High Standardized Uptake Value Research Articles

Is There Novel 18F-FDG Biodistribution in the Digital PET/CT Era? A Real-World Data Analysis.

Background: This retrospective multicenter study investigated the biodistribution of Fluorodeoxyglucose (18F-FDG) in the positron emission tomography (PET)/computed tomography (CT) in digital PET/CT (dPET) compared to analog PET/CT (aPET), focusing differences in physiological uptake in reference and small structures across various scanner models. Materials and Methods: One hundred thirty patients with similar preimaging conditions underwent both dPET and aPET imaging within 6 months. Visual evaluations and paired comparative analyses of semiquantitative parameters were performed for small and reference structures. Results: 18F-FDG uptake was higher in both reference and small structures for dPET compared to three different aPET scanners. The Siemens mCT20-4R (mCT20) demonstrated comparable results to dPET. Notably, mCT20 had higher standardized uptake value (SUVmax) for the conus medullaris (CM) (3.20 vs. 2.76). CM was most highly visible with dPET on visual evaluation by physicians. Conclusions: Digital PET/CT provides higher SUV values in both small and reference structures. This leads to improved visualization of 18F-FDG physiological biodistribution. Given the growing adoption of dPET technology, these advancements should be carefully considered in image interpretation and clinical research.

Does FDG PETCT have a predictive value for neoadjuvant chemotherapy response in nonmetastatic breast cancer?

A pathological complete response (pCR) rate after neoadjuvant chemotherapy (NAC) is important for the prognosis of early-stage breast cancer. The prediction of an NAC response plays a key role in managing neoadjuvant treatment. The aim of this study is to investigate the predictive value of the baseline PETCT FDG (F-18 fluoro-deoxy-glucose (FDG) positron emission tomography/computed tomography) SUVmax (the maximum standardized uptake value) for pCR after NAC in early-stage breast cancer. The patients who performed PETCT before NAC were included in this retrospective study. The basal PETCT SUVmax values were divided into two categories based on the cutoff points of ≥ 8.77 or < 8.77, namely the low SUV max group and the high SUV max group. These two groups were compared according to the general characteristics. The impact of the PETCT SUVmax values on pCR was determined with logistic regression analyses. One hundred forty-eight patients who performed PETCT before NAC were included in this retrospective study. Eighty-one patients were in the low SUV max group and 67 patients were in the high SUVmax group. The pCR trended toward a higher rate in the high SUVmax group than in low SUVmax group but it was not statistically significant (p = 0.052). The baseline PETCT SUVmax value was an independent predictive factor for pCR. (p = 0.025). PETCT SUVmax may be a factor for the predicting complete response to neoadjuvant treatment in early-stage breast cancer.

Better cardiometabolic/inflammatory profile is associated with differences in the supraclavicular adipose tissue activity of individuals with T2DM.

Brown adipose tissue (BAT), located in the supraclavicular region, has been associated with a better cardiometabolic profile and reduced risk of developing non-communicable chronic diseases (NCD), in addition to being associated with a healthier phenotype in obesity. However, it is unknown whether greater supraclavicular adipose tissue activity could be associated with a healthier metabolic profile in people already diagnosed with type 2 diabetes (T2DM). Thus, the present work evaluated if supraclavicular adipose tissue activity is associated with metabolic and molecular markers in individuals with T2DM. Based on a cluster study, individuals with T2DM were divided into groups according to high or low-standard uptake value (SUV) evaluated in the supraclavicular adipose tissue area by [18F]-fluorodeoxyglucose and positron emission tomography-computed tomography (18F-FDG-PET/CT) after mild cold exposure). Functional, biochemical, inflammatory, and molecular markers were measured. When we evaluated the whole sample, women showed higher SUV, which favored a difference between groups in sex-related markers. On the other hand, volunteers in the high-SUV group showed lower BMI, monocytes count, triglycerides/glucose index (TYG-index) and z score of metabolic syndrome (MS) values, as well as lower triglycerides, and VLDL concentrations. Moreover, they also had enhanced expression of thermogenic genes in subcutaneous fat. When analyzing only women, the differences in markers associated with sex disappear, and a lower count of leukocytes, platelets, along with lower TYG-index, z score of MS values, and triglycerides, VLDL, LDL, and TNFα concentrations were observed in women with the high SUV. In addition, higher expression of thermogenic genes and BECN1 were detected. Higher supraclavicular adipose tissue SUV in individuals with T2DM is associated with a better cardiometabolic/inflammatory profile and expression of thermogenic genes. UTN: U1111-1202-1476 - 08/20/2020.

Radiology–pathology correlation of hormonal subtypes of breast cancer based on mammography, ultrasound, and PET imaging

BackgroundBreast cancer is one of the most common cancers among the female population globally and a major cause of death due to cancers among women. It has been classified into histopathological, hormonal, and molecular subtypes based on hormone receptor status. Their management involves a multidisciplinary approach depending on these subtypes, TNM staging, tumour size, and site. The purpose of this study was to assess the correlation between ultrasound and mammography characteristics and the maximum standardized uptake value on PET with hormonal subtypes of breast cancer.MethodsIt was a retrospective study from a single-centre data available for 8 months. In this study, 5 hormonal subtypes were considered; Luminal A, Luminal B, Luminal HER2-positive subtype, HER2-enriched subtype, and triple-negative subtype. The morphology of the lesions analysed on mammography and sonography and the SUV max value on PET were considered for analyses. The prediction performance of these features for the hormonal subtypes of breast cancers was then analysed.ResultsLuminal A and B subtypes of breast cancer had indistinct margins with posterior acoustic shadowing on ultrasound. Triple-negative subtypes were well-circumscribed lesions with posterior acoustic enhancement on ultrasound. HER2-positive lesions characteristically had pleomorphic microcalcifications with mixed posterior acoustic features on mammography. On PET, HER2-enriched cases had the highest SUV, and the Luminal A subtype had the lowest SUV.ConclusionAccording to our observations, there are certain typical morphological imaging characteristics for each hormonal subtype of breast cancer. These imaging modalities may help radiologists and clinicians in stratifying their patients for prognostication and better management.

Dual-Tracer 18 F-FDG and 68 Ga-PSMA PET/CT Imaging of Heterogeneous Phenotypes of Metastatic Castration-Resistant Prostate Cancer for Predicting Response to Novel Hormone Therapy.

This study evaluated interlesion heterogeneity in prostate cancer using dual-tracer imaging (PSMA and FDG) and explored its predictive value for novel hormone therapy (NHT). A total of 205 prostate cancer patients (23 biochemical recurrences, 68 metastatic castration-sensitive prostate cancers, 114 metastatic castration-resistant prostate cancers [mCRPC]) who underwent dual 18 F-FDG and 68 Ga-PSMA PET/CT imaging were retrospectively analyzed. Among them, 62 mCRPC patients received NHT. Patients were classified into 3 groups: PSMA+FDG-, PSMA+FDG+, and PSMA-FDG+. SUV ratio , the ratio of PSMA-SUV max to FDG-SUV max , was evaluated for its predictive value on progression-free survival (PFS). The proportion of PSMA+FDG- patients decreased from biochemical recurrence to mCRPC stages, whereas FDG+ cases increased significantly ( P = 0.001). In the NHT cohort, group 3 (PSMA-FDG+) had significantly shorter median PFS than group 1 (133 vs 497 days; P = 0.027). In group 2, patients with a high SUV ratio had better median PFS than those with a low SUV ratio (368 vs 147 days; P = 0.031). Dual-tracer imaging reveals interlesion heterogeneity in prostate cancer, and SUV ratio may help predict early response to NHT.

Combined [18F]-Fluorodeoxyglucose Positron Emission Tomography-MR Imaging: A Promising Tool for Diagnostics of Small Bowel Crohn’s Disease

Introduction: Diagnostics of small bowel Crohn’s disease (CD) can be difficult. Combined positron emission tomography-magnetic resonance enterography (PET-MRE) can be used to evaluate intestinal metabolism, but clinical use has been limited due to accessibility, costs, absence of standardized methods, and diagnostic thresholds. Our aim was to show that combined PET-MRE can be used to diagnose active small bowel CD. Methods: We performed a fusion PET-MRE scan with [18F]-FDG tracer to 30 patients with suspected small bowel CD in colonoscopy. Standardized uptake values (SUVs) were measured from small bowel. The diagnosis was confirmed with small bowel capsule endoscopy. Clinicians chose appropriate medication to each patient blinded from SUV results. Endoscopic, laboratory, and MRE findings were investigated in relation to SUV. Results: Fusion PET-MRE outperformed MRE in diagnostic accuracy. Patients diagnosed with CD (N = 24) had higher SUV than patients not diagnosed with CD (N = 6) (3.34 vs. 1.84, p = 0.022). A diagnostic cut-off at SUV at 2.5 could be used (AUROC = 0.81). A higher SUV predicts need for immunosuppressive medication (p = 0.0026) and biologics (p = 0.0005). SUV correlates positively with Simple Endoscopic Score for Crohn’s Disease (SES-CD), fecal calprotectin, and CRP and negatively with Hb and serum albumin. Conclusion: In future, [18F]-FDG PET-MRE can be used in diagnostics of small bowel CD as a safe alternative for capsule endoscopy. High SUV can predict a more progressive disease course and need for more advanced therapies.

NIMG-78. THE ROLE OF FDG PET/CT IN MANAGING DIFFUSE MIDLINE GLIOMA WITH H3K27M MUTATION: A CASE STUDY AND PATHOLOGICAL CORRELATION

Abstract The clinical utility of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in the management of high grade gliomas has been a topic of ongoing debate, with limited cases reported that correlated FDG PET/CT findings with pathology, particularly in diffuse midline glioma with HdK27M mutation cases. We present the case of a 24-year-old male patient with diffuse midline glioma with H3K27M mutation centered in the left thalamus. Head FDG PET/CT was used for clinical management decisions with pathological correlation. Patient had stable follow up brain magnetic resonance images(MRIs) after initial Stupp protocol treatment comprised 6-week radiation therapy with concurrent temozolomide, followed by 12 cycles of adjuvant temozolomide. Despite stable MRI scans, subsequent evaluation using FDG PET/CT demonstrated a high standardized uptake value (SUV) of 13.8 that prompted craniotomy and partial resection of the lesion to confirm tissue diagnosis. Pathological findings confirmed the persistence of densely cellular malignant glioma, but with Ki-67 proliferation index of 4-5%. Following the surgery, the patient was closely monitored with surveillance MRIs for approximately four months post-surgery and follow up MRI’s showed slow growth of the tumor prompting additional therapeutic interventions. This case is an example of FDG PET/CT and pathological correlation and highlights the potential role of FDG PET/CT as an adjunctive imaging tool in the management of high grade gliomas.

Perioperative Observations and Outcome in Surgical Treatment of Malignant Peripheral Nerve Sheath Tumors.

This retrospective observational study aimed to investigate the perioperative outcome in Malignant Peripheral Nerve Sheath Tumors (MPNSTs) with and without relation to Neurofibromatosis Type 1 (NF1) and to detect possible influencing factors. Clinical reports, histopathological evaluations, imaging, and treatment characteristics were reviewed in 35 operated MPNSTs in 33 patients. Possible predictive valuables included disease type, preoperative tumor volume, SUV and MIB-1 proliferation index, resection margins, the presence of metastasis, and whether radio-/chemotherapy was received. Patients with NF1 were younger (mean age: 29 ± 13, 8-54 years) than sporadic cases (mean age: 45 ± 13, 24-67 years) and exhibited significantly larger preoperative tumor volumes (mean 299 vs. 18 cm3, p = 0.048). Most tumors were located in the facial/cervical/neck area (34%, n = 12), followed by the trunk (31%, n = 11), lower extremity (17%, n = 6), upper extremity (14%, n = 5), and intraspinal area (3%, n = 1). NF1-associated MPNSTs appeared predominantly on the trunk (39%) and sporadically in the facial/cervical/neck area (50%). Complete resection was possible in 66% and an improvement in or stability of function was achieved in most cases (motor 69%, sensory 74%), as well as a decrease in pain intensity (63%). NF1-associated MPNSTs exhibited more severe pain scores (median VRS scale 2, p = 0.002) compared to sporadic tumors (median VRS scale 0.5). Sporadic MPNSTs located at the head/facial/brachial plexus and upper extremities exhibited better preoperative functions compared to those on the lower extremities. In 12 cases with available [18F]FDG PET, the mean preoperative SUV (9.8 ± 7.2) positively correlated with the mean maximum MIB-1 index (34 ± 26%, p = 0.005) and the mean preoperative tumor volume (474.7 ± 68.6 cm3, p = 0.047). The overall survival (OS) was significantly longer in tumors with higher resection extents (R0, p = 0.01) and without accompanying metastasis (p = 0.046), and tended to be longer, but not significantly so, in sporadic MPNSTs. In six and seven tumors, with R1/R2 resection margins and present metastasis, respectively, solid or combined neo-/adjuvant radio-/chemotherapy led to a significantly shorter OS (p = 0.014). NF1-associated MPNSTs have larger tumor volumes, higher SUVs and MIB-1 proliferation indices, and a shorter overall survival period. Nevertheless, surgery can improve symptoms, particularly medication-resistant pain, and should also be considered in advanced disease for symptom control/improvement.

Does High Standard Uptake Value on Positron Emission Tomography Preclude Sublobar Resection in Stage IA Non-Small Cell Lung Cancer ≤2cm?

Recent randomized trials have shown equivalent survival after sublobar resection vs lobectomy in patients with clinical stage IA non-small cell lung cancer (NSCLC) ≤2 cm. High maximum standard uptake value (SUVmax) is a known risk factor in NSCLC, yet limited data exist on whether a high SUV should preclude a sublobar resection. This study aimed to determine whether there is an association between SUVmax and survival based on the extent of parenchymal resection. A retrospective review of a prospectively maintained institutional database was conducted to identify patients with clinical stage IA NSCLC ≤2 cm (2011-2020) treated with sublobar resection or lobectomy. The primary outcome was cancer-specific survival (CSS). Secondary outcomes were overall survival and disease-free survival. There were 543 patients identified; 36.8% had sublobar resection and 63.2% had lobectomy. Baseline characteristics were similar. Patients who had sublobar resection hadsignificantly worse Eastern Cooperative Oncology Group performance status and higher rates of comorbidities. The 5-year CSS, overall survival, and disease-free survival for the wholecohort were similar between sublobar resection and lobectomy. A receiver operating characteristic curve estimated the SUVmax cutoff point to be 4.15. For the whole cohort, patients with SUVmax >4.15 had worse CSS compared with SUVmax ≤4.15. However, there was no significant difference in 5-year CSS after sublobar resection vs lobectomy in patients with SUVmax ≤4.15 (98% in both groups; P= .77) or patients with SUVmax >4.15 (90% vs 94%, respectively; P= .12). SUVmax may not be a useful clinical determinant of the extent of parenchymal resection in patients with cT1 N0 NSCLC ≤2 cm. Patients treated by sublobar resection had comparable survival to lobectomy, irrespective of positron emission tomography avidity.

52Mn-labelled Beta-cyclodextrin for Melanoma Imaging: A Proof-of-concept Preclinical Study.

As prostaglandin E2 (PGE2) and its receptors (EP2) are over-expressed on tumor cells and microenvironment, radiolabeled cyclodextrins targeting such biomolecules are valuable vector candidates in molecular cancer diagnostics. Using experimental melanoma models, we evaluated the in vivo imaging behavior of novel Manganese-52-labeled (52Mn) randomly methylated beta-cyclodextrin ([52Mn]Mn-DOTAGA-RAMEB) and compared it with the following well-established tumor-specific probes: melanocortin-1 receptor (MC1-R)-affine [68Ga]Ga-DOTA-NAPamide and PGE2 selective [68Ga]Ga-DOTAGA-RAMEB cyclodextrin. Post-injection of [68Ga]Ga-DOTA-NAPamide, [68Ga]Ga-DOTAGA-RAMEB, and [52Mn]Mn-DOTAGA-RAMEB into MC1-R positive B16F10 melanoma-bearing mice, tumor radio-pharmaceutical uptake was quantified in vivo and ex vivo using preclinical positron emission tomography (PET) and high-performance gamma counter. Although all tracers performed well in tumor identification, the highest standardized uptake values were detected in the [68Ga]Ga-DOTA-NAPamide scans. Corresponding to the ex vivo data, meaningful [52Mn]Mn-DOTAGA-RAMEB accumulation 1 h post-injection confirmed the tumor-targeting potential of the tracer. Temporal changes in PGE2/EP2 expression of the neoplasms may explain the significant differences observed between the tumor uptake of the two cyclodextrin probes and that of the 52Mn-labelled compound measured 1 h, 4 h, and 3 days post-injection (p≤0.01, p≤0.05). Although further pharmacokinetical optimization may be required, 52Mn-labelled cyclodextrin holds potential in melanoma diagnostics and the PET-based longitudinal assessment of tumor-associated PGE2/EP2 expression.

The utility of PET-CT in baseline and sequential characterisation of Pulmonary Pleomorphic Carcinoma

Pulmonary Pleomorphic Carcinomas (PPCs) represent a rare and aggressive subtype of Non-Small Cell Lung Cancer (NSCLC) that can only be definitively diagnosed on a surgical specimen. This study utilised PET-CT to evaluate radiological characteristics of PPCs. This study retrospectively evaluated the radiological characteristics of PCCs diagnosed in St James’s Hospital Dublin between 2012-2023. Computed Tomography (CT) and Positron Emission Tomography (FDG-PET) imaging features (size, location, density, shape, invasion, and growth kinetics) and standard uptake value for each lesion were evaluated. 39 PCCs were identified with a mean age of 66.5 years (range: 49-82 years). FDG-PET was performed in all 39 cases. Tumours demonstrated a high FDG uptake at baseline with a mean (SUV) of 12.6 (range: 1.4 - 36.9). A second interval PET-CT on average 3.3 months after the first in 3 cases demonstrated over 120% increase in SUV. The mean tumour size was 4.3 cm (range: 1.0 - 14.5 cm). Tumours developed rapid interval growth, reaching a mean maximum diameter of 6.6 cm (53.4%) within a mean of 2.1 months. Tumours were predominantly located in the upper lobe (71.8 %) and displayed necrotic features in 53.8 % of cases. 82.1% of tumours invaded the mediastinum. This study describes the largest cohort of Pulmonary Pleomorphic Carcinoma in the literature. Tumours demonstrate a high SUV on baseline imaging and demonstrate rapid growth on interval imaging and central necrosis. Please click on the 'PDF' for the full abstract!

Feasibility of Biology-guided Radiotherapy (BgRT) Targeting Fluorodeoxyglucose (FDG) avid liver metastases

IntroductionBiology-guided radiotherapy (BgRT) is a novel radiation delivery approach utilizing fluorodeoxyglucose (FDG) activity on positron emission tomography (PET) imaging performed in real-time to track and direct RT. Our institution recently acquired the RefleXion X1 BgRT system and sought to assess the feasibility of targeting metastatic sites in various organs, including the liver. However, in order for BgRT to function appropriate, adequate contrast in FDG activity between the tumor and the background tissue, referred to as the normalized SUV (NSUV), is necessary for optimal functioning of BgRT.MethodsWe reviewed the charts of 50 lung adenocarcinoma patients with liver metastases. The following variables were collected: SUVmax and SUVmean for each liver metastasis, SUVmean and SUVmax at 5 and 10 mm radially from the lesion, and NSUV at 5 mm and 10 mm (SUVmax of the liver metastasis divided by SUV mean at 5 mm at 10 mm respectively).Results82 measurable liver metastases were included in the final analysis. The average SUVbackground of liver was 2.26 (95% confidence interval [CI] 2.17–2.35); average SUVmean for liver metastases was 5.31 (95% CI 4.87–5.75), and average SUVmax of liver metastases was 9.19 (95% CI 7.59–10.78). The average SUVmean at 5 mm and 10 mm radially from each lesion were 3.08 (95% CI 3.00-2.16) and 2.60 (95% CI 2.52–2.68), respectively. The mean NSUV at 5 mm and 10 mm were 3.13 (95% CI 2.53–3.73) and 3.69 (95% CI 3.00-4.41) respectively. Furthermore, 90% of lesions had NSUV greater than 1.45 at 5 mm and greater than 1.77 at 10 mm.ConclusionsThis is the first study to comprehensively characterize FDG contrast between the liver tumor and background, referred to as NSUV. Due to the high background SUV normally found in the liver, this work will be valuable for guiding optimization of BgRT for treating liver metastases in the future using the RefleXion® X1 and potentially other similar BgRT platforms.

Relationships between postoperative recurrences and standardized uptake value on 18F-fluorodeoxyglucose-positron emission tomography in patients with resectable and borderline resectable pancreatic ductal adenocarcinoma who underwent curative pancreatic resection after neoadjuvant chemoradiotherapy

BackgroundThis study aimed to examine postoperative recurrence after curative pancreatic resection following neoadjuvant chemoradiotherapy (NACRT) in patients with resectable (R-) and borderline resectable (BR-) pancreatic ductal adenocarcinoma (PDAC), focusing on its relationship with the standardized uptake value (SUV) on 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET). MethodThe postoperative initial recurrence patterns were examined in patients with R- and BR-PDAC who underwent NACRT followed by curative pancreatic resection. Data collected from three prospective clinical trials were retrospectively analysed. ResultsAfter a median follow-up of 29 months, 91 (60 %) of 151 patients experienced postoperative recurrence. The median recurrence-free survival (RFS) for all patients was 18 months. The sites of first recurrence were lung-only in 24 (26 %) patients, liver-only in 23 (25 %), local-only in 11 (12 %), peritoneum-only in 10 (11 %), other single site in 5 (5 %), and multiple sites in 19 (21 %) patients. Multivariate analysis identified the maximum standardized uptake value (SUVmax) on FDG-PET at diagnoses ≥5.40 (hazard ratio [HR], 1.62; 95 % confidence interval [CI], 1.01–2.61; p = 0.045) and node-positive pathology (HR, 2.01; 95 % CI, 1.32–3.08; p = 0.001) as significant predictors of RFS. Furthermore, the SUVmax at initial diagnosis and after NACRT correlated with liver metastasis. ConclusionR- and BR-PDACs with high SUV on FDG-PET at diagnosis are risk factors for postoperative recurrence. Among patients who undergo surgery after NACRT, those with a high SUVmax at diagnosis or post-NACRT require careful attention for postoperative liver recurrence.

Interim 18F-FDG-PET based response-adaptive dose escalation of proton therapy for head and neck cancer: a treatment planning feasibility study

BackgroundImage-driven dose escalation to tumor subvolumes has been proposed to improve treatment outcome in head and neck cancer (HNC). We used 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) acquired at baseline and into treatment (interim) to identify biologic target volumes (BTVs). We assessed the feasibility of interim dose escalation to the BTV with proton therapy by simulating the effects to organs at risk (OARs). MethodsWe used the semiautomated just-enough-interaction (JEI) method to identify BTVs in 18F-FDG-PET images from nine HNC patients. Between baseline and interim FDG-PET, patients received photon radiotherapy. BTV was identified assuming that high standardized uptake value (SUV) at interim reflected tumor radioresistance. Using Eclipse (Varian Medical Systems), we simulated a 10% (6.8 Gy(RBE1.1)) and 20% (13.6 Gy(RBE1.1)) dose escalation to the BTV with protons and compared results with proton plans without dose escalation. ResultsAt interim 18F-FDG-PET, radiotherapy resulted in reduced SUV compared to baseline. However, spatial overlap between high-SUV regions at baseline and interim allowed for BTV identification. Proton therapy planning demonstrated that dose escalation to the BTV was feasible, and except for some 20% dose escalation plans, OAR doses did not significantly increase. ConclusionOur in silico analysis demonstrated the potential for interim 18F-FDG-PET response-adaptive dose escalation to the BTV with proton therapy. This approach may give more efficient treatment to HNC with radioresistant tumor subvolumes without increasing normal tissue toxicity. Studies in larger cohorts are required to determine the full potential for interim 18F-FDG-PET-guided dose escalation of proton therapy in HNC.

Prognostic relevance of tumor-infiltrating CD4+ cells and total metabolic tumor volume-based risk stratification in diffuse large B-cell lymphoma.

In order to elucidate the relationship between pretreatment radiomic parameters and the proportions of various tumor-infiltrating (TI) cells, we retrospectively analyzed the association of total metabolic tumor volume (TMTV) and TI cells on biopsied tumor lesions in 171 patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). The surface markers of TI cells were analyzed by multicolor flow cytometry using a dissected single-cell suspension. In examining the correlation between TI cells and positron-emission tomography-derived parameters (maximum standardized uptake value [SUVmax], total metabolic tumor volume [TMTV], and total lesion glycolysis), intratumoral cell types minimally influenced the results, except for a weak negative correlation between CD4+ cells and SUVmax (R=-0.16, P=0.045). Even for the lesion fluorodeoxyglucose uptake at the biopsied site, CD19+ cells (indicative of malignant burden) showed only a weak correlation with the highest SUV (R=0.21, P=0.009), whereas CD3+ (R=-0.25, P=0.002) and CD4+ cells (R=-0.29, P<0.001) demonstrated a similarly weak inverse correlation. High TMTV and low TI CD4+ cells were independently associated with poor prognosis and their combination identified the most adverse population (3-year progression-free survival: 32.3%, 95% confidence interval [CI]: 19.4-53.7; 3-year overall survival: 48.4%, 95% CI: 33.6-69.6). Moreover, radiomic parameters incorporating the international prognostic index significantly improved the 3-year survival prediction (area under the curve: 0.76, P<0.05) compared to their standalone use. This study underscores the prognostic impact of TI CD4+ cells on DLBCL and suggests that integration of TMTV and TI cell analysis enhances the accuracy of prognostic prediction.

Differentiation of benign and metastatic lymph nodes in soft tissue sarcoma

Lymph node metastasis (LNM) occurs in less than 5% of soft tissue sarcoma (STS) patients and indicates an aggressive course of disease. Suspicious lymph nodes (LN) in staging imaging are a frequent topic of discussion in multidisciplinary tumor boards. Predictive markers are needed to facilitate stratification and improve treatment of STS patients. In this study, 56 STS patients with radiologically suspicious and subsequently histologically examined LN were reviewed. Patients with benign (n = 26) and metastatic (n = 30) LN were analyzed with regard to clinical, laboratory and imaging parameters. Patients with LNM exhibited significantly larger short axis diameter (SAD) and long axis diameter (LAD) vs. patients with benign LN (median 22.5 vs. 14 mm, p < 0.001 and median 29.5 vs. 21 mm, p = 0.003, respectively). Furthermore, the presence of central necrosis and high maximal standardized uptake value (SUVmax) in FDG-PET-CT scans were significantly associated with LNM (60 vs. 11.5% of patients, p < 0.001 and median 8.59 vs. 3.96, p = 0.013, respectively). With systemic therapy, a slight median size regression over time was observed in both metastatic and benign LN. Serum LDH and CRP levels were significantly higher in patients with LNM (median 247 vs. 187.5U/L, p = 0.005 and 1.5 vs. 0.55 mg/dL, p = 0.039, respectively). This study shows significant associations between LNM and imaging features as well as laboratory parameters of STS patients. The largest SAD, SUVmax in FDG-PET-CT scan, the presence of central necrosis, and high serum LDH level are the most important parameters to distinguish benign from metastatic LNs.

Imaging to predict early relapses after treatment discontinuation in patients with large vessel giant cell arteritis – A cohort study

ObjectivesTo investigate the value of [18F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) in predicting relapse after treatment discontinuation in patients with large-vessel giant cell arteritis (LV-GCA). MethodsThis study included patients with LV-GCA whose treatment was discontinued between 2018 and 2023. All patients underwent PET/CT and/or MRI at the time of treatment discontinuation in clinical remission. Qualitative and quantitative PET/CT scores, by measuring standardized uptake values (SUV), and semiquantitative MRI scores of the aorta and supraaortic vessels were compared between patients who relapsed within 4 months after treatment discontinuation and those who did not. ResultsForty patients were included (median age 67.4 years, interquartile range (IQR) 60.8–74.0; 77.5 % females). Eleven patients (27.5 %) relapsed after treatment discontinuation (time to relapse 1.9 months, IQR 1.4–3.3). Patients who relapsed were comparable to those who remained in remission with respect to the presence of active vasculitis on MRI and/or PET/CT (54.5% vs. 58.6 %, p = 1.0), the number of segments with vasculitic findings on MRI (0, IQR 0.0–1.5, vs. 2, IQR 0.0–3.0, p = 0.221) or the highest SUV artery/liver ratio on PET/CT (1.5, IQR 1.4–1.6, vs. 1.3, IQR 1.2–1.6, p = 0.505). The median number of vasculitic segments on PET/CT was 2.5 (IQR 0.5–4.5) in those with vs. 0 (IQR 0.0–1.5, p = 0.085) in those without relapse, and the PET/CT scores 4.5 (IQR 0.75–8.25) vs. 0 (IQR 0.0–3.0, p = 0.172). ConclusionPET/CT or MRI at treatment stop did not predict relapse and may not be suited to guide treatment decisions in patients with LV-GCA in remission.

The Nature of High-Risk Defining Events in Follicular Lymphoma Determines Overall Survival

Background: A subset of follicular lymphoma (FL) patients will experience a ‘high-risk defining event’ (HRDE) that portends poor survival due to early progression of disease or transformation to diffuse large B cell lymphoma (TFL). Progression of disease within 24 months (POD24) from front-line immunochemotherapy (ICT) identifies patients with a subsequent five-year OS of 50% compared to a reference group of 90% (Casulo et al. JCO 2015). Although a robust surrogate endpoint for OS in clinical trials (Casulo et al. Blood 2022), it remains to be established if the OS of patents is influenced by the nature of the HRDE. In this study, we examined whether characteristics and clinical trajectory of those with relapsed/progressive FL is the same as that of patients experiencing TFL. Methods: We conducted an international retrospective analysis of newly diagnosed FL patients requiring treatment across 14 academic centres between 2002 and 2021 in the era of rituximab and PET-CT staging. Patients were included with grade 1-3A FL requiring first-line (1L) treatment (ICT, rituximab monotherapy or radiotherapy). We excluded patients with untreated FL, de novo TFL and those with &amp;lt;24 months follow up provided they did not experience a HRDE. Baseline clinical, imaging and laboratory values, treatment details and outcomes were collected. We defined HRDE groups as persistent (relapse or progression) FL within 24 months of 1L treatment (FL24), early TFL (&amp;lt;24 months of 1L treatment) or late TFL (&amp;gt;24 months of 1L treatment). Patients not experiencing a HRDE formed the FL reference group. Landmark overall survival (OS) analysis was performed by Cox regression using risk status as a time-varying covariate for time of HRDE. For the FL reference group, landmark was defined at 24 months after 1L treatment. Results: 501 patients met the inclusion criteria and were categorised as: reference FL (n=378), FL24 (n=50), early TFL (n=28), late TFL (n=15). 24 patients who died within 24 months of 1L treatment without documentation of preceding HRDE and were omitted. Median follow up for patients alive beyond 24 months was 5.1 years. Median age at diagnosis was 60 years, 91% had ECOG performance status 0-1 and 38% were high-risk (&amp;gt;3) FLIPI. 1L chemotherapy regimens included: bendamustine (59%), CHOP (24%), CVP (8%), other (9%); a majority received rituximab (80%) vs obinutuzumab (20%). Maintenance therapy was used in 54% of pts. Expectedly, those experiencing HRDE had an inferior OS compared to the reference group (HR 5.23, p&amp;lt;0.001)(Figure 1). However, among HRDE group, median OS significantly differed: early TFL patients (3.0 yrs) and FL24 (12.6yrs)(HR 2.27, p=0.02) (Table 1). There was no difference in OS after HRDE between early TFL and late TFL ( p=0.81). Biopsy was performed in 84% of TFL cases with no difference in OS between biopsy-proven vs clinically suspected cases ( p=0.23). Multivariate OS analysis assessing HRDE and treatment demonstrated no significant interaction between HRDE group and 1L chemotherapy ( p=0.52), monoclonal antibody ( p=0.29) or maintenance therapy ( p=0.27). Several established prognostic features at baseline were enriched in patients who went on to experience HRDE including: ECOG &amp;gt;1 ( p&amp;lt;0.001), raised LDH ( p&amp;lt;0.001), advanced-stage disease (( p&amp;lt;0.011) and high risk FLIPI ( p=0.005). Baseline FDG-PET was available in 259 patients. Adverse PET metrics were enriched in only early TFL, and not FL24 or late TFL patients, including high SUV max( p=0.009), total metabolic tumor volume ( p=0.015) and total lesional glycolysis ( p=0.01). Conclusions: HRDEs after 1L treatment are associated with inferior OS in FL compared with standard-risk patients. Unlike POD24, this study demonstrates disparate clinical outcomes between patients experiencing early progression with persistent FL and those experiencing TFL. Adverse metabolic characteristics on baseline FDG-PET also suggest biological distinction between HRDE subsets. These findings have important implications for epidemiological studies, biomarker development and clinical trials aiming to improve outcomes in this underserved high-risk FL cohort.

Association between the Preoperative Standard Uptake Value (SUV) and Survival Outcomes after Robotic-Assisted Segmentectomy for Resectable Non-Small Cell Lung Cancer (NSCLC).

Lung-sparing procedures, specifically segmentectomies and wedge resections, have increased over the years to treat early-stage non-small cell lung cancer (NSCLC). We investigate here the perioperative and long-term outcomes of patients who underwent robotic-assisted segmentectomy (RAS) at an NCI-designated cancer center and aim to show associations between the preoperative standard update value (SUV) to tumor stage, recurrence patterns, and overall survival. A retrospective analysis was performed on 166 consecutive patients who underwent RAS at a single institution from 2010 to 2021. Of this number, 121 robotic-assisted segmentectomies were performed for primary NSCLC, and a total of 101 patients were evaluated with a PET-CT scan. The SUV from the primary tumor was determined from the PET-CT. The clinical, surgical, and pathologic profiles and perioperative outcomes were summarized via descriptive statistics. Numerical variables were described as the median and interquartile range because all numerical variables were not normally distributed as assessed by the Shapiro-Wilk test of normality. Categorical variables were described as the count and proportion. Chi-square or Fisher's exact test was used for association. The main outcomes were overall survival (OS) and recurrence-free survival (RFS). Kaplan-Meier (KM) curves were constructed to visualize the OS and RFS, which were also stratified according to tumor histology, the pathologic stage, and standard uptake value. A log-rank test for the equality of survival curves was performed to determine significant differences between groups. The most common postoperative complications were atrial fibrillation (8.8%, 9/102), persistent air leak (7.84%, 8/102), and pneumonia (4.9%, 5/102). The median operative duration was 168.5 min (IQR 59), while the median estimated blood loss was 50 mL (IQR 125). The conversion rate to thoracotomy in this cohort was 3.9% (4/102). Intraoperative complications occurred in 2.9% (3/102). The median hospital length of stay was 3 days (IQR 3). The median chest tube duration was 3 days (IQR 2), but 4.9% (5/102) of patients were sent home with a chest tube. The recurrence for this cohort was 28.4% (29/102). The time to recurrence was 353 days (IQR 504), while the time to mortality was 505 days (IQR 761). The NSCLC patients were divided into the following two groups: low SUV (<5, n = 55) and high SUV (≥5, n = 47). Statistically significant associations were noted between SUV and the tumor histology (p = 0.019), tumor grade (p = 0.002), lymph-vascular invasion (p = 0.029), viscera-pleural invasion (p = 0.008), recurrence (p < 0.001) and the site of recurrence (p = 0.047). KM survival analysis showed significant differences in the curves for OS (log-rank p-value 0.0204) and RFS (log-rank p-value 0.0034) between the SUV groups. Robotic-assisted segmentectomy for NSCLC has reasonable perioperative and oncologic outcomes. Furthermore, we demonstrate here the prognostic implication of preoperative SUV to pathologic outcomes, recurrence-free survival, and overall survival.

Novel SPECT/CT biomarker in transthyretin cardiac amyloidosis: correlation with myocardial amyloid load and cardiac structure and function

Abstract Background Single photon emission computed tomography/computed tomography (SPECT/CT) with determination of standardized uptake value (SUV) allows quantification of cardiac amyloid deposition. Purpose We aimed to investigate the relationship between quantitative cardiac tracer uptake determined by SPECT/CT and myocardial amyloid load, as well as cardiac structure and function in patients with transthyretin amyloid cardiomyopathy (ATTR-CM), and to identify nuclear imaging biomarkers for monitoring disease progression. Methods ATTR-CM patients underwent [99mTc]-radiolabeled diphosphono-1,2-propanodicarboxylic acid ([99mTc]-DPD) scintigraphy and SPECT/CT imaging (n=40) with determination of SUV, as well as cardiac magnetic resonance imaging (CMR, n=25) and transthoracic echocardiography (TTE, n=40). Results We observed significant correlations (r, Pearson's correlation coefficient) between SUV retention index and myocardial amyloid load [CMR extracellular volume (ECV): r=0.565, p=0.004, Figure 1A], cardiac structure [CMR interventricular septum: r=0.409, p=0.042, Figure 1B; CMR left ventricular mass index: r=0.508, p=0.010, Figure 1C], longitudinal cardiac function [TTE left ventricular global longitudinal strain (LV GLS): r=0.531, p=0.003, Figure 1D; TTE right ventricular free wall longitudinal strain: r=0.470, p=0.024, Figure 1E; TTE left atrial reservoir strain (LASr): r=-0.434, p=0.038, Figure 1F] and cardiac biomarkers [N-terminal prohormone of brain natriuretic peptide (NT-proBNP): r=0.475, p=0.004; high-sensitive troponin T (hs-TnT): r=0.358, p=0.027]. ATTR-CM patients were divided into two cohorts based on the median (4.32 mg/dL) of SUV retention index (low SUV uptake cohort: ≤4.32 mg/dL, n=20; high SUV uptake cohort: &amp;gt;4.32 mg/dL, n=20). We observed significant between-cohort differences with respect to LV ejection fraction (low SUV uptake: 51.8% vs. high SUV uptake: 46.2%, p=0.045), LV GLS (-14.5% vs. -11.1%, p=0.001), LASr (11.6% vs. 7.1%, p=0.023), NT-proBNP (1300 pg/mL vs. 2786 pg/mL, p&amp;lt;0.001), hs-TnT (42.9 ng/L vs. 62.2 ng/L, p=0.016) and 6-min walk distance (440.1 m vs. 330.1 m, p=0.022). Conclusions Using quantitative SPECT/CT imaging, we demonstrated that SUV retention index correlates with myocardial amyloid load, cardiac structure and function, and cardiac biomarkers. Our data suggest that quantitative SPECT/CT imaging with determination of SUV retention index may be a valid tool to monitor disease progression in ATTR-CM patients.Figure 1