Relationship between maximum standardized uptake value (SUVmax) of lung cancer and lymph node metastasis on FDG-PET

Multidisciplinary Postoperative Validation of 18F-FDG PET/CT Scan in Nodal Staging of Resected Non-Small Cell Lung Cancer

BACKGROUND

The aim of this study was to examine the validity of PET/CT scans in the preoperative identification of lymph node metastases (LNM) and compare them with postoperative outcomes.

METHODS

In this retrospective study, we included 87 patients with a solitary lung nodule or biopsy-proven non-small cell lung cancer treated in our institution from 2009 to 2015. Patients were divided into two groups and four subgroups, depending on pre- and postoperative findings.

RESULTS

According to our analysis, PET/CT scan has a sensitivity of 50%, a specificity of 88.89%, a positive predictive value of 63.16%, and a negative predictive value of 82.35%. Among the patients, 13.8% were downstaged in PET-CT, while 8% were upstaged. In 78.2% of cases, the PET/CT evaluation was consistent with the histology. Metastases without extracapsular invasion were seldom recognized on PET/CT.

CONCLUSIONS

This analysis showed the significance of extracapsular tumor invasion, which causes an inflammatory reaction, on LNM, which is probably responsible for preoperative false-positive findings. In conclusion, PET/CT scans are very effective in identifying patients without tumors. Furthermore, it is highly probable that patients with negative findings are free of disease.

Type of lymphadenectomy does not influence survival in pIa NSCLC patients who underwent VATS lobectomy: Results from the national VATS group database

INTRODUCTION

Stage Ia presents an optimal survival rate after surgical resection, but the type of lymphadenectomy to use in these patients is still debated. The aim of this study is evaluate if one type of lymphadenectomy adopted influences survival in patients who underwent VATS lobectomy for stage Ia NSCLC.

METHODS

Clinical and pathological data from pIa patients in the prospective VATS Italian nationwide registry were reviewed and analysed. Patients and tumour characteristics,type of lymphadenectomy (sampling or radical nodal dissection,MRLD), were collected and correlated to Overall Survival(OS) and Disease free Survival(DFS). The Kaplan-Meier product-limit method was used to estimate OS and DFS and the log-rank test was adopted to evaluate the differences between groups. A propensity match was performed to reduce bias due to the retrospective study design.

RESULTS

The final analysis was conducted on 2039 patients, 179 died during follow-up,recurrence rate was 13%. MRLD was performed in 1287(63.1%)patients. The univariable analysis identified as favourable prognostic factors for OS the female sex(p = 0.023), low ECOG-score(0.008),low SUVmax(p < 0.001), GGO appearance(p < 0.001), pT < 2 cm(p = 0.002) and low tumour grading(p = 0.002). The multivariable analysis confirmed as independent prognostic factors low ECOG-score(p = 0.012), low SUVmax(p < 0.001) and low tumour grading(p < 0.001). Analysing survival in patients with solid/sub-solid nodules and after propensity score matching for pTdimension and number of N2 resected lymphnodes, no OS differences were present comparing sampling vs MRLD.

CONCLUSION

Survival in pIa patients seems to be determined by patient and tumour characteristics such as performance status,grading and SUVmax. Type of lymphadnectomy did not seem to be correlated with OS in these patients.

FDG-PET/CT tumor to liver SUV ratio (TLR), tumor SUVmax, and tumor size: can this help in differentiating squamous cell carcinoma from adenocarcinoma of the lung?

Background

PET/CT plays an essential role in the diagnosis, staging, and follow-up of lung cancer. We aimed to assess the ability of PET/CT to differentiate between adenocarcinomas (AC) and squamous cell carcinomas (SCC) of the lung using tumor size, tumor maximum standardized uptake value (SUVmax), lymph nodes SUVmax, and tumor to liver SUV ratio (TLR).

Results

A total of 60 patients pathologically proved to have non-small cell lung cancer either AC or SCC were retrospectively evaluated. The mean tumor size, SUVmax of the tumor, and TLR were significantly higher in SCC lesions compared to AC lesions. The mean SCC tumoral size was 7.96 ± 2.18 cm compared to 5.66 ± 2.57 cm in AC lesions (P = 0.008). The mean tumor SUVmax in SCC lesions was 18.95 ± 8.3 compared to 12.4 ± 7.55 in AC lesions (P = 0.04). While the mean TLR of SCC lesions was 10.32 ± 4.03 compared to 7.36 ± 4.61 in AC lesions (P = 0.028). All three parameters showed the same sensitivity (75%), while TLR showed the highest specificity (77.78%) followed by tumor size (76.47%) and then SUVmax of the tumor (72.22%).

Conclusions

SCC of the lung has a higher mean tumor size, SUVmax of the tumor, and TLR as compared to AC which can be helpful tools in differentiation between them using PET/CT.

Efficacy of a combined tool for stage I non‑small cell lung cancer against lymph node metastasis

In patients with clinical stage I non-small cell lung cancer (NSCLC), the prediction of occult lymph node metastasis (LNM) based on a combination of morphology using high-resolution computed tomography (HRCT) and metabolism using positron emission tomography (PET)-CT is unknown. The present study evaluated the use of predictive radiological tools, chest CT and PET-CT, for occult LNM in patients with clinical stage I NSCLC. The records of patients who underwent lobectomy between July 2014 and November 2021 were retrospectively reviewed. The differences in clinicopathological parameters, including CT and PET, between the LNM and non-LNM groups were assessed. Pure solid tumor was defined as a consolidation-to-tumor ratio of 1. The optimal cut-off value for predictive radiological tools for LNM was assessed according to the area under the receiver operating characteristic (ROC) curve. The present study included 288 patients, of whom 39 (13.5%) had LNM; of these 38 (97.4%) were pure solid type. Larger consolidation size (CS), higher maximal standardized uptake (SUVmax) value and histological type were statistically associated with LNM (all P<0.05). The optimal cutoff values of CS and SUVmax for predicting LNM were 19 mm and 5.5 respectively, as assessed using the area under the ROC curve. The combination of CS ≥19 mm and SUVmax ≥5.5 demonstrated a markedly higher odds ratio (9.184; 95% CI, 4.345-19.407) than each parameter individually. The minimum values of CS and SUVmax associated with LNM were 10 mm and 0.8 respectively. Pure solid formation and CS as morphology and SUVmax as metabolism were useful tools that complemented each other in predicting LNM. The combined method of evaluating SUVmax and CS may identify eligibility for LN dissection. However, considering the minimum values of CS and SUVmax in LNM, it cannot affirm the omission of LN dissection for cases that do not meet the combined criteria using HRCT and PET-CT.

Prognostic Radiological Tools for Clinical Stage IA Pure Solid Lung Cancer

In this study, we analyzed prognostic radiological tools and surgical outcomes for radiologically pure solid adenocarcinomas (AD) and squamous cell carcinoma (SQ) in clinical stage IA. We retrospectively investigated 130 patients who underwent surgical resections. We assessed the predictive risk factors for recurrence and pathological lymph node metastasis (LNM). There was no statistical difference in recurrence free survival (RFS) or cancer-specific survival (CSS) between AD and SQ groups (p = 0.642 and p = 0.403, respectively). In the whole cohort, tumor size on lung window and mediastinal settings, and tumor disappearance ratio using high-resolution computed tomography (HRCT) were not prognostic parameters (p = 0.127, 0.066, and 0.082, respectively). The maximal standardized uptake value (SUVmax) using positron emission tomography-CT was associated with recurrence (p = 0.016). According to the receiver operating characteristic curve, the cut-off value of SUVmax for recurrence was 4.6 (p = 0.016). The quantitative continuous variables using any radiological tools were not associated with LNM. However, tumor diameter on mediastinal setting ≥8 mm with SUVmax ≥2.4 could be a risk factor for LNM. Pure solid AD and SQ were equivalent for the RFS and CSS. SUVmax was useful to predict recurrence. The tumor diameter on a mediastinal setting and SUVmax were useful in predicting pathological LNM.

Application of Artificial Neural Network to Preoperative 18F-FDG PET/CT for Predicting Pathological Nodal Involvement in Non-small-cell Lung Cancer Patients

Purpose: To evaluate the performance of artificial neural networks (aNN) applied to preoperative ¹⁸F-FDG PET/CT for predicting nodal involvement in non-small-cell lung cancer (NSCLC) patients.

Methods: We retrospectively analyzed data from 540 clinically resectable NSCLC patients (333 M; 67.4 ± 9 years) undergone preoperative ¹⁸F-FDG PET/CT and pulmonary resection with hilo-mediastinal lymphadenectomy. A 3-layers NN model was applied (dataset randomly splitted into 2/3 training and 1/3 testing). Using histopathological reference standard, NN performance for nodal involvement (N0/N+ patient) was calculated by ROC analysis in terms of: area under the curve (AUC), accuracy (ACC), sensitivity (SE), specificity (SP), positive and negative predictive values (PPV, NPV). Diagnostic performance of PET visual analysis (N+ patient: at least one node with uptake ≥ mediastinal blood-pool) and of logistic regression (LR) was evaluated.

Results: Histology proved 108/540 (20%) nodal-metastatic patients. Among all collected data, relevant features selected as input parameters were: patients' age, tumor parameters (size, PET visual and semiquantitative features, histotype, grading), PET visual nodal result (patient-based, as N0/N+ and N0/N1/N2). Training and testing NN performance (AUC = 0.849, 0.769): ACC = 80 and 77%; SE = 72 and 58%; SP = 81 and 81%; PPV = 50 and 44%; NPV = 92 and 89%, respectively. Visual PET performance: ACC = 82%, SE = 32%, SP = 94%; PPV = 57%, NPV = 85%. Training and testing LR performance (AUC = 0.795, 0.763): ACC = 75 and 77%; SE = 68 and 55%; SP = 77 and 82%; PPV = 43 and 43%; NPV = 90 and 88%, respectively.

Conclusions: aNN application to preoperative ¹⁸F-FDG PET/CT provides overall good performance for predicting nodal involvement in NSCLC patients candidate to surgery, especially for ruling out nodal metastases, being NPV the best diagnostic result; a high NPV was also reached by PET qualitative assessment. Moreover, in such population with low a priori nodal involvement probability, aNN better identify the relatively few and unexpected nodal-metastatic patients than PET analysis, so supporting the additional aNN use in case of PET-negative images.

Elective neck dissection versus positron emission tomography-computed tomography-guided management of the neck in clinically node-negative early oral cavity cancer: A cost-utility analysis

BACKGROUND

In early oral cavity cancer, elective neck dissection (END) for the clinically node-negative (cN0) neck improves survival compared with observation. This paradigm has been challenged recently by the use of positron emission tomography-computed tomography (PET-CT) imaging in the cN0 neck. To inform this debate, we performed an economic evaluation comparing PET-CT-guided therapy with routine END in the cN0 neck.

METHODS

Patients with T1-2N0 lateralized oral tongue cancer were analyzed. A Markov model over a 40-year time horizon simulated treatment, disease recurrence, and survival from a US health care payer perspective. Model parameters were derived from a review of the literature.

RESULTS

The END strategy was dominant, with a cost savings of $1576.30 USD, an increase of 0.055 quality-adjusted life years (QALYs), a net monetary benefit of $4303 USD, and a 0.22 life-year advantage. END was sensitive to variation in cost and utilities in deterministic and probabilistic sensitivity analyses. PET-CT became the preferred strategy when decreasing occult nodal disease to 18% and increasing the negative predictive value (NPV) of PET-CT to 89% in 1-way sensitivity analyses. In probabilistic sensitivity analysis, assuming a cost effectiveness threshold of $50,000 USD/QALY, END was dominant in 64% of simulations and cost effective in 69.8%.

CONCLUSION

END is a cost-effective strategy compared with PET-CT in patients who have node-negative oral cancer. Although lower PET standardized uptake value thresholds would result in fewer false negatives and improved NPV, it is still uncertain that PET-CT would be cost effective, as this would likely result in more false positive tests.

A PET/CT nomogram incorporating SUVmax and CT radiomics for preoperative nodal staging in non-small cell lung cancer

Objectives

To develop and validate a PET/CT nomogram for preoperative estimation of lymph node (LN) staging in patients with non-small cell lung cancer (NSCLC).

Methods

A total of 263 pathologically confirmed LNs from 124 patients with NCSLC were retrospectively analyzed. Positron-emission tomography/computed tomography (PET/CT) examination was performed before treatment according to the clinical schedule. In the training cohort (N = 185), malignancy-related features, such as SUVmax, short-axis diameter (SAD), and CT radiomics features, were extracted from the regions of LN based on the PET/CT scan. The Minimum-Redundancy Maximum-Relevance (mRMR) algorithm and the Least Absolute Shrinkage and Selection Operator (LASSO) regression model were used for feature selection and radiomics score building. The radiomics score (Rad-Score) and SUVmax were incorporated in a PET/CT nomogram using the multivariable logistic regression analysis. The performance of the proposed model was evaluated with discrimination, calibration, and clinical application in an independent testing cohort (N = 78).

Results

The radiomics scores consisting of 14 selected features were significantly associated with LN status for both training cohort with AUC of 0.849 (95% confidence interval (CI), 0.796–0.903) and testing cohort with AUC of 0.828 (95% CI, 0.782–0.919). The PET/CT nomogram incorporating radiomics score and SUVmax showed moderate improvement of the efficiency with AUC of 0.881 (95% CI, 0.834–0.928) in the training cohort and AUC of 0.872 (95% CI, 0.797–0.946) in the testing cohort. The decision curve analysis indicated that the PET/CT nomogram was clinically useful.

Conclusion

The PET/CT nomogram, which incorporates Rad-Score and SUVmax, can improve the diagnostic performance of LN metastasis.

Key Points

• The PET/CT nomogram (Int-Score) based on lymph node (LN) PET/CT images can reliably predict LN status in NSCLC.

• Int-Score is a relatively objective diagnostic method, which can play an auxiliary role in the process of clinicians making treatment decisions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07624-9.

A nomogram for predicting the risk of lymph node metastasis in T1-2 non-small-cell lung cancer based on PET/CT and clinical characteristics

Background

Accurately predicting the risk level for a lymph node metastasis is critical in the treatment of non-small cell lung cancer (NSCLC). This study aimed to construct a novel nomogram to identify patients with a risk of lymph node metastasis in T1–2 NSCLC based on positron emission tomography/computed tomography (PET/CT) and clinical characteristics.

Methods

From January 2011 to November 2017, the records of 318 consecutive patients who had undergone PET/CT examination within 30 days before surgical resection for clinical T1–2 NSCLC were retrospectively reviewed. A nomogram to predict the risk of lymph node metastasis was constructed. The model was confirmed using bootstrap resampling, and an independent validation cohort contained 156 patients from June 2017 to February 2020 at another institution.

Results

Six factors [age, tumor location, histology, the lymph node maximum standardized uptake value (SUVmax), the tumor SUVmax and the carcinoembryonic antigen (CEA) value] were identified and entered into the nomogram. The nomogram developed based on the analysis showed robust discrimination, with an area under the receiver operating characteristic curve of 0.858 in the primary cohort and 0.749 in the validation cohort. The calibration curve for the probability of lymph node metastasis showed excellent concordance between the predicted and actual results. Decision curve analysis suggested that the nomogram was clinically useful.

Conclusions

We set up and validated a novel and effective nomogram that can predict the risk of lymph node metastasis for individual patients with T1–2 NSCLC. This model may help clinicians to make treatment recommendations for individuals.

Nodal recurrences after stereotactic body radiotherapy for early stage non-small-cell lung cancer

Lobectomy is considered the standard of care for early stage non-small-cell lung cancer. However, for those patients who remain unfit to undergo surgery due to advanced age, poor performance status, comorbidities, poor pulmonary reserve or a combination of these are now treated with stereotactic body radiation therapy (SBRT). Due to its noninvasive nature, lower cost, lower toxicity, reduced recovery time and equivalent efficacy, even medically operable patients are attracted to the option of SBRT despite the lack of level I evidence. Thus, studying the incidence and patterns of recurrence after SBRT help in understanding the magnitude of the problem, risk factors associated with the different patterns of recurrence, and aid in devising strategies to prevent them in future. Nodal recurrences are not uncommon after SBRT and can potentially lead to further seeding for distant metastases and ultimately poor survival. This review is aimed at reviewing the published data on the incidence of nodal recurrences after SBRT and compare it to surgery, identify potential risk factors for recurrence, salvage treatment options and prevention strategies.

Does Tumor FDG-PET Avidity Represent Enhanced Glycolytic Metabolism in Non-Small Cell Lung Cancer?

BACKGROUND

In non-small cell lung cancer (NSCLC), 18fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) assists in diagnosis, staging, and evaluating treatment response. One variable of FDG-PET, the maximum standard uptake value (SUVm), is considered an objective measure of glucose uptake. However, little is known about the fate of glucose in FDG-avid lung tumors in vivo. This study used stable glucose isotope tracing to determine whether the SUVm predicts glycolytic metabolism or other glucose fates in tumors.

METHODS

In this prospective Institutional Review Board-approved clinical trial, 52 untreated potentially resectable confirmed NSCLC patients underwent FDG-PET computed tomography. During the surgical procedure, the patients were infused with 13C-labeled glucose. Blood, tumor, and normal lung samples were analyzed by mass spectrometry to determine 13C enrichment in glycolytic intermediates. These values were compared with clinical variables, including SUVm, maximum tumor diameter, stage, grade, and MIB-1/Ki67 proliferation index.

RESULTS

For each patient, 13C enrichment in each metabolite was compared between tumor and adjacent lung. Although all tumors metabolized glucose, SUVm did not correlate with glycolytic intermediate labeling. Rather, SUVm correlated with markers indicating the use of other respiratory substrates, including lactate, and with the proliferation index.

CONCLUSIONS

SUVm does not correlate with glycolytic metabolism in human NSCLC but does correlate with the proliferation index, suggesting that SUVm predicts glucose use by pathways other than glycolysis. These pathways may offer alternative therapeutic targets, including biosynthetic pathways required for cell proliferation. The research techniques in this study offer the opportunity to understand the relationships between SUVm, tumor metabolism, and therapeutic vulnerabilities in human NSCLCs.

Is SUVmax Helpful in the Differential Diagnosis of Enlarged Mediastinal Lymph Nodes? A Pilot Study

Objective

To explore the diagnostic value of maximum standard uptake value (SUVmax) from ¹⁸F-FDG PET/CT images in enlarged mediastinal lymph nodes of unknown etiology.

Methods

We performed a retrospective study of patients with enlarged mediastinal lymph nodes on ¹⁸F-FDG PET/CT scans. SUVmax and the short axis and long axis of lymph nodes were recorded. These parameters were compared among the five commonest causes of mediastinal lymphadenopathy: lymphoma, metastatic disease, sarcoidosis, tuberculosis, and lymphadenitis. Histopathologic diagnosis was recorded as the final golden standard.

Results

A total of 94 patients (62 men and 32 women; age range 7-85 y) were included with final diagnoses of 42 patients with benign pathology and 52 patients with malignancies. The sensitivity, specificity, and the accuracy of PET/CT in diagnosis of the benign and malignant mediastinal lymph nodes were 94.2%, 73.8%, and 85.1%, respectively. The SUVmax of benign and malignant groups were 13.10 ± 5.21 and 12.59 ± 5.50, respectively, which had no statistical difference (P > 0.05). However, the long axis and the short axis of lymph nodes in the benign and malignant groups were 2.86 ± 1.02 cm, 1.77 ± 0.60 cm and 6.04 ± 3.83 cm, 3.95 ± 2.08 cm, respectively (P < 0.05). The diagnostic values of PET/CT were higher than those of the long or short axis. However, the specificity of PET/CT was lower (73.8%) than that from the long or short axis (90.5% and 92.9%, respectively), although no statistical difference existed. Among the five common causes of mediastinal lymphadenopathy, significant differences could be seen in SUVmax and in the long axis and the short axis of lymph nodes (P < 0.05).

Conclusions

SUVmax, a commonly used semiquantitative measurement, was not helpful for differentiation between benign and malignant lesions in patients with enlarged mediastinal lymph nodes in this study. Many benign lesions, such as sarcoidosis and tuberculosis, had high FDG uptake, possibly a trend that the size of the lymph nodes seems to have some diagnostic value.

Impact of Enlarged Nonhypermetabolic Lymph Nodes on Outcomes After Stereotactic Body Radiotherapy for Early-Stage Non-Small-Cell Lung Cancer

BACKGROUND

Up to 15% of patients undergoing positron emission tomography (PET)/computed tomography (CT) before stereotactic body radiotherapy (SBRT) harbor occult nodal disease. In the absence of invasive mediastinal staging, the clinical significance of enlarged nonhypermetabolic lymph nodes (LNs) remains unclear. We performed what is to our knowledge the first study to address whether enlarged nonhypermetabolic LNs were associated with higher post-SBRT failure rates.

PATIENTS AND METHODS

Two academic centers assessed 157 consecutive patients treated with SBRT for cT1-2aN0M0 non-small-cell lung cancer who underwent PET/CT without pathologic nodal staging. The cutoff of an enlarged node was ≥ 1.0 cm, although a 7 mm threshold was also evaluated. Local recurrence-free survival (RFS), regional RFS, distant metastasis-free survival, RFS, and overall survival (OS) were calculated by Kaplan-Meier methodology. Multivariate Cox modeling addressed factors associated with RFS and OS.

RESULTS

There were 120 patients (76%) with LNs < 1 cm and 37 (24%) with nodes ≥ 1 cm. Most patients had peripheral and/or T1 tumors. Median follow-up was 25.5 months. There were no differences between cohorts in actuarial local RFS, regional RFS, distant metastasis-free survival, RFS, or OS (P > .05 for all). Thirteen percent of patients experienced any nodal relapse, 15% of which occurred in the same station as that of the largest pre-SBRT LN. Stratification by largest LN location in an N1 versus N2 station showed no differences in RFS or OS (P > .05 for both). A 7 mm cutoff also showed no differences in outcomes (P > .05 for all). LN size was not correlated with RFS/OS on multivariable analysis (P > .05 for both).

CONCLUSION

The presence of enlarged nonhypermetabolic LNs on PET/CT is not associated with increased post-SBRT failure rates.

A novel iterative modified bicubic interpolation method enables high-contrast and high-resolution image generation for F-18 FDG-PET

Positron emission tomography (PET) has become a useful and important technique in oncology. However, spatial resolution of PET is not high; therefore, small abnormalities can sometimes be overlooked with PET. To address this problem, we devised a novel algorithm, iterative modified bicubic interpolation method (IMBIM). IMBIM generates high resolution and -contrast image. The purpose of this study was to investigate the utility of IMBIM for clinical FDG positron emission tomography/X-ray computed tomography (PET/CT) imaging.We evaluated PET images from 1435 patients with malignant tumor and compared the contrast (uptake ratio of abnormal lesions to background) in high resolution image with the standard bicubic interpolation method (SBIM) and IMBIM. In addition to the contrast analysis, 340 out of 1435 patients were selected for visual evaluation by nuclear medicine physicians to investigate lesion detectability. Abnormal uptakes on the images were categorized as either absolutely abnormal or equivocal finding.The average of contrast with IMBIM was significantly higher than that with SBIM (P < .001). The improvements were prominent with large matrix sizes and small lesions. SBIM images showed abnormalities in 198 of 340 lesions (58.2%), while IMBIM indicated abnormalities in 312 (91.8%). There was statistically significant improvement in lesion detectability with IMBIM (P < .001).In conclusion, IMBIM generates high-resolution images with improved contrast and, therefore, may facilitate more accurate diagnoses in clinical practice.

Risk Factors for Predicting Occult Lymph Node Metastasis in Patients with Clinical Stage I Non-small Cell Lung Cancer Staged by Integrated Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

BACKGROUND

Lymph nodes in patients with non-small cell lung cancer (NSCLC) are often staged using integrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT). However, this modality has limited ability to detect micrometastases. We aimed to define risk factors for occult lymph node metastasis in patients with clinical stage I NSCLC diagnosed by preoperative integrated FDG-PET/CT.

METHODS

We retrospectively reviewed the records of 246 patients diagnosed with clinical stage I NSCLC based on integrated FDG-PET/CT between April 2007 and May 2015. All patients were treated by complete surgical resection. The prevalence of occult lymph node metastasis in patients with clinical stage I NSCLC was analysed according to clinicopathological factors. Risk factors for occult lymph node metastasis were defined using univariate and multivariate analyses.

RESULTS

Occult lymph node metastasis was detected in 31 patients (12.6 %). Univariate analysis revealed CEA (P = 0.04), SUV_max of the primary tumour (P = 0.031), adenocarcinoma (P = 0.023), tumour size (P = 0.002) and pleural invasion (P = 0.046) as significant predictors of occult lymph node metastasis. Multivariate analysis selected SUV_max of the primary tumour (P = 0.049), adenocarcinoma (P = 0.003) and tumour size (P = 0.019) as independent predictors of occult lymph node metastasis.

CONCLUSIONS

The SUV_max of the primary tumour, adenocarcinoma and tumour size were risk factors for occult lymph node metastasis in patients with NSCLC diagnosed as clinical stage I by preoperative integrated FDG-PET/CT. These findings would be helpful in selecting candidates for mediastinoscopy or endobronchial ultrasound-guided transbronchial needle aspiration.

Prognostic Value of Metabolic Parameters of Metastatic Lymph Nodes on 18F-FDG PET/CT in Patients With Limited-stage Small-cell Lung Cancer With Lymph Node Involvement

INTRODUCTION

We assessed the prognostic value of the metabolic parameters of different lesions, including primary tumors and metastatic lymph nodes (LNs), measured by fluorine-18 fluorodeoxyglucose positron emission tomography (PET)/computed tomography in patients with limited-stage small-cell lung cancer (LS-SCLC) with LN metastasis.

MATERIALS AND METHODS

The present retrospective study included 46 patients with clinical stage II-III N1-N2 LS-SCLC who had undergone pretreatment fluorine-18 fluorodeoxyglucose PET/computed tomography scanning from January 2011 to December 2014. All patients underwent complete first-line therapy (concurrent chemoradiotherapy and prophylactic cranial irradiation). The metabolic parameters, including maximal standardized uptake value, mean standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) values of the PTs and metastatic LNs were measured on PET. Kaplan-Meier survival curves were used for evaluation of progression-free survival (PFS) and overall survival (OS). Univariate and multivariate Cox proportional hazards models were used to analyze the prognostic factors.

RESULTS

The median OS and PFS were 25.9 months (range, 8.2-63.5 months) and 21 months (range, 6.4-55.3 months), respectively. Univariate analysis demonstrated that the Eastern Cooperative Oncology Group performance status, N1 station involvement, subcarinal LN metastasis, LN MTV, LN TLG, sum of the MTV, and summary of the TLG were significant predictive factors (P < .05). The Eastern Cooperative Oncology Group performance status, subcarinal nodal metastasis, LN MTV, and LN TLG were independent predictive factors of PFS and OS on multivariate analysis.

CONCLUSION

The metabolic parameters of metastatic LNs, other than lung lesions, are independent prognostic factors in patients with LS-SCLC with LN metastasis. These parameters could further stratify the prognosis of these patients, and these findings might provide functional imaging evidence for the future study of the mechanisms of metastasis.

SUV navigator enables rapid [18F]-FDG PET/CT image interpretation compared with 2D ROI and 3D VOI evaluations

PURPOSE

Positron emission tomography (PET) and the maximum standardized uptake value (SUV_max) is a useful technique for assessing malignant tumors. Measurements of SUV_max in multiple lesions per patient frequently require many time-consuming procedures. To address this issue, we designed a novel interface named SUV Navigator (SUVnavi), and the purpose of this study was to investigate its utility.

MATERIALS AND METHODS

We measured SUV_max in 661 lesions from 100 patients with malignant tumors. Diagnoses and SUV_max measurements were made with SUVnavi, 2D, and 3D measurements. SUV measurement accuracy in each method were also evaluated.

RESULTS

The average reduction in time with SUVnavi versus 2D was 53.8% and 3D was 37.5%; time required with SUVnavi was significantly shorter than with 2D and 3D (P < 0.001 and P < 0.001, respectively). The time reduction and lesion number had a positive correlation (P < 0.001 and P < 0.001, respectively). SUV_max agreed with precise SUV_max in all lesions measured with SUVnavi and 3D but in only 466 of 661 lesions (70.5%) measured with 2D.

CONCLUSION

SUVnavi may be useful for rapid [¹⁸F]-fluorodeoxyglucose positron emission tomography/computed tomography ([¹⁸F]-FDG PET/CT) image interpretation without reducing the accuracy of SUV_max measurement.

Identification of false-negative and false-positive diagnoses of lymph node metastases in non-small cell lung cancer patients staged by integrated (18F-)fluorodeoxyglucose-positron emission tomography/computed tomography: A retrospective cohort study

Background

The aim of this study was to evaluate the diagnostic accuracy of integrated ¹⁸ F‐fluorodeoxyglucose positron emission tomography/computed tomography (FDG‐PET/CT) in hilar and mediastinal lymph node (HMLN) staging of non‐small cell lung cancer (NSCLC), and to investigate potential risk factors for false‐negative and false‐positive HMLN metastases.

Methods

We examined the data of 388 surgically resected NSCLC patients preoperatively staged by integrated FDG‐PET/CT. Risk factors for false‐negative and false‐positive HMLN metastases were analyzed using univariate and multivariate analyses of clinicopathological factors.

Results

The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of integrated FDG‐PET/CT in detecting HMLN metastases were 47.4%, 91.0%, 56.3%, 87.7%, and 82.5%, respectively. On multivariate analysis, the maximum standardized uptake value (SUVmax) of the tumor (P = 0.042), adenocarcinoma (P = 0.003), and tumor size (P = 0.017) were risk factors for false‐negative HMLN metastases, and history of lung disease (P = 0.006) and tumor location (central; P = 0.025) were risk factors for false‐positive HMLN metastases.

Conclusions

The present study identified risk factors for false‐negative and false‐positive HMLN metastases in NSCLC patients staged by preoperative integrated FDG‐PET/CT. These findings would be helpful in selecting appropriate candidates for mediastinoscopy or endobronchial ultrasound‐guided transbronchial needle aspiration.

Evaluation of the factors affecting the maximum standardized uptake value of metastatic lymph nodes in different histological types of non-small cell lung cancer on PET-CT

Background

To evaluate the factors affecting the maximum standardized uptake value (SUVmax) of metastatic lymph nodes in different histological types of non-small cell lung cancer (NSCLC) on integrated positron emission tomography and computed tomography (PET-CT).

Methods

This was a retrospective, single-institution review of 122 patients with pathologically proven NSCLC who had PET-CT scanning at the same center. Lymph node metastases were pathologically confirmed in tissue specimens from surgical patients. Statistical evaluation of PET-CT results was performed on a per-nodal-station basis.

Results

The tumor SUVmax of squamous cell carcinoma (SCC) (11.0 ± 4.1) was higher than that of adenocarcinoma (AC) (7.4 ± 4.4) (P < 0.01), however, the SUVmax of the metastatic lymph nodes did not differ between the SCC (4.6 ± 3.1) and AC groups(3.6 ± 2.5) (P = 0.221). The SUVmax of metastatic lymph nodes was positively correlated with lymph node size but not with the primary tumor SUVmax, primary tumor size, tumor location and tumor differentiation. The frequency of a SUVmax of lymph nodes ≥2.5 was 44%, 80%,100% in SCC group and 39%, 59%, 90% in AC group when the short-axis diameter of metastatic lymph node was <10 mm, 10–15 mm, and > 15 mm, respectively. The low sensitivity for metastatic lymph nodes on PET-CT was increased when the SUVmax cut-off for malignancy was considered to be above the normal background compared with that when the SUVmax cut-off was above 2.5.

Conclusions

There was no difference in the SUVmax of metastatic lymph nodes in the SCC and AC groups. The SUVmax of metastatic lymph nodes was positively correlated with metastatic lymph node size. There was a high false negative rate if lymph nodes with a short-axis diameter less than 10 mm and a extremely low false negative rate if lymph nodes with a short-axis diameter higher than 15 mm. Although an increased sensitivity may be achieved by decreasing the SUVmax cut-off, invasive staging may still be required for negative lymph nodes due to the lower sensitivity of PET-CT in both SCC and AC.

Impact of point spread function modelling and time of flight on FDG uptake measurements in lung lesions using alternative filtering strategies

BACKGROUND

The use of maximum standardised uptake value (SUVmax) is commonplace in oncology positron emission tomography (PET). Point spread function (PSF) modelling and time-of-flight (TOF) reconstructions have a significant impact on SUVmax, presenting a challenge for centres with defined protocols for lesion classification based on SUVmax thresholds. This has perhaps led to the slow adoption of these reconstructions. This work evaluated the impact of PSF and/or TOF reconstructions on SUVmax, SUVpeak and total lesion glycolysis (TLG) under two different schemes of post-filtering.

METHODS

Post-filters to match voxel variance or SUVmax were determined using a NEMA NU-2 phantom. Images from 68 consecutive lung cancer patients were reconstructed with the standard iterative algorithm along with TOF; PSF modelling - Siemens HD·PET (HD); and combined PSF modelling and TOF - Siemens ultraHD·PET (UHD) with the two post-filter sets. SUVmax, SUVpeak, TLG and signal-to-noise ratio of tumour relative to liver (SNR(T-L)) were measured in 74 lesions for each reconstruction. Relative differences in uptake measures were calculated, and the clinical impact of any changes was assessed using published guidelines and local practice.

RESULTS

When matching voxel variance, SUVmax increased substantially (mean increase +32% and +49% for HD and UHD, respectively), potentially impacting outcome in the majority of patients. Increases in SUVpeak were less notable (mean increase +17% and +23% for HD and UHD, respectively). Increases with TOF alone were far less for both measures. Mean changes to TLG were <10% for all algorithms for either set of post-filters. SNR(T-L) were greater than ordered subset expectation maximisation (OSEM) in all reconstructions using both post-filtering sets.

CONCLUSIONS

Matching image voxel variance with PSF and/or TOF reconstructions, particularly with PSF modelling and in small lesions, resulted in considerable increases in SUVmax, inhibiting the use of defined protocols for lesion classification based on SUVmax. However, reduced partial volume effects may increase lesion detectability. Matching SUVmax in phantoms translated well to patient studies for PSF reconstruction but less well with TOF, where a small positive bias was observed in patient images. Matching SUVmax significantly reduced voxel variance and potential variability of uptake measures. Finally, TLG may be less sensitive to reconstruction methods compared with either SUVmax or SUVpeak.

Can Initial (18)F-FDG PET-CT Imaging Give Information on Metastasis in Patients with Primary Renal Cell Carcinoma?

Purpose

The aim of this study was to investigate the relationship between the maximum standardized uptake values (SUVmax) of primary renal cancers with and without metastatic lesions, if any. We also studied the relationship between the size of primary renal cancers and their SUVmax, and tried to find a clinical value of ¹⁸F-FDG PET-CT for the initial evaluation of renal cell carcinoma (RCC).

Methods

The cases of 23 patients, 16 men and 7 women, who underwent PET-CT examination before operation were retrospectively reviewed. We measured the SUVmax of the primary renal cancers and those of any existing metastatic lesions, and the size of the primary renal cancers. We compared the SUVmax of primary RCCs with metastases and those without metastases, SUVmax of primary RCC and those of metastases, and studied the correlation between the size and SUVmax of primary RCCs.

Results

The SUVmax of primary RCC of the 16 patients without metastasis ranged from 1.1 to 5.6 with a median value of 2.6. Those of the patients with metastasis ranged from 2.9 to 7.6 with a median of 5.0. The size of the all 23 primary renal cancers ranged from 1.7 cm to 13.5 cm, with a median of 4.5 cm, and their SUVmax ranged from 1.1 to 7.6, with a median of 2.9. There was a statistically significant difference between the SUVmax of the primary RCC with metastasis (5.3 ± 1.7) and those without metastasis (2.9 ± 1.0). There was a moderate positive correlation between the sizes and SUVmax of all 23 primary RCCs. However, there was no statistically significant correlation between the sizes and SUVmax of primary RCCs with metastatic lesions and the same for RCCs without metastasis. The cutoff value of SUVmax for predicting extra-renal lesion was 4.4 and that for size was 5.8 cm according to the receiver operating characteristic curves.

Conclusions

Those who have primary RCC with high SUVmax are suggested to have a likelihood of metastasis. Also, there was a moderate trend of increasing value of SUVmax of primary RCC as their size increases. Physicians should beware of missing extra-renal lesions elsewhere.

The maximum standardized FDG uptake on PET-CT in patients with non-small cell lung cancer

Background

Non-small cell lung cancer (NSCLC) accounts for approximately 80% of new diagnoses of pulmonary carcinoma. This study investigated the correlation between 18 F-fluorodeoxyglucose uptake in computerized tomography integrated positron emission tomography and tumor size, lymph node metastasis, and distant metastasis in patients with NSCLC.

Methods

The records of 151 NSCLC patients (139 male, 12 female; mean age 59.60 years) were evaluated retrospectively.

Results

Forty-one cases were adenocarcinomas; 45 squamous cell carcinomas; and 65 unspecified NSCLC. When the cases were categorized according to tumor size (group 1, ≤ 3 cm; group 2, > 3 and ≤ 5 cm; group 3, > 5 cm), the maximum standardized uptake value (SUVmax) was significantly lower in groups 1 and 2 compared with group 3 (p = 0.006 for each). Considering all cases, tumor SUVmax was not correlated with age, gender, or histopathological type. Lymph node metastases were pathologically proven in 24 cases: 24% of these were adenocarcinomas, 6% squamous cell carcinomas, and 16% unspecified NSCLC. Neither lymph node involvement nor distant metastases were correlated with tumor SUVmax, although lymph node size was positively correlated with lymph node SUVmax (r = 0.775; p < 0.001).

Conclusions

SUVmax was significantly associated with tumor size, but not with distant metastases or lymph node involvement. Therefore, SUVmax on positron emission tomography is not predictive of the presence of metastases.

Clinicopathological determinants of positron emission tomography computed tomography fluorodeoxyglucose standardised uptake value in head and neck carcinoma

BACKGROUND

Although positron emission tomography computed tomography has proven diagnostic and staging value in head and neck carcinoma, it does not have optimal sensitivity or specificity. The positron emission tomography computed tomography fluorodeoxyglucose standardised uptake value has been shown to be associated with carcinoma stage. This study evaluated the impact of major clinicopathological factors on the standardised uptake value at the primary site and at neck lymph node metastases.

SUBJECTS AND METHODS

Two hundred and forty-three oral cavity and laryngopharyngeal carcinoma patients who underwent positron emission tomography computed tomography were included. Correlation between the positron emission tomography computed tomography standardised uptake value and various clinicopathological factors was analysed.

RESULTS

A positive correlation was found between the standardised uptake value and the size and depth of tumour infiltration, and lymph node positivity. Higher standardised uptake values were seen for more advanced tumour stages. The presence of perineural invasion, lymphatic invasion and extracapsular spread were all associated with increased standardised uptake values.

CONCLUSION

Most of the clinicopathological features of head and neck carcinoma which are well known to be poor prognostic factors have a significant impact on positron emission tomography computed tomography fluorodeoxyglucose standardised uptake value.

Risk factors for predicting the occult nodal metastasis in T1-2N0M0 NSCLC patients staged by PET/CT: potential value in the clinic

BACKGROUND AND OBJECTIVE

The aims of our study were to evaluate the occult nodal metastasis in clinical stage I patients by PET/CT, further investigate the potential risk factors for nodal involvement, since a successful prediction could be helpful in selection appropriate candidates for SABR or limited surgery.

METHODS

We retrospectively reviewed the records of 189 patients who diagnosed as clinical stage I NSCLC by (18)F-FDG PET/CT from January 2004 to July 2011. All patients underwent lobectomy and systematic lymph node dissection and preoperative (18)F-FDG PET/CT scanning. The prevalence of occult nodal metastasis in patients as clinical N0 was analyzed according to clinicopathological factors such as tumor location, tumor size, tumor subtype, grade of differentiation and primary tumor SUV(max). Risk factors for occult nodal metastasis were defined by univariate and multivariate analysis.

RESULTS

Occult nodal metastasis was detected in 18.0% (34/189) of the patients. SUV(max) of the primary tumor and tumor size were independent predictors of occult nodal metastasis for patients with clinical N(0)NSCLC by FDG PET/CT. Accordingly we divided our patients into three groups: group 1 (low-risk group) ∼T ≤ 3 cm and SUV(max) ≤ 4.3; group 2 (moderate-risk group) ∼T ≤ 3 cm and SUV(max) > 4.3 or SUV(max) ≤ 4.3 and T > 3 cm; group 3 (high-risk group) ∼T > 3 cm and SUV(max) > 4.3. The occult lymph node metastasis rate in groups 1, 2, 3 was 1/82 (1.2%), 19/75 (25.3%) and 14/32 (43%) respectively.

CONCLUSIONS

T(1-2N0M0) NSCLC patients by PET/CT showing larger tumor size and high SUV(max) constitute a high-risk group for occult nodal metastasis. The combined information of primary tumor SUV(max) and tumor size before treatment have potential values in the clinic. These findings would be helpful in selection of SABR or limited surgery candidates.

The correlation of SUVmax with pathological characteristics of primary tumor and the value of Tumor/ Lymph node SUVmax ratio for predicting metastasis to lymph nodes in resected NSCLC patients

Background

We aimed to investigate the correlation of maximum standardized uptake value (SUVmax) with pathological characteristics of primary tumor and to determine a Tumor/ Lymph node (T/LN) SUVmax ratio predicting metastasis to lymph nodes in NSCLC patients.

Methods

Eighty-one NSCLC patients who had PET/CT examination at initial staging and subsequently underwent surgical resection were retrospectively evaluated. There were 100 PET/CT positive mediastinal or hilar lymph node stations. Pathological characteristics of the tumor such as largest tumor diameter, tumor histology, differentiation, number of mitosis, degree of stromal inflammation, necrosis; etiology of PET/CT positive lymph node stations; SUVmax of primary tumor and positive lymph node stations were recorded. A T/LN SUVmax ratio was calculated for each lymph node station.

Results

SUVmax of the primary tumor was positively correlated with the largest tumor diameter (p = 0.001, r = 0.374), number of mitosis (p < 0.001, r = 0.405), and postoperative pathological stage (p = 0.007, r = 0.298). Patients with squamous cell carcinoma had a statistically significant higher mean SUVmax, number of mitosis and advanced N stages compared to adenocarcinoma. The etiology of 100 PET/CT positive lymph node stations were metastasis in 14, anthracosis in 40, reactive in 39, granulomatous in 4, and silicosis in 3 patients. A T/LN SUVmax ratio of 5 or lower was suggestive for a malignant lymph node with a sensitivity of 92.8% and specificity of 47%.

Conclusions

SUVmax of a primary tumor is related to certain pathological characteristics, such as largest diameter, histology, and number of mitosis. A T/LN SUVmax ratio lower than 5 predicts the metastasis to lymph nodes with a high sensitivity.

[Correlation between regional node metastasis and imageological characteristics in non-small cell lung cancer]

非小细胞肺癌（non-small cell lung cancer, NSCLC）局部淋巴结（N）分期是影响患者治疗方案选择的关键因素之一。目前临床所使用的无创和有创性N分期方法均有其局限性。研究发现NSCLC的某些影像学特点可预测淋巴结转移的危险性，包括大小、CT密度和氟代脱氧葡萄糖（fluorodeoxyglucose, FDG）标准化摄取值（standardized uptake value, SUV）等。期待系统性多因素分析，以发现影响肺癌淋巴结转移的关键因素。

The role of 18F-FDG PET/CT in the metabolic characterization of lung nodules in pediatric patients with bone sarcoma

BACKGROUND

The principal aim of this study was to identify the lowest nodule diameter and the SUV(max) capable of characterizing lung nodules in pediatric patients with bone sarcoma.

PROCEDURE

Eighteen consecutive bone sarcoma patients (M/F = 11:7; mean age 14 years) with suspicious lung lesions at CT were enrolled. Overall, 63 lung nodules with a mean diameter of 3.35 mm (range 1.2-39.8 mm) were investigated. (18) F-FDG PET was performed according to standard procedure using a hybrid PET/CT system and results were compared with histology and/or clinical/radiological follow-up. For each lesion, we evaluated SUV(max) , SUV(ratio) to the mediastinal blood pool and maximum nodule diameter.

RESULTS

Of the 63 nodules, 32 proved to be benign and 31 malignant. On a visual basis, (18) F-FDG PET had an accuracy of 88.9%, a sensitivity of 90.3%, a specificity of 87.5%, a PPV of 87.5%, and a NPV of 90.3%. ROC curve analysis of SUV(max) for all nodules showed a value around 1 (>1.09) to be capable of differentiating metastases from benign lesions: sensitivity and specificity were 90.3% and 93.8%, respectively (accuracy 92.1%). Similar analysis revealed a cut-off value around 1 (>0.83) for SUV(ratio) (sensitivity and specificity were 90.3% and 90.6%, respectively) and a cut-off value of ca. 6 mm (>5.8 mm) for nodule diameter (sensitivity and specificity of 90.3% and 81.3%, respectively).

CONCLUSIONS

(18) F-FDG PET/CT is an accurate modality for the metabolic characterization of lung nodules in the pediatric population with bone sarcoma, and a SUV(max) (or SUV(ratio) ) >1 is capable of discriminating malignant from benign lesions.

Prognostic value of tumor burden measurement using the number of tumors in non-surgical patients with non-small cell lung cancer

BACKGROUND

No study to test the feasibility and prognostic value of the number of primary tumors, the number of positive lymph nodes, and the total number of tumors in the whole body as tumor burden measurements on FDG PET/CT imaging has been reported.

PURPOSE

To determine whether the number of tumors seen in 18F-FDG PET scans can be a prognostic factor in non-surgical patients with non-small cell lung cancer (NSCLC).

MATERIAL AND METHODS

One hundred and forty patients with histologically proven NSCLC and baseline 18F-FDG PET scan before therapy were identified in this retrospective analysis. The total number of tumors (TTn) in the whole body, the number of primary tumors (Tn), positive lymph nodes (Nn), and distant metastases (Mn), along with the maximum standardized uptake values (SUV(max)) of the tumors were measured. Inter-observer variability of the total number of tumors, counted by two radiologists, was assessed. Survival analyses were performed to determine the prognostic value of the number of tumors.

RESULTS

Concordance correlation coefficients for the TTn, Tn, Nn, and Mn were all greater than 0.85. TTn and Nn were strong prognostic factors of NSCLC patients' overall survival (OS). In univariate Cox regression models, gender, stage, TTn, Nn, and Mn were statistically significant factors (P = 0.016, 0.032, <0.001, <0.001, and 0.006, respectively). In multivariate Cox regression models, TTn and Nn remained as statistically significant predictors for survival with hazard ratios (HR) of 1.06 (P = 0.001) and 1.11 (P = 0.002), respectively, after adjusting for clinical stage based 7th edition of TNM staging system, age, gender, and SUV(max). Patients with a TTn ≤4 (cutpoint based on median value) had a median OS of 15.2 months compared with 9.0 months for those with TTn >4.

CONCLUSION

Measuring the number of tumors on FDG PET imaging is easy to perform with minimal inter-observer variability. The total number of tumors and number of nodal metastases, as metabolic tumor burden measurements in 18F-FDG PET/CT, are prognostic markers independent of clinical stage, age, gender, and SUV measurement in non-surgical patients with NSCLC.

Independent prognostic value of whole-body metabolic tumor burden from FDG-PET in non-small cell lung cancer

PURPOSE

To determine whether whole-body metabolic tumor burden, measured as either metabolic tumor volume (MTVWB) or total lesion glycolysis (TLGWB), using FDG-PET/CT is an independent prognostic marker in non-small cell lung cancer (NSCLC).

METHODS

328 patients with histologically proven NSCLC were identified for this retrospective analysis. This study was approved by our Institutional Review Board. All patients underwent baseline (18)F-FDG-PET/CT scan imaging before therapy. The MTVWB, TLGWB, maximum standardized uptake value (SUVmaxWB) and mean standardized uptake value (SUVmeanWB) of tumors throughout the whole body were measured from FDG-PET images with semi-automated 3D contouring software.

RESULTS

In univariate analysis, there was a statistically significant association of overall survival (OS) with the MTVWB (hazard ratio (HR) = 1.62, p < 0.001), TLGWB (HR = 1.47, p < 0.001). The patients with a MTVWB ≤ median of 65.7 ml and TLGWB ≤ median of 205.11 SUVmean * ml had a median OS of 41.1 and 35.4 months compared with 9.5 and 9.7 months for those with a MTVWB > 65.7 ml and TLGWB > 205.11 SUVmean * ml, respectively. From a series of multivariate Cox regression models, the MTVWB and TLGWB were significantly better than SUVmaxWB and SUVmeanWB at prognostication and significantly associated with patients' OS with HRs of 1.50 (p < 0.001) and 1.42 (p < 0.001), respectively, after adjustment for patient's age, gender and treatment intent as well as the tumor SUVmaxWB, histology and stage.

CONCLUSIONS

MTVWB and TLGWB as metabolic tumor burden measurements in (18)F-FDG-PET/CT are independent prognostic markers and are significantly better than SUVmaxWB and SUVmeanWB at prognostication.

Application of 18F-fluorodeoxyglucose positron emission tomography in diagnosis of malignant diseases

OBJECTIVE

To testify the efficacy of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in the diagnosis of cancer.

METHODS

A total of 170 patients with diagnosed cancer or suspicious cancer were enrolled in this study, and underwent 18F-FDG PET. The standard uptake value (SUV) and diameter for each abnormal region in PET images were analyzed. All data were analyzed by SPSS 11.5.

RESULTS

PET scan identified a primary cancer in 45.8% (11/24) patients. The sensitivity and specificity of PET scan in differentiating malignant lesions from benign ones were 78.8% (52/66) and 77.1% (27/35) respectively. Twenty-nine out of 68 (42.6%) lesions were detected earlier by PET than by computed tomography. The SUV of primary cancer was significantly higher than that of metastatic lymph nodes (5.84 +/- 3.12 vs. 3.14 +/- 2.24, P<0.001). And SUV of primary lung cancer was also significantly higher than that of metastatic lung cancer (6.30 +/- 3.01 vs. 2.86 +/- 2.37, P<0.01).

CONCLUSION

18F-FDG PET plays a very important role in cancer diagnosis.