Clinical significance of dual-time-point 18F-FDG PET imaging in resectable non-small cell lung cancer

The prognostic value of bone marrow retention index and bone marrow-to-liver ratio of baseline 18F-FDG PET/CT in diffuse large B-cell lymphoma

OBJECTIVE

To determine prognostic value of bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) measured on baseline dual-phase 18F-FDG PET/CT in a series of newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL) treated homogeneously with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy.

PATIENTS AND METHODS

This prospective study enrolled 135 patients with newly diagnosed DLBCL. All patients underwent dual-phase 18F-FDG PET/CT. The following PET parameters were calculated for both tumor and bone marrow: maximum standardized uptake value (SUVmax) at both time points (SUVmax early and SUVmax delayed), SUVmax increment (SUVinc), RI, and BLR. Patients were treated with R-CHOP regimen and response at end of treatment was assessed.

RESULTS

The final analysis included 98 patients with complete remission. At a median follow-up of 22 months, 57 patients showed no relapse, 74 survived, and 24 died. The 2-year relapse-free survival (RFS) values for patients with higher and lower RI-bm were 20% and 65.1%, respectively (p < 0.001), and for patients with higher and lower BLR were 30.2% and 69.6%, respectively (p < 0.001). The 2-year overall survival (OS) values for patients with higher and lower RI-bm were 60% and 76.3%, respectively (p = 0.023), and for patients with higher and lower BLR were 57.3% and 78.6%, respectively (p = 0.035). Univariate analysis revealed that RI-bm and BLR were independent significant prognostic factors for both RFS and OS (hazard ratio [HR] = 4.02, p < 0.001, and HR = 3.23, p < 0.001, respectively) and (HR = 2.83, p = 0.030 and HR = 2.38, p = 0.041, respectively).

CONCLUSION

Baseline RI-bm and BLR were strong independent prognostic factors in DLBCL patients.

CLINICAL RELEVANCE STATEMENT

Bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) could represent suitable and noninvasive positron emission tomography/computed tomography (PET/CT) parameters for predicting pretreatment risk in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) who were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy.

KEY POINTS

• Bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) are powerful prognostic variables in diffuse large B-cell lymphoma (DLBCL) patients. • High BLR and RI-bm are significantly associated with poor overall survival (OS) and relapse-free survival (RFS). • RI-bm and BLR represent suitable and noninvasive risk indicators in DLBCL patients.

Correlation between 18-FDG standardized uptake value and tumor grade in patients with resectable non-small cell lung cancer

Background

Positron-emission tomography (PET) is widely used for staging lung cancer. Although a correlation between the fluorodeoxyglucose standardized uptake value (SUV) and the histologic grade of the tumor has been shown in several studies, little is known about the impact of different clinical variables on this correlation. This study aimed to evaluate the correlation between tumor SUV and tumor grade in a large cohort of patients and to analyse the impact of clinical factors on this correlation.

Methods

This retrospective cohort study including patients with non-small cell lung cancer age 18-90 years, with clinical stage I-IVA, who underwent curative-intent lung resection.

Results

Data from 726 patients was included in this study. There was a strong correlation between SUV and primary tumor grade in the whole cohort (P<0.001), which was significant in both sexes (P<0.001) and in all selected age groups (P<0.001-0.03). There was a significant SUV-grade correlation for the right upper and left lower lobes, as well as for the central location in the right lung (P<0.001, P=0.005 and P=0.04, respectively). Moreover, a significant SUV-grade correlation was found for squamous cell cancer and adenocarcinoma (P<0.001 and P=0.01, respectively), and for T1-T3 factors (P<0.001, P=0.006, P=0.005 respectively).

Conclusions

In patients with resectable lung cancer, a significant correlation was observed between the SUV of the primary tumor and its grade. This correlation was maintained for both sexes, age groups, most common histological types and T factors T1-T3.

Impact of retention index on the neoadjuvant chemotherapy effect and the prognosis in oesophageal cancer

OBJECTIVE

The relationship between retention index calculated from dual-time point 18F-fluorodeoxyglucose positron emission tomography-computed tomography and oesophageal cancer prognosis remains unknown. This study aimed to determine usefulness of retention index as a predictor of long-term prognosis of oesophageal cancer and neoadjuvant chemotherapy efficacy.

METHODS

A total of 151 patients with oesophageal cancer who underwent esophagectomy were evaluated retrospectively in this study. We acquired positron emission tomography scans 60 and 120 min (SUVmax1 and SUVmax2, respectively) after the intravenous administration of 3.7 Mbq/kg 18F-fluorodeoxyglucose. The patients were divided into two groups: high-retention index (retention index ≥29%, 107 patients) and low-retention index (retention index <29%, 44 patients). Retention index was calculated as follows: retention index (%) = [(SUVmax2 - SUVmax1)/SUVmax1] × 100.

RESULTS

The overall survival and relapse-free survival rates in the high-retention index group were significantly lower than those in the low-retention index group (P < 0.001). Our multivariate analysis identified that the high-retention index group contained independent risk factors for overall survival (hazard ratio: 2.44, P = 0.009) and relapse-free survival (hazard ratio: 2.61, P = 0.002). The high-retention index group exhibited a lower partial response rate to neoadjuvant chemotherapy evaluated by computed tomography (P < 0.001) and a lower pathological therapeutic effect in the resected specimen (P = 0.019) than the low-retention index group.

CONCLUSIONS

The retention index was associated with neoadjuvant chemotherapy responses and long-term prognosis for oesophageal cancer.

Dual-phase FDG PET/CT for predicting prognosis in operable breast cancer

Purpose

We aimed to investigate the role of dual-phase FDG PET/CT in predicting the prognosis of patients with operable breast cancer.

Methods

We retrospectively reviewed the data of 998 patients who underwent radical treatment for breast cancer. Before treatment, PET/CT scans were performed 1 and 2 h after FDG administration. The maximum standardized uptake value (SUVmax) at both time points (SUVmax1 and SUVmax2) in the primary tumor and the retention index (RI) were calculated. PET recurrence risk (PET-RR) was determined based on the SUVmax1 and RI, and disease-free survival (DFS) and overall survival (OS) were evaluated according to the metabolic parameters. Propensity score matching was performed to adjust for biological characteristics.

Results

The cut-off values for SUVmax1 and RI were 3 and 5%, respectively. The 5-year DFS was 94.9% and 86.1% (P < 0.001), and the 5-year OS was 97.6% and 92.7% (P < 0.001) in the low and high PET-RR groups, respectively. In multivariate analysis, high T status, nodal metastasis, the triple-negative subtype, and high PET-RR were independent factors of poor DFS. Propensity score matching revealed similar findings (5-year DFS 91.8% vs. 88.6%, P = 0.041 and 5-year OS 97.1% vs. 94.2%, P = 0.240, respectively).

Conclusion

The combined parameters of SUVmax1 and RI on dual-phase FDG PET/CT were useful for predicting prognosis of patients with breast cancer. Patients with a high SUVmax1 and a negative time course of FDG uptake had a favorable prognosis.

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SUVmax and retention index on FDG PET/CT are related with breast cancer prognosis.

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Breast cancer with high SUVmax but no increase over time has a favorable prognosis.

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Dual-phase FDG PET/CT is useful to predict the prognosis in operable breast cancer.

Retention index of FDG-PET/CT SUVmax of the primary tumor in non-small cell lung cancer as a predictor of lymph node metastasis: a retrospective study

Background

Accurate staging of non-small cell lung cancer is key in treatment planning and prediction of prognosis. We investigated the correlation between the maximum standardized uptake value (SUVmax) retention index (RI) of the primary tumor and lymph node metastasis in non-small cell lung carcinoma. We also evaluated the tendencies according to the histological types.

Methods

We retrospectively evaluated 218 non-small cell lung cancer (NSCLC) tumors from 217 patients who underwent preoperative fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) followed by lung surgery and lymph node resection between July 2015 and August 2020. All primary tumors were calculated as the SUVmax at 50 min (SUVmax_early [SUVmax_e]) and 120 min (SUVmax_delayed [SUVmax_d]), and RI. The clinicopathological factors of interest were compared based on lymph node metastasis status and NSCLC histopathological subtype.

Results

The median SUVmax_e and SUVmax_d of the primary tumors were 3.3 and 4.2, respectively, and the median RI was 0.25. The RI was significantly higher in the pN(+) (n = 44) group (0.30) compared to the pN0 (n = 174) group (0.24) (p = 0.01). In patients with adenocarcinoma (n = 145), the RI was also significantly higher in the pN(+) (n = 29) group (0.29) compared to the pN0 (n = 116) group (0.16) (p < 0.01). A high RI of the primary tumor was an independent risk factor for lymph node metastasis, particularly in patients with adenocarcinoma (odds ratio: 12.30, p < 0.05).

Conclusions

The RI of primary NSCLC tumors can help predict lymph node metastases, particularly in patients with adenocarcinoma.

The value of diffusion kurtosis imaging, diffusion weighted imaging and 18F-FDG PET for differentiating benign and malignant solitary pulmonary lesions and predicting pathological grading

Objective

To explore the value of PET/MRI, including diffusion kurtosis imaging (DKI), diffusion weighted imaging (DWI) and positron emission tomography (PET), for distinguishing between benign and malignant solitary pulmonary lesions (SPLs) and predicting the histopathological grading of malignant SPLs.

Material and methods

Chest PET, DKI and DWI scans of 73 patients with SPL were performed by PET/MRI. The apparent diffusion coefficient (ADC), mean diffusivity (MD), mean kurtosis (MK), maximum standard uptake value (SUV_max), metabolic total volume (MTV) and total lesion glycolysis (TLG) were calculated. Student’s t test or the Mann–Whitney U test was used to analyze the differences in parameters between groups. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy. Logistic regression analysis was used to evaluate independent predictors.

Results

The MK and SUV_max were significantly higher, and the MD and ADC were significantly lower in the malignant group (0.59 ± 0.13, 10.25 ± 4.20, 2.27 ± 0.51[×10^-3 mm²/s] and 1.35 ± 0.33 [×10^-3 mm²/s]) compared to the benign group (0.47 ± 0.08, 5.49 ± 4.05, 2.85 ± 0.60 [×10^-3 mm²/s] and 1.67 ± 0.33 [×10^-3 mm²/s]). The MD and ADC were significantly lower, and the MTV and TLG were significantly higher in the high-grade malignant SPLs group (2.11 ± 0.51 [×10^-3 mm²/s], 1.35 ± 0.33 [×10^-3 mm²/s], 35.87 ± 42.24 and 119.58 ± 163.65) than in the non-high-grade malignant SPLs group (2.46 ± 0.46 [×10^-3 mm²/s], 1.67 ± 0.33[×10^-3 mm²/s], 20.17 ± 32.34 and 114.20 ± 178.68). In the identification of benign and malignant SPLs, the SUV_max and MK were independent predictors, the AUCs of the combination of SUV_max and MK, SUV_max, MK, MD, and ADC were 0.875, 0.787, 0.848, 0.769, and 0.822, respectively. In the identification of high-grade and non-high-grade malignant SPLs, the AUCs of MD, ADC, MTV, and TLG were 0.729, 0.680, 0.693, and 0.711, respectively.

Conclusion

DWI, DKI, and PET in PET/MRI are all effective methods to distinguish benign from malignant SPLs, and are also helpful in evaluating the pathological grading of malignant SPLs.

Clinical Impact of Dual Time Point 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Fusion Imaging in Pancreatic Cancer

We examined the value of preoperative dual time point (DTP) 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (FDG PET/CT) as a predictor of early recurrence or the outcomes in patients with pancreatic cancer. Standardized uptake values (SUVs) in DTP FDG PET/CT were performed as preoperative staging. SUVmax1 and SUVmax2 were obtained in 60 min and 120 min, respectively. ΔSUVmax% was defined as (SUVmax2 − SUVmax1)/SUVmax1 × 100. The optimal cut-off values for SUVmax parameters were selected based on tumor relapse within 1 year of surgery. Optimal cut-off values for SUVmax1 and ΔSUVmax% were 7.18 and 24.25, respectively. The combination of SUVmax1 and ΔSUVmax% showed higher specificity and sensitivity, and higher positive and negative predictive values for tumor relapse within 1 year than SUVmax1 alone. Relapse-free survival (RFS) was significantly worse in the subgroups of high SUVmax1 and high ΔSUVmax% (median 7.0 months) than in the other subgroups (p < 0.0001). The multivariate Cox analysis of RFS identified high SUVmax1 and high ΔSUVmax% as independent prognostic factors (p = 0.0060). DTP FDG PET/CT may effectively predict relapse in patients with pancreatic cancer. The combination of SUVmax1 and ΔSUVmax% identified early recurrent patient groups more precisely than SUVmax1 alone.

Is Delayed Image of 18F-FDG PET/CT Necessary for Mediastinal Lymph Node Staging in Non-Small Cell Lung Cancer Patients?

PURPOSE

The purpose of this study was to evaluate the diagnostic accuracies of dual-time-point (DTP) 18F-FDG PET/CT for detection of mediastinal lymph node (LN) metastasis in non-small cell lung cancer (NSCLC) patients through a systematic review and meta-analysis.

PATIENTS AND METHODS

The PubMed, Cochrane database, and EMBASE database, from the earliest available date of indexing through October 31, 2021, were searched for studies evaluating diagnostic performance of DTP 18F-FDG PET/CT for detection of metastatic mediastinal LN in NSCLC patients. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves.

RESULTS

Ten studies (758 patients) were included in the current study. In patient-based analysis, early image showed a sensitivity of 0.76 and a specificity of 0.75. Delayed image revealed a sensitivity of 0.84 and a specificity of 0.71. In LN-based analysis, early image showed a sensitivity of 0.80 and a specificity of 0.83. Delayed image revealed a sensitivity of 0.84 and a specificity of 0.87. Retention index or %ΔSUVmax is superior to early or delayed images of DTP 18F-FDG PET/CT for detection of mediastinal LN metastasis.

CONCLUSIONS

Dual-time-point 18F-FDG PET/CT showed a good diagnostic performances for detection of metastatic mediastinal LNs in NSCLC patients. Early and delayed images of DTP 18F-FDG PET/CT revealed similar diagnostic accuracies for LN metastasis. However, retention index or %ΔSUVmax is superior to early or delayed images of DTP 18F-FDG PET/CT for detection of mediastinal LN metastasis in NSCLC patients. Further large multicenter studies would be necessary to substantiate the diagnostic accuracy of DTP 18F-FDG PET/CT for mediastinal LN staging in NSCLC patients.

Different Prognostic Values of Dual-Time-Point FDG PET/CT Imaging Features According to Treatment Modality in Patients with Non-Small Cell Lung Cancer

This study was aimed to investigate whether dual-time-point F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) imaging features had different prognostic values according to the treatment modality in patients with non-small cell lung cancer (NSCLC). We retrospectively reviewed 121 NSCLC patients with surgical resection (surgery group) and 69 NSCLC patients with chemotherapy and/or radiotherapy (CRT group), who underwent pretreatment dual-time-point FDG PET/CT. The maximum standardized uptake value (SUV), metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUV histogram entropy of primary cancer, and the percent changes in these parameters (Δparameters) were measured. In multivariate analysis, MTV, TLG, and entropy on both early and delayed PET/CT scans were significantly associated with progression-free survival (PFS) in the surgery group, but all Δparameters failed to show a significant association. In the CRT group, TLG on the early PET, maximum SUV on the delayed PET, ΔMTV, and ΔTLG were significant independent predictors for PFS. In the surgery group, patients with high values of MTV, TLG, and entropy had worse survival, whereas, in the CRT group, patients with high values of ΔMTV and ΔTLG had better survival. Dual-time-point FDG PET/CT parameters showed different prognostic values between the surgery and CRT groups of NSCLC patients.

Reproducibility of Standardized Uptake Values Including Volume Metrics Between TOF-PET-MR and TOF-PET-CT

Purpose

To investigate the reproducibility of tracer uptake measurements, including volume metrics, such as metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) obtained by TOF-PET-CT and TOF-PET-MR.

Materials and Methods

Eighty consecutive patients with different oncologic diagnoses underwent TOF-PET-CT (Discovery 690; GE Healthcare) and TOF-PET-MR (SIGNA PET-MR; GE Healthcare) on the same day with single dose−18F-FDG injection. The scan order, PET-CT following or followed by PET-MR, was randomly assigned. A spherical volume of interest (VOI) of 30 mm was placed on the liver in accordance with the PERCIST criteria. For liver, the maximum and mean standard uptake value for body weight (SUV) and lean body mass (SUL) were obtained. For tumor delineation, VOI with a threshold of 40 and 50% of SUVmax was used (VOI40 and VOI50). The SUVmax, SUVmean, SUVpeak, MTV and TLG were calculated. The measurements were compared between the two scanners.

Results

In total, 80 tumor lesions from 35 patients were evaluated. There was no statistical difference observed in liver regions, whereas in tumor lesions, SUVmax, SUV mean, and SUVpeak of PET-MR were significantly underestimated (p < 0.001) in both VOI40 and VOI50. Among volume metrics, there was no statistical difference observed except TLG on VOI50 (p = 0.03). Correlation between PET-CT and PET-MR of each metrics were calculated. There was a moderate correlation of the liver SUV and SUL metrics (r = 0.63–0.78). In tumor lesions, SUVmax and SUVmean had a stronger correlation with underestimation in PET-MR on VOI 40 (SUVmax and SUVmean; r = 0.92 and 0.91 with slope = 0.71 and 0.72, respectively). In the evaluation of MTV and TLG, the stronger correlations were observed both on VOI40 (MTV and TLG; r = 0.75 and 0.92) and VOI50 (MTV and TLG; r = 0.88 and 0.95) between PET-CT and PET-MR.

Conclusion

PET metrics on TOF-PET-MR showed a good correlation with that of TOF-PET-CT. SUVmax and SUVpeak of tumor lesions were underestimated by 16% on PET-MRI. MTV with % threshold can be regarded as identical volumetric markers for both TOF-PET-CT and TOF-PET-MR.

Differentiation Between Malignant and Benign Pulmonary Nodules by Using Automated Three-Dimensional High-Resolution Representation Learning With Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography

Background

The investigation of incidental pulmonary nodules has rapidly become one of the main indications for 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), currently combined with computed tomography (PET-CT). There is also a growing trend to use artificial Intelligence for optimization and interpretation of PET-CT Images. Therefore, we proposed a novel deep learning model that aided in the automatic differentiation between malignant and benign pulmonary nodules on FDG PET-CT.

Methods

In total, 112 participants with pulmonary nodules who underwent FDG PET-CT before surgery were enrolled retrospectively. We designed a novel deep learning three-dimensional (3D) high-resolution representation learning (HRRL) model for the automated classification of pulmonary nodules based on FDG PET-CT images without manual annotation by experts. For the images to be localized more precisely, we defined the territories of the lungs through a novel artificial intelligence-driven image-processing algorithm, instead of the conventional segmentation method, without the aid of an expert; this algorithm is based on deep HRRL, which is used to perform high-resolution classification. In addition, the 2D model was converted to a 3D model.

Results

All pulmonary lesions were confirmed through pathological studies (79 malignant and 33 benign). We evaluated its diagnostic performance in the differentiation of malignant and benign nodules. The area under the receiver operating characteristic curve (AUC) of the deep learning model was used to indicate classification performance in an evaluation using fivefold cross-validation. The nodule-based prediction performance of the model had an AUC, sensitivity, specificity, and accuracy of 78.1, 89.9, 54.5, and 79.4%, respectively.

Conclusion

Our results suggest that a deep learning algorithm using HRRL without manual annotation from experts might aid in the classification of pulmonary nodules discovered through clinical FDG PET-CT images.

Prognostic value of metabolic parameters measured by pretreatment dual-time-point 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with intrahepatic or perihilar cholangiocarcinoma: A STROBE study

The purpose of this study was to determine the glucose metabolism at delay phase measured by pretreatment dual-time-point 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/ computed tomography (CT) provides prognostic information independent of well-known prognostic factors in patients with intrahepatic or perihilar cholangiocarcinoma (ICC or PCC).From July 2012 to December 2017, 55 patients (men 27, women 28, mean age 68 ± 11 years) with pathologically proven ICC or PCC were enrolled in this retrospective study. The dual-time-point 18F-FDG PET/CT as part of a staging workup was performed in all patients. The patient's data includes age, sex, serum CA19-9, presence of LN or distant metastasis, early SUVmax (early maximum standardized uptake value [eSUV]), delay SUVmax (delay maximum standardized uptake value [dSUV]), retention index of SUVmax (percent change of maximum standardized uptake values [ΔSUV]), neutrophil to lymphocyte ratio (NLR) and histopathology including pCEA, p53, Ki-67 index. The analysis of the relationship between metabolic parameters and survival was done using the Kaplan-Meier curve and Cox proportional hazards regression model.Median survival for all patients was 357 days. Median early and delay SUVmax was 5.2 (range: 2.0-21.4) and 6.5 (range 2.7-24.5), respectively. The overall survival was found to be significantly related to eSUV, dSUV, ΔSUV, age, serum CA19-9 and NLR in univariate analysis. In multivariate analysis, dSUV (P = .014, 95%CI; 1.30-10.7, HR 3.74) and ΔSUVmax (P = .037, 95%CI; 1.05-6.12, HR 2.5) were independent factors of overall survival. Kaplan-Meier curve analysis clearly showed the significant difference of overall survival between 2 groups (high eSUV, low eSUV + high ΔSUV vs low eSUV and ΔSUV, P < .001) among the comparisons of the SUV parameters on FDG PET. In the receiver operating characteristic analysis using combinations of the SUV parameters, the 2 groups [eSUV + ΔSUV (P = .0001, area under the curve [AUC] 0.68) and dSUV + ΔSUV (P = .0002, AUC 0.71)] showed significantly larger AUC than the other groups applying eSUV or dSUV alone (AUC 0.61 and AUC 0.68).dSUV and ΔSUV on pretreatment dual-time-point 18F-FDG PET/CT can be useful parameters in the prediction of survival in patients with ICC or PCC.

Utility of PET/CT in the diagnosis and staging of lung cancer after ecobronchoscopy in mining population

INTRODUCTION

Positron emission tomography (PET) with computerized axial tomography (CT) in a single device is known as PET/CT. It has been widely documented and validated, and it is currently a core part of the diagnosis and staging of lung cancer. However, its reliability has not been analysed in specific populations. The objective of this study is to determine the usefulness of PET/CT in patients exposed to mining activities in which an endobronchial ultrasound (EBUS) has been performed for the diagnosis and/or staging of lung cancer.

PATIENTS AND METHODS

With a prospective and real-time database, all the patients who had undergone an EBUS with suspicion of lung cancer and who had previously undergone a PET/CT were selected. The observation unit was the lymph node and, based on their history of exposure to mining activities, the sample was divided into two categories, group 1: not exposed; and group 2: exposed. In each group, and with the results from anatomical pathology as a dependent variable, logistic models were established to look for independent risk factors for malignancy.

RESULTS

In group 1, lymph nodes larger than 1 cm and PET/CT uptake with maximum standardized uptake value (SUVmax) over 2.5 were independent risk factors for malignancy. However, in group 2 (exposed patients), none of those factors were predictors for malignancy.

DISCUSSION

In the population of individuals with occupational exposure to mining, PET/CT is an imaging technique with diagnostic limitations for lung cancer.

Initial and Delayed Metabolic Activity of Palatine Tonsils Measured with the PET/CT-Dedicated Parameters

One of the most critical elements in the palatine tonsils (PT) patients' management is to distinguish chronic tonsillitis and malignant tumor. The single-time-point (STP) 2-deoxy-2-[¹⁸ F]fluoro-D-glucose positron emission tomography/computed tomography (¹⁸ F-FDG PET/CT) examination offers the most significant sensitivity and specificity in the head and neck (H&N) region evaluation among commonly used methods of imaging. However, introducing dual-time-point (DTP) scanning might improve the specificity and sensitivity of the technique, limited by the ¹⁸ F-FDG non-tumor-specific patterns, especially when comparing different metabolic parameters. The study aims to compare several surrogates of the maximal standardized uptake value (SUVmax), obtained in 36 subjects, divided into confirmed by pathologic study PT cancer and tonsillitis in patients who underwent DTP ¹⁸ F-FDG PET/CT scanning. In this study, we observed the increased sensitivity and the specificity of the DTP ¹⁸ F-FDG PET/CT when compared with the standard PET/CT protocol. It could be concluded that DTP ¹⁸ F-FDG PET/CT improves the PT cancer and chronic tonsillitis differential diagnosis.

Metabolic changes in breast cancer on dual-time-point 18F-FDG PET/CT imaging according to primary tumor uptake and background parenchymal enhancement

OBJECTIVE

This study was aimed at investigating metabolic changes in breast cancer on dual-time-point ¹⁸F-FDG PET/CT imaging (DTPI) according to primary tumor uptake and determining whether this technique is affected by background parenchymal enhancement (BPE).

METHODS

A total of 189 patients with newly diagnosed breast cancer who underwent DTPI examination were retrospectively evaluated. DTPI was performed using a standard FDG/PET protocol followed by delayed image acquisition at 120 min after injection. Patients were divided into two groups according to primary tumor uptake as breast cancer with low maximum standard uptake value (SUVmax) (< 2.5) and high SUVmax (≥ 2.5). The maximal SUV of the primary breast tumor (T-SUVmax), contralateral breast parenchyma uptake (B-SUVmax) according to different BPE grades, tumor to background ratio (T/B-SUVmax), and their percentage changes between early and delayed images (retention index, RI) were calculated.

RESULTS

For primary tumor uptake, tumors with high SUV had a significant increase in mean T-SUVmax between early and delayed images (8.17 vs. 9.16, P < 0.001), and %RI T-SUVmax was 10.52%. Conversely, mean T-SUVmax did not change between early and delayed images for tumors with low SUV (1.96 vs. 1.94, P = 0.610), and %RI T-SUVmax was - 1.41%. The mean %RI B-SUVmax was - 12.43% for minimal BPE, - 14.19% for mild BPE, - 19.49% for moderate BPE, and - 21.25% for marked BPE grade, indicating that higher BPE grades undergo better washouts on delayed imaging (β = - 3.220, P < 0.001 for trend). The %RI T/B-SUVmax of both breast cancer groups with low SUV and high SUV was 18.86% and 32.47%, respectively.

CONCLUSIONS

Breast cancer with low SUV undergoes no significant change in SUV on DTPI; however, washing of background parenchymal activity was evident over time, resulting in significantly increased tumor contrast in delayed images, which leads to increased sensitivity. Breast parenchymal washout was more significant with increased BPE level. Therefore, DTPI is expected to be more useful for evaluating breast lesions in regions with marked BPE on MRI.

Sequential delayed [18 F]FDG PET/CT examinations in the pharynx

This study aimed to evaluate the usefulness of the biphasic 2-deoxy-2-[18 F]fluoro-D-glucose positron emission tomography/computed tomography ([18 F]FDG PET/CT) examinations in terms of distinguishing benign and malignant lesions within the pharynx. 139 patients underwent sequential biphasic [18 F]FDG PET/CT examinations at 60 and 90 minutes (min) post intravenous injection (p.i.) of the [18 F]FDG. We evaluated the metabolic activity of 93 malignant lesions and 59 benign findings within pharynx as well as 70 normal blood vessels. We evaluated the maximal and mean standardized uptake value (SUVmax, SUVmean) and the retention index (RI-SUVmax). We used the receiver operating characteristics (ROC) analysis to obtain the prognostic metabolic indices cut-off which may differentiate between benign and malignant lesions. The SUVmax value cut-off at 60 and 90 min p.i. differentiating between normal and abnormal metabolic activity in the pharynx was 1.9 and 2.0, respectively. When compared benign and malignant lesions, the SUVmax on initial and delayed scans were 3.1 and 3.6, respectively. In this material, the increase of the SUVmax value over time of 1.7% suggested abnormality, while RI-SUVmax of 5.7% indicated malignant etiology. The biphasic [18 F]FDG PET/CT study protocol is useful in better stratification of normal and abnormal glucose metabolism activity in the pharynx.

Dual time point 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in primary breast cancer

BACKGROUND

To evaluate the clinicopathological and prognostic significance of the percentage change between maximum standardized uptake value (SUV_max) at 60 min (SUV_max1) and SUV_max at 120 min (SUV_max2) (ΔSUV_max%) using dual time point ¹⁸F-fluorodeoxyglucose emission tomography/computed tomography (¹⁸F-FDG PET/CT) in breast cancer.

METHODS

Four hundred and sixty-four patients with primary breast cancer underwent ¹⁸F-FDG PET/CT for preoperative staging. ΔSUV_max% was defined as (SUV_max2 - SUV_max1) / SUV_max1 × 100. We explored the optimal cutoff value of SUV_max parameters (SUV_max1 and ΔSUV_max%) referring to the event of relapse by using receiver operator characteristic curves. The clinicopathological and prognostic significances of the SUV_max1 and ΔSUV_max% were analyzed by Cox's univariate and multivariate analyses.

RESULTS

The optimal cutoff values of SUV_max1 and ΔSUV_max% were 3.4 and 12.5, respectively. Relapse-free survival (RFS) curves were significantly different between high and low SUV_max1 groups (P = 0.0003) and also between high and low ΔSUV_max% groups (P = 0.0151). In Cox multivariate analysis for RFS, SUV_max1 was an independent prognostic factor (P = 0.0267) but ΔSUV_max% was not (P = 0.152). There was a weak correlation between SUV_max1 and ΔSUV_max% (P < 0.0001, R² = 0.166). On combining SUV_max1 and ΔSUV_max%, the subgroups of high SUV_max1 and high ΔSUV_max% showed significantly worse prognosis than the other groups in terms of RFS (P = 0.0002).

CONCLUSION

Dual time point ¹⁸F-FDG PET/CT evaluation can be a useful method for predicting relapse in patients with breast cancer. The combination of SUV_max1 and ΔSUV_max% was able to identify subgroups with worse prognosis more accurately than SUV_max1 alone.

Prognostic value of dual-point fluorine-18 fluorodeoxyglucose PET imaging, partial volume correction and glucose transporter-1 expression in resected nonsmall cell lung cancer patients

OBJECTIVE

To investigate the relationship between the prognosis and glucose transporter-1 (Glut-1) expression or fluorine-18 fluorodeoxyglucose uptake using partial volume correction and dual-point imaging in surgically resected nonsmall cell lung cancer (NSCLC) patients.

METHODS

Our patient population consisted of 108 NSCLC cases. The early maximum standardized uptake value (ESUVmax), delayed SUVmax (DSUVmax), partial volume correction SUVmax (cSUVmax) and retention index of primary lesions were calculated. Cox proportional hazard model was applied to evaluate the effects of PET parameters and Glut-1 expression. Overall survival (OS) and disease-free survival (DFS) were evaluated by Kaplan-Meier methods, and the difference in survival between subgroups was analyzed by log-rank test.

RESULTS

On the Cox regression analysis, ESUVmax, DSUVmax, cSUVmax and Glut-1 were significantly related to DFS [ESUVmax, hazard ratio = 2.301, 95% confidential interval (CI) = 1.146-4.618, P = 0.019; DSUVmax, hazard ratio = 2.483, 95% CI = 1.257-4.905, P = 0.009; cSUVmax, hazard ratio = 2.205, 95% CI = 1.038-4.686, P = 0.04; Glut-1, hazard ratio = 2.095, 95% CI = 1.086-4.041, P = 0.001] and OS (ESUVmax, hazard ratio = 3.197, 95% CI = 1.339-7.633, P = 0.009; DSUVmax, hazard ratio = 3.599, 95% CI = 1.521-8.516, P = 0.004; cSUVmax, hazard ratio = 8.655, 95% CI = 2.048-36.658, P = 0.003; Glut-1, hazard ratio = 2.427, 95% CI = 5.140, P = 0.021). Retention index had no significant association with DFS or OS. On the Kaplan-Meier survival curves, the patients with high ESUVmax, DSUVmax, cSUVmax and Glut-1 showed significantly worse prognosis than those with low values (ESUVmax: DFS, P = 0.001, OS, P = 0.003; DSUVmax: DFS, P = 0.002, OS, P = 0.004; cSUVmax: DFS, P < 0.001, OS, P = 0.013; Glut-1: DFS, P = 0.012, OS, P = 0.002).

CONCLUSIONS

cSUVmax, ESUVmax, DSUVmax and Glut-1 may be more useful biomarkers than retention index for predicting outcomes in NSCLC patients.

Validation of Independent Prognostic Value of Asphericity of 18F-Fluorodeoxyglucose Uptake in Non-Small-Cell Lung Cancer Patients Undergoing Treatment With Curative Intent

BACKGROUND

In patients with non-small-cell lung cancer (NSCLC), asphericity (ASP) of the primary tumor's metabolic tumor volume (MTV) has shown prognostic significance. This study aimed at validation in an independent and sufficiently large cohort.

PATIENTS AND METHODS

A retrospective study was performed of 311 NSCLC patients undergoing ¹⁸F-fluorodeoxyglucose positron emission tomography / computed tomography (¹⁸F-FDG PET/CT) before curatively intended treatment (always including surgery). A total of 140 patients had International Union Against Cancer (UICC) stage I disease, 78 had stage II disease, and 93 had stage III disease (adenocarcinoma, n = 153; squamous-cell carcinoma, n = 141). Primary tumor MTV was delineated with semiautomated background-adapted threshold relative to the standardized maximum uptake value (SUV_max). Cox regression (progression-free survival [PFS] and overall survival [OS]) analysis for positron emission tomography (MTV, ASP, SUV_max) as well as for clinical (T/N descriptor, UICC stages), histologic, and treatment variables (Rx/1 vs. R0 resection, chemotherapy/radiotherapy yes/no) were performed.

RESULTS

Events (progression and relapse) occurred in 167 of 311 patients; 137 died (median survivor follow-up, 37 months). In multivariable Cox regression for OS, ASP > 33.3% (hazard ratio, 1.58 [1.04-2.39]), male sex (1.84), age (1.04 per year), Eastern Cooperative Oncology Group performance status ≥ 2 versus 0/1 (2.68), stage II versus I (1.96), and Rx/1 versus R0 resection (2.1) were significant. Among separate UICC stages, ASP only predicted OS in stage II (optimal, > 19.5%; median OS, 33 vs. 59 months). Regarding PFS, ASP > 21.2%, male sex, Eastern Cooperative Oncology Group performance status ≥ 2, stage II versus I disease, and Rx/1 resection were prognostic. ASP remained prognostic for stage II disease (optimal, > 19.5%; PFS, 12 vs. 47 months). Log-rank test for ASP was significant at any cutoff ≥ 18% (OS) or from 9% to 59% (PFS).

CONCLUSION

ASP was validated as prognostic factor for PFS and OS in patients with NSCLC and curative treatment intent, especially stage II. High ASP in stage II could imply intensified treatment or intensified follow-up.

Relationship between KRAS mutations and dual time point 18F-FDG PET/CT imaging in colorectal liver metastases

PURPOSE

To investigate the association between metabolic parameters of dual time point ¹⁸F-FDG PET/CT imaging and Kirsten rat sarcoma (KRAS) mutation status in colorectal liver metastases (CRLM).

METHODS

Forty-nine colorectal cancer patients with 87 liver metastatic lesions were included in this retrospective study. KRAS gene mutation tests were also performed for all the patients. The maximum standardized uptake value (SUV_max) was measured for each hepatic metastatic lesion on both early and delayed scans, and the change of SUV_max (ΔSUV_max) and retention index (RI) were calculated. Uni-variate and multi-variate analyses were employed to determine the relationship between any PET/CT parameters and KRAS mutation status.

RESULTS

Thirty-seven (42.5%) liver metastatic lesions harboring KRAS mutations were identified. The SUV_max of CRLM with KRAS mutation both on early and delayed scans was significantly higher than those with wild-type KRAS (10.7 ± 6.0 vs. 7.8 ± 3.3, P = 0.002; 15.5 ± 10.1 vs. 10.0 ± 4.2, P < 0.001, respectively). Compared with wild-type KRAS CRLM, ΔSUV_max and RI (%) of CRLM with KRAS mutation were also significantly higher than those with wild-type KRAS (4.8 ± 4.7 vs. 2.2 ± 2.0, P < 0.001; 45.3 ± 28.2 vs. 29.6 ± 24.7, P = 0.003, respectively). Multi-variate analyses showed that the SUV_max on both early and delayed scans, ΔSUV_max, and RI (%) were the 4 independent factors to predict CRLM patients harboring KRAS mutations.

CONCLUSION

The SUV_max on both early and delayed scans, ΔSUV_max, and RI (%) may be the 4 independent factors to predict CRLM patients harboring KRAS mutations.

Prognostic value of metabolic tumor burden calculated using dual-time-point 18F-fluorodeoxyglucose positron emission tomography/CT in patients with oropharyngeal or hypopharyngeal cancer

BACKGROUND

This study investigates the prognostic value of metabolic tumor burden calculated using dual-time-point 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT in patients with locally advanced cancer.

METHODS

This study examines 42 patients (35 men and 7 women, 38-73 years old) with locally advanced oropharyngeal or hypopharyngeal cancer who had undergone FDG-PET/CT before receiving chemoradiotherapy. Maximum standardized uptake value (SUV_max ), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured for the early and delayed phases. Statistical analyses included receiver operating characteristic curve, univariate and multivariate analysis.

RESULTS

ΔSUV_max , both phases of MTV_2.5 and TLG_2.5 , early TLG_40% , ΔTLG_2.5 , and ΔTLG_40% were significantly associated with progression-free survival (PFS). In multivariate analysis, early TLG_2.5 (P = .005) was an independent prognostic factor of PFS.

CONCLUSION

Not the percent change but the value calculated in the early phase in several parameters using dual-time-point FDG-PET/CT is significantly associated with the outcomes of patients with locally advanced oropharyngeal or hypopharyngeal cancer.

Evaluation of physiologic and abnormal glucose uptake in palatine tonsils: differential diagnostics with sequential dual-time-point 2-deoxy-2-[18F]FDG PET/CT

BACKGROUND

The aim of this article was to evaluate the usefulness of sequential dual-time-point 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (DTP [18F]FDG PET/CT) in distinguishing physiologic, inflammatory and malignant palatine tonsils as difficult to differentiate in the oncological practice.

METHODS

A total of 90 patients before the treatment underwent sequential DTP [18F]FDG PET/CT examinations. We analyzed 104 structures in 90 patients: 31 physiologic tonsils, 28 histopathologically confirmed inflammatory tonsils of non-specified origin, 31 histopathologically confirmed palatine tonsils cancer and 14 non-malignant contralateral tonsils in patients with histopathologically confirmed unilateral palatine tonsil malignancy. Patients underwent sequential [18F]FDG PET/CT examinations at 60 and 90 minutes post-injection of the [18F]FDG. We analyzed the SUVmax and SUVmean values at 60 and 90 minutes post-injection changes over time and the Retention Index (RI-SUVmax). To find the predictive SUV value and the RI cut-off between physiology, inflammatory and malignancy, we used the ROC analysis.

RESULTS

The average SUVmax values at 60 and 90minutes post-injection within physiologic palatine tonsils were 1.36±0.26 and 1.31±0.26, respectively, P>0.05. The average SUVmax values at 60 and 90 minutes post-injection within inflammatory and malignant tonsils were 3.74±1.45, 3.80±1.47 (P>0.05) and 5.19±2.19, 5.81±2.50 (P<0.05), respectively. The RI-SUVmax fluctuation over time were 5±28% within physiologic, -4±11% within contralateral non-malignant tonsils in patients with one tonsil involved, 2±11% within inflammatory and 13±13% within malignant tonsils.

CONCLUSIONS

The sequential dual-time-point [18F]FDG PET/CT examinations may increase the sensitivity and the specificity of the PET/CT method in differential palatine tonsils diagnosis.

Improved discrimination between benign and malignant LDCT screening-detected lung nodules with dynamic over static 18F-FDG PET as a function of injected dose

Lung cancer mortality rate can be significantly reduced by up to 20% through routine low-dose computed tomography (LDCT) screening, which, however, has high sensitivity but low specificity, resulting in a high rate of false-positive nodules. Combining PET with CT may provide more accurate diagnosis for indeterminate screening-detected nodules. In this work, we investigated low-dose dynamic 18F-FDG PET in discrimination between benign and malignant nodules using a virtual clinical trial based on patient study with ground truth. Six patients with initial LDCT screening-detected lung nodules received 90 min single-bed PET scans following a 10 mCi FDG injection. Low-dose static and dynamic images were generated from under-sampled list-mode data at various count levels (100%, 50%, 10%, 5%, and 1%). A virtual clinical trial was performed by adding nodule population variability, measurement noise, and static PET acquisition start time variability to the time activity curves (TACs) of the patient data. We used receiver operating characteristic (ROC) analysis to estimate the classification capability of standardized uptake value (SUV) and net uptake constant K i from their simulated benign and malignant distributions. Various scan durations and start times (t *) were investigated in dynamic Patlak analysis to optimize simplified acquisition protocols with a population-based input function (PBIF). The area under curve (AUC) of ROC analysis was higher with increased scan duration and earlier t *. Highly similar results were obtained using PBIF to those using image-derived input function (IDIF). The AUC value for K i using optimized t * and scan duration with 10% dose was higher than that for SUV with 100% dose. Our results suggest that dynamic PET with as little as 1 mCi FDG could provide discrimination between benign and malignant lung nodules with higher than 90% sensitivity and specificity for patients similar to the pilot and simulated population in this study, with LDCT screening-detected indeterminate lung nodules.

The role of dual time point PET/CT for distinguishing malignant from benign focal 18F-FDG uptake duodenal lesions

The aim of this study was to evaluate the diagnostic criteria of dual time point Fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) in differentiating malignant from benign focal hypermetabolic lesions of duodenum.A total of 50 patients underwent F-FDG PET/CT at 2 points: 60 ± 13.7 minutes (early imaging) and 120 ± 26.4 minutes (delayed imaging) after tracer injection. Early maximum standardized uptake value (SUVE), delayed maximum standardized uptake value (SUVD), difference between early and delayed maximum standardized uptake value (D-SUVmax), and retention index (RI) were calculated for each duodenal lesion. Receiver operating characteristic analysis (ROC) was performed to evaluate the discriminating validity of the parameters.There were 32 malignant and 18 benign focal F-FDG uptake duodenal lesions. The values of SUVE, SUVD, and D-SUVmax were significantly different between malignant and benign lesions (12.5 ± 6.3 vs 5.8 ± 1.2, 13.5 ± 6.5 vs 5.5 ± 1.1 and 0.3 ± 0.8 vs 1.0 ± 1.0, respectively). The areas under the curves (AUCs) of SUVE, SUVD, D-SUVmax were 0.932, 0.964 and 0.707, respectively. There was no significantly difference between SUVE and SUVD based on AUC. In detecting malignant lesions, SUVE=6.9 yielded a sensitivity of 88.9% and specificity of 84.4%, SUVD=7.2 yielded a sensitivity of 94.6% and specificity of 90.6%, D-SUVmax=0.5 yielded a sensitivity of 72.2% and specificity of 68.8%. SUVD was the best diagnostic indicator, regarding specificity and specificity.SUVE and SUVD had good sensitivity, specificity for differentiating duodenal lesions. But there was no significantly difference between diagnostic value of SUVE and SUVD. F-FDG uptake patterns are helpful for differentiating benign and malignant duodenal lesions.

Predictive value of dual-time 18F-FDG PET/CT to distinguish primary lung and metastatic adenocarcinoma in solitary pulmonary nodule

AIMS AND BACKGROUND

Distinction between primary lung adenocarcinoma and metastatic adenocarcinoma from extrapulmonary origin in solitary pulmonary nodule (SPN) is crucial for cancer treatment. We investigated the predictive role of dual-time-point ¹⁸F-FDG PET/CT to distinguish primary and metastatic lung adenocarcinoma in SPN.

METHODS

A total of 96 consecutive patients with newly diagnosed SPN and biopsy-proven adenocarcinoma were enrolled in this study, retrospectively (54 male; 42 female; age 59.68 ± 8.2 years). They all underwent dual-time-point ¹⁸F-FDG PET/CT at 60 minutes (early) for whole body and 120 minutes (delayed) for chest region after FDG injection. Maximum standardized uptake values (early SUVmax and delayed SUVmax) and retention index (RI) were acquired for analysis. Final pathology results were confirmed by surgical specimens.

RESULTS

Metastatic adenocarcinoma showed significantly higher early SUVmax, delayed SUVmax, and RI compared to primary lung adenocarcinoma. Delayed SUVmax and RI presented superior diagnostic performance for prediction of metastatic adenocarcinoma than early ¹⁸F-FDG PET/CT. Among metastatic adenocarcinoma, metastasis from colorectal origin showed significantly higher RI than from other origins. In addition, RI significantly predicted metastatic adenocarcinoma from colorectal cancer than early or delayed SUVmax.

CONCLUSIONS

Dual-timepoint ¹⁸F-FDG PET/CT can be useful to distinguish primary and metastatic lung adenocarcinoma in SPN. Furthermore, it may also be useful to predict metastatic adenocarcinoma from colorectal origin.

The maximum standardized uptake value increment calculated by dual-time-point 18F-fluorodeoxyglucose positron emission tomography predicts survival in patients with oral tongue squamous cell carcinoma

The aim of this study was to investigate the prognostic value of dual-time-point (DTP) ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) imaging in primary oral tongue squamous cell carcinoma (OTSCC). The study included 52 patients who underwent preoperative ¹⁸F-FDG PET scans at two time points, namely 1 h and 2 h after injection. The following PET parameters were calculated: maximum standardized uptake value (SUVmax) for both time points (SUV early, SUV delayed); retention index (RI); and SUVmax increment (ΔSUVmax). Receiver operating characteristic (ROC) curve analysis was performed to define the optimal cutoff point for these parameters. Overall survival was calculated using the Kaplan–Meier method. Prognostic factors for patients with OTSCC were evaluated using the univariate log-rank test and a multivariate Cox proportional hazards model. ROC analysis revealed that the area under the curve was higher and more accurate for ΔSUVmax than for the other parameters. Additionally, patients with a ΔSUVmax ≥0.9 had significantly worse survival outcomes (28.9% vs 92.6%; p < 0.01). Univariate analysis showed that prognosis was significantly correlated with clinical T stage, local recurrence, perineural invasion, vascular invasion, and PET parameters (p < 0.05 for all). Multivariate analysis showed that local recurrence (hazard ratio = 3.60; p = 0.02) and ΔSUVmax (hazard ratio = 8.43; p < 0.01) were independent prognostic factors. ΔSUVmax determined using DTP ¹⁸F-FDG PET may be an additional prognostic factor in OTSCC patients.

Prognostic value of the standardized uptake value maximum change calculated by dual-time-point (18)F-fluorodeoxyglucose positron emission tomography imaging in patients with advanced non-small-cell lung cancer

Purpose

The purpose of this study was to investigate the prognostic value of the standardized uptake value maximum (SUVmax) change calculated by dual-time-point ¹⁸F-fluorodeoxyglucose positron emission tomography (PET) imaging in patients with advanced non-small-cell lung cancer (NSCLC).

Patients and methods

We conducted a retrospective review of 115 patients with advanced NSCLC who underwent pretreatment dual-time-point ¹⁸F-fluorodeoxyglucose PET acquired at 1 and 2 hours after injection. The SUVmax from early images (SUVmax1) and SUVmax from delayed images (SUVmax2) were recorded and used to calculate the SUVmax changes, including the SUVmax increment (ΔSUVmax) and percent change of the SUVmax (%ΔSUVmax). Progression-free survival (PFS) and overall survival (OS) were determined by the Kaplan–Meier method and were compared with the studied PET parameters, and the clinicopathological prognostic factors in univariate analyses and multivariate analyses were constructed using Cox proportional hazards regression.

Results

One hundred and fifteen consecutive patients were reviewed, and the median follow-up time was 12.5 months. The estimated median PFS and OS were 3.8 and 9.6 months, respectively. In univariate analysis, SUVmax1, SUVmax2, ΔSUVmax, %ΔSUVmax, clinical stage, and Eastern Cooperative Oncology Group (ECOG) scores were significant prognostic factors for PFS. Similar results were significantly correlated with OS, except %ΔSUVmax. In multivariate analysis, ΔSUVmax and %ΔSUVmax were significant factors for PFS. On the other hand, ECOG scores were only identified as independent predictors of OS.

Conclusion

Our results demonstrated the prognostic value of the SUVmax change in predicting the PFS of patients with advanced NSCLC. However, SUVmax change could not predict OS.