.

OBJECTIVE: In this study, the potential advantage of FAPI over 18 F-labelled deoxyglucose ( 18 F-FDG) in evaluation of the initial staging colorectal cancer (CRC) was investigated. MATERIALS AND METHODS: Thirty-two patients with histopathologically confirmed primary CRC were included in our study. They all underwent both 18 F-FDG and FAPI PET/CT. Lesion detectability and tracer uptakes, mainly quantified by maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR), were compared for paired lesions between both modalities using the Wilcoxon signed-rank test and paired t-test. RESULTS: Thirty-five CRC lesions in 32 patients were diagnosed. The sensitivity of FAPI PET/CT in diagnosis of the CRC lesions was 100% while 93.8% of 18 F-FDG PET/CT. FAPI and 18 F-FDG had a similar uptake in CRC lesion (mean SUVmax: 14.3 ±â€…8.6 vs. 15.4 ±â€…9.8, P  = 0.604), but lesions contained mucus and/or signet-ring cell carcinoma seemed to have a trend of higher FAPI uptake although there was no statistical difference (mean SUVmax: 12.7 ±â€…5.6 vs. 8.5 ±â€…4.1, P  = 0.152) and higher TBR (13.4 ±â€…6.2 vs. 4.9 ±â€…2.2, P  = 0.004) than those of 18 F-FDG. For regional lymph node metastases, both FAPI and FDG PET/CTs showed high sensitivity (7/8 vs. 7/8), specificity (7/8 vs. 6/8) and accuracy (14/16 vs. 13/16) (all P  > 0.05). For distant metastasis, FAPI PET/CT depicted more positive lesions in distant lymph node (46 vs. 26), liver (13 vs. 7) and peritoneum (107 vs. 45) than 18 F-FDG PET/CT. FAPI PET/CT also had a higher peritoneal cancer index score (median 11 vs 4; P  < 0.001) than 18 F-FDG PET/CT in evaluation of peritoneal metastases. CONCLUSION: FAPI PET/CT showed high sensitivity in detection of primary CRC and superiority to 18 F-FDG PET/CT in detection of metastases to distant lymph node, liver and peritoneum.

Superiority of 11 C-Choline PET/CT in the Delineation of a Rare Intracranial Diffuse Embryonic Tumor.

ABSTRACT: Intracranial diffuse embryonal tumor in the adult is rare. We report a young woman with a diffuse embryonal malignancy in the saddle area, which was depicted well by 11 C-choline PET/CT, superior to 18 F-FDG PET/CT and contrast-enhanced MRI. Under the guiding of 11 C-choline PET/CT, the biopsy was successfully performed and the diagnosis was established. This case highlights that 11 C-chione PET/CT may be useful to diagnose and delineate the intracranial diffuse embryonic tumors.

Superiority of 68Ga-FAPI-04 in Delineation of Soft Tissue and Liver Metastases in Chromophobe Renal Cell Carcinoma for Restaging.

ABSTRACT: Chromophobe renal cell carcinoma (RCC) is a rare tumor. We described findings of 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT of metastatic chromophobe RCC in a 56-year-old woman. 68Ga-FAPI-04 PET/CT demonstrated that the metastatic lesions in the liver, left posterior abdominal wall, and the left waist had intense uptake of 68Ga-FAPI-04, which was higher than that of 18F-FDG on 18F-FDG PET/CT. 68Ga-FAPI-04 PET/CT also delineated the metastatic lesions more clearly than 18F-FDG PET/CT. This case highlights 68Ga-FAPI-04 PET/CT may be promising in restaging of chromophobe RCC.