Intra-arterial PSMA injection using hepatic arterial infusion pump in intrahepatic cholangiocarcinoma: a proof-of-concept study.

Prostate-specific membrane antigen (PSMA) targeted tracers show increased uptake in several malignancies, indicating a potential for peptide radioligand therapy. Intra-arterial injection of radiotracers can increase the therapeutic window. This study aimed to evaluate the feasibility of intra-arterial injection of [68Ga]Ga-PSMA-11 for intrahepatic cholangiocarcinoma and compare tracer uptake after intrahepatic arterial injection and intravenous injection. Three patients with intrahepatic cholangiocarcinoma received [68Ga]Ga-PSMA-11 through a hepatic arterial infusion pump, followed by positron emission tomography/computed tomography (PET/CT). Two-three days later, patients underwent PET/CT after intravenous [68Ga]Ga-PSMA-11 injection. All tumours showed higher uptake on the intra-arterial scan compared with the intravenous scan: the intra-arterial / intravenous standardised uptake value normalised by lean body mass ratios were 1.40, 1.46, and 1.54. Local intra-arterial PSMA injection is possible in patients with intrahepatic cholangiocarcinoma. Local injection increases tumour-to-normal tissue ratios, increasing the therapeutic window for theranostic applications. RELEVANCE STATEMENT: Intra-arterial Prostate specific membrane antigen (PSMA) injection increases the therapeutic window for potential theranostic application in intrahepatic cholangiocarcinoma. KEY POINTS: Three patients with intrahepatic cholangiocarcinoma underwent PET/CT after intra-arterial and intravenous injection of [68Ga]Ga-PSMA-11. Intra-arterial injection showed higher uptake than intravenous injection. PSMA-targeted imaging could be valuable for a subset of intrahepatic cholangiocarcinoma patients.

Comparing the diagnostic value of 68Ga-prostate-specific membrane antigen PET/CT and multiparametric MRI in pelvic lymph node metastasis of locally advanced prostate cancer.

Background: Multiparametric magnetic resonance imaging (mpMRI) is a commonly used method to diagnose pelvic lymph node metastasis (PLNM) in prostate cancer (PCa) patients, but there are few comparative studies on mpMRI and 68Ga-prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) in locally advanced PCa (LAPC) patients. Therefore, we designed a retrospective study to compare the diagnostic value of 68Ga-PSMA PET/CT and mpMRI for PLNM of LAPC. Methods: A retrospective study was performed on 50 patients with LAPC who underwent radical prostatectomy (RP) in Tongji Hospital from 2021 to 2023. All patients underwent PET/CT and mpMRI examination, and were diagnosed as LAPC before surgery, followed by robot-assisted laparoscopic prostatectomy or laparoscopic RP and extended pelvic lymph node dissection (ePLND). Routine postoperative pathological examination was performed. According to the results, the sensitivity, specificity, positive predictive value, and negative predictive value of 68Ga-PSMA PET/CT and mpMRI for the diagnosis of PLNM of LAPC were compared. Results: Among the 50 patients, the mean age was 65.5±10.3 years, the preoperative total serum prostate-specific antigen (PSA) was 30.7±12.3 ng/mL, and the Gleason score was 7 [7, 8]. The difference in diagnostic efficacy between 68Ga-PSMA PET/CT and mpMRI in the preoperative diagnosis of PLNM of PCa was determined by postoperative pathological results. Based on the number of patients who developed PLNM, the sensitivity, specificity, positive predictive value, and negative predictive value of 68Ga-PSMA PET/CT were as follows: 93.75%, 100.00%, 100.00%, 97.14%, and 68.75%, 97.06%, 91.67%, 86.84% for mpMRI, respectively. Based on the number of pelvic metastatic lymph nodes, the sensitivity, specificity, positive predictive value, and negative predictive value of 68Ga-PSMA PET/CT were 95.24%, 100.00%, 100.00%, 99.48%, and 65.08%, 99.13%, 89.13%, 96.30% for mpMRI, respectively. It turned out that PET/CT was more sensitive than mpMRI in detecting PLNM of PCa, and the difference was statistically significant. Conclusions: 68Ga-PSMA PET/CT is more sensitive than mpMRI in the detection of PLNM in patients with LAPC. It is a promising method in the diagnosis and preoperative assessment of PLNM in LAPC.

Breast Cancer Subtype Prediction Model Employing Artificial Neural Network and 18F-Fluorodeoxyglucose Positron Emission Tomography/ Computed Tomography.

Introduction: Although positron emission tomography/computed tomography (PET/CT) is a common tool for measuring breast cancer (BC), subtypes are not automatically classified by it. Therefore, the purpose of this research is to use an artificial neural network (ANN) to evaluate the clinical subtypes of BC based on the value of the tumor marker. Materials and Methods: In our nuclear medical facility, 122 BC patients (training and testing) had 18F-fluoro-D-glucose (18F-FDG) PET/CT to identify the various subtypes of the disease. 18F-FDG-18 injections were administered to the patients before the scanning process. We carried out the scan according to protocol. Based on the tumor marker value, the ANN's output layer uses the Softmax function with cross-entropy loss to detect different subtypes of BC. Results: With an accuracy of 95.77%, the result illustrates the ANN model for K-fold cross-validation. The mean values of specificity and sensitivity were 0.955 and 0.958, respectively. The area under the curve on average was 0.985. Conclusion: Subtypes of BC may be categorized using the suggested approach. The PET/CT may be updated to diagnose BC subtypes using the appropriate tumor maker value when the suggested model is clinically implemented.

68Ga-DOTATATE PET/CT: How is it reliable in imaging of cases having clinical suspicion of insulinomas?

PURPOSE: This retrospective study evaluates the value of 68Ga-DOTATATE PET/CT in the diagnosis and localization of insulinomas, whether sporadic, malignant or MEN-1 associated insulinoma. METHOD: The study included 43 patients, having clinical (symptomatic hypoglycemia) and/or laboratory suspicion of having insulinoma (72 h fasting test with serum insulin ≥18 pmol/L), with available pre-operative 68Ga-DOTATATE PET/CT and CE-CT, and diagnosed with insulinoma confirmed by post-operative histopathology. Preoperative imaging was retrospectively analyzed by two radiologists who were blinded to the final diagnosis and to the results of other imaging modalities. Histopathology of specimen was considered the reference standard, and head-to-head comparison of preoperative CE-CT and PET imaging findings. Findings were classified as true positive (TP), true negative (TN), false positive (FP), and false negative (FN) for each modality. Based on these results, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CE-CT, and 68Ga-DOTATATE PET/CT for the detection of insulinoma were calculated. RESULTS: 43 patients (N = 43 patients, L = 56 lesions), out of these, 37 patients had benign sporadic insulinoma (N = 37, L = 42), only 3 patients had malignant sporadic insulinoma (N = 2, L = 9), and 3 patients had MEN-1 syndrome associated insulinoma (N = 3, L = 5). There was no significant statistical difference in sensitivity (P = 0.3058) and PPV (P = 0.5533) for insulinoma localization in the overall cohort with 68Ga-DOTATATE PET/CT (87.5 %, 90.74 %) compared to CE-CT (80.36 %, 93.75 %). CONCLUSION: 68Ga-DOTATATE PET/CT is a non-invasive imaging modality that can identify most insulinomas. Still, it offers limited additional information when the tumor is localized by other anatomic imaging studies, so should be used as an adjunct when imaging studies fail to localize the tumor in insulinoma patients, especially when minimally invasive surgical is intended.

Detection of Hepatic Metastasis from Early Delayed Images of Modified Dual-Time-Point F-18 FDG PET/CT Images in a Patient with Breast Cancer.

We present a rare case of focal F-18-2-fluoro-2-deoxyglucose (FDG) uptake in the liver observed during a modified dual-time-point F-18 FDG positron emission tomography (PET)/computed tomography (CT), so-called early delayed scanning, in a 53-year-old woman diagnosed with breast cancer. This metastatic lesion was revealed in 80 min delayed images after FDG injection, but not in the usual one-hour images after injection. Modified dual-time-point F-18 FDG PET/CT is convenient because compared to the 2 h delayed images of dual-time-point PET/CT, it has a shorter scanning time and avoids additional radiation exposure.

The Effect of Therapeutic Hypothermia on Ischemic Brain Injury in a Rat Model of Cardiac Arrest: An Assessment Using 18F-FDG PET.

PURPOSE: Therapeutic hypothermia (TH) is widely acknowledged as one of the interventions for preventing hypoxic ischemic brain injury in comatose patients following cardiac arrest (CA). Despite its recognized efficacy, recent debates have questioned its effectiveness. This preclinical study evaluated the impact of TH on brain glucose metabolism, utilizing fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in a rat model of CA. METHODS: Asphyxia CA was induced in Sprague-Dawley rats using vecuronium. Brain PET images using 18F-FDG were obtained from 21 CA rats, who were randomized to receive either TH or no intervention. Of these, 9 rats in the TH group received hypothermia under general anesthesia and mechanical ventilation for eight hours, while the remaining 12 rats in the non-TH group were observed without intervention. We conducted regional and voxel-based analyses of standardized uptake values relative to the pons (SUVRpons) to compare the two groups. RESULTS: Survival rates were identical in both the TH and non-TH groups (67%). There was no discernible difference in the SUVRpons across the brain cortical regions between the groups. However, in a subgroup analysis of the rats that did not survive (n = 7), those in the TH group (n = 3) displayed significantly higher SUVRpons values across most cortical regions compared to those in the non-TH group (n = 4), with statistical significance after false-discovery rate correction (p < 0.05). CONCLUSIONS: The enhancement in SUVRpons due to TH intervention was only observed in the cortical regions of rats with severe encephalopathy that subsequently died. These findings suggest that the beneficial effects of TH on brain glucose metabolism in this asphyxia CA model may be confined to cases of severe ischemic encephalopathy.

Mucociliary Clearance is Impaired in Small Airways of Cystic Fibrosis Pigs.

Cystic fibrosis is a genetic disorder characterized by recurrent airway infections, inflammation, impaired mucociliary clearance and progressive decline in lung function. The disease may start in the small airways; however, this is difficult to prove due to limited accessibility of the small airways with the current single photon mucociliary clearance assay. Here, we developed a dynamic positron emission tomography assay with high spatial and temporal resolution. We tested that mucociliary clearance is abnormal in the small airways of newborn cystic fibrosis pigs. Clearance of [68Ga] tagged macro-aggregated albumin from small airways started immediately after delivery and continued for the duration of the study. Initial clearance was fast but slowed down few minutes after delivery. Cystic fibrosis pig small airways cleared significantly less than non-CF pig small airways (non-CF 25.1±3.1% vs. CF 14.6±0.1%). Stimulation of the cystic fibrosis airways with the purinergic secretagogue UTP further impaired clearance (non-CF with UTP 20.9±0.3% vs. CF with UTP 13.0±1.8%). None of the cystic fibrosis pig treated with UTP (N = 6) cleared more than 20% of the delivered dose. These data indicate that mucociliary clearance in the small airways is fast and can easily be missed if the assay is not sensitive enough. The data also indicate that mucociliary clearance is impaired in the small airways of cystic fibrosis pigs. This defect is exacerbated by stimulation of mucus secretions with purinergic agonists.

The Sensitivity and Specificity of Multiparametric Magnetic Resonance Imaging and Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography for Predicting Seminal Vesicle Invasion in Clinically Significant Prostate Cancer: A Multicenter Retrospective Study.

Background/Objectives: The presence of seminal vesicle invasion (SVI) in prostate cancer (PCa) is associated with poorer postoperative outcomes. This study evaluates the predictive value of magnetic resonance imaging (MRI) and prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) for SVI in PCa. Methods: This cohort study included consecutive robotic prostatectomy patients for PCa at three Australian tertiary referral centres between April 2016 and September 2022. MRI and PSMA PET/CT results, clinicopathological variables, including age, BMI, prostate-specific antigen (PSA), PSA density, DRE, Biopsy Gleason score, Positive biopsy cores, PIRADS v2.1 score, MRI volume and MRI lesion size were extracted. The sensitivity, specificity, and accuracy of MRI and PSMA PET/CT for predicting SVI were compared with the histopathological results by receiver operating characteristic (ROC) analysis. Subgroup univariate and multivariate analysis was performed. Results: Of the 528 patients identified, 86 had SVI on final pathology. MRI had a low sensitivity of 0.162 (95% CI: 0.088-0.261) and a high specificity of 0.963 (95% CI: 0.940-0.979). The PSMA PET/CT had a low sensitivity of 0.439 (95% CI: 0.294-0591) and a high specificity of 0.933 (95% CI: 0.849-0.969). When MRI and PSMA PET/CT were used in combination, the sensitivity and specificity improved to 0.514 (95%CI: 0.356-0.670) and 0.880 (95% CI: 0.813-0.931). The multivariate regression showed a higher biopsy Gleason score (p = 0.033), higher PSA (p < 0.001), older age (p = 0.001), and right base lesions (p = 0.003) to be predictors of SVI. Conclusions: MRI and PSMA PET/CT independently underpredicted SVI. The sensitivity and AUC improved when they were used in combination. Multiple clinicopathological factors were associated with SVI on multivariate regression and predictive models incorporating this information may improve oncological outcomes.

18F-FDG PET/CT semi-quantitative parameters combined with SCC-Ag in predicting lymph node metastasis in stage I-II cervical cancer.

Objective: To explore the value of 18F-fluordeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) semi-quantitative parameters of primary tumor combined with squamous cell carcinoma antigen (SCC-Ag) in predicting lymph node metastasis (LNM) of cervical cancer (FIGO 2018 stage I-II). Materials and Methods: A total of 65 patients with stage I-II cervical cancer underwent 18F-FDG PET/CT were included in our study. Comparing the primary tumor 18F-FDG PET/CT semi-quantitative parameters and SCC-Ag between the LNM group and the non-LNM group. Logistic regression and receiver operating characteristic (ROC) were used to analyze the value of 18F-FDG PET/CT metabolic parameters and SCC-Ag in predicting LNM. Results: There were 14 and 51 patients were classified as having LNM and NLNM. The semi-quantitative parameters, including the maximum standardized uptake value (SUVmax), the mean standardized uptake value (SUVmean), the peak standardized uptake value (SUVpeak), the total lesion glycolysis (TLG), the metabolic tumor volume (MTV) of the tumor and SCC-Ag were all significantly higher in LNM than in NLNM (SUVmax, 16.07 ± 7.81 vs 11.19 ± 4.73, SUVmean, 9.16 ± 3.48 vs 6.29 ± 2.52, SUVpeak, 12.70 ± 5.26 vs 7.65 ± 3.26, MTV, 22.77 ± 12.36 vs 7.09 ± 5.21, TLG, 211.01 ± 154.25 vs 43.38 ± 36.17, SCC-Ag, 5.39 ± 4.56 vs 2.13 ± 2.50, all p<0.01). Logistic regression analysis showed that TLG was an independent predictor of LNM in stage I-II cervical cancer (OR 1.032, 95% CI 1.013-1.052, p<0.01). Moreover, the predictive value of TLG combined with SUVpeak and SCC-Ag increased and the area under the curve increased compared SUVpeak and SCC-Ag. Conclusion: 18F-FDG PET/CT semi-quantitative parameters and SCC-Ag have promise for assessing LNM in stage I-II cervical cancer. TLG of primary tumor provides independent and increasing values in predicting LNM in stage I-II cervical cancer.

Metallosis: A Rare Complication to Common Procedure with Its Imaging Finding.

Metallosis is a medical condition that shows local and systemic clinical symptoms due to the deposition of heavy metal debris in soft tissues and bones due to metallic prostheses. The estimated incidence of Metallosis is around 5%. Clinical presentation and imaging findings can mimic tumor likely situation, However local reactions of Metallosis shows some peculiar features on cross-sectional imaging, and here we present two such cases of Metallosis with its imaging findings.

Follicular Thyroid Carcinoma with Unusual Mandible Metastasis.

Follicular thyroid cancer is the second-most common type of thyroid cancer after papillary thyroid cancer. Metastases to the mandible and maxillofacial region are rare. Our study presents a 55-year-old patient who underwent total thyroidectomy for follicular thyroid cancer and subsequent radioactive iodine therapy. Sixteen years after diagnosis, elevated thyroglobulin levels suggested disease recurrence. Using advanced imaging techniques - Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan, bone scintigraphy, and posttreatment I-131 scan-an unexpected metastatic site was identified: the left mandibular condyle. A biopsy confirmed the presence of metastatic follicular thyroid cancer.

Odd Sites of Parathyroid Adenomas: 18F-fluorocholine PET/CT Pointing to the Right Place.

Primary hyperparathyroidism is mostly caused by parathyroid adenoma(s) which are generally localized using routine imaging modalities such as neck ultrasonography and 99mTc-SestaMIBI scintigraphy. However, these can miss ectopic parathyroid adenomas due to their limited sensitivities. These ectopic lesions can later lead to failure of surgical excision and necessitate the need for a re-exploration. 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) can help in the localization of these ectopic adenomas due to its superior detection rates and spatial resolution. Herein, we report a case of ectopic parathyroid adenomas that were localized on FCH PET/CT.

18-F FDG PET/CT in a Case of Recurrent Pericardial Effusion Diagnosed as Cardiac Sarcoma.

Recurrent pericardial effusion poses a diagnostic challenge, especially in young patients. We present a case of a 22-year-old female who experienced recurrent pericardial effusion and cardiac tamponade. Despite initial treatment with anti-tubercular drugs and prednisolone, the patient had a relapse of symptoms, necessitating further investigation. Imaging studies revealed massive pericardial effusion with septations, suggestive of constrictive pericarditis with impending cardiac tamponade. To establish a definitive diagnosis, the patient underwent an FDG PET-CT scan after adhering to a specific dietary regimen. The scan revealed an ill-defined mediastinal mass with high metabolic activity, along with a gross pericardial effusion showing metabolic activity in the periphery and septations. Subsequent biopsy of the mediastinal mass confirmed a diagnosis of high-grade sarcoma.Primary malignant cardiac tumors are rare, and their prognosis is generally poor due to limited treatment options. While echocardiography and MRI are commonly used imaging techniques, FDG PET-CT is not routinely employed for evaluating cardiac tumors. However, in this case, FDG PET-CT played a crucial role in identifying the mediastinal mass and confirming the diagnosis.Early detection and accurate diagnosis of cardiac tumors are vital for initiating appropriate treatment strategies. Further studies are needed to explore the utility of FDG PET-CT in the evaluation of cardiac tumors, especially in cases of recurrent pericardial effusion.

FDG Avid Intracholecystic Papillary Neoplasm Mimicking Hepatic Metastasis in a Patient with Head-and-neck Cancer.

A 75-year-old male with head-and-neck squamous cell cancer received a staging f-18-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) scan which showed additional focal abnormal uptake in the right hepatic lobe. The patient was treated for probable metastatic disease. Restaging FDG PET/CT scan revealed resolution of uptake in the head-and-neck and persistent focal uptake in the presumed liver metastasis. An abdominal CT with intravenous contrast revealed an enhancing mass in the gallbladder, without extension into the liver. Cholecystectomy revealed an intracholecystic papillary neoplasm of the gallbladder. The initial appearance of hepatic metastasis was due to a misregistration artifact.

Prognostic Strength of CA 19-9, Demographic Parameters, and Maximum Standardized Uptake Value of Baseline 18F-FDG PET/CT in Treatment-naïve Patients with Pancreatic Carcinoma.

Aim and Background: The aim of this study was to evaluate the prognostic value of imaging-based variables and tumor marker in predicting the progression-free survival (PFS) in treatment-naïve pancreatic cancer (PC) using baseline 18-fluorodeoxyglucose (18FDG) positron emission tomography/computed tomography (PET/CT). Materials and Methods: This retro-prospective study was conducted at PET/CT imaging facility of JCIA health-care facility of Pakistan. Total 68 patients with PCs were retrospectively included who had 18FDG PET/CT for staging from March 2017 to December 2020. Thirty-two patients had unresectable Stage IV disease on baseline imaging while the remaining 36 underwent Whipple's procedure and both categories were followed by chemotherapy with/without immunotherapy. These patients were followed for a median period of 18 months (1-62 months) for PFS. Logistic regression analysis and receiver operating characteristic (ROC) analysis were used for independent predictors of patients' demographics, tumor characteristics, CA 19-9, and maximum standardized uptake value (SUVmax) in PFS. Kaplan-Meier's survival curves were analyzed to measure PFS using ROC-derived significant cutoff values of CA 19-9 and SUVmax. Results: Median PFS was 18 months (11-45) with 60% (41/68) patients were either died or labelled having metabolic progressive disease (MPD. Using logistic regression analysis, significant correlations were found for Stage IV disease and pancreatic body/tail tumor with disease progression (odd ratio: 7.535 and 4.803, respectively; P < 0.05). Gender, obesity, histological tumor type, and 18FDG-avid regional nodes did not show a significant impact on PFS. On ROC analysis, SUVmax >5.3 of primary tumor and baseline CA 19-9 >197 U/ml were found to have a significant negative correlation with PFS (area under the curve: 0.827 and 0.911, respectively; P < 0.0001) and no association of age and primary tumor size in PFS. Significantly, shorter PFS was found using ROC-derived cutoff values of SUVmax >5.3 versus ≤5.3 of primary tumor (mean and 95% confidence interval [CI]: 16.7 vs. 48.5 and 10-23 vs. 41-56; log-rank = 25.014; P < 0.0001) and baseline CA 19-9 >197 versus ≤197 U/ml (mean and 95% CI: 11.8 vs. 46.9 and 7-16 vs. 39-55; log-rank = 38.217; P < 0.0001). Conclusion: SUVmax >5.3 of primary tumor and baseline CA 19-9 >197 U/ml were found to have a significant negative correlation with PFS in treatment-naïve PC patients. Among demographics, only Stage IV disease and pancreatic tail and body tumors were found to have a negative association with disease progression.

Uncommon Site of Metastasis: A Case Report of Breast Carcinoma Spreading to the Pancreas.

The metastatic lesions to pancreas are reported in various malignancies. However, pancreatic metastasis from breast cancer is rare and difficult to diagnose due to nonspecific symptoms and imaging findings. At the time of diagnosis, there may already be an associated widespread metastasis. In this case report, a woman in her forties with a history of breast cancer was found to have widespread metastases, including in the pancreas. The patient was treated with chemotherapy and hormonal therapy.

Small Cell Carcinoma Prostate: A Case Report with Findings on 18-F FDG PET/CT.

Small-cell carcinoma of the prostate (SCCP) is a rare and very aggressive malignancy with neuroendocrine differentiation. In contrast to conventional prostate adenocarcinoma, SCCP is an aggressive carcinoma and portends to have a poor prognosis. Around 50% of these patients have metastatic disease at the first clinical presentation. We report the findings of 18-F fluorodeoxyglucose positron emission tomography/computed tomography in a case of histologically proven SCCP with an unusual finding of the left internal mammary lymph node.

Rare Presentation of En Cuirasse Detected on 18-F FDG PET/CT in a Case of Recurrent Breast Carcinoma.

Carcinoma en cuirasse is a type of cutaneous metastasis from different malignancies. En cuirasse although is a rare entity, most commonly occurs in cases of recurrent breast carcinoma after surgery or very rarely months or years after diagnosis of primary tumor. We report a rare case of neck carcinoma en cuirasse in a 47-year-old Indian female who is a known case of recurrent carcinoma left breast postmodified radical mastectomy, chemotherapy, and radiotherapy referred for fluorodeoxyglucose positron emission tomography-computed tomography following another six cycles of chemotherapy for response assessment.