SUVmax Ratio Research Articles

Correlation between NEN Bone Metastasis Performance and Tumor Proliferation: 112 Cases of [68Ga]Ga-DOTA-TATE Result Analysis

Purpose: This study aimed to analyze neuroendocrine neoplasm (NEN) bone metastasis (BM) and gallium-68 (⁶⁸Ga)-DOTA-TATE performance and to explore their correlation with the immunohistochemical proliferation index (Ki-67). Procedures: A total of 112 patients with BMs were screened from 1082 NEN patients who underwent [⁶⁸Ga]Ga-DOTA-TATE imaging. All patients had pathological results, and BMs were affirmed by clinical/imaging follow-up and/or histopathology. The maximum standard uptake value (SUVmax) ratio of BM to normal bone determined for each patient was used in the final analysis. Results: The incidence rate of BMs in NENs was 10.35%. BMs occurred in the spine (75%), pelvis (72.3%), ribs (58%), clavicles and scapulae (41.1%), limbs (37.5%), and skull (28.6%). Most cases were associated with liver metastases (70.5%) and lymph node metastases (65.2%) simultaneously. The SUVmax ratio of G3b (median ratio = 3.77, Ki-67 >55%) was significantly lower than that of G1 (11.43, Ki-67 ≤2%) and G2a (11.15, 3% ≤ Ki-67 ≤10%) separately (p < 0.05), while no differences were found for G2b (8.5, 11% ≤ Ki-67 ≤55%) and G3a (6.64, Ki-67 >55%) groups. In the total patients, there was a significant negative correlation between the SUVmax ratio of BMs to normal bone and Ki-67 (r = −0.267, p < 0.01). According to the changes in bone density on CT scans, the cases were divided into 4 groups: osteogenesis, osteolysis, no change, and a mixed group (median Ki-67: 6.5%, 15%, 12%, and 22.5%). The Ki-67 values were significantly different between the osteogenesis group and the other groups (p < 0.05). Conclusion: BM is present in 10.35% of NEN patients and most have simultaneous liver and/or lymph node metastases. The occurrence of osteogenesis indicates relatively good differentiation, and there is a negative correlation between SUVmax ratio of BMs and NEN proliferation.

Ga-68 PSMA PET/CT in recurrent high-grade gliomas: evaluating PSMA expression in vivo.

We planned this prospective study to evaluate PSMA expression in recurrent high-grade gliomas (rHGG), including anaplastic astrocytoma and glioblastoma using Glu-NH-CO-NH-Lys-(Ahx)-[Ga-68 (HBED-CC)]- (Ga-68 PSMA) positron emission tomography (PET), with its theranostic potential in mind. This was a prospective study enrolling patients with clinical and MRI evidence of rHGG on follow-up. Three treated cases of HGG with RN on MRI were also included as negative controls. Abnormal tracer accumulation in the brain parenchyma, more than the contralateral hemisphere was interpreted as positive study. For semiquantitative analysis, a 3D spherical region of interest (ROI) was drawn around the site of the abnormal Ga-68 PSMA uptake, and the ratio of SUVmax of tumor (T) to SUVmax of the contralateral corresponding area (TBR) was calculated. Each patients' PSMA brain PET was fused to the corresponding MRI and reviewed for concordance. Thirty patients were included in the study, a total of 49 lesions were detected on MRI, and fused PET/MR images showed increased Ga-68 PSMA uptake in all these lesions. Multifocal lesions were better appreciated on fused PET-MR images, and concordance between MRI and PET was 100 % for patient and lesion-wise detection. Recurrent glioma lesions showed SUVmax and SUVmean values (median and IQR) 6.0 (4.4-8.2) and 3.3 (2.8-3.7), respectively. Lesions labeled as radiation necrosis on MRI did not show tracer accumulation. Ga-68 PSMA has potential utility for evaluating recurrence in HGG and its potential for theranostics would encourage its use in the evaluation of these patients.

Multiparametric Magnetic Resonance Imaging, 68Ga Prostate-Specific Membrane Antigen Positron Emission Tomography-Computed Tomography, and Respective Quantitative Parameters in Detection and Localization of Clinically Significant Prostate Cancer in Intermediate- and High-Risk Group Patients: An Indian Demographic Study.

Objectives:The objective of this study was to evaluate the diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI) and 68Ga prostate-specific membrane antigen positron emission tomography–computed tomography (PSMA PET-CT) and respective quantitative parameters (Ktrans – influx rate contrast, Kep – efflux rate constant, ADC – apparent diffusion coefficient, and SUVmax ratio – prostate SUVmax to background SUVmax ratio) in detection and localization of clinically significant prostate cancer (CSPCa) in D’Amico intermediate- and high-risk group patients (prostate-specific antigen [PSA] >10 ng/ml).Methodology:The study included thirty-three consecutive adult men with serum prostate specific antigen >10ng/ml, and systematic 12 core prostate biopsy proven prostate cancer. All the 33 patients, were evaluated with mpMRI, and 68Ga PSMA PET-CT. The biopsy specimens and imaging were evaluated for 12 sectors per prostate by a predetermined scheme.Results:MpMRI Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) score ≥3 showed higher sensitivity than 68Ga PSMA PET-CT (96.3% vs. 82.4%), with similar specificity (54.5% vs. 54.5%) (n = 33 patients, 396 sectors). Combined use of MRI and 68Ga PSMA PET-CT in parallel increased sensitivity (99.5%) and NPV (98.7%) for detection of CSPCa and combined use of MRI and 68Ga PSMA PET-CT in series increased specificity (71.8%) and PPV (71.5%) (n = 33 patients, 396 sectors). ADC showed a strong negative correlation with Gleason score (r = −0.77), and the highest discriminative ability for detection and localization of CSPCa (area under curve [AUC]: 0.91), followed by Ktrans (r = 0.74; AUC: 0.89), PI-RADS (0.73; 0.86), SUVmax ratio (0.49; 0.74), and Kep (0.24; 0.66).Conclusion:MpMRI PI-RADS v2 score and 68Ga PSMA PET-CT (individually as well as in combination) are reliable tool for detection and localization of CSPCa. Quantitative MRI and 68Ga PSMA PET-CT parameters have potential to predict Gleason score and detect CSPCa.

The Added Value of 68Ga-FAPI PET/CT in Patients with Head and Neck Cancer of Unknown Primary with 18F-FDG-Negative Findings.

18F-FDG PET/CT plays an important role in locating the primary tumor for patients with head and neck cancer of unknown primary (HNCUP). Nevertheless, in some cases it can be challenging to locate the primary malignancy on 18F-FDG PET/CT scans. Because 68Ga-radiolabeled fibroblast activation protein inhibitor (FAPI) PET/CT has promising results in detecting different tumor entities, our study aimed to evaluate the performance of 68Ga-FAPI PET/CT for detecting the primary tumor in HNCUP patients with negative 18F-FDG findings. Methods: Eighteen patients (16 men and 2 women; median age, 55 y; age range, 24-72 y) with negative 18F-FDG findings were enrolled in this study. All patients underwent 18F-FDG and 68Ga-FAPI PET/CT within 1 wk. Biopsy and histopathologic examinations were performed in the sites with positive 68Ga-FAPI PET/CT findings. Results:68Ga-FAPI PET/CT detected the primary tumor in 7 of 18 patients (38.89%). Among these 7 patients, primary tumor sites included the nasopharynx (n = 1), palatine tonsil (n = 2), submandibular gland (n = 2), and hypopharynx (n = 2). The primary tumors showed moderate to intensive uptake of 68Ga-FAPI (mean SUVmax, 8.79; range, 2.60-16.50) and excellent tumor-to-contralateral normal-tissue ratio (mean SUVmax ratio, 4.50; range, 2.17-8.21). In lesion-based analysis, 65 lymph nodes and 17 bone metastatic lesions were identified. The mean SUVmax of lymph node metastases was 9.05 ± 5.29 for 18F-FDG and 9.08 ± 4.69 for 68Ga-FAPI (P = 0.975); the mean SUVmax of bone metastases was 8.11 ± 3.00 for 18F-FDG and 6.96 ± 5.87 for 68Ga-FAPI (P = 0.478). The mean tumor-to-background ratios of lymph node and bone metastases were 10.65 ± 6.59 versus 12.80 ± 8.11 (P = 0.100) and 9.08 ± 3.35 versus 9.14 ± 8.40 (P = 0.976), respectively. Conclusion: We present the first evidence, to our knowledge, of a diagnostic role of 68Ga-FAPI PET/CT in HNCUP. Our study demonstrated that 68Ga-FAPI PET/CT has the potential to improve the detection rate of primary tumor in HNCUP patients with negative 18F-FDG findings. Moreover, 68Ga-FAPI had a performance in assessing metastases similar to that of 18F-FDG.

Testicular FDG Uptake on PET/CT in Patients with Lymphoma: Correlation with Age

The purpose of this observational study was to investigate whether the standard uptake value (SUV) measurement has practical utility in distinguishing secondary testicular involvement from physiologic uptake in patients with lymphoma. A Radiology Information System (RIS) search was conducted for all PET/CT studies performed from 2010-2016 on adult male patients with a diagnosis of lymphoma. Patients with clinical or pathologic diagnosis of testicular lymphoma were excluded to undergo a separate analysis. PET/CT images of 606 patients with 1087 scans, in which 2045 testes were included in the field of view, were reviewed and measurements were performed for standardized uptake values of both testicles (SUVmax) as well as of the liver (SUVmax and SUVmean). The mean SUVmax of the testicles was 3.75 ± 0.90 (range 1.16-8.38). The mean ratio of testis SUVmax / liver SUVmean (T/L) was 1.78 ± 0.43. Trends in SUVmax and age were significant for a negative correlation by a small magnitude of 0.066 per 10 years (P < 0.001). T/L had similar changes with significant low magnitude decrease with increasing age (0.059 per 10-year increase, P < 0.001). In our separate analysis of 3 patients with clinical or pathology proven testicular lymphoma, the average pathologic SUVmax was 13.47 (range 11.39-15.97). This study has the largest known sample size for quantifying physiologic uptake in the testes. SUV measurements to quantify F-18 Fluorodeoxyglucose (FDG) uptake on PET/CT likely have practical utility in discriminating between physiologic and pathologic uptake of FDG in cases of secondary testicular lymphoma.

Dual-Time-Point 18F-Fluorocholine PET/CT Improves Characterization of Thyroid Nodules in Patients Referred for Primary Hyperparathyroidism: A Proof of Concept Study.

Thyroid nodules frequently coexist with primary hyperparathyroidism (pHPT). Because of the increasing use of 18F-fluorocholine (18F-FCH) PET/CT in patients with pHPT, evaluation of its clinical utility for thyroid nodules characterization in this population is of paramount importance. Herein, we investigate the value of dual-point 18F-FCH PET/CT in the diagnosis of thyroid cancer in patients referred for pHPT imaging who have thyroid nodules. All pHPT patients who underwent a dual-time point 18F-FCH PET/CT (at 5 and 60 minutes postinjection) between July 2019 and December 2020 were analyzed. Only those with a thyroid nodule greater than 10-mm and pathological analysis (criterion standard) were included. Nodule-to-thyroid SUVmax ratio was calculated at the 2 study points, as well as the 18F-FCH washout index (WO%). Twenty-seven patients (32 nodules) were included in this study. The final diagnoses were as follows: 27 benign nodules including 2 NIFTPs (noninvasive follicular thyroid neoplasm with papillary-like nuclear features) and 5 cancers of follicular origin. Early uptake ratio was significantly higher in malignant lesions than in benign nodules (P = 0.0008). Thyroid cancers were also characterized by a marked 18F-FCH washout index (WO% benign vs cancer: 2.9% ± 4.1% vs 45.5% ± 13.4%, P = 0.0001). Using a WO% threshold of 22.1%, 25/27 benign nodules and 5/5 malignant lesions were accurately classified (sensitivity of 100%, specificity of 92.6%, positive predictive value of 71.4%, and negative predictive value of 100%). The false-positive findings were related to the 2 NIFTPs that share similarities with thyroid cancer. Our preliminary results suggest to perform a dual-time-point PET/CT acquisition protocol in pHPT patients with uncharacterized centimeter thyroid nodules. However, the real impact of these promising results should be assessed by prospective studies on a larger cohort of patients.

Diagnostic utility of metabolic parameters on FDG PET/CT for lymph node metastasis in patients with cN2 non-small cell lung cancer

BackgroundThe aim of this study was to assess the diagnostic utility of metabolic parameters on fluorine-18-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET)/computed tomography (CT) for predicting lymph node (LN) metastasis in patients with cN2 non-small cell lung cancer (NSCLC).MethodsWe retrospectively reviewed patients who underwent surgery for cN2 NSCLC between 2007 and 2020. Those who had clinically diagnosed positive hilar and mediastinal LNs by routine CT and PET/CT imaging were investigated. To measure the metabolic parameters of LNs, the data according to maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and LN-to-primary tumor ratio of SUVmax (LPR) were examined. The diagnosis of each retrieved LN was confirmed based on histopathological examination of surgical tissue specimens. Receiver operating characteristics (ROC) curves with area under the curve (AUC) calculations and multivariate analysis by logistic regression were performed.ResultsForty-five patients with 84 clinically diagnosed positive hilar or mediastinal LNs were enrolled in the present study. Of the 84 LNs, 63 LNs were pathologically proven as positive (75%). The SUVmax, MTV, TLG, and LPR of LN metastasis were significantly higher than those of benign nodes. In the ROC analysis, the AUC value of LPR [AUC, 0.776; 95% confidence interval (CI), 0.640–0.913] was higher than that of LN SUVmax (AUC, 0.753; 95% CI, 0.626–0.880) or LN TLG3.5 (AUC, 0.746; 95% CI, 0.607–0.885). Using the optimal LPR cutoff value of 0.47, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 84.1, 66.7, 88.3, 58.3, and 79.8%, respectively. Multivariate analysis by logistic regression showed that LPR was an independent predictor for LN metastasis (odds ratio, 6.45; 95% CI, 1.785–23.301; P = 0.004). In the subgroup analysis of adenocarcinoma patients (n = 18; 32 LNs), TLG3.5 was a better predictor (AUC, 0.816; 95% CI, 0.639–0.985) than LPR (AUC, 0.792; 95% CI, 0.599–0.986) or LN SUVmax (AUC, 0.792; 95% CI, 0.625–0.959).ConclusionsOur findings suggest that LPR on FDG-PET is a useful predictor for LN metastasis in patients with cN2 NSCLC. TLG can be a good predictor for LN metastasis in patients with adenocarcinoma.

18F-FDG texture analysis predicts the pathological Fuhrman nuclear grade of clear cell renal cell carcinoma

PurposeThis article analyzes the image heterogeneity of clear cell renal cell carcinoma (ccRCC) based on positron emission tomography (PET) and positron emission tomography-computed tomography (PET/CT) texture parameters, and provides a new objective quantitative parameter for predicting pathological Fuhrman nuclear grading before surgery.MethodsA retrospective analysis was performed on preoperative PET/CT images of 49 patients whose surgical pathology was ccRCC, 27 of whom were low grade (Fuhrman I/II) and 22 of whom were high grade (Fuhrman III/IV). Radiological parameters and standard uptake value (SUV) indicators on PET and computed tomography (CT) images were extracted by using the LIFEx software package. The discriminative ability of each texture parameter was evaluated through receiver operating curve (ROC). Binary logistic regression analysis was used to screen the texture parameters with distinguishing and diagnostic capabilities and whose area under curve (AUC) > 0.5. DeLong's test was used to compare the AUCs of PET texture parameter model and PET/CT texture parameter model with traditional maximum standardized uptake value (SUVmax) model and the ratio of tumor SUVmax to liver SUVmean (SUL)model. In addition, the models with the larger AUCs among the SUV models and texture models were prospectively internally verified.ResultsIn the ROC curve analysis, the AUCs of SUVmax model, SUL model, PET texture parameter model, and PET/CT texture parameter model were 0.803, 0.819, 0.873, and 0.926, respectively. The prediction ability of PET texture parameter model or PET/CT texture parameter model was significantly better than SUVmax model (P = 0.017, P = 0.02), but it was not better than SUL model (P = 0.269, P = 0.053). In the prospective validation cohort, both the SUL model and the PET/CT texture parameter model had good predictive ability, and the AUCs of them were 0.727 and 0.792, respectively.ConclusionPET and PET/CT texture parameter models can improve the prediction ability of ccRCC Fuhrman nuclear grade; SUL model may be the more accurate and easiest way to predict ccRCC Fuhrman nuclear grade.Graphic abstract

The value of preoperative 18F-FDG PET metabolic and volumetric parameters in predicting microvascular invasion and postoperative recurrence of hepatocellular carcinoma.

Microvascular invasion (MVI) is very important in the evaluation of hepatocellular carcinoma (HCC), but diagnosis is determined by postoperative pathology; thus, preoperative noninvasive methods will play an active role. The purpose of the study was to assess the performance of metabolic parameters of preoperative 18F-fluorodeoxyglucose PET/computerized tomography (18F-FDG PET/CT) in the prediction of MVI and postoperative recurrence in primary hepatocellular carcinoma. We retrospectively collected 72 patients with HCC who have performed 18F-FDG PET/CT scan before partial hepatectomy between 2016 and 2019. We used both normal liver tissue and inferior vena cava as the reference background and combined with clinicopathological features, 18F-FDG PET/CT metabolic and volumetric indices to predict MVI and postoperative recurrence of primary HCC before surgery. Twenty-one of the 72 patients recurred, in recurrent cases showed higher maximum standard uptake value (SUVmax), TNR (ratio of tumor SUVmax to mean SUV [SUVmean] of the background tissue), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) than nonrecurrence cases (P < 0.001). All 18F-FDG PET metabolic and volumetric indices for predicting postoperative HCC recurrence were significant on receiver-operating-characteristic (ROC) curve analyses (P < 0.05). TNRIVC, TNRNL, MTVIVC, MTVNL TLGIVC and TLGNL were significant factors for predicting MVI in HCC (P < 0.05). On multivariate analyses, MVI, SUVmax, TNRIVC, TNRNL, MTVIVC, MTVNL, TLGIVC and TLGNL (P < 0.05) are independent risk factors for predicting postoperative HCC recurrence. TNRIVC is the most relevant PET/CT parameter for predicting MVI in HCC, and MTVIVC is the most valuable for predicting postoperative HCC recurrence. Moreover, the PET/CT parameters are more accurate for prognosis with inferior vena cava as a reference background than with normal liver tissue. 18F-FDG PET/CT metabolic and volumetric indices are effective predictors, and could noninvasively provide more comprehensive predictive information on MVI and postoperative recurrence of primary HCC before surgery.

The role of fluorodeoxyglucose-PET/computed tomography as a predictor of breast cancer characteristics and prognosis.

Fluorodeoxyglucose-PET/computed tomography (FDG-PET/CT) affects the management of patients with breast cancer. Our study aimed to determine the predictive ability of characteristics such as lymph node involvement or subtype and the prognostic value of pretreatment FDG-PET/CT in breast cancer. A total of 270 patients who were confirmed with breast cancer histopathologically and underwent pretreatment FDG-PET/CT were enrolled in the study. Nuclear medicine specialists obtained the readings and measured the maximum standardized uptake value (SUVmax) of the images. Tumor and lymph node SUVmax were evaluated according to lymph node metastasis and subtype status. Survival outcomes were analyzed by the Kaplan-Meier method. The lymph node SUVmax and the lymph node/tumor SUVmax ratio were significantly higher in the subgroup of patients with lymph node metastasis than in those without lymph node metastasis. High cutoff lymph node SUVmax value and lymph node/tumor SUVmax ratio were confirmed as significant predictive factors in multivariate analysis. In a comparison of the tumor SUVmax values, the more biological aggressive subtype showed higher tumor SUVmax values. In survival analysis, tumor SUVmax and lymph node SUVmax were significant predisposing factors for disease-free survival in breast cancer. In subgroup analysis, tumor SUVmax was a more significant prognostic factor in patients who had breast cancer with tumor sizes of ≤2 cm. The lymph node SUVmax was more a significant prognostic factor in patients who had breast cancer with lymph node metastasis. In this study, we showed that the SUVmax of FDG-PET/CT was a useful predictor of lymph node metastasis and breast cancer prognosis.

Functional Characterization of Adrenocortical Masses in Nononcologic Patients Using 68Ga-Pentixafor.

We aimed to investigate the diagnostic and prognostic value of 68Ga-pentixafor PET/CT imaging in noncancer patients with suspected adrenal masses. Methods: Sixty-four patients who had benign adrenal masses on CT were retrospectively included in our study. All patients underwent 68Ga-pentixafor PET/CT, and 56 of these patients subsequently underwent adrenalectomy. The subtypes of 81 adrenal tumors, including 14 nonfunctioning adrenal nodules, 4 cortisol-producing adenomas, 41 aldosterone-producing adenomas, 5 cases of suspected unilateral adrenal hyperplasia, 15 cases of idiopathic aldosterone hyperplasia, and 2 pheochromocytomas, were determined by histology or follow-up evaluations. The diagnostic efficiency of functional lateralization was calculated by visual analysis. Semiquantitative parameters of these lesions, including SUVmax, the ratio of lesional SUVmax to normal liver SUVmean (LLR), and the ratio of lesional SUVmax to contralateral adrenal tissue SUVmean (LCR), were also calculated. Dynamic analysis was also performed on 15 patients. In addition, clinical outcomes were assessed and compared in patients who underwent adrenalectomy. Results: The sensitivity and specificity of 68Ga-pentixafor PET for functional lateralization in patients with adrenocortical lesions were 97.8% (45/46) and 87.5% (14/16), respectively. The 2 pheochromocytoma lesions had lower pentixafor uptake than the normal adrenal glands. Functioning (active) adrenocortical adenomas showed an elevated SUVmax of 16.3 ± 7.9, in comparison to 4.4 ± 1.7 in nonfunctioning (inactive) adenomas and 5.5 ± 2.7 in hyperplasia lesions (P < 0.0001). To identify active adrenocortical adenomas, a cutoff of 7.1 for SUVmax showed a sensitivity of 90.9% and a specificity of 85.3% (area under receiver-operating-characteristic curve, 0.96; P < 0.0001); a cutoff of 2.5 for LLR showed a sensitivity of 95.5% and a specificity of 88.2% (area under receiver-operating-characteristic curve, 0.97; P < 0.0001); and a cutoff of 2.4 for LCR showed a sensitivity of 88.6% and a specificity of 91.8% (area under receiver-operating-characteristic curve, 0.95; P < 0.0001). The graphical influx rate constant of active adrenocortical adenomas was significantly higher than that of inactive adenomas. Uptake values for 68Ga-pentixafor were significantly higher in patients with preferable outcomes (cured/improved) (SUVmax, 15.5 ± 8.0; LLR, 6.5 ± 4.3; LCR, 6.2 ± 5.0) than in patients with nonpreferable outcomes (no improvement) (SUVmax, 4.2 ± 0.5; LLR, 1.3 ± 0.2; LCR, 1.5 ± 0.6; all P < 0.0001). Conclusion:68Ga-pentixafor PET/CT imaging exhibits great potential for noninvasive functional lateralization and characterization in patients with adrenocortical masses.

Prognostic value of inflammatory response biomarkers using peripheral blood and [18F]-FDG PET/CT in advanced NSCLC patients treated with first-line chemo- or immunotherapy

ObjectivesWe aimed to compare the prognostic value of inflammatory biomarkers extracted from pretreatment peripheral blood and [18F]-FDG PET for estimating outcomes in non-small cell lung cancer (NSCLC) patients treated with first-line immunotherapy (IT) or chemotherapy (CT). Materials and methodsIn this retrospective multicenter study, we evaluated 111 patients with advanced NSCLC who underwent baseline [18F]-FDG PET/CT before IT or CT between 2016 and 2019. Several blood inflammatory indices were evaluated: derived neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (PLR), C-reactive protein (CRP) and systemic immune-inflammation index (SII). FDG-PET inflammatory parameters were extracted from lymphoid tissues (BLR and SLR: bone marrow or spleen-to-Liver SUVmax ratios). Association with survival and relationships between parameters were evaluated using Cox prediction models and Spearman's correlation respectively. ResultsOverall, 90 patients were included (IT:CT) (51:39pts). Median PFS was 8.6:6.6 months and median OS was not reached:21.2 months. In the IT cohort, high dNLR (>3), high SII (≥1,270) and high SLR (0.77) were independent statistically significant prognostic factors for one-year progression-free survival (1y-PFS) and two-year overall survival (2y-OS) on multivariable analysis. In the CT cohort, high BLR (≥0.80) and high dNLR (>3) were associated with shorter 1y-PFS (HR 2.2, 95% CI 1.0–4.9) and 2y-OS (HR 3.4, 95CI 1.1–10.3) respectively, on multivariable analysis. Finally, BLR significantly but moderately correlated with most blood-based inflammatory indices (CRP, PLR and SII) while SLR was only associated with CRP (p < 0.01 for all). ConclusionIn advanced NSCLC patients undergoing first-line IT or CT, pretreatment blood and inflammatory factors evaluating the spleen or bone marrow on [18F]-FDG PET/CT provided prognostic information for 1y-PFS and 2y-OS. These biomarkers should be further evaluated for potential clinical application.

Dual-time point brain FDG PET to differentiate tumor progression from radionecrosis after stereotactic radiotherapy for brain metastases

Dual phase 18[F]-FDG brain PET (dual-PET) is useful to distinguish tumor recurrence (TR) from radionecrosis (RN) after stereotaxic radiosurgery (SRS) of brain metastases, when contrast-enhanced MRI is inconclusive. We aimed to compare six different visual and quantitative interpretation criteria to enhance diagnostic performances. In this retrospective french multicentric study (Clermont-Ferrand, Montpellier, Rennes), we evaluated 45 patients previously treated with SRS for BM, addressed for a dual-PET by the local neuro-oncological committees for an evolving lesion on MRI inconclusive between TR and RN, at least 3 months after the last SRS session. Dual-PET included both an “early” and a “delayed” acquisition, respectively 30 to 60 minutes and 4 to 5 hours after 18[F]-FDG injection. After measuring SUVmax values of both lesion (L) and mirror contralateral grey matter (GM) at early (1) and delayed (2) acquisitions, three quantitative metrics were calculated: ratios of L SUVmax to GM SUVmax at “early” (L1/GM1) and “delayed” (L2/GM2) acquisitions and the retention index which is the variation over time of the standardized SUVmax ratio (RI = [(Delayed-Early)/Early]). Visual analysis was also conducted using a subjective 6 points visual scale of the lesion uptake at both acquisitions. The five interpretation criteria were compared according to their area under the ROC curve (AUC), and to their diagnostic accuracy applying the best cut off value (maximizing the Youden's index) by the Cochran Q test. The final diagnosis was based on pathology, or by default radiological and clinical follow-up criteria after at least 6 months. Final diagnoses were TR for 24 patients and RN for 21 patients. There was no statistically significant difference regarding AUC between the different interpretation methods. AUC ranged from 0,78 [95 %CI 0,63; 0,89] with the L1/GM1 Ratio, to 0.85 [95 %CI 0.72; 0.94] with the L2/GM2 ratio. Visual analyses AUC were excellent at both early (0.835 [95 %CI 0.7; 0.93]) and delayed acquisitions (0.83 [95 %CI 0.69; 0.92]). There was no statistically significant difference between accuracies ( p = 0.87) ranging from 0.71 with the RI ratio to 0.80 with both the “delayed” visual and quantitative analyses. Dual-PET protocol distinguishes RN and TR after SRS with robust diagnostic performances in case of doubtful MR, with an accuracy up to 80 %.

Role of 18F-FDG PET/CT in the Management of Patients Affected by HHV-8-Associated Multicentric Castleman’s Disease

Our aim was to investigate the usefulness of 18fluorine-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the diagnosis, treatment response evaluation, and follow-up of human herpesvirus-8 (HHV-8)-associated multicentric Castleman’s disease (MCD). Fifteen patients with histologically diagnosis of HHV-8-associated MCD were retrospectively included. For all patients, a 18F-FDG PET/CT scan was performed before any treatment for diagnosis and PET/CT scans after Rituximab (4 cycles) for the evaluation of treatment response; moreover, 22 PET/CT were performed during the follow-up to check disease status. To evaluate treatment response, we applied Deauville criteria. PET/CT findings were compared with other conventional imaging (CI) findings. At diagnosis, 18F-FDG PET/CT showed an increased FDG-uptake in all cases corresponding to lymph nodes and confirming the MCD. The average SUVmax of the FDG avid lesions were 8.75, average lesion-to-liver SUVmax ratio was 3.6, and average lesion-to-blood pool SUVmax ratio was 3.9. After first-line therapy, 18F-FDG PET/CT resulted negative (Deauville score &lt; 4) in seven patients and positive in the remaining eight (Deauville score 4–5). A negative restaging PET/CT was associated with a lower risk of relapse. During follow-up, PET/CT detected the presence of relapse or progression in 5 (23%) cases with an accuracy higher than CI. 18F-FDG PET/CT seems to be an useful tool in studying HHV-8-associated MCD both at diagnosis and during follow-up.

18F-fluorodeoxyglucose positron emission tomography-based prediction for splenectomy in patients with suspected splenic lymphoma.

BackgroundDiagnostic splenectomy is often performed on patients with suspected splenic lymphoma. However, unnecessary splenectomy entails more harm than benefit for patients. Therefore, a preliminary screening method for patients with suspected splenic lymphoma that has high sensitivity and specificity is urgently needed.MethodsFrom the pathology database at Huadong and Huashan Hospital, we retrospectively identified 60 patients of suspected splenic lymphoma who underwent fluorodeoxyglucose (FDG)-positron emission tomography (PET) before receiving a splenectomy and did not show any increase in FDG uptake except in the spleen. We compared the indicators of PET-CT, such as the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and the SUVmax of 18F-FDG uptake ratios between the spleen/liver, spleen/bone marrow, and liver/bone marrow.ResultsNo significant differences were detected in SUVmax, TLG, MTV, or the SUVmax ratio of the liver/bone marrow between the lymphoma and benign groups. However, the SUVmax ratios of the spleen/liver and spleen/bone marrow were significantly higher in the lymphoma group than in the benign group (P=0.001; P=0.001). Receiver operating characteristic (ROC) curve analysis determined a spleen/liver SUVmax ratio of >2.42 and a spleen/bone marrow SUVmax ratio of >1.45 to be the indications for requiring a diagnostic splenectomy for lymphoma. Parallel testing increased the specificity and sensitivity of the test.ConclusionsPatients whose PET-CT results are inconclusive regarding the need for splenectomy may benefit from our prediction model. Future large-scale prospective clinical trials are required to verify these findings.

18F-FDG cerebellum/liver index as a prognostic factor for progression-free survival in diffuse large B-cell lymphoma.

18F-FDG PET/CT provides valuable informations regarding the prognosis of DLBCL. The aim of this study is to test a novel index based on cerebellar uptake to predict progression free survival in DLBCL patients. Data from patients with de novo DLBCL between January 2011 and December 2018 were retrospectively collected and PFS was determined. The conventional PET parameters (SUVmax and total metabolic tumor volume) and the CLIP, corresponding to the ratio of the cerebellum SUVmax over the liver SUVmean, were extracted from baseline 18F-FDG PET. Ninety-five patients were included. When using a threshold of 3.24, CLIP was a significant predictor of PFS on univariate analysis (HR 3.4, p < 0.001) with different 5-year survival rates: 68% (CLIP ≥ 3.24) versus 32% (CLIP < 3.24). Multivariate analysis confirmed the prognostic value of CLIP, as it is one of the two factors remaining significant with β2-microglobulin (HR 2.1 and 2.5 respectively, p = 0.04 and p = 0.03). A score associating β2-microglobulin and CLIP allowed to separate the population into three groups of different outcome in terms of 5-year PFS: low risk (80%), intermediate risk (42%) and high risk (17%). The CLIP derived from pre-therapeutic 18F-FDG PET seems to be an interesting predictive marker of PFS in DLBCL treated by immunochemotherapy.

Identification of specific SUVmax ratios enhances diagnostic accuracy for staging of intrathoracic nodes in lung cancer.

Studies demonstrating limited accuracy of 'positive' and 'negative' lymph nodes on fluorodeoxyglucose (FDG) PET-CT in staging for lung cancer have led to guidelines stating mediastinal nodes enlarged on computed tomography, irrespective of FDG uptake, require endobronchial ultrasound (EBUS)-transbronchial needle aspiration (TBNA). However FDG uptake occurs on a continuous spectrum and the use of standardised uptake value (SUV)max ratios, rather than a binary classification, may have improved diagnostic accuracy. This was a retrospective analysis of patients with lung cancer who had PET-CT and EBUS-TBNA in 2015-2018. Results from EBUS and the SUVmax ratio of sampled lymph nodes to mediastinal blood pool (SUVmax LN/MBP) were analysed. From 99 patients 102 malignant and 54 benign nodes were identified. The SUVmax range was 2.5-52 for malignant and 1.6-5.4 for benign nodes. The SUVmax LN/MBP was 1.3-23 for malignant and 0.7-2.3 for benign nodes. All nodes with SUVmax LN/MBP <1.3 were benign with 100% negative predictive value (NPV). All nodes with SUVmax LN/MBP >2.3 were malignant with 100% positive predictive value (PPV). In this relatively small sample, SUVmax LN/MBP <1.3 had a NPV of 100% for excluding malignant nodes and SUVmax LN/MBP >2.3 had a PPV of 100% for diagnosing malignant nodes. Using SUVmax ratios could obviate the need for staging EBUS in selected patients with resultant time and cost savings. Selecting different SUVmax ratios, chosen to provide high accuracies for the parameter of interest to change management, is a potentially powerful diagnostic tool that is overlooked when FDG uptake is only classified as 'positive' or 'negative'.

Prognostic Impact of Pretreatment 2-[18F]-FDG PET/CT Parameters in Primary Gastric DLBCL.

Background and Objectives: Primary gastric diffuse large-B cell lymphoma (DLBCL) is an aggressive lymphoma subtype with high 18F-FDG avidity but unclear criteria for 2-[18F]-FDG PET/CT in the evaluation of treatment response and prognostication. Our aim was to investigate whether the pretreatment 2-[18F]-FDG PET/CT variables may predict treatment response (at end of first-line therapy) and prognosis in primary gastric DLBCL. Materials and Methods: we included 57 patients with a diagnosis of primary gastric DLBCL and a baseline 2-[18F]-FDG PET/CT and an end of treatment PET/CT after 6 cycles of R-CHOP chemotherapy. We analyzed PET images qualitatively and semi-quantitatively by deriving the maximum standardized uptake value body weight (SUVbw), the maximum standardized uptake value lean body mass (SUVlbm), the maximum standardized uptake value body surface area (SUVbsa), lesion to liver SUVmax ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), metabolic tumor volume and total lesion glycolysis of gastric lesion (gMTV and gTLG), and total MTV (tMTV) and TLG. Survival curves were plotted according to the Kaplan–Meier analysis. Results: at a median follow up of 80 months, the median PFS and OS were 69 and 80 months. Baseline gMTV, gTLG, tMTV, and TLG were significantly higher in patients with incomplete response (partial response and progression) compared to complete response group. tMTV and TLG were confirmed to be independent prognostic factors both for PFS (p = 0.023 and p = 0.038) and OS (p = 0.038 and p = 0.026); instead, the other metabolic parameters were not related to outcome survival. Conclusions: high tMTV and TLG were significantly correlated with shorter survival (PFS and OS) and may predict incomplete response after therapy.

Correlations between DW-MRI and 18 F-FDG PET/CT parameters in head and neck squamous cell carcinoma following definitive chemo-radiotherapy.

BackgroundPosttreatment diffusion–weighted magnetic resonance imaging (DW‐MRI) and 18F‐fluorodeoxygluocose (18F‐FDG) positron emission tomography (PET) with computed tomography (PET/CT) have potential prognostic value following chemo‐radiotherapy (CRT) for head and neck squamous cell carcinoma (HNSCC). Correlations between these PET/CT (standardized uptake value or SUV) and DW‐MRI (apparent diffusion coefficient or ADC) parameters have only been previously explored in the pretreatment setting.AimTo evaluate stage III and IV HNSCC at 12‐weeks post‐CRT for the correlation between SUVmax and ADC values and their interval changes from pretreatment imaging.MethodsFifty‐six patients (45 male, 11 female, mean age 59.9 + − 7.38) with stage 3 and 4 HNSCC patients underwent 12‐week posttreatment DW‐MRI and 18F‐FDG PET/CT studies in this prospective study. There were 41/56 patients in the cohort with human papilloma virus‐related oropharyngeal cancer (HPV OPC). DW‐MRI (ADCmax and ADCmin) and 18F‐FDG PET/CT (SUVmax and SUVmax ratio to liver) parameters were measured at the site of primary tumors (n = 48) and the largest lymph nodes (n = 52). Kendall's tau evaluated the correlation between DW‐MRI and 18F‐FDG PET/CT parameters. Mann‐Whitney test compared the post‐CRT PET/CT and DW‐MRI parameters between those participants with and without 2‐year disease‐free survival (DFS).ResultsThere was no correlation between DW‐MRI and 18F‐FDG PET/CT parameters on 12‐week posttreatment imaging (P = .455‐.794; tau = −0.075‐0.25) or their interval changes from pretreatment to 12‐week posttreatment imaging (P = .1‐.946; tau = −0.194‐0.044). The primary tumor ADCmean (P = .03) and the interval change in nodal ADCmin (P = .05) predicted 2‐year DFS but none of the 18F‐FDG PET/CT parameters were associated with 2‐year DFS.ConclusionsThere is no correlation between the quantitative DWI‐MRI and 18F‐FDG PET/CT parameters derived from 12‐week post‐CRT studies. These parameters may be independent biomarkers however in this HPV OPC dominant cohort, only selected ADC parameters demonstrated prognostic significance.Study was prospectively registered at http://www.controlled-trials.com/ISRCTN58327080

Establishment and verification of a prediction model based on clinical characteristics and positron emission tomography/computed tomography (PET/CT) parameters for distinguishing malignant from benign ground-glass nodules

To develop and verify a prediction model for distinguishing malignant from benign ground-glass nodules (GGNs) combined with clinical characteristics and 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) parameters. We retrospectively analyzed 170 patients (56 males and 114 females) with GGNs who underwent PET/CT and high-resolution CT examination in our hospital from November 2011 to December 2019. The clinical and imaging data of all patients were collected, and the nodules were randomly divided into a derivation set and a validation set. For the derivation set, we used multivariate logistic regression to develop a prediction model for distinguishing benign from malignant GGNs. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of the model, and the data in the validation set were used to verify the prediction model. Among the 170 patients, 197 GGNs were confirmed via postoperative pathological examination or clinical follow-up. There were 21 patients with 27 GGNs in the benign group and 149 patients with 170 GGNs in the adenocarcinoma group. A total of five parameters, including the patient's sex, nodule location, margin, pleural indentation, and standardized uptake value (SUV) index (the ratio of nodule SUVmax to liver SUVmean), were selected to develop a prediction model for distinguishing benign from malignant GGNs. The area under the curve (AUC) of the model was 0.875 in the derivation set, with a sensitivity of 0.702 and a specificity of 0.923. The positive likelihood ratio was 9.131, and the negative likelihood ratio was 0.322. In the validation set, the AUC of the model was 0.874, which was not significantly different from the derivation set (P=0.989). This study developed and validated a prediction model based on 18F-FDG PET/CT imaging and clinical characteristics for distinguishing malignant from benign GGNs. The model showed good diagnostic efficacy and high specificity, which can improve the preoperative diagnosis of high-risk GGNs.