Correlation between remnant thyroid gland I-131 uptake and serum thyroglobulin levels: can we rely on I-131 whole body scans?

BACKGROUND

I-131 treatment (RAI) decision relies heavily on serum thyroglobulin (Tg) levels, as higher Tg levels are assumed to be correlated with higher I-131 uptake. Tg elevation, negative iodine scintigraphy (TENIS) definition is becoming more clinically relevant as alternative treatment methods are available. This study examined the correlation between Tg levels with I-131 uptake in remnant thyroid gland to evaluate the reliability of serum Tg levels in predicting I-131 uptake.

METHODS

From March 2012 to July 2019, 281 papillary thyroid cancer patients treated with 150 mCi RAI were retrospectively enrolled. Early (2nd day) and Delayed (7th day) post-RAI whole-body scan (WBS) neck counts were correlated with clinical and pathologic findings. Patients with normal neck ultrasound and undetectable level of serum Tg (< 0.2 ng/mL) and thyroglobulin antibody (TgAb) (< 10 IU/mL) were defined as ablation success within 2 years after I-131 ablation.

RESULTS

Thyroid gland weight, tumor size and thyroiditis were independent factors of preoperative serum Tg levels. Serum off-Tg levels correlated with Early and Delayed WBS neck counts, and thyroiditis pathology contributed to lower neck counts in both Early and Delayed WBSs. In multivariable analysis, Delayed WBS neck count, serum off-Tg and off-TgAb were significant factors for predicting ablation success.

CONCLUSION

I-131 uptake and retention in remnant thyroid gland correlates with serum off-Tg levels, thyroiditis, and ablation success in thyroid cancer patients receiving high-dose I-131 therapy. Semi-quantitative I-131 analysis with Early and Delayed WBSs provides additional information in evaluating ablation success, with the potential application for metastasis treatment response evaluation.

Does high [18F]FDG uptake always mean poor prognosis? Colon cancer with high-level microsatellite instability is associated with high [18F]FDG uptake on PET/CT

OBJECTIVES

High-level microsatellite instability (MSI-high) is generally associated with higher F-18 fluorodeoxyglucose ([18F]FDG) uptake than stable microsatellite (MSI-stable) tumors. However, MSI-high tumors have better prognosis, which is in contrast with general understanding that high [18F]FDG uptake correlates with poor prognosis. This study evaluated metastasis incidence with MSI status and [18F]FDG uptake.

METHODS

We retrospectively reviewed 108 right-side colon cancer patients who underwent preoperative [18F]FDG PET/CT and postoperative MSI evaluations using a standard polymerase chain reaction at five Bethesda guidelines panel loci. The maximum standard uptake value (SUVmax), SUVmax tumor-to-liver ratio (TLR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured using SUV 2.5 cut-off threshold. Student's t-test or Mann-Whitney U test was performed for continuous variables, and χ2 test or Fisher's exact test was performed for categorical variables (p value of  < 0.05 for statistical significance). Medical records were reviewed for metastasis incidence.

RESULTS

Our study population had 66 MSI-stable and 42 MSI-high tumors. [18F]FDG uptake was higher in MSI-high tumors than MSI-stable tumors (TLR, median (Q1, Q3): 7.95 (6.06, 10.54) vs. 6.08 (4.09, 8.82), p = 0.021). Multivariable subgroup analysis demonstrated that higher [18F]FDG uptake was associated with higher risks of distant metastasis in MSI-stable tumors (SUVmax: p = 0.025, MTV: p = 0.008, TLG: p = 0.019) but not in MSI-high tumors.

CONCLUSION

MSI-high colon cancer is associated with high [18F]FDG uptake, but unlike MSI-stable tumors, the degree of [18F]FDG uptake does not correlate with the rate of distant metastasis.

CLINICAL RELEVANCE STATEMENT

MSI status should be considered during PET/CT assessment of colon cancer patients, as the degree of [18F]FDG uptake might not reflect metastatic potential in MSI-high tumors.

KEY POINTS

• High-level microsatellite instability (MSI-high) tumor is a prognostic factor for distant metastasis. • MSI-high colon cancers had a tendency of demonstrating higher [18F]FDG uptake compared to MSI-stable tumors. • Although higher [18F]FDG uptake is known to represent higher risks of distant metastasis, the degree of [18F]FDG uptake in MSI-high tumors did not correlate with the rate at which distant metastasis occurred.

Acetate-Mediated Odorant Receptor OR51E2 Activation Results in Calcitonin Secretion in Parafollicular C-Cells: A Novel Diagnostic Target of Human Medullary Thyroid Cancer

Medullary thyroid cancer originates from parafollicular C-cells in the thyroid. Despite successful thyroidectomy, localizing remnant cancer cells in patients with elevated calcitonin and carcinoembryonic antigen levels remains a challenge. Extranasal odorant receptors are expressed in cells from non-olfactory tissues, including C-cells. This study evaluates the odorant receptor signals from parafollicular C-cells, specifically, the presence of olfactory marker protein, and further assesses the ability of the protein in localizing and treating medullary thyroid cancer. We used immunohistochemistry, immunofluorescent staining, Western blot, RNA sequencing, and real time-PCR to analyze the expression of odorant receptors in mice thyroids, thyroid cancer cell lines, and patient specimens. We used in vivo assays to analyze acetate binding, calcitonin secretion, and cAMP pathway. We also used positron emission tomography (PET) to assess C¹¹-acetate uptake in medullary thyroid cancer patients. We investigated olfactory marker protein expression in C-cells in patients and found that it co-localizes with calcitonin in C-cells from both normal and cancer cell lines. Specifically, we found that OR51E2 and OR51E1 were expressed in thyroid cancer cell lines and human medullary thyroid cancer cells. Furthermore, we found that in the C-cells, the binding of acetate to OR51E2 activates its migration into the nucleus, subsequently resulting in calcitonin secretion via the cAMP pathway. Finally, we found that C¹¹-acetate, a positron emission tomography radiotracer analog for acetate, binds competitively to OR51E2. We confirmed C¹¹-acetate uptake in cancer cells and in human patients using PET. We demonstrated that acetate binds to OR51E2 in C-cells. Using C¹¹-acetate PET, we identified recurrence sites in post-operative medullary thyroid cancer patients. Therefore, OR51E2 may be a novel diagnostic and therapeutic target for medullary thyroid cancer.

A National Referral Service for Paediatric Brachytherapy: An Evolving Practice and Outcomes Over 13 Years

AIMS

Most children requiring radiotherapy receive external beam treatment and few have tumours suitable for brachytherapy. No paediatric radiotherapy centre will treat enough patients from its own normal catchment population for expertise in brachytherapy to be developed and sustained. Following discussion and agreement in the national paediatric radiotherapy group, a service for paediatric brachytherapy in the UK has been developed. We report the process that has evolved over more than 10 years, with survival and functional outcome results.

MATERIALS AND METHODS

Since 2009, potential patients have been referred to the central paediatric oncology multidisciplinary team meeting, where imaging, pathology and treatment options are discussed. Since 2013, the National Soft Tissue Sarcoma Advisory Panel has also reviewed most patients, with the principal aim of advising on the most suitable primary tumour management for complex patients. Clinical assessment and examination under anaesthetic with biopsies may be undertaken to confirm the appropriateness of brachytherapy, either alone or following conservative surgery. Fractionated high dose rate brachytherapy was delivered to a computed tomography planned volume after implantation of catheters under ultrasound imaging guidance. Since 2019, follow-up has been in a dedicated multidisciplinary clinic.

RESULTS

From 2009 to 2021 inclusive, 35 patients (16 female, 19 male, aged 8 months to 17 years 6 months) have been treated. Histology was soft-tissue sarcoma in 33 patients and carcinoma in two. The treated site was pelvic in 31 patients and head and neck in four. With a median follow-up of 5 years, the local control and overall survival rates are 100%. Complications have been few, and functional outcome is good.

CONCLUSION

Brachytherapy is effective for selected paediatric patients, resulting in excellent tumour control and good functional results. It is feasible to deliver paediatric brachytherapy at a single centre within a national referral service.

18F-FDG PET Visualizes Systemic STING Agonist-Induced Lymphocyte Activation in Preclinical Models

Stimulator of interferon genes (STING) is a mediator of immune recognition of cytosolic DNA, which plays important roles in cancer, cytotoxic therapies, and infections with certain pathogens. Although pharmacologic STING activation stimulates potent antitumor immune responses in animal models, clinically applicable pharmacodynamic biomarkers that inform of the magnitude, duration, and location of immune activation elicited by systemic STING agonists are yet to be described. We investigated whether systemic STING activation induces metabolic alterations in immune cells that can be visualized by PET imaging. Methods: C57BL/6 mice were treated with systemic STING agonists and imaged with 18F-FDG PET after 24 h. Splenocytes were harvested 6 h after STING agonist administration and analyzed by single-cell RNA sequencing and flow cytometry. 18F-FDG uptake in total splenocytes and immunomagnetically enriched splenic B and T lymphocytes from STING agonist-treated mice was measured by γ-counting. In mice bearing prostate or pancreas cancer tumors, the effects of STING agonist treatment on 18F-FDG uptake, T-lymphocyte activation marker levels, and tumor growth were evaluated. Results: Systemic delivery of structurally distinct STING agonists in mice significantly increased 18F-FDG uptake in the spleen. The average spleen SUVmax in control mice was 1.90 (range, 1.56-2.34), compared with 4.55 (range, 3.35-6.20) in STING agonist-treated mice (P < 0.0001). Single-cell transcriptional and flow cytometry analyses of immune cells from systemic STING agonist-treated mice revealed enrichment of a glycolytic transcriptional signature in both T and B lymphocytes that correlated with the induction of immune cell activation markers. In tumor-bearing mice, STING agonist administration significantly delayed tumor growth and increased 18F-FDG uptake in secondary lymphoid organs. Conclusion: These findings reveal hitherto unknown functional links between STING signaling and immunometabolism and suggest that 18F-FDG PET may provide a widely applicable approach toward measuring the pharmacodynamic effects of systemic STING agonists at a whole-body level and guiding their clinical development.

Prognosis of resected invasive mucinous adenocarcinoma compared with the IASLC histologic grading system for invasive nonmucinous adenocarcinoma: Surgical database study in the TKIs era in Korea

BACKGROUND

The prognosis of invasive mucinous adenocarcinoma (IMA) remains controversial and should be clarified by comparison with the International Association for the Study of Lung Cancer (IASLC) histologic grading system for invasive nonmucinous adenocarcinoma (INMA).

METHODS

This study included patients with IMA who underwent curative resection. Their clinicopathological outcomes were compared with those of patients with INMA. Propensity score matching was performed to compare the prognosis of IMA with IASLC grade 2 or 3. Kaplan-Meier survival curves and log-rank tests were used to analyze recurrence-free survival (RFS) and overall survival (OS).

RESULTS

The prognoses of IMA and IASLC grade 2 were similar in terms of RFS and OS. Although patients with IMA had better RFS than patients with IASLC grade 3, the OS was not significantly different. After propensity score matching, IMA demonstrated similar RFS to IASLC grade 2 but superior to IASLC grade 3; there was no difference in the OS compared with grades 2/3. Multivariate analysis revealed that tumor size (hazard ratio [HR] = 1.20, p = 0.028), lymphovascular invasion (HR = 127.5, p = 0.003), and maximum standardized uptake value (HR = 1.24, p = 0.005) were poor prognostic predictors for RFS. Patients with IMA demonstrated RFS similar to and significantly better than that of patients with IASLC grades 2 and 3, respectively. For OS, IMA prognosis was between that of IASLC grades 2 and 3.

CONCLUSIONS

Since the prognosis of IMA among lung adenocarcinomas appears to be relatively worse, further clinical studies investigating IMA-specific treatment and follow-up plans are necessary to draw more inferences.

Purine nucleoside phosphorylase enables dual metabolic checkpoints that prevent T cell immunodeficiency and TLR7-associated autoimmunity

Purine nucleoside phosphorylase (PNP) enables the breakdown and recycling of guanine nucleosides. PNP insufficiency in humans is paradoxically associated with both immunodeficiency and autoimmunity, but the mechanistic basis for these outcomes is incompletely understood. Here, we identify two immune lineage-dependent consequences of PNP inactivation dictated by distinct gene interactions. During T cell development, PNP inactivation is synthetically lethal with downregulation of the dNTP triphosphohydrolase SAMHD1. This interaction requires deoxycytidine kinase activity and is antagonized by microenvironmental deoxycytidine. In B lymphocytes and macrophages, PNP regulates Toll-like receptor 7 signaling by controlling the levels of its (deoxy)guanosine nucleoside ligands. Overriding this regulatory mechanism promotes germinal center formation in the absence of exogenous antigen and accelerates disease in a mouse model of autoimmunity. This work reveals that one purine metabolism gene protects against immunodeficiency and autoimmunity via independent mechanisms operating in distinct immune lineages and identifies PNP as a potentially novel metabolic immune checkpoint.

Prognosis Associated with Glycolytic Activity in Regional Lymph Nodes of Patients with Previously Untreated Metastatic Breast Cancer: A Preliminary Study

Better mechanisms of predicting prognoses in patients with metastatic breast cancer will improve the identification of patients for whom curative treatments may be the most effective. In this study, the prognostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) was assessed in patients with metastatic breast cancer. A retrospective analysis of women who underwent 18F-FDG PET/CT for staging of newly diagnosed metastatic breast cancer was conducted. In each patient, the maximum standardized uptake value (SUV) and total lesion glycolysis (TLG) of primary tumors and regional lymph nodes were measured and analyzed for association with survival using the Cox proportional hazards regression model. From 346 consecutive patients, 32 with metastatic invasive ductal carcinoma of the breast were included in the study. The median duration of follow-up was 22.5 months. Disease progression occurred in 26 patients, and 11 patients died. When multivariate analyses with a stepwise forward regression were applied, only the maximum SUV and TLG of regional lymph nodes showed a significant correlation with progression-free survival and overall survival, respectively. This study demonstrates that increased 18F-FDG uptake in regional lymph nodes is a strong independent predictor of survival in women with metastatic invasive ductal carcinoma of the breast.

Predicting treatment outcomes using 18F-FDG PET biomarkers in patients with non-small-cell lung cancer receiving chemoimmunotherapy

Background

Predictive markers for treatment response and survival outcome have not been identified in patients with advanced non-small-cell lung cancer (NSCLC) receiving chemoimmunotherapy. We aimed to evaluate whether imaging biomarkers of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) and routinely assessed clinico-laboratory values were associated with clinical outcomes in patients with advanced NSCLC receiving pembrolizumab plus platinum-doublet chemotherapy as a first-line treatment.

Methods

We retrospectively enrolled 52 patients with advanced NSCLC who underwent baseline ¹⁸F-FDG PET/CT before treatment initiation. PET/CT parameters and clinico-laboratory variables, constituting the prognostic immunotherapy scoring system, were collected. Optimal cut-off values for PET/CT parameters were determined using the maximized log-rank test for progression-free survival (PFS). A multivariate prediction model was developed based on Cox models for PFS, and a scoring system was established based on hazard ratios of the predictive factors.

Results

During the median follow-up period of 16.7 months (95% confidence interval: 15.7-17.7 months), 43 (82.7%) and 31 (59.6%) patients experienced disease progression and death, respectively. Objective response was observed in 23 (44.2%) patients. In the multivariate analysis, maximum standardized uptake value, metabolic tumour volume_2.5, total lesion glycolysis_2.5, and bone marrow-to-liver uptake ratio from the PET/CT variables and neutrophil-to-lymphocyte ratio (NLR) from the clinico-laboratory variables were independently associated with PFS. The scoring system based on these independent predictive variables significantly predicted the treatment response, PFS, and overall survival.

Conclusion

PET/CT variables and NLR were useful biomarkers for predicting outcomes of patients with NSCLC receiving pembrolizumab and chemotherapy as a first-line treatment, suggesting their potential as effective markers for combined PD-1 blockade and chemotherapy.

Reprogramming of nucleotide metabolism by interferon confers dependence on the replication stress response pathway in pancreatic cancer cells

We determine that type I interferon (IFN) response biomarkers are enriched in a subset of pancreatic ductal adenocarcinoma (PDAC) tumors; however, actionable vulnerabilities associated with IFN signaling have not been systematically defined. Integration of a phosphoproteomic analysis and a chemical genomics synergy screen reveals that IFN activates the replication stress response kinase ataxia telangiectasia and Rad3-related protein (ATR) in PDAC cells and sensitizes them to ATR inhibitors. IFN triggers cell-cycle arrest in S-phase, which is accompanied by nucleotide pool insufficiency and nucleoside efflux. In combination with IFN, ATR inhibitors induce lethal DNA damage and downregulate nucleotide biosynthesis. ATR inhibition limits the growth of PDAC tumors in which IFN signaling is driven by stimulator of interferon genes (STING). These results identify a cross talk between IFN, DNA replication stress response networks, and nucleotide metabolism while providing the rationale for targeted therapeutic interventions that leverage IFN signaling in tumors.

Altered Glucose Metabolism and Glucose Transporters in Systemic Organs After Bariatric Surgery

The Roux-en-Y gastric bypass (RYGB) is highly effective in the remission of obesity and associated diabetes. The mechanisms underlying obesity and type 2 diabetes mellitus remission after RYGB remain unclear. This study aimed to evaluate the changes in continuous dynamic FDG uptake patterns after RYGB and examine the correlation between glucose metabolism and its transporters in variable endocrine organs using ¹⁸F-fluoro-2-deoxyglucose positron emission tomography images. Increased glucose metabolism in specific organs, such as the small intestine and various fat tissues, is closely associated with improved glycemic control after RYGB. In Otsuka Long-Evans Tokushima Fatty rats fed with high-fat diets, RYGB operation increases intestine glucose transporter expression and various fat tissues' glucose transporters, which are not affected by insulin. The fasting glucose decrement was significantly associated with RYGB, sustained weight loss, post-RYGB oral glucose tolerance test (OGTT) area under the curve (AUC), glucose transporter, or glycolytic enzymes in the small bowel and various fat tissues. High intestinal glucose metabolism and white adipose tissue-dependent glucose metabolism correlated with metabolic benefit after RYGB. These findings suggest that the newly developed glucose biodistribution accompanied by increased glucose transporters is a mechanism associated with the systemic effect of RYGB.

Serum glucose excretion after Roux-en-Y gastric bypass: a potential target for diabetes treatment

OBJECTIVE

The mechanisms underlying type 2 diabetes resolution after Roux-en-Y gastric bypass (RYGB) are unclear. We suspected that glucose excretion may occur in the small bowel based on observations in humans. The aim of this study was to evaluate the mechanisms underlying serum glucose excretion in the small intestine and its contribution to glucose homeostasis after bariatric surgery.

DESIGN

2-Deoxy-2-[¹⁸F]-fluoro-D-glucose (FDG) was measured in RYGB-operated or sham-operated obese diabetic rats. Altered glucose metabolism was targeted and RNA sequencing was performed in areas of high or low FDG uptake in the ileum or common limb. Intestinal glucose metabolism and excretion were confirmed using ¹⁴C-glucose and FDG. Increased glucose metabolism was evaluated in IEC-18 cells and mouse intestinal organoids. Obese or ob/ob mice were treated with amphiregulin (AREG) to correlate intestinal glycolysis changes with changes in serum glucose homeostasis.

RESULTS

The AREG/EGFR/mTOR/AKT/GLUT1 signal transduction pathway was activated in areas of increased glycolysis and intestinal glucose excretion in RYGB-operated rats. Intraluminal GLUT1 inhibitor administration offset improved glucose homeostasis in RYGB-operated rats. AREG-induced signal transduction pathway was confirmed using IEC-18 cells and mouse organoids, resulting in a greater capacity for glucose uptake via GLUT1 overexpression and sequestration in apical and basolateral membranes. Systemic and local AREG administration increased GLUT1 expression and small intestinal membrane translocation and prevented hyperglycaemic exacerbation.

CONCLUSION

Bariatric surgery or AREG administration induces apical and basolateral membrane GLUT1 expression in the small intestinal enterocytes, resulting in increased serum glucose excretion in the gut lumen. Our findings suggest a novel, potentially targetable glucose homeostatic mechanism in the small intestine.

Different roles of surveillance positron emission tomography according to the histologic subtype of non-Hodgkin's lymphoma

BACKGROUND/AIMS

Although the use of surveillance 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is discouraged in patients with diffuse large B-cell lymphoma, its usefulness in different subtypes has not been thoroughly investigated.

METHODS

We retrospectively evaluated 157 patients who showed positive results on surveillance FDG-PET/CT every 6 months following complete response for up to 5 years. All of the patients also underwent biopsies.

RESULTS

Seventy-eight (49.6%) of 157 patients had true positive results; the remaining 79 (50.3%), including eight (5.1%) with secondary malignancies, were confirmed to yield false positive results. Among the 78 patients with true positive results, the disease in seven (8.9%) had transformed to a different subtype. The positive predictive value (PPV) of FDG-PET/CT for aggressive B-cell non-Hodgkin's lymphoma (NHL) was lower than that for indolent B-cell or aggressive T-cell NHL (p = 0.003 and p = 0.018, respectively), especially in patients with a low/low-intermediate international prognostic index (IPI) upon a positive PET/CT finding. On the other hand, indolent B-cell and aggressive T-cell NHL patients showed PPVs of > 60%, including those with low/low-intermediate secondary IPIs.

CONCLUSION

The role of FDG-PET/CT surveillance is limited, and differs according to the lymphoma subtype. FDG-PET/CT may be useful in detecting early relapse in patients with aggressive T-cell NHL, including those with low/low-intermediate risk secondary IPI; as already known, FDG-PET/CT has no role in aggressive B-cell NHL. Repeat biopsy should be performed to discriminate relapse or transformation from false positive findings in patients with positive surveillance FDG-PET/CT results.

Prognostic value of metabolic tumor volume and total lesion glycolysis on preoperative 18F-FDG PET/CT in patients with localized primary gastrointestinal stromal tumors

Background

This study aimed to evaluate the prognostic value of pretreatment ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in patients with localized primary gastrointestinal stromal tumors (GISTs) and to compare the predictive values of ¹⁸F-FDG PET/CT parameters with those of clinicopathological prognostic factors.

Methods

Sixty-two localized GIST patients who underwent staging with ¹⁸F-FDG PET/CT from January 2007 to December 2013 before surgery were retrospectively enrolled. A volume of interest with a standardized uptake value (SUV) threshold of 2.5 was used to determine the metabolic tumor volume (MTV) and total lesion glycolysis (TLG). These metabolic indices, along with the maximum SUV (SUVmax), were analyzed to evaluate recurrence-free survival (RFS). Other significant clinical and pathologic indices were also retrospectively reviewed for RFS analysis.

Results

Patients were followed up for a median of 42.0 months (range, 5.6–111.5). During the follow-up period, 13 patients (21.0%) experienced disease recurrence. In univariate analysis, tumor size (> 5 cm), mitotic count (> 5/high-power field), modified National Institutes of Health (NIH) consensus criteria, adjuvant imatinib treatment, SUVmax (≥ 7.04), MTV (≥ 50.76 cm³), and TLG (≥ 228.79 g) were significant prognostic factors affecting RFS (p < 0.05). In multivariate analysis, only MTV (hazard ratio, 17.69; 95% confidence interval [CI], 2.03–154.17, p = 0.009) and TLG (hazard ratio, 20.48; 95% CI, 2.19–191.16, p = 0.008) were independent prognostic factors for RFS. The 5-year RFS rates were 96.4% and 96.6% in patients with a low MTV and TLG and 27.3% and 23.6% in patients with a high MTV and TLG, respectively (p < 0.001).

Conclusion

MTV and TLG are independent prognostic factors for predicting recurrence in patients with localized primary GIST. Patients with a high MTV or TLG are at risk for poor prognosis and should be closely observed for disease recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40170-021-00244-x.

European dermatology forum - updated guidelines on the use of extracorporeal photopheresis 2020 - part 1

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multi‐disciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐versus‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines are divided in two parts: PART I covers cutaneous T‐cell lymphoma, chronic graft‐versus‐host disease and acute graft‐versus‐host disease while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatrics practice, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

European dermatology forum: Updated guidelines on the use of extracorporeal photopheresis 2020 - Part 2

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multidisciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐vs.‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines were divided into two parts: PART I covers Cutaneous T‐cell lymphoma, chronic graft‐vs.‐host disease and acute graft‐vs.‐host disease, while PART II will cover scleroderma, solid organ transplantation, Crohn’s disease, use of ECP in paediatric patients, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Abstract 6649: Inhibiting adenosine signaling and KRAS enhances the effect of α-PD-1 therapy in a KRASG12C/TP53R172H/+ pancreatic cancer model

Introduction: High levels of adenosine (ADO) in the tumor microenvironment have been shown to suppress immune responses and curtail T cell activation in the presence of anti-PD-1/PD-L1 blocking antibodies. CD73 catalyzes the extracellular generation of ADO from adenosine monophosphate (AMP). KRAS mutations, of which 60% were derived from pancreatic ductal adenocarcinoma (PDAC) samples, were associated with significantly upregulated CD73 expression, which resulted in a worsening prognosis. These immunosuppressive effects can be counteracted by CD73 inhibitors or by a dual ADO receptor (A2aR/A2bR) antagonist.

Method: Linear models were used to evaluate the ability of 299 pan-cancer consensus oncogenic drivers to predict CD73 expression independent of tumor type in the TCGA dataset. Changes in gene expression induced by KRAS inhibition were determined by RNAseq. Metabolic and proteomic alterations induced by KRAS inhibition were determined by LC-MS. C57BL/6J mice bearing established KP4662-G12C (KRASG12C/TP53R172H/+) tumors (at least 150 mm3) were treated as indicated: A1421 (CD73i; 30 mg/kg/day, s.c.), anti-PD1 (Clone RMP 1-14; 10 mg/kg; twice per week, i.p), and MRTX-1257 (KRASi, 100 mg/kg/day, p.o.). Treatment efficacy was monitored in a blinded manner using micro-computed tomography (mCT). A1412 and MRTX-1257 were provided by Arcus Biosciences.

Data: Direct KRAS inhibition reduced but did not abolish CD73 and A2aR/A2bR expression in multiple PDAC models. Metabolic analyses indicated that KRAS inhibition increased ADO and AMP levels. KRAS inhibition in PDAC models induced gene expression changes consistent with increased tumor immunogenicity. In a murine model of pancreatic cancer-bearing the KRASG12C mutation, co-administration of a CD73 inhibitor with anti-PD-1 in established tumors resulted in significant tumor growth retardation, comparable to KRASG12C inhibition alone. Durable tumor regression was observed when mice were treated with the triple combination therapy. These data support the rationale for the clinical development of modulators of immunosuppressive adenosine signaling in pancreatic cancer.

Conclusion: Here, we show that direct inhibition of mutant KRAS in pancreatic cancer models yields complex immunomodulatory effects. While antigen presentation pathways are transcriptionally upregulated and the expression of immunosuppressive chemokine is reduced, KRAS inhibition also reprograms nucleotide metabolism leading to elevated levels of ADO. These findings suggest that co-targeting mutant KRAS and adenosine signaling may enhance immunotherapy against pancreatic cancer and potentially other KRAS driven malignancies.

Citation Format: THUC LE, Evan Abt, Woosuk Kim, Akshata Udyavar, Arthur Cho, Joe Capri, Jing Cui, Razmik Ghukasyan, Luyi Li, Daniel DiRenzo, Brandon Rosen, Timothy Donahue, Matt Walters, Caius Radu. Inhibiting adenosine signaling and KRAS enhances the effect of α-PD-1 therapy in a KRASG12C/TP53R172H/+ pancreatic cancer model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6649.

External beam for the Heavy Ion Accelerator Facility

Radiotherapy using protons and heavier ions is emerging as an alternative to traditional photon radiotherapy for cancer treatment. Ions have a depth-dose profile that results in high energy deposition at the end of the particle’s path, with a relatively low dosage elsewhere. However, the specifics of ion interactions with cellular biology are not yet fully understood. To study the induced biological effects of the ions on cell cultures, an external beam is required as biological specimens cannot be placed in vacuum. The Heavy Ion Accelerator Facility (HIAF) at the Australian National University hosts accelerators for a wide variety of ion-beam research applications. However, HIAF does not currently have an external beam capability. Here, we present an initial design for a radiobiological research capability at HIAF. A systems engineering approach was used to develop the architecture of the apparatus and determine the feasibility of adapting the current facilities to external beam applications. This effort included ion optics calculations, coupled to a Geant4 simulation, to characterise ion beam transitions through a thin window into the air. The beam spread, intensity distributions, and energy of proton and carbon ions were studied as a function of distance travelled from the window, as well as the effects of alternative window materials and thicknesses. It was determined that the proposed line at the HIAF would be suitable for the desired applications. Overall, this feasibility study lays the foundations of an external beam design, a simulation test framework, and the basis for a grant application for an external beam at the HIAF.

Clinicopathologic risk factors of radioactive iodine therapy based on response assessment in patients with differentiated thyroid cancer: a multicenter retrospective cohort study

PURPOSE

We investigated whether predictive clinicopathologic factors can be affected by different response criteria and how the clinical usefulness of radioactive iodine (RAI) therapy should be evaluated considering variable factors in patients with differentiated thyroid carcinoma (DTC).

METHODS

A total of 1563 patients with DTC who underwent first RAI therapy after total or near total thyroidectomy were retrospectively enrolled from 25 hospitals. Response to therapy was evaluated with two different protocols based on combination of biochemical and imaging studies: (1) serum thyroglobulin (Tg) and neck ultrasonography (US) and (2) serum Tg, neck US, and radioiodine scan. The responses to therapy were classified into excellent and non-excellent or acceptable and non-acceptable to minimize the effect of non-specific imaging findings. We investigated which factors were associated with response to therapy depending on the follow-up protocols as well as response classifications. Multivariate logistic regression analysis was performed to identify factors significantly predicting response to therapy.

RESULTS

The proportion of patients in the excellent response group significantly decreased from 76.5 to 59.6% when radioiodine scan was added to the follow-up protocol (P < 0.001). Preparation method (recombinant human TSH vs. thyroid hormone withdrawal) was a significant factor for excellent response prediction evaluated with radioiodine scan (OR 2.129; 95% CI 1.687-2.685; P < 0.001) but was not for other types of response classifications. Administered RAI activity, which was classified as low (1.11 GBq) or high (3.7 GBq or higher), significantly predicted both excellent and acceptable responses regardless of the follow-up protocol.

CONCLUSIONS

The clinical impact of factors related to response prediction differed depending on the follow-up protocol or classification of response criteria. A high administered activity of RAI was a significant factor predicting a favorable response to therapy regardless of the follow-up protocol or classification of response criteria.

Metabolic Modifier Screen Reveals Secondary Targets of Protein Kinase Inhibitors within Nucleotide Metabolism

Biosynthesis of the pyrimidine nucleotide uridine monophosphate (UMP) is essential for cell proliferation and is achieved by the activity of convergent de novo and salvage metabolic pathways. Here we report the development and application of a cell-based metabolic modifier screening platform that leverages the redundancy in pyrimidine metabolism for the discovery of selective UMP biosynthesis modulators. In evaluating a library of protein kinase inhibitors, we identified multiple compounds that possess nucleotide metabolism modifying activity. The JNK inhibitor JNK-IN-8 was found to potently inhibit nucleoside transport and engage ENT1. The PDK1 inhibitor OSU-03012 (also known as AR-12) and the RAF inhibitor TAK-632 were shown to inhibit the therapeutically relevant de novo pathway enzyme DHODH and their affinities were unambiguously confirmed through in vitro assays and co-crystallization with human DHODH.

P1634Comparison of inflammation based prognostic scores in patients with stable heart failure with reduced ejection fraction

Background

Elevated inflammatory markers and malnutrition are characteristic for heart failure with reduced ejection fraction (HFrEF) correlating with disease severity and prognosis. Nutritional decline is closely linked to inflammation. Evidence emerges that heart failure can be triggered by inflammation directly, meaning that progression of HF is a function of individual inflammatory host response. We aimed to investigate and compare the impact of well-established inflammation based scores and inflammation-related nutritional scores on survival in HFrEF.

Methods

Stable HFrEF-patients undergoing routine ambulatory care between 2011 and 2017 have been identified from a prospective registry. Comorbidities and laboratory data at baseline were assessed. All-cause mortality was defined the primary endpoint. The modified Glasgow Prognostic Score (mGPS: 0/1/2 based on CRP and albumin), the neutrophil-to-lymphocyte ratio (NLR), the monocyte-to-lymphocyte ratio (MLR), the platelet-to-lymphocyte ratio (PLR) as well as the Nutritional Risk Index (NRI = (1.519 × serum albumin, g/dL) + (41.7 × present weight (kg)/ideal body weight (kg)) and the Prognostic Nutritional Index (PNI = albumin (g l–1) × total lymphocyte count × 109 l–1) were calculated. The association of the scores with HF severity and impact on overall survival were determined.

Results

Data of 443 patients receiving well titrated guideline directed HF therapy have been analyzed. Median age was 64 years (IQR 53–72), 73% were male. Median body mass index (BMI) was 26.6kg/m2 (IQR 23.8–30.2), median NT-proBNP was 2053pg/ml (IQR 842–4345) with most patients presenting in NYHA class II (178, 40%) and III (173, 39%). The mGPS was 0 for 352 (80%), 1 for 76 (17%) and 2 for 14 (3%) patients, respectively. All scores correlated with HF severity reflected by NT-proBNP [p<0.001 for mGPS, r=−0.48; p<0.001 for PNI] and NYHA class [p<0.001 for mGPS and PNI]. All scores were associated with all-cause mortality in univariate analysis. After adjustment for age, gender and kidney function only mGPS, PLR, NRI and PNI remained significantly associated with outcome. Out of these the ROC were highest for PNI and mGPS [0.674 and 0.652 respectively] and solely these scores remained significantly associated with mortality after including NT-proBNP in the multivariate model [adj.HR 1.87 (95% CI: 1.20–2.91), p=0.006 for mGPS; 0.62 (95% CI: 0.40–0.96), p=0.032 for PNI]. Kaplan Meier analysis confirmed the discriminatory power of mGPS and PNI (Figure 1).

Conclusions

Enhanced inflammation and malnutrition are more common in advanced heart failure. Among established inflammation and nutritional scores merely mGPS and PNI are associated with survival in HFrEF patients independently of NT-proBNP. This relationship emphasizes the significance of the individual proinflammatory response on prognosis.This easily available score may help clinicians to identify HFrEF patients with worse prognosis with urgent need for intensified therapy and/or alternate treatment options.

P1620Association of granulocyte neprilysin (CD10) expression with prognosis in heart failure with reduced ejection fraction

Background

The exact mechanism of action of neprilysin inhibition (NEPi) is still a subject of debate. The soluble form of the enzyme (sNEP), detectable in plasma, is discussed controversially as a potential biomarker in heart failure with reduced ejection fraction (HFrEF). NEP is present on solid tissues but identically to CD10, expressed on the surface of leukocytes under physiological conditions. The possible impact of NEP expression on peripheral leukocytes on prognosis and its association with sNEP levels have not been investigated yet.

Methods

99 stable HFrEF patients were prospectively enrolled and clinically followed-up. Laboratory markers including NT-proBNP were assessed. NEP (CD10) expression on peripheral blood cells were measured by flow cytometry using a combination of six antibodies with fluorescence minus one samples as control [CD3 (#555339), CD19 (#555413), CD56 (#335826), CD16 (#561306), CD14 (#562692), +/−CD10 (#332777); BD Biosciences,USA]. sNEP levels were determined by a specific ELISA [SEB785Hu, USCN, China].Associations between NEP expression and heart failure severity, sNEP levels and all-cause mortality were determined.

Results

Median age was 65 years (IQR: 55–73), 75% were male. Median NT-proBNP level was 1700pg/ml (IQR: 794–4009).NEP was expressed on granulocytes with 94.8% (IQR: 90.5–97.4) of CD10+ cells and measurable on B-cells and monocytes with 8.5% (IQR: 5.3–13.5) and 0.8% (IQR: 0.4–1.5) of CD10+ cells of the respective leukocyte subtype. NEP expression on T-cells was not detectable. The mean fluorescence intensity (MFI) of CD10+ cells was 5461 (IQR: 4028–6904) for granulocytes, 640 (IQR: 535–740) for B-cells and 1589 (IQR: 1395–1975) for monocytes. Granulocyte NEP expression, but not NEP expression on B-cells or monocytes, correlated inversely with heart failure severity reflected by NT-proBNP level (r=−0.46, p<0.001) and NYHA class (p=0.013) (Figure A). sNEP concentrations correlated weakly with NEP expression on granulocytes (r=0.22, p=0.030) as well as the MFI of CD10+ granulocytes (r=0.31, p=0.003). 15% of the patients died during a median FUP of 24 (IQR: 23–28) months. Increased NEP expression on granulocytes was indicative for better overall survival even after adjustment for age and kidney function [adj. HR per 1-IQR increase of MFI 0.41 (95% CI: 0.18–0.94), p=0.035]. Kaplan-Meier analysis illustrates the impact of granulocyte NEP expression on outcome graphically (Figure B).

Figure 1

Conclusions

Albeit beneficial effects of NEPi by ARNI therapy, NEP expression on granulocytes is inversely correlated with heart failure severity and mortality. The results support the inverse relationship between BNP and plasma NEP activity reported for a mixed population of heart failure patients. The positive correlation of granulocyte NEP expression and sNEP indicates a possible contribution of shed membrane NEP molecules to plasma NEP levels as a surrogate marker. The utility of granulocyte NEP expression or sNEP as biomarkers in HFrEF have to be further evaluated.

P5449Neurohumoral regulation of the low-, medium- and high-renin HFrEF phenotypes

Background

Previous investigations of plasma Renin-Angiotensin-System (RAS) fingerprints of patients with heart failure with reduced ejection fraction (HFrEF) revealed the existence of low, medium and high renin phenotypes independently of disease severity. Plasma renin serves as an excellent surrogate for angiotensin levels. The different renin phenotypes could not only hypothetically respond differently to RAS blockade but associated alterations of other vasoactive peptide systems could elucidate disease mechanisms and novel targets for heart failure therapy. The study aimed to investigate the relation between RAS regulation and pathophysiologically relevant vasoactive peptide systems based on different renin phenotypes.

Methods

We prospectively enrolled 369 patients with stable HFrEF. Laboratory markers including NT-proBNP and active renin concentration (ARC) were assessed. Plasma NEP levels (sNEP), bioactive adrenomedullin (bio-ADM) and big-endothelin1 (bigET-1) were measured by ELISA (R&D systems, UK; Sphingotec GmbH, Germany and Eagle Biosciences, Austria). NEP activity was determined by a fluorimetric peptide cleavage assay. The correlation between biomarkers and association with all-cause mortality was assessed. sNEP, bio-ADM and bigET-1 levels as well as NEP activity between the different renin phenotypes (i.e. <15. percentile, 15.-85. percentile and >85. percentile of ARC) was compared.

Results

Median age was 65 (IQR 53–73) years, 75% of patients were male. Median NT-proBNP levels were 1936 (IQR 855–4126) pg/mL. Median ARC was 155 (29–569) μIE/mL, the low, medium and high renin HFrEF phenotypes showed median ARC levels of 4.2μIE/mL (IQR 2.0–7.8), 155.1μIE/mL (IQR 43.3–353.5) and 2360μIE/mL (IQR 1483–3250) μIE/mL. Median bigET-1 was 0.62pmol/L (IQR 0.42–1.10), bio-ADM 26.0pg/mL (IQR 16.1–46.7), sNEP 413pg/mL (IQR 0–4111) and NEP activity 2.36nmol/mL/min (IQR 1.16–4.59). There was no correlation between sNEP and NEP activity [r=0.09, p=0.088]. ARC did not show a meaningful correlation with any of the four biomarkers [p=ns for sNEP, NEP activity and bigET-1; r=0.13, p=0.018 for bio-ADM]. In the univariate analysis ARC, bigET-1, bio-ADM but not sNEP and NEP activity, were associated with outcome. This association remained significant after adjustment for age, gender and kidney function for all three markers and for ARC after adding NT-proBNP [adj. HR per 1-IQR increase of ARC 1.27 (95% CI 1.04–1.22), p=0.003]. There were no differences in bigET-1, bio-ADM and sNEP or NEP activity stratified by the different renin phenotypes (Figure1).

Figure 1

Conclusions

ARC is a risk factor for mortality in HFrEF patients, independently of NT-proBNP. Plasma NEP levels and activity neither correlated with each other nor were associated with outcome. Bio-ADM and bigET-1 were strong risk factors for all-cause mortality. Interestingly, neither NEP nor bio-ADM or bigET-1 were related to RAS-activation, suggesting that there is no direct relationship with RAS regulation.

Access for retroperitoneoscopic surgery

Retroperitoneoscopic surgery is used for a variety of renal and adrenal procedures in the paediatric population. This can be a challenging procedure but has advantages over open and transperitoneal laparoscopic approaches. This VideoBank article aims to aid the surgeon in gaining safe and efficient access for retroperitoneal surgery by demonstrating key steps including patient positioning and optimal trocar placement.

[Cutaneous graft-versus-host disease]

BACKGROUND

Graft-versus-host disease (GvHD) is a complex multiorgan disease, which can occur as a complication following allogeneic stem cell transplantation. Involvement of the skin represents the most common appearance of GvHD. The role of the dermatologist is critical for diagnosis and initiation of treatment.

OBJECTIVES

The aim of this article is to provide a comprehensive review of the cutaneous types of GvHD and to present the most recent data on diverse therapy options for its acute and chronic form allowing the clinician to establish a definite diagnosis and to initiate proper therapy.

MATERIALS AND METHODS

Possible clinical appearances and recommended criteria to assist in making the right diagnosis are presented by means of expert recommendations.

RESULTS AND CONCLUSION

GvHD is still a complex entity whose diagnosis is often associated with challenges due to its variable presentation. Proper diagnosis and subsequent therapy is paramount for the optimal clinical outcome.

Targeted TNF-α Overexpression Drives Salivary Gland Inflammation

Chronic inflammation of the salivary glands from pathologic conditions such as Sjögren's syndrome can result in glandular destruction and hyposalivation. To understand which molecular factors may play a role in clinical cases of salivary gland hypofunction, we developed an aquaporin 5 (AQP5) Cre mouse line to produce genetic recombination predominantly within the acinar cells of the glands. We then bred these mice with the TNF-αglo transgenic line to develop a mouse model with salivary gland-specific overexpression of TNF-α; which replicates conditions seen in sialadenitis, an inflammation of the salivary glands resulting from infection or autoimmune disorders such as Sjögren's syndrome. The resulting AQP5-Cre/TNF-αglo mice display severe inflammation in the salivary glands with acinar cell atrophy, fibrosis, and dilation of the ducts. AQP5 expression was reduced in the salivary glands, while tight junction integrity appeared to be disrupted. The immune dysregulation in the salivary gland of these mice led to hyposalivation and masticatory dysfunction.

Retroperitoneoscopic lower pole heminephrectomy

INTRODUCTION

Retroperitoneoscopic heminephrectomy is a challenging procedure but with advantages over open and transperitoneal laparoscopic approaches. Lower pole heminephrectomy is less commonly undertaken compared with the upper pole.s OBJECTIVE: This VideoBank article aims to aid the surgeon in reducing the associated risks by demonstrating key steps including patient positioning, access and demonstrating key critical views.

MATERIALS AND METHODS

This is a video article with audio commentary of a pediatric patient undergoing a retroperitoneoscopic lower pole heminephrectomy.

CONCLUSION

Lower pole heminephrectomy can be safely undertaken via a retroperitoneoscopic approach.

The clinical implications of FDG-PET/CT differ according to histology in advanced gastric cancer

BACKGROUND

The prognostic impact of preoperative ¹⁸F-FDG PET/CT in advanced gastric cancer (AGC) remains a matter of debate. This study aims to evaluate the prognostic impact of SUV_max in preoperative ¹⁸F-FDG PET/CT of AGC according to histologic subtype, with a focus on the differences between tubular adenocarcinoma and signet ring cell (SRC) carcinoma.

METHODS

As a discovery set, a total of 727 AGC patients from prospective database were analyzed according to histologic subtype with Cox proportional hazard model and p-spline curves. In addition, another 173 patients from an independent institution was assessed as an external validation set.

RESULTS

In multivariate analysis, high SUV_max in preoperative ¹⁸F-FDG PET/CT of AGC was negatively correlated with disease-free survival (DFS) and overall survival (OS) in patients with diffuse type (DFS: HR 2.17, P < 0.001; OS: HR 2.47, P < 0.001) or SRC histology (DFS: HR 2.26, P = 0.005; OS: HR 2.61, P = 0.003). This negative prognostic impact was not observed in patients with intestinal type or well or moderately differentiated histology. These findings have been consistently confirmed in a validation set. The p-spline curves also showed a gradual increase in log HR as SUV_max rises only for SRC histology and for diffuse-type AGC. Finally, a novel predictive model for recurrence of AGC with diffuse type or SRC histology was generated and validated based on the preoperative SUV_max.

CONCLUSIONS

Preoperative high SUV_max of AGC is a poor prognostic factor in those with diffuse type or SRC histology. This study is the first to demonstrate the differential prognostic impact of preoperative PET/CT SUV_max in AGC according to histologic subtype and provide a clue to explain previous discrepancies in the prognostic impact of preoperative PET/CT in AGC. Prospective studies are required to validate the role of preoperative SUV_max in AGC.

The prognostic value of volume-based parameters using 18F-FDG PET/CT in gastric cancer according to HER2 status

BACKGROUND

We aimed to find the clinical value of metastatic tumor burden evaluated with F18-FDG PET/CT in gastric cancer patients, considering the human epidermal growth factor receptor 2 (HER2) status.

METHODS

We retrospectively reviewed 124 patients with locally advanced or metastatic gastric cancer at Yonsei Cancer Center between January 2006 and December 2014 who had undergone baseline FDG PET/CT before first-line chemotherapy. We measured the maximum standardized uptake value from the primary tumor (SUV_max) and whole-body (WB) PET/CT parameters, including WB SUV_max, WB SUV_mean, WB metabolic tumor volume (WB MTV), and WB total lesion glycolysis (WB TLG), in all metabolically active metastatic lesions (SUV threshold ≥2.5 or 40% isocontour for ≤2.5), and we determined their association with patient survival outcomes.

RESULTS

SUV_max was higher in HER2-positive gastric cancers (median 12.1, range 3.4-34.6) compared to HER-2 negative (7.4, 1.6-39.1, P < 0.001). Among all patients, WB TLG > 600, which is indicative of a high metastatic tumor burden, showed worse progression-free survival (PFS) [hazard ratio (HR), 2.003; 95% CI, 1.300-3.086; P = 0.002] and overall survival (OS) (HR, 3.001; 95% CI, 1.950-4.618; P < 0.001) than did WB TLG ≤ 600. Among HER2-positive gastric cancer patients treated with trastuzumab, higher metabolic tumor burden predicted worse OS, but not PFS.

CONCLUSIONS

HER2-positive gastric cancers had higher SUV_max compared to HER2-negative gastric cancers. In both HER2-negative patients and -positive patients receiving trastuzumab, FDG PET/CT volume-based parameters may have a role in further stratifying the prognosis of stage IV gastric cancer.

Evaluation of 18F-FDG PET/CT Parameters for Detection of Lymph Node Metastasis in Cutaneous Melanoma

PURPOSE

The purpose of this study was to investigate the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) parameters in the detection of regional lymph node (LN) metastasis in patients with cutaneous melanoma.

METHODS

We evaluated patients with cutaneous melanoma who underwent FDG PET/CT for initial staging or recurrence evaluation. A total of 103 patients were enrolled, and 165 LNs were evaluated. LNs that were confirmed pathologically or by follow-up imaging were included in this study. PET parameters, including maximum standardized uptake value (SUVmax), total lesion glycolysis and tumour-to-liver ratio, were used to determine the presence of metastases, and the results were compared with CT-determined LN metastasis. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off values of the FDG PET parameters.

RESULTS

A total of 93 LNs were malignant, and 84 LNs were smaller than 10 mm. In all 165 LNs, an SUVmax of >2.51 showed a sensitivity of 73.1%, a specificity of 88.9%, and an accuracy of 80.0% in detecting metastatic LNs. CT showed a higher specificity (87.3%) and lower accuracy (65.5%). For non-enlarged regional LNs (<10 mm), an SUVmax cut-off value of 1.4 showed the highest negative predictive value (81.3%). For enlarged LNs (≥10 mm), an SUVmax cut-off value of 2.4 showed the highest sensitivity (90.7%) and accuracy (88.9%) in detecting metastatic LNs.

CONCLUSIONS

In patients with cutaneous melanoma, an SUVmax of >2.4 showed a high sensitivity (91%) and accuracy (89%) in detecting metastasis in LNs ≥1 cm, and LNs <1 cm with an SUVmax <1.4 were likely to be benign.

Hydronephrotic kidney with multiple extra-renal calyces

Extra-renal calyces are a rare anomaly of the renal collecting system, characterised by the presence of calyces and pelvis outside the renal parenchyma. It may also be associated with other anomalies, such as renal ectopia, fusion and malrotation. We describe an unusual case of extra-renal calyces with six long calyces arising from a suspected multicystic dysplastic kidney that was successfully managed laparoscopically.

Volumetric parameters on FDG PET can predict early intrahepatic recurrence-free survival in patients with hepatocellular carcinoma after curative surgical resection

PURPOSE

This study assessed the prognostic values of volumetric parameters on ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in predicting early intrahepatic recurrence-free survival (RFS) after curative resection in patients with hepatocellular carcinoma (HCC).

METHODS

A retrospective analysis was performed on 242 patients with HCC who underwent staging FDG PET and subsequent curative surgical resection. The tumor-to-non-tumorous liver uptake ratio, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the HCC lesions on PET were measured. The prognostic values of clinical factors and PET parameters for predicting overall RFS, overall survival (OS), extrahepatic RFS, and early and late intrahepatic RFS were assessed.

RESULTS

The median follow-up period was 54.7 months, during which 110 patients (45.5%) experienced HCC recurrence and 62 (25.6%) died. Patients with extrahepatic and early intrahepatic recurrence showed worse OS than did those with no recurrence or late intrahepatic recurrence (p < 0.001). Serum bilirubin level, MTV, and TLG were independent prognostic factors for overall RFS and OS (p < 0.05). Only MTV and TLG were prognostic for extrahepatic RFS (p < 0.05). Serum alpha-fetoprotein and bilirubin levels, MTV, and TLG were prognostic for early intrahepatic RFS (p < 0.05) and hepatitis C virus (HCV) positivity and serum albumin level were independently prognostic for late intrahepatic RFS (p < 0.05).

CONCLUSION

Intrahepatic recurrence showed different prognoses according to the time interval of recurrence in which early recurrence had as poor survival as extrahepatic recurrence. MTV and TLG on initial staging PET were significant independent factors for predicting early intrahepatic and extrahepatic RFS in patients with HCC after curative resection. Only HCV positivity and serum albumin level were significant for late intrahepatic RFS, which is mainly attributable to the de novo formation of new primary HCC.

Correlation between KRAS mutation and 18F-FDG uptake in stage IV colorectal cancer

PURPOSE

The purpose of this study is to evaluate the correlation between KRAS mutation, ¹⁸F-FDG uptake, and metastatic pattern in advanced stage colorectal cancer (CRC) patients.

METHODS

Medical records of stage IV CRC patients who underwent ¹⁸F-FDG PET/CT for staging and KRAS mutation analysis were selected. On PET scans, a volume of interest (VOI) was drawn on the primary lesion. ¹⁸F-FDG indices (SUVmax, SUVmean, MTV, TLG) of the primary lesions were obtained and correlated with KRAS mutation of the primary lesion. Also, metastatic sites were recorded. Association between metastatic pattern and KRAS expression and FDG indices were analyzed.

RESULTS

KRAS mutation was positive in 40 (43%) patients. Evaluation of FDG indices showed that higher SUVmax (14.0 vs. 11.2, p = 0.004), higher SUVmean (5.3 vs. 4.7, p = 0.005), and higher TLG (301.4 vs. 205.5, p = 0.023) were predictive of KRAS mutation compared to wild-type (WT) KRAS. Lung metastasis was more frequently involved in patients with KRAS mutation (50.0% vs. 22.6%, p = 0.006), and liver metastasis was more frequently involved in patients with WT KRAS (81.1% vs. 55.0%, p = 0.007). Multivariate analysis showed that  primary tumor location (OR 3.92, p = 0.07) and KRAS mutation (OR 2.45, p = 0.09) were significant factors in lung metastasis model.

CONCLUSION

KRAS mutation patients had more frequent lung metastasis and had higher ¹⁸F-FDG uptake compared to WT KRAS in stage IV CRC.

Prognostic Value of Pretreatment Metabolic Tumor Volume and Total Lesion Glycolysis Using 18F-FDG PET/CT in Patients With Metastatic Renal Cell Carcinoma Treated With Anti-Vascular Endothelial Growth Factor-Targeted Agents

PURPOSE

The aim of this study was to evaluate the prognostic value of pretreatment metabolic tumor volume (MTV) and total lesion glycolysis (TLG) using F-FDG PET/CT in patients with metastatic renal cell carcinoma (RCC) after treatment with anti-vascular endothelial growth factor-targeted agents.

METHODS

Fifty-six patients with metastatic RCC who underwent F-FDG PET/CT for staging and recurrence evaluation were retrospectively enrolled. SUVmax, MTV, and TLG were measured using F-FDG PET/CT in all patients. The highest SUV in all the metastatic RCC lesions of each patient was defined as SUVmax. Metabolic tumor volume was defined as the total tumor volume greater than 40% of SUVmax. Total lesion glycolysis was calculated as (MTV) · (SUVmean). The prognostic significance of PET/CT parameters and clinical factors for progression-free survival (PFS) and overall survival (OS) were evaluated by univariate and multivariate analyses, along with other clinical factors.

RESULTS

The most common organ for metastases was lung (35 patients). In the univariate analysis, hypercalcemia, time from diagnosis to treatment, SUVmax, MTV, and TLG were significant prognostic factors affecting PFS (P < 0.05), and Karnofsky score, hypercalcemia, time from diagnosis to treatment, SUVmax, MTV, and TLG were significant prognostic factors affecting OS (P < 0.05). In the multivariate analysis, hypercalcemia, MTV, and TLG were independent prognostic factors affecting PFS (P < 0.05), and hypercalcemia, time from diagnosis to treatment, MTV, and TLG were independent prognostic factors affecting OS (P < 0.05). In subgroup analyses, the high MTV or TLG groups showed poor prognosis for PFS and OS in patients with intermediate or poor risk.

CONCLUSIONS

Metabolic tumor volume and TLG are independent prognostic factors for predicting PFS and OS in patients with metastatic RCC. Furthermore, MTV and TLG could provide additional prognostic information in patients with clinically high-risk metastatic RCC treated with anti-vascular endothelial growth factor-targeted therapies.

Regulation of Acetate Utilization by Monocarboxylate Transporter 1 (MCT1) in Hepatocellular Carcinoma (HCC)

Altered energy metabolism is a biochemical fingerprint of cancer cells. Hepatocellular carcinoma (HCC) shows reciprocal [18F]fluorodeoxyglucose (FDG) and [11C]acetate uptake, as revealed by positron emission tomography/computed tomography (PET/CT). Previous studies have focused on the role of FDG uptake in cancer cells. In this study, we evaluated the mechanism and roles of [11C]acetate uptake in human HCCs and cell lines. The expression of monocarboxylate transporters (MCTs) was assessed to determine the transporters of [11C]acetate uptake in HCC cell lines and human HCCs with different [11C]acetate uptake. Using two representative cell lines with widely different [11C]acetate uptake (HepG2 for high uptake and Hep3B for low uptake), changes in [11C]acetate uptake were measured after treatment with an MCT1 inhibitor or MCT1-targeted siRNA. To verify the roles of MCT1 in cells, oxygen consumption rate and the amount of lipid synthesis were measured. HepG2 cells with high [11C]acetate uptake showed higher MCT1 expression than other HCC cell lines with low [11C]acetate uptake. MCT1 expression was elevated in human HCCs with high [11C]acetate uptake compared to those with low [11C]acetate uptake. After blocking MCT1 with AR-C155858 or MCT1 knockdown, [11C]acetate uptake in HepG2 cells was significantly reduced. Additionally, inhibition of MCT1 suppressed mitochondrial oxidative phosphorylation, lipid synthesis, and cellular proliferation in HCC cells with high [11C]acetate uptake. MCT1 may be a new therapeutic target for acetate-dependent HCCs with high [11C]acetate uptake, which can be selected by [11C]acetate PET/CT imaging in clinical practice.