Fluorodeoxyglucose Positron Emission Tomography-computed Tomography Research Articles

Comprehensive Review of the Imaging Recommendations for Diagnosis, Staging, and Management of Thyroid Carcinoma.

Thyroid cancer is the most common head and neck cancer (HNC) in the world. In this article, we comprehensively cover baseline, posttreatment, and follow-up imaging recommendations for thyroid carcinomas along with the eighth edition of the tumor, node, metastasis (TNM) staging system proposed by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC). We include characterization and risk stratification of thyroid nodules on ultrasound (US) proposed by various international bodies. Management guidelines (depending upon the type of thyroid carcinoma) based on the international consensus recommendations (mainly by the American Thyroid Association) are also extensively covered in this article, including the role of a radioiodine scan. The management of recurrent disease is also briefly elucidated in this article. In addition, we cover the risk factors and etiopathogenesis of thyroid carcinoma along with the non-imaging diagnostic workup essential for thyroid carcinoma management, including the significance of genetic mutations. US is the diagnostic imaging modality of choice, with US-guided fine needle aspiration (FNA) being the procedure of choice for tissue diagnosis. The roles of computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) in thyroid carcinoma staging are also specified. Through this article, we aim to provide a comprehensive reference guide for the radiologists and the clinicians in the pursuit of optimal care for patients with thyroid carcinoma.

Insights of Inflammatory Heart Involvement in Cardiac Sarcoidosis – A Systemic Review

Abstract Purpose of the Review The purpose of this paper is to review the current knowledge regarding imaging inflammation in cardiac sarcoidosis (CS). Recent Findings Noninvasive imaging methods like cardiac magnetic resonance (CMR) and 18-fluorodeoxyglucose (18FDG) positron-emission tomography-computed tomography (PET-CT) scans have emerged as the most important modalities in diagnosing and monitor therapy efficacy in CS. The differentiation between an active and a chronic, silent clinical state is crucial for decision making. T1- and T2-mapping by CMR provide a unique opportunity to discriminate normal and diseased myocardium by detecting myocardial edema and fibrosis. While T1-mapping is sensitive to fibrosis and edema, T2 is primarily influenced by tissue water content. Increased 18-fluorodeoxyglucose (18FDG) uptake in positron-emission tomography-computed tomography (PET-CT) scan is a hallmark feature of CS and defines active inflammation. Therefore, the hybrid application of both CMR and 18FDG-PET-CT scans has evolved as the standard procedure to detect CS and monitor the therapeutic response. Summary Imaging inflammation in CS is basically performed by CMR T2-mapping and 18FDG uptake in PET-CT scan. Both are reliable methods in identifying active CS and follow up therapy and can be used synergistically. Additionally CMR provides further prognostic insights by late gadolinium enhancement that increases the risk for malignant arrhythmia and for relapse after therapy weaning.

Narrow interval dual phase 18F-FDG PET/CT: A practical approach for distinguishing tumor recurrence from radiation necrosis in brain metastasis.

Purpose of our research is to demonstrate efficacy of narrow interval dual phase [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging in distinguishing tumor recurrence (TR) from radiation necrosis (RN) in patients treated for brain metastases. 35 consecutive patients (22 female, 13 male) with various cancer subtypes, lesion size > 1.0 cm3, and suspected recurrence on brain magnetic resonance imaging (MRI) underwent narrow interval dual phase FDG-PET/CT (30 and 90 min after tracer injection). Clinical outcome was determined via sequential MRIs or pathology reports. Maximum standard uptake value (SUVmax) of lesion (L), gray matter (GM), and white matter (WM) was measured on early (1) and delayed (2) imaging. Analyzed variables include % change, late phase, and early phase for L uptake, L/GM uptake, and L/WM uptake. Statistical analysis (P < .01), receiver operator characteristic (ROC) curve and area under curve (AUC) cutoff values were obtained. Change in L/GM ratio of > -2% was 95% sensitive, 91% specific, and 93% accurate (P < .001, AUC = 0.99) in distinguishing TR from RN. Change in SUVmax of lesion alone was the second-best indicator (P < .001, AUC = 0.94) with an ROC cutoff > 30.5% yielding 86% sensitivity, 83% specificity, and 84% accuracy. Other variables (L alone or L/GM ratios in early or late phase, all L/WM ratios) were significantly less accurate. Utilizing narrow interval dual phase FDG-PET/CT in patients with brain metastasis treated with radiation therapy provides a practical approach to distinguish TR from RN. Narrow time interval allows for better patient comfort, greater efficiency of PET/CT scanner, and lower disruption of workflow.

Diagnostic challenges in patients with reninomas and extrarenal renin-producing tumours.

Renin-secreting tumours are rare causes of secondary hypertension and hypokalaemia. They are usually surgically curable, hence proper diagnostic work-up and tumour localisation is essential. In this paper, we present three Swedish patients recently diagnosed with renin secreting tumours, two with reninomas and one with an extrarenal renin-producing tumour, to illustrate diagnostic challenges. We also discuss the biochemical work-up, the pros and cons of different imaging techniques (computer tomography [CT], magnetic resonance imaging and [18F]fluorodeoxyglucose-positron emission tomography-CT), as well as how renal vein sampling (RVC) may contribute to localisation of the tumour.

Prospective pilot study utilizing changes in quantitative values obtained on serial fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) in dogs with appendicular osteosarcoma before and after stereotactic body radiation therapy (SBRT) and carboplatin chemotherapy to assess for prediction of survival and therapeutic effectiveness.

Serial fluorine 18 fluorodeoxyglucose (18F-FDG) positron emission tomography-CT (PET/CT) is commonly used in human oncology to prognosticate and evaluate for therapeutic effectiveness. In this pilot study, dogs with naturally occurring appendicular osteosarcoma were evaluated with serial 18F-FDG PET/CT in an attempt to assess for response to therapy, prognostic factors, and appropriateness of imaging intervals. Fourteen dogs were enrolled in the trial. All dogs had the initial 18F-FDG PET/CT (PET1), with nine dogs having their end-of-therapy 18F-FDG PET/CT (EoT PET) 3 months after stereotactic body radiation therapy (SBRT) to the primary tumor. The median percent change from the PET1 to the EoT PET for the standard uptake value maximum (SUVmax%) was -58% (range: -17 to -88%), metabolic tumor volume (MTV%) was -99.8% (range: -65 to -100%), and total lesion glycolysis (TLG%) was -99.8% (range: -75 to -100%), all of which were significant (P<.05, <.05, and <.05, respectively). On evaluation, it was found that volumes of GTV and CTV were significant for survival (P<.05 and <.05), MTV1, TLG1, and SUVmax on the EoT PET (SUVmaxEoT) were predictive of metastasis (P<.05), and the SUVmax% was significantly correlated to the time to first event (P<.05). Based on this data, serial 18F-FDG PET/CT performed 3 months after SBRT can show a significant reduction in avidity, and the quantitative data collected may help predict metastatic disease in canine appendicular osteosarcoma.

Evaluating Prognosis of Gastrointestinal Metastatic Neuroendocrine Tumors: Constructing a Novel Prognostic Nomogram Based on NETPET Score and Metabolic Parameters from PET/CT Imaging.

The goal of this study is to compare the prognostic performance of NETPET scores, based on gallium-68 DOTANOC (68Ga-DOTANOC) and fluorine-18 fluorodeoxyglucose (18F-FDG) Positron Emission Tomography-Computed Tomography (PET-CT), and PET-CT metabolic parameters in metastatic gastrointestinal neuroendocrine tumors (GI-NET), while constructing and validating a nomogram derived from dual-scan PET-CT. In this retrospective study, G1-G3 GI-NET patients who underwent 68Ga-DOTANOC and 18F-FDG PET scans were enrolled and divided into training and internal validation cohorts. Three grading systems were constructed based on NETPET scores and standardized uptake value maximum (SUVmax). LASSO regression selected variables for a multivariable Cox model, and nomograms predicting progression-free survival (PFS) and overall survival (OS) were created. The prognostic performance of these systems was assessed using time-dependent receiver-operating characteristic (ROC) curves, concordance index (C-index), and other methods. Nomogram evaluation involved calibration curves, decision curve analysis (DCA), and the aforementioned methods in both cohorts. In this study, 223 patients (130 males; mean age ± SD: 52.6 ± 12 years) were divided into training (148) and internal validation (75) cohorts. Dual scans were classified based on NETPET scores (D1-D3). Single 68Ga-DOTANOC and 18F-FDG PET-CT scans were stratified into S1-S3 and F1-F3 based on SUVmax. The NETPET score-based grading system demonstrated the best OS and PFS prediction (C-index, 0.763 vs. 0.727 vs. 0.566). Nomograms for OS and PFS exhibited superior prognostic performance in both cohorts (all AUCs > 0.8). New classification based on NETPET score predicts patient OS/PFS best. PET-CT-based nomograms show accurate OS/PFS forecasts.

Do PET-positive supradiaphragmatic lymph nodes predict overall survival or the success of primary surgery in patients with advanced ovarian cancer?

ObjectivesCompared to conventional computed tomography (CT), fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) detects higher rates of lymph node and distant metastases in patients with ovarian cancer. However, FDG-PET/CT is not routinely performed during preoperative work-up. Therefore, we investigated the prognostic value of preoperative FDG-PET/CT in advanced epithelial ovarian cancer (EOC) and its predictive value for surgical resection in patients with no residual disease. The potential significance of PET-positive supradiaphragmatic lymph nodes (SDLNs) for these parameters was evaluated. MethodsAll patients with FIGO IIA-IVB EOC diagnosed between March 2014 and January 2021 at our certified gynaecological cancer centre, who underwent FDG PET/CT before primary surgery were retrospectively included. ResultsFifty-three consecutive patients were included in the study. Eighteen (34 %) patients had PET-positive SDLNs. We could not demonstrate a significant correlation between PET-positive SDLNs and median overall survival (OS; SDLN-positive: 58.76 months, SDLN-negative: 60.76 months; p = 0.137) or intra- or perioperative outcomes. ConclusionsFDG PET/CT has a higher detection rate for SDLNs in patients with ovarian cancer than CT has, as described in the literature. Moreover, PET-positive SDLNs failed to predict intraoperative outcomes or overall survival.

Ultra Low Dose 4 Gy Radiation for Definitive Therapy of Gastric MALT Lymphoma

Introduction Definitive treatment for early-stage gastric MALT (mucosa-associated lymphoid tissue) lymphoma typically includes radiation therapy (RT) to doses of 24-30 Gy. Given the favorable prognosis of this disease, there is considerable interest in decreasing the toxicity profile of treatment. We prospectively investigated outcomes using a response-adapted (RA) approach giving an initial 4 Gy (ultra-low dose (ULD)) RT with an additional 20 Gy only for incomplete response (Figure 1). We hypothesized that this RA-approach would maintain excellent outcomes with limited toxicity. Methods We performed a single-arm prospective trial of ULD RT in 24 patients (age ≥18 years) with newly diagnosed or relapsed stage I-IV H. pylori (HP) negative gastric MALT lymphoma (NCT03680586). Patients with residual lymphoma after HP eradication were eligible. Patients with bulky disease (&amp;gt;10 cm) were excluded. Patients were treated with 4 Gy in 2 fractions and assessed with endoscopy and imaging at 3-4 months post-RT. Patients with a complete response (CR) assessed by endoscopy with biopsies and imaging were observed. Patients with a partial response (PR) by endoscopic, pathologic or radiographic evaluations were re-evaluated in 6-9 months. Biopsy-confirmed residual disease at the second timepoint (9-13 months) or stable disease (SD)/progressive disease (PD) at any time point prompted treatment with an additional 20 Gy in 10 fractions. Systemic therapy was permitted if clinically indicated. Results We enrolled 24 patients from 2019-2021. Median age was 67 (range 40-85) with 15 female patients (63%). Patients had stage I (n=20, 83%), II (n=1, 4%), and IV (n=3, 13%) disease. Of 15 tested patients, 4 were positive for t(11;18). Patients had pre-treatment imaging with fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) (n=21), contrasted CT (n=2), and contrasted magnetic resonance imaging (MRI) (n=1). Eight patients had prior treatment including systemic therapy (n=2, 8%) or antibiotics for HP positive (n=3, 13%) or HP negative (n=3, 13%) disease. Of 3 patients with prior HP positive disease, residual lymphoma was documented after eradication at 18 months (PR), 11 months (SD), and 8 months (disease relapse after CR) post-diagnosis. Median follow-up for the entire cohort was 34 months (95% CI 22-40) based on the reverse Kaplan-Meier estimator. Sixteen patients had a CR at first evaluation (3-4 months) after 4 Gy, and an additional 4 patients had disease conversion to CR at second evaluation (9-13 months), for a total of 20 patients (83%) who had a CR to 4 Gy at a median time of 4 months (range 3-12). No patients had positive imaging findings with a pathologic CR. One local relapse occurred 14 months post-treatment after a CR to 4 Gy. This patient received 20 Gy and again experienced a CR. Four patients received an additional 20 Gy for SD/PD or residual disease after 4 Gy. Two patients received 20 Gy for symptomatic SD at 3-4 months, both with a CR following RA therapy. Two patients received 20 Gy for residual disease at 10 and 13 months. One patient had a CR and one is pending last follow-up. Two of the 4 patients (50%) with a positive t(11;18) required an additional 20 Gy RT compared with 3 of 11 (27%) patients without the translocation (p=0.56) The rate of 3-year LC for 23 patients who had complete follow-up was 100%, with 19 of 24 patients (79%) with a CR at last follow-up after only the initial 4 Gy. One patient with stage IV disease experienced distant relapse with diffuse large B cell lymphoma and is in CR after systemic therapy. No additional patients received systemic therapy after RT. RT was well tolerated with no grade 3 or higher acute or late toxicities. Conclusions Most patients with gastric MALT lymphoma experienced a CR after only 4 Gy RT; for those requiring an additional 20 Gy with completed follow-up, all experienced a CR. This strategy could be considered to select only those patients who benefit from longer RT courses and spare most patients from unnecessary treatment toxicity. It is important to allow adequate time for response with this indolent disease. Additional follow-up is required to confirm long-term excellent outcomes with RA ULD treatment.

An Innovative Non-Linear Prediction Model for Clinical Benefit in Women with Newly Diagnosed Breast Cancer Using Baseline FDG-PET/CT and Clinical Data.

Objectives: We aimed to develop a novel non-linear statistical model integrating primary tumor features on baseline [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT), molecular subtype, and clinical data for treatment benefit prediction in women with newly diagnosed breast cancer using innovative statistical techniques, as opposed to conventional methodological approaches. Methods: In this single-center retrospective study, we conducted a comprehensive assessment of women newly diagnosed with breast cancer who had undergone a FDG-PET/CT scan for staging prior to treatment. Primary tumor (PT) volume, maximum and mean standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured on PET/CT. Clinical data including clinical staging (TNM) but also PT anatomical site, histology, receptor status, proliferation index, and molecular subtype were obtained from the medical records. Overall survival (OS), progression-free survival (PFS), and clinical benefit (CB) were assessed as endpoints. A logistic generalized additive model was chosen as the statistical approach to assess the impact of all listed variables on CB. Results: 70 women with newly diagnosed breast cancer (mean age 63.3 ± 15.4 years) were included. The most common location of breast cancer was the upper outer quadrant (40.0%) in the left breast (52.9%). An invasive ductal adenocarcinoma (88.6%) with a high tumor proliferation index (mean ki-67 expression 35.1 ± 24.5%) and molecular subtype B (51.4%) was by far the most detected breast tumor. Most PTs displayed on hybrid imaging a greater volume (12.8 ± 30.4 cm3) with hypermetabolism (mean ± SD of PT maximum SUVmax, SUVmean, MTV, and TLG, respectively: 8.1 ± 7.2, 4.9 ± 4.4, 12.7 ± 30.4, and 47.4 ± 80.2). Higher PT volume (p < 0.01), SUVmax (p = 0.04), SUVmean (p = 0.03), and MTV (<0.01) significantly compromised CB. A considerable majority of patients survived throughout this period (92.8%), while five women died (7.2%). In fact, the OS was 31.7 ± 14.2 months and PFS was 30.2 ± 14.1 months. A multivariate prediction model for CB with excellent accuracy could be developed using age, body mass index (BMI), T, M, PT TLG, and PT volume as predictive parameters. PT volume and PT TLG demonstrated a significant influence on CB in lower ranges; however, beyond a specific cutoff value (respectively, 29.52 cm3 for PT volume and 161.95 cm3 for PT TLG), their impact on CB only reached negligible levels. Ultimately, the absence of distant metastasis M displayed a strong positive impact on CB far ahead of the tumor size T (standardized average estimate 0.88 vs. 0.4). Conclusions: Our results emphasized the pivotal role played by FDG-PET/CT prior to treatment in forecasting treatment outcomes in women newly diagnosed with breast cancer. Nevertheless, careful consideration is required when selecting the methodological approach, as our innovative statistical techniques unveiled non-linear influences of predictive biomarkers on treatment benefit, highlighting also the importance of early breast cancer diagnosis.

Avelumab treatment for patients with metastatic Merkel cell carcinoma can be safely stopped after 1 year and a PET/CT-confirmed complete response.

Immune checkpoint inhibitor treatment of patients with metastatic Merkel cell carcinoma (mMCC) has shown high response rates, ranging from 33% to 73%. The ideal duration of treatment, however, is currently unknown. The aim of this study was to evaluate if avelumab treatment for mMCC can be safely stopped after 1year of treatment and a complete response (CR) confirmed by fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging. Patients who receivedmore than one dose of avelumab treatment for mMCC between November 2017 and February 2022 were included in this study. Treatment was discontinued in case of a FDG-PET/CT confirmed CR after 1year (26 cycles) of avelumab or a CR and unacceptable toxicity earlier. The primary end point was recurrence-free survival (RFS). Sixty-five patients were included: 25 (38%) had a FDG-PET/CT-confirmed CR at discontinuation of avelumab. In those 25 patients, reasons for discontinuation of treatment were completion of 1year of treatment in 13 (52%), toxicity in five (20%), and patient preference in seven (28%). Median duration of treatment in this group was 11months (interquartile range, 6.1-11.7). Median follow-up was 27months (interquartile range, 15.8-33.8). The 12-month RFS was 88% (95% CI, 0.74-1) and median RFS was not reached. Two patients (8%) had a recurrence at 4 and 7months after discontinuation of treatment. Patients with mMCC who acquire a CR on PET/CT imaging appear to have durable responses after discontinuation of treatment after 1 year.

18Fluorodeoxyglucose positron emission tomography-computed tomography findings in bilateral adrenal metastases in renal cell carcinoma

Abstract Bilateral adrenal metastases is a rare manifestation which can be seen in malignancies such as breast, lung carcinoma and melanomas. Adrenal metastases are usually detected on one side or more rarely on both sides. Molecular imaging with 18fluorodeoxyglucose positron emission tomography-computed tomography often shows unilateral or bilateral adrenal metastases in various malignancies. Here, we present a case of renal cell carcinoma that presented with widespread skeletal and bilateral adrenal metastases.

Correlation of Post-Treatment Biopsy and Fluorodeoxyglucose PET/CT Findings Following Definitive Chemotherapy and Radiation for Cervical Cancer

Concurrent chemotherapy and external beam radiation with brachytherapy boost is considered standard of care for treatment of locally advanced cervical cancer. Post treatment surveillance fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging is recommended 3-6 months after completion of therapy. Persistent FDG avidity is commonly observed at the cervix on surveillance scans, indeterminate for residual malignancy versus post treatment inflammatory change. To better understand the clinical significance of residual hypermetabolic activity, we performed an analysis of surveillance FDG-PET/CT images, correlating findings with post treatment cervical biopsy results after completion of therapy. The medical records of all patients treated with definitive chemotherapy and radiation for locally advanced (FIGO IB3 to IVA) cervical cancer at a single academic medical center between 2017 and 2022 were reviewed. Patients were treated with curative intent using a combination of pelvic external beam radiation with concurrent cisplatin chemotherapy followed by intracavitary or combined intracavitary/interstitial brachytherapy boost. Patients underwent FDG-PET/CT imaging at 3-6 months upon completion of therapy, followed by biopsy either for suspected residual disease or equivocal findings on physical exam or FDG-PET/CT scans. Biopsies were obtained within 100 days of FDG-PET/CT imaging (median, 14 days). Twenty-three patients met inclusion criteria. One patient was excluded from analysis due to lack of FDG avidity on her pre-treatment FDG-PET/CT. Among the 22 evaluable scans, median pre-treatment FDG- PET/CT SUVmax of the cervix was 16.3 (range, 4.9-55). Median post-treatment SUVmax was 4.4 (range, 2.1-7.4). Median change in SUVmax from pre-treatment to post-treatment was 11.8 (range, 1.1 to 50.6). Twenty patients had a post-treatment SUVmax of greater than 3. Among post treatment scans, eight showed no residual uptake; two showed uptakes equal to the liver; eleven showed uptakes moderately higher than liver; and one showed uptake markedly increased relative to liver. None of the biopsy specimens showed evidence of residual malignancy, instead showing fibroinflammatory necrosis and reactive changes. None of the patients developed clinical evidence of disease progression at the cervix within one year of treatment completion. Residual hypermetabolic activity at the cervix is common following definitive chemotherapy and radiation for cervical cancer. This is unlikely to represent residual viable malignancy. Post treatment FDG-PET/CT imaging remains valuable for detecting locoregional or distant disease progression/persistence following therapy.

Exploring the efficacy of 18F-FDG PET/CT in hepatocellular carcinoma diagnosis: role of Ki-67 index and tumor differentiation

PurposeThe sensitivity of [18F] fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) for detecting hepatocellular carcinoma (HCC) has not been clarified thoroughly. Our study seeks to explore the association between the Ki-67 index and FDG-avidity in HCC tumors using 18F-FDG PET/CT.Methods112 HCC lesions from 109 patients detected by 18F-FDG PET/CT were included retrospectively between August 2017 and May 2022, comprising 82 lesions in the training cohort and 30 in the validation cohort to simulate prospective studies. In the training cohort, lesions were stratified by a lesion-to-liver maximum standardized uptake value (SUVmax) ratio cut-off of 1.59. The relationships between lesion-to-liver SUVmax ratios and several clinical factors including tumor differentiation, alpha fetoprotein (AFP), carcinoembryonic antigen (CEA), hepatitis B virus (HBV) infection, Ki-67 index et al. were assessed. These findings were subsequently validated in the independent validation cohort.ResultsIn the training cohort, group A1 lesions demonstrated a higher Ki-67 index (%, 40.00 [30.00, 57.50] vs. 10.00 [5.00, 28.75], p<0.001) than group A0, the positive correlation between FDG-avidity and Ki-67 index was revealed by multivariate analysis, OR=1.040, 95% CI of OR [1.004–1.077], p=0.030. The calculated cut-off value was 17.5% using the receiver operating characteristic (ROC) curve, with an area under curve (AUC) of 0.834 and 95% CI [0.742–0.926], p<0.001. These findings were further validated in the independent validation cohort, with similar results (AUC=0.875, 95% CI [0.750–1.000], p<0.001).ConclusionIn comparison to tumor differentiation, Ki-67 index demonstrates a stronger association with FDG-avidity in HCC tumors, and when the Ki-67 index exceeds 17.5%, 18F-FDG PET/CT might serve as a useful indicator for HCC.Graphical abstract

Use of Oral Empagliflozin to Obtain Optimal Blood Sugar Levels for Conducting 18 F-FDG PET-CT in Patients with Hyperglycemia-A Pilot Study.

Background Flourine-18 fluorodeoxyglucose positron emission tomography-computed tomography ( 18 F-FDG PET-CT) is a well-established imaging modality for the evaluation of patients with oncological and nononcological conditions. The underlying principle of imaging is the preferentially increased glucose consumption by cancer cells, due to overexpression of glucose type 1 receptors that are insulin independent. Thus, one of the factors that leads to decreased sensitivity of an 18 F-FDG PET-CT is elevated blood sugar levels, leading to decreased glucose uptake by cancer cells due to competitive inhibition. A significant percentage of patients scheduled for PET-CT scan has diabetes mellitus type II as a comorbid condition and often has elevated random blood sugar (RBS) precluding an upfront PET-CT evaluation. Such cases must be rescheduled. This causes delay in the evaluation and management of such patients. Empagliflozin is a novel sodium glucose type 2 inhibitor that prevents tubular reabsorption of glucose and increases renal glycosuria resulting in decreased blood sugar. This drug does not cause significant hypoglycemia or increase endogenous insulin secretion. This study was undertaken to evaluate a potential role for empagliflozin in facilitating optimal blood sugar control in patients with hyperglycemia on the day of the scheduled PET scan. Methods This is an interventional prospective study and patients detected to have RBS more than 200 mg/dL on the day of the scheduled scan were included in the study. The patients were administered two tablets of 10 mg empagliflozin and kept under observation. Samples for RBS were taken at approximately 2nd and 4th hour post administration by bedside method. These patients underwent scan on the same day after adequate sugar control and when an RBS of less than 200 mg/dL was achieved. The primary outcome studied was change in RBS values in the patient cohort and evaluation of PET SUV (standardized uptake value) compared with the rest of the patients scheduled on the same day. Secondary outcome was assessment of any side effects in the patients. Results Total of 10 patients were found to have elevated blood sugar (RBS > 200 mg/dL; irrespective of being on medication) and did not meet the evaluation criteria for a PET-CT scan on the scheduled day. Following administration of the drug, all 10 patients were able to attain blood sugar levels and fulfill the criteria for undergoing a PET-CT scan. No obvious side effect was noted in any of the patient. The SUV values of the patient cohort were comparable with the rest of the patient scanned on the day. Conclusion In this pilot study, 20 mg of empagliflozin (2 tablets of 10 mg) appears to be a safe and effective method for achieving optimal decrease in the RBS without causing hypoglycemia or hyperinsulinemia. It can be safely employed in the subset of population with RBS between 201 and 300 mg/dL to adequately bring the sugar levels at acceptable levels RBS less than 200 mg/dl and fulfill the FDG PET-CT criteria as per European Association of Nuclear Medicine (EANM) norms.

Prognostic impact of highly solid component in early-stage solid lung adenocarcinoma.

Based on computed tomography (CT) findings of lung cancer, solid nodules have a much worse prognosis than subsolid nodules, even if the nodules are subcentimeter in size. There is, however, no systematic method for determining the prognosis of solid tumors on CT. This study aimed to discover the prognostic factor of early-stage solid lung adenocarcinoma using three-dimensional CT volumetry. Patients with pathological stage I solid lung adenocarcinoma who underwent complete resection between 2007 and 2012 were selected in this retrospective study. Clinicopathological data and preoperative multidetector CT findings, such as tumor size on the two-dimensional axial image, three-dimensional tumor volume between -600 and 199 HU, and three-dimensional solid volume between 0 and 199 HU, which corresponded to highly solid components, were compared between recurrence and non-recurrence. Furthermore, these radiological values were compared to pathological invasive volume (PIV). During this time, 709 patients had their lung cancer completely removed. From this cohort, 90 patients with pathological stage I solid lung adenocarcinoma were selected. In addition, recurrence was found in 26 patients (28.9%). Although two-dimensional axial image, serum carcinoembryonic antigen (CEA) level, and SUVmax on 18F fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) did not differ statistically between recurrent and non-recurrent patients, three-dimensional tumor and solid tumor volume did. Multivariate analysis indicated that three-dimensional solid tumor volume [hazard ratio: 2.440; 95% confidence interval (CI): 1.110-5.361, P=0.026] and epidermal growth factor receptor (EGFR) mutation (hazard ratio: 4.307; 95% CI: 1.328-13.977, P=0.015) were significantly associated with disease-free survival (DFS). When three-dimensional tumor and solid tumor volume were compared to PIV, three-dimensional solid tumor volume (3,091 mm3 on average) showed a highly similar value with PIV (2,930 mm3 on average), whereas three-dimensional tumor volume (6,175 mm3 on average) was significantly larger than PIV (P<0.001). In patients with early-stage solid lung adenocarcinoma, the measurement of three-dimensional solid tumor volume, which is correlated with PIV, accurately predicted the postoperative outcome.

Real-time Fluorescent ICG and 99m-Tc Nanocolloid Tracer Navigation in Bilateral Sentinel Lymph Node Mapping of Vulvar Cancer

The effectiveness of sentinel lymph node (SLN) biopsy has been validated by two prospective trials, GROINS VI and GOG 1731-2. According to ESGO guideline in patients with unifocal tumors with a diameter of <4 cm, in the absence of suspected inguinal lymph nodes, SLN biopsy is recommended. The use of a radioactive tracer is mandatory.2 Using Indocyanine green (ICG) increase the detection of the vulvar sentinel node from 89.7 to 100%3. Aim of this video is to share our experience about the feasibility, safety and usefulness of the surgical identification of SLN in vulvar cancer using real-time fluorescent indocyanine green with 99m-technetium nanocolloid. Stepwise demonstration of the technique with narrated video footage. Tertiary level hospital "IRCCS Istituto Nazionale dei Tumori", Milano, Italy. A 50-year-old woman was diagnosed with vulvar cancer on biopsy of 1.5 cm size vulvar lesion under the clitoris area and referred to our Operative Unit. F-18 fluorodeoxyglucose positron-emission tomography-computed tomography (PET) showed no extra-vulvar disease. The patient was scheduled for radical vulvectomy and bilateral inguinal sentinel lymph-node biopsy (SLN). In this video the surgical procedure involved double location of SLN, first with the 99m-technetium detector followed by ICG identification. We used an ICG dilution of 2.5 mg/mL in sterile water and injected 4 mL around the tumor 5-10 min before visualization. First a handheld gamma probe used to identify the location of the SLN(s) with 99m-technetium. The fluorescence imaging was performed by the quest imaging system (FLUOPTICS©, Middenmeer, The Netherlands) that combine autofluorescence and fluorescence perfusion imaging. Second, we carried out the SLN biopsy using a dark mood procedure to identify the IGC tracer. The fluorescence imaging enables the detection of these markers through some millimeters of tissue and ICG has the advantage that is visible through the skin4. This video shows a successful combined 99m-technetium and ICG fluorescence image-guided bilateral SLN biopsy in a vulvar cancer patient using a near-infrared (NIR) optical imaging system (FLUOPTICS©). ICG for SLN mapping appears to be safe in women with vulvar cancer with a satisfactory detection rate. This may help in retaining surgical radicality while minimizing operative complications.

Staging fluorodeoxyglucose positron emission tomography/computed tomography for muscle-invasive bladder cancer: a nationwide population-based study.

To provide insight into the use and staging information on lymph-node involvement added by fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with muscle-invasive bladder cancer (MIBC), based on a nationwide population-based cohort study. We analysed a nationwide cohort of patients with MIBC without signs of distant metastases, newly diagnosed in the Netherlands between November 2017 and October 2019. From this cohort, we selected patients who underwent pre-treatment staging with CT only or CT and FDG-PET/CT. The distribution of patients, disease characteristics, imaging findings, nodal status (clinical nodal stage cN0 vs cN+) and treatment were described for each imaging modality group (CT only vs CT and FDG-PET/CT). We identified 2731 patients with MIBC: 1888 (69.1%) underwent CT only; 606 (22.2%) underwent CT and FDG-PET/CT, 237 (8.6%) underwent no CT. Of the patients who underwent CT only, 200/1888 (10.6%) were staged as cN+, vs 217/606 (35.8%) who underwent CT and FDG-PET/CT. Stratified analysis showed that this difference was found in patients with clinical tumour stage (cT)2 as well as cT3/4 MIBC. Of patients who underwent both imaging modalities and were staged with CT as cN0, 109/498 (21.9%) were upstaged to cN+ based on FDG-PET/CT. Radical cystectomy (RC) was the most common treatment within both imaging groups. Preoperative chemotherapy was more frequently applied in cN+ disease and in FDG-PET/CT-staged patients. Concordance of pathological N stage after upfront RC was higher among patients staged as cN+ with CT and FDG-PET/CT (50.0% pN+) than those staged as cN+ with only CT (39.3%). Patients with MIBC who underwent pre-treatment staging with FDG-PET/CT were more often staged as lymph node positive, regardless of cT stage. In patients with MIBC who underwent CT and FDG-PET/CT, FDG-PET/CT led to clinical nodal upstaging in approximately one-fifth. Additional imaging findings may influence subsequent treatment strategies.

Prospective study of integrating post-radiotherapy [18F] fluorodeoxyglucose-positron emission tomography/computed tomography scan and plasma Epstein-Barr virus DNA in surveillance of locoregionally advanced nasopharyngeal carcinoma.

6072 Background: To evaluate the role of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scan at 12-weeks after the end of Radiotherapy (RT) integrated with plasma EBV DNA in surveillance and standardized implementation of locoregionally advanced nasopharyngeal carcinoma (LA-NPC). Methods: This prospective study was conducted in patients with stage III-IVa LA-NPC. FDG-PET/CT examination and plasma Epstein-Barr virus (EBV) DNA measurements was performed pretreatment and at 12-weeks after the end RT. The primary study endpoint was the negative predictive value (NPV) and other supporting diagnostic test characteristics of 12-weeks FDG-PET/CT for the surveillance of residual locoregional disease and new distant metastasis. Results: From June 2018 to December 2019, 506 eligible patients were enrolled and entered follow-up (median,45 months). At 12 weeks after the end of RT, there were 22 (4.3%) patients have residual locoregional disease, 30 (5.9%) patients developed distant metastasis and 6 (1.2%) patients presented both residual locoregional disease and distant metastasis. The NPV of 12-weeks FDG-PET/CT for overall residual diseases and distant metastasis was 96.3% (95% confidence interval [CI], 94.0%-97.8%) with sensitivity of 72.4% (95%CI, 58.9%-83.0%), specificity of 93.3% (95%CI, 90.5%-95.4%), positive predictive value (PPV) of 58.3% (95%CI, 46.1%-69.6%) and accuracy of 90.9% (95%CI, 88.4%-93.4%). In EBV DNA-based risk subgroups, the NPV of 12-weeks PDG-PET/CT was 96.8% (95%CI, 94.5%-98.2%) in patients with undetectable 12-weeks plasma EBV DNA and 87.0% (95%CI, 65.3%-96.5%) in patients with detectable 12-weeks plasma EBV DNA. Conclusions: 12-weeks PDG-PET/CT was reliable in the surveillance of LA-NPC and could help optimize the follow-up strategy and provide implications for timely and effective therapeutic regimen, especially for patients in different EBV DNA-based risk groups. Clinical trial information: NCT03601390 .

DMCT-Net: dual modules convolution transformer network for head and neck tumor segmentation in PET/CT

Objective. Accurate segmentation of head and neck (H&N) tumors is critical in radiotherapy. However, the existing methods lack effective strategies to integrate local and global information, strong semantic information and context information, and spatial and channel features, which are effective clues to improve the accuracy of tumor segmentation. In this paper, we propose a novel method called dual modules convolution transformer network (DMCT-Net) for H&N tumor segmentation in the fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) images. Approach. The DMCT-Net consists of the convolution transformer block (CTB), the squeeze and excitation (SE) pool module, and the multi-attention fusion (MAF) module. First, the CTB is designed to capture the remote dependency and local multi-scale receptive field information by using the standard convolution, the dilated convolution, and the transformer operation. Second, to extract feature information from different angles, we construct the SE pool module, which not only extracts strong semantic features and context features simultaneously but also uses the SE normalization to adaptively fuse features and adjust feature distribution. Third, the MAF module is proposed to combine the global context information, channel information, and voxel-wise local spatial information. Besides, we adopt the up-sampling auxiliary paths to supplement the multi-scale information. Main results. The experimental results show that the method has better or more competitive segmentation performance than several advanced methods on three datasets. The best segmentation metric scores are as follows: DSC of 0.781, HD95 of 3.044, precision of 0.798, and sensitivity of 0.857. Comparative experiments based on bimodal and single modal indicate that bimodal input provides more sufficient and effective information for improving tumor segmentation performance. Ablation experiments verify the effectiveness and significance of each module. Significance. We propose a new network for 3D H&N tumor segmentation in FDG-PET/CT images, which achieves high accuracy.

Diagnostic accuracy of f18-fluorodeoxyglucose positron emission tomography-computed tomography in the evaluation of carcinoma of unknown primary: A single-center study

Background: The term carcinoma of unknown primary (CUP) is not a single disease entity that it can be explicated as the recognition of metastasized tumor, in which the primary origin of the malignancy from an organ or site remains occult. The term refers to a clinical disorder that revolves around and represents a diversified metastatic tumor group, for whom the diagnostic investigations are unable to pinpoint the primary site of the tumor, comprising extensive radiological techniques, invasive endoscopic procedures, and histopathology, many which fail to diagnose the primary site. Aims and Objectives: The study was conducted to ascertain the diagnostic accuracy of fluorine-18 labeled fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) in the evaluation of CUP. The secondary objective of the study was to identify rate of the primary malignancies localized on 18F-FDG PET-CT that presents as CUP in local settings. Materials and Methods: The prospective and cross-sectional study included patients with CUP who underwent 18F-FDG PET-CT scans between October 2021 and February 2022. The primary site localized on 18F-FDG PET-CT was confirmed through biopsy and histology. False-negative and false-positive patients were ascertained through biopsy and/or follow-up of 6 months. Results: Of a total of 63 patients, 57.1% were male, while 42.9% were female with a mean age of 56.27 years. The overall detection rate of primary tumor (PT) site on 18F-FDG PET-CT was 88.8%. Abnormal sites and indicative of primary malignant tumor were correctly detected in 79.36% that were truly positive proven on biopsy. False-negative rate of scan was 4.76%, though malignancy was proven through other investigations or follow-up, while 6.36% had true negative and 9.52% showed false-positive results on the scan. In this study, the calculated diagnostic accuracy of 18F-FDG PET-CT identified as 85.7%, sensitivity 94%, specificity 40%, positive predictive value 89.2%, and negative predictive value 57.1%. Conclusion: 18F-FDG PET-CT demonstrated high sensitivity and diagnostic accuracy ascertaining the PT site in patients with CUP in our study population.