Tumor Standardized Uptake Value Research Articles

Prognostic value of lymph node to primary tumor standardized uptake value ratio in unresectable esophageal cancer

BackgroundUnresectable esophageal cancer harbors high mortality despite chemoradiotherapy. Better patient selection for more personalized management may result in better treatment outcomes. We presume the ratio of maximum standardized uptake value (SUV) of metastatic lymph nodes to primary tumor (NTR) in 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) may provide prognostic information and further stratification of these patients.MethodsThe patients with non-metastatic and unresectable esophageal squamous cell carcinoma (SCC) receiving FDG PET/CT staging and treated by chemoradiotherapy were retrospectively reviewed. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cut-off value for NTR. Kaplan-Meier method and Cox regression model were used for survival analyses and multivariable analyses, respectively.ResultsFrom 2010 to 2016, 96 eligible patients were analyzed. The median follow-up time was 10.2 months (range 1.6 to 83.6 months). Using ROC analysis, the best NTR cut-off value was 0.46 for prediction of distant metastasis. The median distant metastasis-free survival (DMFS) was significantly lower in the high-NTR group (9.5 vs. 22.2 months, p = 0.002) and median overall survival (OS) (9.5 vs. 11.6 months, p = 0.013) was also significantly worse. Multivariable analysis revealed that NTR was an independent prognostic factor for DMFS (hazard ratio [HR] 1.81, p = 0.023) and OS (HR 1.77, p = 0.014).ConclusionsHigh pretreatment NTR predicts worse treatment outcomes and could be an easy-to-use and helpful prognostic factor to provide more personalized treatment for patients with non-metastatic and unresectable esophageal SCC.

Primary tumor standardized uptake value (SUVmax) measured on 18F-FDG PET/CT and mixed NSCLC components predict survival in surgical-resected combined small-cell lung cancer

PurposeThe combined small-cell lung cancer (c-SCLC) is rare and has unique clinicopathological futures. The aim of this study is to investigate 18F-FDG PET/CT parameters and clinicopathological factors that influence the prognosis of c-SCLC.MethodsBetween November 2005 and October 2014, surgical-resected tumor samples from c-SCLC patients who received preoperative 18F-FDG PET/CT examination were retrospectively reviewed. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to evaluate metabolic parameters in primary tumors. The survivals were evaluated with the Kaplan–Meier method. Univariate and multivariate analyses were used to evaluate potential prognostic factors.ResultsThirty-one patients were enrolled, with a median age of 62 (range: 35 − 79) years. The most common mixed component was squamous cell carcinoma (SCC, n = 12), followed by large-cell carcinoma (LCC, n = 7), adenocarcinoma (AC, n = 6), spindle cell carcinoma (n = 4), adenosquamous carcinoma (n = 1) and atypical carcinoid (n = 1). The median follow-up period was 53.0 (11.0–142.0) months; the 5-year overall survival (OS) and progression-free survival(PFS) rate were 48.4% and 35.5%, respectively. Univariate survival analysis showed that gender, smoking history, tumor location were associated with PFS (P = 0.036, P = 0.043, P = 0.048), SUVmax and TNM stage were closely related to PFS in both Mixed SCC and non-SCC component groups (P = 0.007, P = 0.048). SUVmax, smoking history, tumor size and mixed SCC component were influencing factors of OS in patients (P = 0.040, P = 0.041, P = 0.046, P = 0.029). Multivariate survival analysis confirmed that TNM stage (HR = 2.885, 95%CI: 1.323–6.289, P = 0.008) was the most significantly influential factor for PFS. High SUVmax value (HR = 9.338, 95%CI: 2.426–35.938, P = 0.001) and mixed SCC component (HR = 0.155, 95%CI: 0.045–0.530, P = 0.003) were poor predictors for OS.ConclusionSurgical-resected c-SCLCs have a relatively good prognosis. TNM stage is the most significant factor influencing disease progression in surgical-resected c-SCLCs. SUVmax and mixed NSCLC components within c-SCLCs had a considerable influence on the survival. Both high SUVmax and mixed SCC component are poor predictors for patients with c-SCLCs.

Tumor-to-liver standard uptake ratio using fluorine-18 fluorodeoxyglucose positron emission tomography computed tomography effectively predict occult lymph node metastasis of non-small cell lung cancer patients.

We aimed to investigate predictive factors of occult lymph node metastasis and to explore the diagnostic value of various standardized uptake value (SUV) parameters using fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography computed tomography (PET/CT) in predicting occult lymph node metastasis of clinical N0 non-small cell lung cancer patients. We retrospectively analyzed PET/computed tomography parameters of tumor and clinical data of 124 clinical N0 non-small cell lung cancer patients who underwent both preoperative F-FDG PET/computed tomography and anatomical pulmonary resection with systematic lymph node dissections. The SUVmax, SUVmean, metabolic total volume, and total lesion glycolysis of the primary tumor was automatically measured on the PET/computed tomography workstation. Standardized uptake ratio (SUR) were derived from tumor standardized uptake value divided by blood SUVmean (B-SUR) or liver SUVmean (L-SUR), respectively. According to postoperative pathology, 19 (15%) were diagnosed as occult lymph node metastasis among 124 clinical N0 non-small cell lung cancer patients. On univariate analysis, carcinoembryonic antigen, cytokeratin 19 fragment, lobulation, and all PET parameters were associated with occult lymph node metastasis. The area under the receiver operating characteristic curve, sensitivity, and negative predictive value of L-SURmax were the highest among all PET parameters (0.778, 94.7%, and 98.4%, respectively). On multivariate analysis, carcinoembryonic antigen, cytokeratin 19 fragment, and L-SURmax were independent risk factors for predicting occult lymph node metastasis. Compared to L-SURmax alone and the combination of carcinoembryonic antigen and cytokeratin 19 fragment, the model consisting of three independent risk factors achieved a greater area under the receiver operating characteristic curve (0.901 vs. 0.778 vs. 0.780, P = 0.021 and 0.0141). L-SURmax showed the most powerful predictive performance than the other PET parameters in predicting occult lymph node metastasis. The combination of three independent risk factors (carcinoembryonic antigen, cytokeratin 19 fragment, and L-SURmax) can effectively predict occult lymph node metastasis in clinical N0 non-small cell lung cancer patients.

Alpha-fetoprotein and 18F-FDG standard uptake value predict tumor recurrence after liver transplantation for hepatocellular carcinoma with portal vein tumor thrombosis: Preliminary experience

Portal vein tumor thrombosis (PVTT) is regarded as a contraindication for liver transplantation (LT) in hepatocellular carcinoma (HCC). However, some of these patients may have a favorable prognosis after LT. In this study, we evaluated the biological behavior of HCC with PVTT using tumor biomarker (alpha-fetoprotein, AFP) and 18F-FDG positron emission tomography (tumor standard uptake value) to identify a subset of patients who may be suitable for LT. Seventy-five HCC-PVTT liver recipients transplanted during February 2016 and June 2018 were analyzed. Different pre-transplant prognostic factors were identified by univariate and multivariate analyses. PVTT status was identified following Vp classification (Vp1-Vp4). Three-year recurrence-free survival and overall survival rates were 40% and 65.4% in Vp2-Vp3 PVTT patients, 21.4% and 30.6% in Vp4 PVTT patients (P<0.05). Total tumor diameter >8cm, pre-transplant AFP level >1000ng/mL and intrahepatic tumor maximal standard uptake value (SUVmax-tumor >5) were independent risk factors for HCC recurrence and overall survival after LT in Vp2-3 PVTT patients. Low risk patients were defined as total tumor diameter ≤8cm; or if total tumor diameter more than 8cm, with both pre-transplant AFP level less than 1000ng/mL and intrahepatic tumor SUVmax less than 5, simultaneously. Twenty-two Vp2-3 PVTT HCC patients (46.8%) were identified as low risk patients, and their 3-year recurrence-free and overall survival rates were 67.6% and 95.2%, respectively. Patients with segmental or lobar PVTT and biologically favorable tumors defined by AFP and 18F-FDG SUVmax might be suitable for LT.

18F-fluorodeoxyglucose positron emission tomography/computed tomography in predicting overall survival of oral cavity squamous cell carcinoma: Ongoing controversy.

We aimed to retrospectively determine if initial staging 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/ CT) can predict overall survival (OS) in oral cavity squamous cell carcinoma (OCSCC), which is currently a source of ongoing controversy in the literature. Forty-six consecutive patients with nonmetastatic (Stage M0) OCSCC had 18F-FDG PET/CT prior to definitive surgical treatment followed by observation or adjuvant treatment at our institution between 2006 and 2012. The median follow-up time was 18 months (range 0.1–76 months). Univariate and multivariate analysis were used to determine the ability of imaging, pathologic, and demographic factors to predict OS. 18F-FDG PET/CT parameters were standardized uptake value (SUV) maximum and mean, metabolic tumor volume, and total lesional glycolysis (TLG) of primary tumor and regional nodes. Significant predictors of OS in the multivariate analysis were primary tumor SUV mean, nodal TLG, and age. Two-year OS of patients with primary tumor SUV mean below and above the median of 6.26 was 68% and estimated 28%, respectively. Two-year OS of patients with nodal TLG below and above median of 7.9 was 69% and 34%, respectively. Two-year OS of patients younger and older than median age of 57 was 60% and 43%, respectively. Our results suggest that 18F-FDG PET/CT may be a valuable addition to multifactorial models predicting outcome for OCSCC. Thus, continued research aiming to incorporate 18F-FDG PET/CT parameters in risk-stratification algorithms for OCSCC is warranted and should be conducted using more standardized prognostic models driven by a specific clinical question.

Prognostic Value of Lymph Node-To-Primary Tumor Standardized Uptake Value Ratio in Esophageal Squamous Cell Carcinoma Treated with Definitive Chemoradiotherapy.

We aimed to investigate the prognostic value of the relative maximum standardized uptake value (SUV) of metastatic lymph node (LN) compared with that of primary tumor (SUVLN/SUVTumor) based on a pretreatment [18F]-FDG PET/CT scan in patients with clinically node-positive esophageal squamous cell carcinoma (cN+ ESCC) treated with definitive chemoradiotherapy (dCRT). We retrospectively evaluated cN+ ESCC patients who underwent a PET/CT scan before dCRT. Time-dependent receiver operating characteristics analysis was performed to identify the optimal cutoff value for SUVLN/SUVTumor. Prognostic influences of SUVLN/SUVTumor on distant metastasis-free survival (DMFS) and overall survival (OS) were evaluated using the Kaplan–Meier method and log-rank test for univariate analysis and Cox’s proportional hazards regression model for multivariate analysis. We identified 112 patients with newly diagnosed cN+ ESCC. After a median follow-up of 32.0 months, 50 (44.6%) patients had distant failure and 84 (75.0%) patients died. Patients with high SUVLN/SUVTumor (≥ 0.39) experienced worse outcomes than low SUVLN/SUVTumor (< 0.39) (two-year DMFS: 26% vs. 70%, p < 0.001; two-year OS: 21% vs. 48%, p = 0.001). Multivariate analysis showed that SUVLN/SUVTumor was an independent prognostic factor for both DMFS (adjusted HR 2.24, 95% CI 1.34–3.75, p = 0.002) and OS (adjusted HR 1.61, 95% CI 1.03–2.53, p = 0.037). Pretreatment of SUVLN/SUVTumor is a simple and useful marker for prognosticating DMFS and OS in cN+ ESCC patients treated with dCRT, which may help in tailoring treatment and designing future clinical trials.

Preoperative 18F-FDG PET/CT tumor markers outperform MRI-based markers for the prediction of lymph node metastases in primary endometrial cancer

ObjectivesTo compare the diagnostic accuracy of preoperative 18F-FDG PET/CT and MRI tumor markers for prediction of lymph node metastases (LNM) and aggressive disease in endometrial cancer (EC).MethodsPreoperative whole-body 18F-FDG PET/CT and pelvic MRI were performed in 215 consecutive patients with histologically confirmed EC. PET/CT-based tumor standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), and PET-positive lymph nodes (LNs) (SUVmax > 2.5) were analyzed together with the MRI-based tumor volume (VMRI), mean apparent diffusion coefficient (ADCmean), and MRI-positive LN (maximum short-axis diameter ≥ 10 mm). Imaging parameters were explored in relation to surgicopathological stage and tumor grade. Receiver operating characteristic (ROC) curves were generated yielding optimal cutoff values for imaging parameters, and regression analyses were used to assess their diagnostic performance for prediction of LNM and progression-free survival.ResultsFor prediction of LNM, MTV yielded the largest area under the ROC curve (AUC) (AUC = 0.80), whereas VMRI had lower AUC (AUC = 0.72) (p = 0.03). Furthermore, MTV > 27 ml yielded significantly higher specificity (74%, p < 0.001) and accuracy (75%, p < 0.001) and also higher odds ratio (12.2) for predicting LNM, compared with VMRI > 10 ml (58%, 62%, and 9.7, respectively). MTV > 27 ml also tended to yield higher sensitivity than PET-positive LN (81% vs 50%, p = 0.13). Both VMRI > 10 ml and MTV > 27 ml were significantly associated with reduced progression-free survival.ConclusionsTumor markers from 18F-FDG PET/CT outperform MRI markers for the prediction of LNM. MTV > 27 ml yields a high diagnostic performance for predicting aggressive disease and represents a promising supplement to conventional PET/CT reading in EC.Key Points• Metabolic tumor volume (MTV) outperforms other 18F-FDG PET/CT and MRI markers for preoperative prediction of lymph node metastases (LNM) in endometrial cancer patients.• Using cutoff values for tumor volume for prediction of LNM, MTV > 27 ml yielded higher specificity and accuracy than VMRI> 10 ml.• MTV represents a promising supplement to conventional PET/CT reading for predicting aggressive disease in EC.

Is there a difference in FDG PET findings of invasive ductal carcinoma of the breast with and without coexisting DCIS?

Objective(s):Studies have reported that invasive ductal carcinoma (IDC) with coexisting ductal carcinoma in situ (DCIS) show lower metastatic potential and recurrence and better overall survival than pure IDC. In this study, we assessed F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images of patients with newly diagnosed IDC to determine if there is any difference in PET findings in IDC-DCIS and pure IDC cases.Methods:FDG PET/CT images of patients with newly diagnosed IDC of the breast who subsequently underwent breast surgery and had histopathology result in our records were further evaluated. Tumor grade, pathological staging, and presence of DCIS were noted from the histopathology results. Standardized uptake value (SUV) of the primary tumor (SUVmax and SULmax), other hypermetabolic foci in the breast, and ipsilateral normal breast were measured. Presence of axillary and distant metastases was noted. Results:Fifty seven (57) patients with IDC were included. Coexisting DCIS was present in 44 (IDC-DCIS) and not present in 13 (pure IDC) cases. Per histopathology, the primary tumor was unifocal in 33 IDC-DCIS (75%) and 12 pure IDC (92.3%) cases, and multifocal in 11 IDC-DCIS cases (25%), and 1 pure IDC case (7.7%). FDG uptake was multifocal in 20 IDC-DCIS cases (45.5%) and 1 pure IDC case (7.7%), and unifocal in 24 IDC-DCIS (54.5%), and 12 pure IDC (92.3%) cases. There was no significant difference in patient age, size of the primary tumor, SUVmax and SULmax of the primary tumor and SUVmax of the normal breast in IDC-DCIS and pure IDC cases (p>0.05). Pathology showed axillary metastasis in all 13 pure IDC (100%), and 27 IDC-DCIS (61.4%) cases. PET showed axillary uptake in 25 IDC-DCIS (56.8%), and 8 pure IDC (61.5%) cases, and abnormal/questionable distant uptake in 12 IDC-DCIS cases and 1 pure IDC case.Conclusion:In our preliminary findings, multifocal breast FDG uptake and multifocal tumor appear to be more common in IDC-DCIS than pure IDC. There is no significant difference in SUV and size of the primary tumor in IDC-DCIS and pure IDC cases. Axillary metastases appear to be more common in pure IDC than IDC-DCIS cases.

18F-fluorodeoxyglucose PET/CT as an independent predictor for patients with hepatocellular carcinoma combined with major portal vein tumor thrombus.

PurposeHepatocellular carcinoma (HCC) patients with major portal vein tumor thrombosis (mPVTT) complications were generally characterized by extremely poor prognoses. The aim of this study was to explore the role of 18F-fluorodeoxyglucose (18F-FDG) PET/CT imaging in predicting HCC complicated by mPVTT.MethodsFive hundred one HCC patients received surgery in our hospital during November 2008 to December 2014, among which 32 patients (6.4%) were diagnosed as HCC complicated by mPVTT. Six cases were excluded for reasons of complex medical conditions, including 2 cases of salvage liver transplantation, 2 cases of re-resection, 1 case of mPVTT combined with inferior vina cava tumor thrombosis, and 1 case of residual portal vein tumor thrombosis. Ultimately, 26 cases were enrolled in this study. The maximal tumor standardized uptake value (SUVmax) was identified as a predictive factor and detected. The univariate and multivariate regression analyses were performed to identify the prognostic factors for recurrence-free survival (RFS) and overall survival (OS) of HCC patients complicated by mPVTT.ResultsOur results showed that the median OS was 16 months. The 1-, 3-, and 5-year cumulative OS was 55.6%, 31.7%, and 31.7%, respectively. The multivariate regression analysis revealed that SUVmax ≥ 4.65 was the only independent risk factor for RFS and OS.ConclusionSUVmax was an independent predictor for RFS and OS of patients suffering from both HCC and mPVTT. L ow SUVmax could serve as an effective factor for selecting candidates with low recurrence risks and for helping with improving patient survival after surgical resection.

Preclinical PERCIST and 25% of SUVmax Threshold: Precision Imaging of Response to Therapy in Co-clinical 18F-FDG PET Imaging of Triple-Negative Breast Cancer Patient-Derived Tumor Xenografts.

Numerous recent works highlight the limited utility of established tumor cell lines in recapitulating the heterogeneity of tumors in patients. More realistic preclinical cancer models are thought to be provided by transplantable, patient-derived xenografts (PDXs). The inter- and intratumor heterogeneity of PDXs, however, presents several challenges in developing optimal quantitative pipelines to assess response to therapy. The objective of this work was to develop and optimize image metrics for 18F-FDG PET to assess response to combination docetaxel and carboplatin therapy in a co-clinical trial involving triple-negative breast cancer PDXs. We characterized the reproducibility of standardized uptake value (SUV) metrics to assess response to therapy, and we optimized a preclinical PERCIST paradigm to complement clinical standards. Considerations in this effort included variability in tumor growth rate and tumor size, solid tumors versus tumor heterogeneity and a necrotic phenotype, and optimal selection of tumor slices versus whole tumor. Methods: A test-retest protocol was implemented to optimize the reproducibility of 18F-FDG PET SUV thresholds, SUVpeak metrics, and preclinical PERCIST parameters. In assessing response to therapy, 18F-FDG PET imaging was performed at baseline and 4 d after therapy. The reproducibility, accuracy, variability, and performance of imaging metrics to assess response to therapy were determined. We defined an index called the Quantitative Response Assessment Score to integrate parameters of prediction and precision and thus aid in selecting the optimal image metric to assess response to therapy. Results: Our data suggest that a threshold of 25% of SUVmax (SUV25) was highly reproducible (<9% variability). The concordance and reproducibility of preclinical PERCIST were maximized at α = 0.7 and β = 2.8 and exhibited a high correlation with SUV25 measures of tumor uptake, which in turn correlated with the SUV of metabolic tumor. Conclusion: The Quantitative Response Assessment Score favors SUV25 followed by SUVpeak for a sphere with a volume of 14 mm3 (SUVP14) as optimal metrics of response to therapy. Additional studies are warranted to fully characterize the utility of SUV25 and preclinical PERCIST SUVP14 as image metrics for response to therapy across a wide range of therapeutic regimens and PDX models.

Development and Characterization of a Genetic Mouse Model of KRAS Mutated Colorectal Cancer.

Patients with KRAS mutated colorectal cancer (CRC) represent a cohort with unmet medical needs, with limited options of FDA-approved therapies. Representing 40–45% of all CRC patients, they are considered ineligible to receive anti-EGFR monoclonal antibodies that have added a significant therapeutic benefit for KRAS wild type CRC patients. Although several mouse models of CRC have been developed during the past decade, one genetically resembling the KRAS mutated CRC is yet to be established. In this study C57 BL/6 mice with truncated adenomatous polyposis coli (APC) floxed allele was crossed with heterozygous KRAS floxed outbred mice to generate an APCf/f KRAS+/f mouse colony. In another set of breeding, APC floxed mice were crossed with CDX2-Cre-ERT2 mice and selected for APCf/f CDX2-Cre-ERT2 after the second round of inbreeding. The final model of the disease was generated by the cross of the two parental colonies and viable APC f/f KRAS +/f CDX2-Cre-ERT2 (KPC: APC) were genotyped and characterized. The model animals were tamoxifen (TAM) induced to generate tumors. Micro-positron emission tomography (PET) scan was used to detect and measure tumor volume and standard uptake value (SUV). Hematoxylin and eosin (H&E) staining was performed to establish neoplasm and immunohistochemistry (IHC) was performed to determine histological similarities with human FFPE biopsies. The MSI/microsatellite stable (MSS) status was determined. Finally, the tumors were extensively characterized at the molecular level to establish similarities with human CRC tumors. The model KPC: APC animals are conditional mutants that developed colonic tumors upon induction with tamoxifen in a dose-dependent manner. The tumors were confirmed to be malignant within four weeks of induction by H&E staining and higher radioactive [18F] fluoro-2-deoxyglucose (FDG) uptake (SUV) in micro-PET scan. Furthermore, the tumors histologically and molecularly resembled human colorectal carcinoma. Post tumor generation, the KPC: APC animals died of cachexia and rectal bleeding. Implications: This model is an excellent preclinical platform to molecularly characterize the KRAS mutated colorectal tumors and discern appropriate therapeutic strategies to improve disease management and overall survival.

The metabolic clinical risk score as a new prognostic model for surgical decision-making in patients with colorectal liver metastases.

Selection for surgery in patients with colorectal liver metastases (CRLM) remains inaccurate. We evaluated if CRLM baseline metabolic characteristics, assessed by [18]F-fluorodeoxyglucose-positron emission tomography/computed tomography (18 FDG-PET/CT), could predict postoperative outcomes. In a retrospective series of patients undergoing surgery for CRLM, we defined two groups: the long-term survival (LTS) and early relapse (ER) groups, where the postoperative recurrence-free survivals were ≥5 years or <1 year, respectively. We analyzed the patients in whom baseline 18 FDG-PET/CT was available. Clinicopathologic parameters, clinical risk score (CRS), and baseline 18 FDG-PET/CT characteristics were compared between LTS and ER groups. A metabolic CRS (mCRS) was implemented, adding one point to the standard five-point CRS when the highest tumor standardized uptake values (SUVmax )/normal liver mean SUV (SUVmean(liver) ) ratios were >4.3, defining low- and high-risk mCRS by scores of 0 to 2 and 3 to 6, respectively. From a series of 450 patients operated for CRLM (mean follow-up of 58 months), we included for analysis 23 and 30 patients in the LTS and ER groups, respectively. Clinicopathologic parameters and CRS were similar in the LTS and ER groups. Median SUVmax /SUVmean(liver) ratios were higher in ER vs LTS patients (4.2 and 2.8, P = .008, respectively). mCRS was increased in ER patients (P = .024); 61% of LTS patients had low-risk mCRS and 73% of the ER patients had high-risk mCRS (P = .023). 18 FDG-PET/CT characteristics combined with traditional CRS may represent a new tool to improve selection for surgery in patients with CRLM.

Multi-Modal MR/PET Imaging of Natural Killer Cell Immunotherapy Against Glioblastoma with Correlated Histology

Hypothesis: Immunotherapies hold great promise for treatment of highly resistant cancers, such as glioblastoma (GBM). We hypothesized that high powered imaging can be effectively combined to quantitatively assess the therapeutic efficacy of human derived natural killer (hNK) cells in an orthoptic xenografted mouse model of GBM.&#x0D; Methods: Tumor take (TT) was established via fluorescence. Mice in the treatment (n=5) and control (n=4) groups were given IV hNK cells and physiological saline, respectively. MRI and PET scans were performed four and six weeks after tumor implantation. Histological slices were taken at time of death. Software analysis of tumor volume, standardized uptake value (SUV), and tumor-to-brain ratio (TBR) was conducted via Qimage and Indica Labs - HALO.&#x0D; Results: Mean growth rates are as follows: T1 volume (mL) – 4.1 in the control group vs 2.3 in treatment. T2 volume (mL) – 6.0 in control vs 2.7 in treatment. PET volume (mL) – 3.1 in control vs 2.1 in treatment, SUV (g/mL) – 5.4 in control vs 3.0 in treatment. Two-tailed t-test analysis showed statistical significance (p &lt; 0.01) in T1 volume data.&#x0D; Conclusion and Potential Impact: Treatment group mice showed a trend in reduction in growth rate of tumor volume and SUV compared to control, with a correlated lower histology TBR, suggesting effective in vivo assessment of hNK therapeutic efficacy in the mouse model of GBM via MR/PET imaging. Future trials should provide a larger population size to increase reliability, precision and power.

Prognostic Value of Lymph Node to Primary Tumor Standardized Uptake Value Ratio in Esophageal Cancer

Esophageal cancer harbors high mortality rate despite current standard concurrent chemoradiotherapy followed by operation. Thus, further stratification of the patients may offer better therapeutic outcome to those having a favorable nature of disease. We presume the lymph node to primary tumor standardized uptake value (SUVmax) ratio (NTR) in 18F-FDG PET/CT may provide further prognostic information. The patients with non-metastatic and unresectable esophageal cancer receiving 18F-FDG PET/CT staging and treated by chemoradiotherapy were retrospectively reviewed. The SUVmax of the metastatic lymph nodes and the primary tumor were collected and NTR was calculated. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cut-off value for NTR. Kaplan-Meier method and Cox proportional hazard model were used for overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS) analysis. From 2009 to 2016, 96 eligible patients were collected and analyzed. The median follow-up time was 9.72 months (1.6 to 82.6 months). The median OS was significantly higher (18.3 vs. 9.2 months, p = 0.009) in the group with NTR lower than 0.64. A significantly better median PFS (9.2 vs. 5.9 months, p = 0.022) and DMFS (31.2 vs. 9.5 months, p = 0.002) were also found in the groups with lower NTR (using 0.42 and 0.46 as cut-off values respectively). Multivariable analysis revealed that NTR was an independent prognostic factor for OS (hazard ratio [HR] 2.24, p = 0.039) and DMFS (HR 2.84, p = 0.009). High pretreatment NTR predicts worse treatment outcomes for patients with non-metastatic and unresectable esophageal cancer.

Evaluation of Lung Cancer and Neuroendocrine Neoplasm in a Single Scan by Targeting Both Somatostatin Receptor and Integrin αvβ3

This pilot study aimed to prove the complementary value of a novel Gallium-labeled heterodimeric peptide, Ga-NOTA-3P-TATE-RGD, in detection and evaluation of tumors with somatostatin receptor subtype 2 or integrin αvβ3 overexpression, including non-small cell lung cancer (NSCLC), small-cell lung cancer (SCLC), neuroendocrine tumor (NET), and neuroendocrine carcinoma (NEC). With institute review board approval and written informed consent, 32 patients with pathologically diagnosed lung cancer (18 NSCLC, 14 SCLC) and 12 patients with neuroendocrine neoplasm (8 NET, 4 NEC) patients were recruited to undergo Ga-NOTA-3P-TATE-RGD PET/CT. For comparison, the NSCLC patients also underwent Ga-NOTA-TATE PET/CT, the SCLC patients underwent Ga-NOTA-RGD PET/CT, and the neuroendocrine neoplasm patients underwent F-FDG PET/CT within 3 days. The maximum standardized uptake value (SUV) of the primary tumor (T) and mean SUV of the blood pool (B) were measured, and the T/B ratios were calculated for comparison. In the primary tumors of NSCLC, the T/B ratios of Ga-NOTA-3P-TATE-RGD were significantly higher than those of Ga-NOTA-TATE (4.54 ± 3.00 versus 4.10 ± 2.83, P = 0.0058). In SCLC, the T/B ratios of Ga-NOTA-3P-TATE-RGD were significantly higher than those of Ga-NOTA-RGD (6.06 ± 6.09 versus 2.65 ± 1.19, P = 0.0344). In NET, the T/B ratios of Ga-NOTA-3P-TATE-RGD were 36.13 ± 33.84, significantly higher than those of F-FDG (2.91 ± 1.71, P = 0.0234). In NEC, there were no significant difference between the T/B ratios of Ga-NOTA-3P-TATE-RGD (4.80 ± 0.85) and those of F-FDG (3.56 ± 0.74, P = 0.1833). This proof-of-concept study preliminarily demonstrates the efficacy of the dual targeting Ga-NOTA-3P-TATE-RGD PET/CT in the evaluation of lung cancer and neuroendocrine neoplasm in a single scan.

The metabolic clinical risk score (mCRS) as a new prognostic model for surgical decision in patients with colorectal liver metastases.

e15094 Background: Selection for surgery in patients with colorectal liver metastases (CRLM) remains poorly accurate. We evaluated if baseline metabolic characteristics of CRLM, as assessed by [18]-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18FDG-PET/CT), may predict the postoperative outcome in patients operated for CRLM. Methods: In a series of 450 patients operated for CRLM, we retrospectively identified 2 groups: The long-term survival (LTS), as defined by postoperative recurrence-free survival (RFS)≥5 years, and the early relapse groups (ER), as defined by RFS &lt; 1 year. Clinicopathologic characteristics, Clinical Risk Score (CRS) and baseline 18FDG-PET/CT metabolic parameters were analyzed. Baseline 18FDG-PET/CT was performed at the time of diagnosis of CRLM, before any preoperative treatment. Low and high-risk CRS were defined by scores of 0 to 2 and 3 to 5, respectively. Metabolic CRS (mCRS) was implemented, using 1 additional point to the standard CRS when the highest tumor standardized uptake value (SUVmax) and normal liver mean SUV (SUVmean(liver)) ratio was &gt; 4.3. Low and high-risk mCRS were defined by scores of 0 to 2 and 3 to 6, respectively. Results: We analyzed 53 patients. No difference was observed between LTS (n = 23) and ER (n = 30) groups for clinicopathologic parameters related to the primary tumor and CRLM, CRS and rates of low/high risk CRS. All metabolic parameters analyzed, including SUVmax and SUVpeak, at the exception of metabolic tumor volume, were significantly increased in ER group. Median SUVmax/SUVmean(liver) ratio was significantly increased in the ER vs LTS, respectively of 4.2 and 2.8 (p = 0.008). mCRS was significantly higher in ER as compared to LTS patients (p = 0.024), while 61% of the LTS patients had a low-risk mCRS and 73% of the ER patients had a high-risk mCRS (p = 0.023). Conclusions: Baseline 18FDG-PET/CT characteristics demonstrate an increased tumor glucose uptake in patients who rapidly recur after curative-intent surgery for CRLM. The introduction of these data into clinical risk model may represent a new tool to improve selection for surgery in patients with CRLM.

18F-FDG-PET Can Predict Microvessel Density in Head and Neck Squamous Cell Carcinoma.

Aim: Positron emission tomography (PET) with 18F-fluordeoxyglucose (18F-FDG) plays an essential role in the staging and tumor monitoring of head and neck squamous cell carcinoma (HNSCC). Microvessel density (MVD) is one of the clinically important histopathological features in HNSCC. The purpose of this study was to analyze possible associations between 18F-FDG-PET findings and MVD parameters in HNSCC. Materials and Methods: Overall, 22 patients with a mean age of 55.2 ± 11.0 and with different HNSCC were acquired. In all cases, whole-body 18F-FDG-PET was performed. For each tumor, the maximum and mean standardized uptake values (SUVmax; SUVmean) were determined. The MVD, including stained vessel area and total number of vessels, was estimated on CD105 stained specimens. All specimens were digitalized and analyzed by using ImageJ software 1.48v. Spearman’s correlation coefficient (r) was used to analyze associations between investigated parameters. p-values of <0.05 were taken to indicate statistical significance. Results: SUVmax correlated with vessel area (r = 0.532, p = 0.011) and vessel count (r = 0.434, p = 0.043). Receiver operating characteristic analysis identified a threshold SUVmax of 15 to predict tumors with high MVD with a sensitivity of 72.7% and specificity of 81.8%, with an area under the curve of 82.6%. Conclusion: 8F-FDG-PET parameters correlate statistically significantly with MVD in HNSCC. SUVmax may be used for discrimination of tumors with high tumor-related MVD.

Inter-observer and segmentation method variability of textural analysis in pre-therapeutic FDG PET/CT in head and neck cancer.

AimCharacterizing tumor heterogeneity with textural indices extracted from 18F-fluorodeoxyglucose positron emission tomography (FDG PET/CT) is of growing interest in oncology. Several series showed promising results to predict survival in patients with head and neck squamous cell carcinoma (HNSCC), analyzing various tumor segmentation methods and textural indices. This preliminary study aimed at assessing the inter-observer and inter-segmentation method variability of textural indices in HNSCC pre-therapeutic FDG PET/CT.Materials and methodsConsecutive patients with HNSCC referred in our department for a pre-therapeutic FDG PET/CT from January to March 2016 were retrospectively included. Two nuclear medicine physicians separately segmented all tumors using 3 different segmentation methods: a relative standardized uptake value (SUV) threshold (40%SUVmax), a signal-to-noise adaptive SUV threshold (DAISNE) and an image gradient-based method (PET-EDGE). SUV and metabolic tumor volume were recorded. Thirty-one textural indices were calculated using LIFEx software (www.lifexsoft.org). After correlation analysis, selected indices’ inter-segmentation method and inter-observer variability were calculated.ResultsForty-three patients (mean age 63.8±9.3y) were analyzed. Due to a too small segmented tumor volume of interest, textural analysis could not be performed in 6, 11 and 15 cases with respectively DAISNE, 40%SUVmax and PET-EDGE segmentation methods. Five independent textural indices were selected (Homogeneity, Correlation, Entropy, Busyness and LZLGE). There was a high inter-contouring method variability for Homogeneity, Correlation, Entropy and LZLGE (p<0.0001 for each index). The inter-observer reproducibility analysis revealed an excellent agreement for 3 indices (Homogeneity, Correlation and Entropy) with an intraclass correlation coefficient higher than 0.90 for the 3 methods.ConclusionsThis preliminary study showed a high variability of 4 out of 5 textural indices (Homogeneity, Correlation, Entropy and LZLGE) extracted from pre-therapeutic FDG PET/CT in HNSCC using 3 different contouring methods. However, for each method, there was an excellent agreement between observers for 3 of these textural indices (Homogeneity, Correlation and Entropy).

Technical Note: Simplified and practical pretherapy tumor dosimetry - Afeasibility study for 131 I-MIBG therapy of neuroblastoma using 124 I-MIBG PET/CT.

Radiation dose calculated on tumors for radiopharmaceutical therapy varies significantly from tumor to tumor and from patient to patient. Accurate estimation of radiation dose requires multiple time point measurements using radionuclide imaging modalities such as SPECT or PET. In this report, we show our technical development of reducing the number of scans needed for reasonable estimation of tumor and normal organ dose in our pretherapy imaging and dosimetry platform of 124 I-metaiodobenzylguanidine (MIBG) positron emission tomography/computed tomography (PET/CT) for 131 I-MIBG therapy of neuroblastoma. We analyzed the simplest kinetic data, areas of two-time point data for five patients with neuroblastoma who underwent 3 or 4 times of 124 I-MIBG PET/CT scan prior to 131 I-MIBG therapy. The data for which we derived areas were percent of injected activity (%IA) and standardized uptake value of tumors. These areas were correlated with time-integrated activity coefficients (TIACs) from full data (3 or 4 time points). TIACs are direct correlates with radiation dose as long as the volume and the radionuclide are known. The areas of %IAs between data obtained from all the two-time points with time points 1 and 2 (day 0 and day 1), time points 2 and 3 (day 1 and day 2), and time points 1 and 3 (day 0 and day 2) showed reasonable correlation (Pearson's correlation coefficient |r|>0.5) with not only tumor and organ TIACs but also tumor and organ absorbed doses. The tumor and organ doses calculated using %IA areas of time point 1 and time point 2 were our best fits at about 20% individual percent difference compared to doses calculated using 3 or 4 time points. We could achieve reasonable accuracy of estimating tumor doses for subsequent radiopharmaceutical therapy using only the two-time point imaging sessions. Images obtained from these time points (within the 48-h after administration of radiopharmaceutical) were also viewed as useful for diagnostic reading. Although our analysis was specific to 124 I-MIBG PET/CT pretherapy imaging data for 131 I-MIBG therapy of neuroblastoma and the number of imaging datasets was not large, this feasible methodology would generally be applicable to other imaging and therapeutic radionuclides with an appropriate data analysis similar to our analysis to other imaging and therapeutic radiopharmaceuticals.

Interobserver variability of image-derived arterial blood SUV in whole-body FDG PET

BackgroundToday, the standardized uptake value (SUV) is essentially the only means for quantitative evaluation of static [18F-]fluorodeoxyglucose (FDG) positron emission tomography (PET) investigations. However, the SUV approach has several well-known shortcomings which adversely affect the reliability of the SUV as a surrogate of the metabolic rate of glucose consumption. The standard uptake ratio (SUR), i.e., the uptake time-corrected ratio of tumor SUV to image-derived arterial blood SUV, has been shown in the first clinical studies to overcome most of these shortcomings, to decrease test-retest variability, and to increase the prognostic value in comparison to SUV. However, it is unclear, to what extent the SUR approach is vulnerable to observer variability of the additionally required blood SUV (BSUV) determination. The goal of the present work was the investigation of the interobserver variability of image-derived BSUV.MethodsFDG PET/CT scans from 83 patients (72 male, 11 female) with non-small cell lung cancer (N = 46) or head and neck cancer (N = 37) were included. BSUV was determined by 8 individuals, each applying a dedicated delineation tool for the BSUV determination in the aorta. Two of the observers applied two further tools. Altogether, five different delineation tools were used. With each used tool, delineation was performed for the whole patient group, resulting in 12 distinct observations per patient. Intersubject variability of BSUV determination was assessed using the fractional deviations for the individual patients from the patient group average and was quantified as standard deviation (SD is), 95% confidence interval, and range.Interobserver variability of BSUV determination was assessed using the fractional deviations of the individual observers from the observer-average for the considered patient and quantified as standard deviations (SD p, SD d) or root mean square (RMS), 95% confidence interval, and range in each patient, each observer, and the pooled data respectively.ResultsInterobserver variability in the pooled data amounts to RMS = 2.8% and is much smaller than the intersubject variability of BSUV (SD is= 16%). Averaged over the whole patient group, deviations of individual observers from the observer average are very small and fall in the range [ − 0.96, 1.05]%. However, interobserver variability partly differs distinctly for different patients, covering a range of [0.7, 7.4]% in the investigated patient group.ConclusionThe present investigation demonstrates that the image-based manual determination of BSUV in the aorta is sufficiently reproducible across different observers and delineation tools which is a prerequisite for accurate SUR determination. This finding is in line with the already demonstrated superior prognostic value of SUR in comparison to SUV in the first clinical studies.