Prognostic significance of [(18)F]fluorodeoxyglucose uptake on positron emission tomography in patients with pathologic stage I lung adenocarcinoma

Beneficial implications of adjuvant chemotherapy for stage IB lung adenocarcinoma exhibiting elevated SUVmax in FDG-PET/CT: a retrospective study from a single center

Background

Controversy surrounds the efficacy of adjuvant chemotherapy (ACT) in the treatment of stage I lung adenocarcinoma (LUAD). The objective of this study was to examine the impact of the maximum standardized uptake value (SUVmax) as measured by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) on the efficacy of ACT in patients diagnosed with stage I LUAD.

Methods

We scrutinized the medical records of 928 consecutive patients who underwent complete surgical resection for pathological stage I LUAD at our institution. The ideal cut-off value for primary tumor SUVmax in terms of disease-free survival (DFS) and overall survival (OS) was determined using the X-tile software. The Kaplan-Meier method and Cox regression analysis were used for survival analysis.

Results

Based on the SUVmax algorithm, the ideal cutoff values were determined to be 4.9 for DFS and 5.0 for OS. We selected 5.0 as the threshold because OS is the more widely accepted predictive endpoint. In a multivariate Cox regression analysis, SUVmax ≥ 5.0, problematic IB stage, and sublobectomy were identified as independent risk factors for poor DFS and OS. It is noteworthy that patients who were administered ACT had significantly longer DFS and OS than what was observed in the subgroup of patients with pathological stage IB LUAD and SUVmax ≥ 5.0 (p < 0.035 and p ≤ 0.046, respectively). However, there was no observed survival advantage for patients in stages IA or IB who had an SUVmax < 5.0.

Conclusion

The preoperative SUVmax of tumors served as an indicator of the impact of ACT in the context of completely resected pathological stage I LUAD. Notably, patients within the Stage IB category exhibiting elevated SUVmax levels emerged as a subgroup experiencing substantial benefits from postoperative ACT.

Histopathologic Basis for a Chest CT Deep Learning Survival Prediction Model in Patients with Lung Adenocarcinoma

Background A preoperative CT-based deep learning (DL) prediction model was proposed to estimate disease-free survival in patients with resected lung adenocarcinoma. However, the black-box nature of DL hinders interpretation of its results. Purpose To provide histopathologic evidence underpinning the DL survival prediction model and to demonstrate the feasibility of the model in identifying patients with histopathologic risk factors through unsupervised clustering and a series of regression analyses. Materials and Methods For this retrospective study, data from patients who underwent curative resection for lung adenocarcinoma without neoadjuvant therapy from January 2016 to September 2020 were collected from a tertiary care center. Seven histopathologic risk factors for the resected adenocarcinoma were documented: the aggressive adenocarcinoma subtype (cribriform, morular, solid, or micropapillary-predominant subtype); mediastinal nodal metastasis (pN2); presence of lymphatic, venous, and perineural invasion; visceral pleural invasion (VPI); and EGFR mutation status. Unsupervised clustering using 80 DL model-driven CT features was performed, and associations between the patient clusters and the histopathologic features were analyzed. Multivariable regression analyses were performed to investigate the added value of the DL model output to the semantic CT features (clinical T category and radiologic nodule type [ie, solid or subsolid]) for histopathologic associations. Results A total of 1667 patients (median age, 64 years [IQR, 57-71 years]; 975 women) were evaluated. Unsupervised patient clusters 3 and 4 were associated with all histopathologic risk factors (P < .01) except for EGFR mutation status (P = .30 for cluster 3). After multivariable adjustment, model output was associated with the aggressive adenocarcinoma subtype (odds ratio [OR], 1.03; 95% CI: 1.002, 1.05; P = .03), venous invasion (OR, 1.03; 95% CI: 1.004, 1.06; P = .02), and VPI (OR, 1.08; 95% CI: 1.06, 1.10; P < .001), independently of the semantic CT features. Conclusion The deep learning model extracted CT imaging surrogates for the histopathologic profiles of lung adenocarcinoma. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Yanagawa in this issue.

Relationships between SUVmax of lung adenocarcinoma and different T stages, histological grades and pathological subtypes: a retrospective cohort study in China

OBJECTIVES

Cancer cell has aberrant metabolism. The purpose of this study aimed to investigate relationships between maximum standard uptake value (SUVmax）of ¹⁸fluoro-2-deoxy-d-glucose and T stages, histological grades and pathological subtypes of lung adenocarcinoma.

DESIGN

Retrospective cohort study, employing the Kruskal-Wallis, Bonferroni-Dunn and Mann-Whitney tests to compare SUVmax of different T stages, histological grades and pathological subtypes of lung adenocarcinoma.

SETTING

The outpatients who had aberrant positron emission tomography/CT (PET/CT) images in chest were enrolled this study from August 2016 to November 2018 in Shanghai, China.

PARTICIPANT

Initial 11 270 patients with suspected lung cancer who underwent PET/CT examinations were surveyed. A total of 1454 patients who were diagnosed as lung adenocarcinoma by pathologist were included in this project.

PRIMARY OUTCOME MEASURES

SUVmax value at different tumour-node-metastasis stages of lung adenocarcinoma before surgery.

RESULTS

The mean SUVmax of patients with lung adenocarcinoma was significantly elevated with the increase in T stages. There were significant evident differences in SUVmax among T1a-T1c (p<0.05). However, after the staging of patients was more than T1 stage, SUVmax of T2a, T2b, T2 visceral pleural invasion, T3 and T4 had not dramatic changes. SUVmax value of lung adenocarcinoma in the same T stage group was the highest in patients with the high grade of malignancy and solid-predominant invasive adenocarcinoma.

CONCLUSIONS

SUVmax value was significantly associated with T stages, grades of malignancy and pathological subtypes of lung adenocarcinoma.

Correlation of preoperative PET/computer tomography 18F-fluorodeoxyglucose uptake (maximum standardized uptake value) with prognosis in patients with operated lung cancer

PURPOSE

The aim of this study was to investigate the correlation of preoperative 18F-fluorodeoxyglucose PET/computed tomography maximum standardized uptake value (SUVmax) in operated non-small cell lung cancer (NSCLC) cases with other prognostic parameters and survival.

PATIENTS AND METHODS

NSCLC patients treated by surgical resection were imaged with PET within 60 days before surgery.

RESULTS

Overall, 525 cases consecutive patients were retrospectively reviewed. The median value of SUVmax in a total of 525 cases was 12.1, and the mean was 13.3 ± 7.13. Logistic regression analysis performed to identify the variables that have an impact on SUVmax revealed that histology [hazard ratio (HR: 1.893; 95% CI; P = 0.001) and T status (HR: 8.991; 95% CI; P = 0.000) are correlated with SUVmax. Kaplan-Meier analysis revealed a mean survival of 73.7 ± 1.95 months and a median survival of 85.6 ± 6.03 months. In the group with an SUVmax value of less than 10, the mean survival was 81.9 ± 3.02 months (76.0-87.8), and in the group with SUVmax greater than 10.1, the mean survival was 68.6 ± 2.4 months (63.9-73.3) (P = 0.000). In the multivariate analysis, SUVmax, age, tumor histology, lymph node metastasis, comorbid diseases and complete/incomplete status of the resection were identified as the factors predictive of prognosis.

CONCLUSION

It is seen that preoperative SUVmax is a parameter with prognostic significance at least as much as histopathology, age, complete/incomplete status of resection and lymph node involvement.

Update on Molecular Imaging and Precision Medicine in Lung Cancer

Precision medicine integrates molecular pathobiology, genetic make-up, and clinical manifestations of disease in order to classify patients into subgroups for the purposes of predicting treatment response and suggesting outcome. By identifying those patients who are most likely to benefit from a given therapy, interventions can be tailored to avoid the expense and toxicity of futile treatment. Ultimately, the goal is to offer the right treatment, to the right patient, at the right time. Lung cancer is a heterogeneous disease both functionally and morphologically. Further, over time, clonal proliferations of cells may evolve, becoming resistant to specific therapies. PET is a sensitive imaging technique with an important role in the precision medicine algorithm of lung cancer patients. It provides anatomo-functional insight during diagnosis, staging, and restaging of the disease. It is a prognostic biomarker in lung cancer patients that characterizes tumoral heterogeneity, helps predict early response to therapy, and may direct the selection of appropriate treatment.

Positron Emission Tomography in Segmentectomy for cT1N0M0 Nonsmall Cell Lung Cancer

BACKGROUND

This study was aimed to examine the significance of fluorodeoxyglucose positron emission tomography in predicting prognosis after segmentectomy in lung cancer.

METHODS

This was a retrospective cohort study, including 227 patients with cT1N0M0 nonsmall cell lung cancer who underwent positron emission tomography followed by segmentectomy between 2012 and 2019. Significance of tumor histology, T-stage, tumor size, and standardized uptake value on positron emission tomography in relation to recurrence-free survival were examined using Cox's proportional hazard analysis. Median follow-up period was 56 months (range: 1-95 months).

RESULTS

Tumor stages were Tis in 25 patients, T1mi/T1a in 51, T1b in 98, and T1c in 53. Twenty-six patients (11%) experienced recurrences, including local (n = 8) and distant (n = 18). Multivariate analysis showed that the significant variables for recurrence-free survival were T-stage and standardized uptake value (p = 0.002 and 0.015, respectively), whereas tumor histology and tumor size were not significant (p = 0.28 and 0.44, respectively). When tumor size was divided into ≤2 cm and >2 cm for analysis, it was not significant again (p = 0.49), whereas standardized uptake value remained significant (p = 0.008). While standardized uptake value of tumors with recurrences was significantly higher than those without (4.9-2.8 and 2.6-2.5, respectively, p < 0.001), there was no significant difference between local and distant recurrences (p = 0.32). Cut-off value of standardized uptake value for recurrences was 3.2. Five-year recurrence-free survival rates in tumors with standardized uptake value <3.2 and ≥3.2 were 86 and 65%, respectively (p < 0.001).

CONCLUSION

Positron emission tomography could predict the prognosis after segmentectomy better than tumor size.

Combining fluorine-18 fluorodeoxyglucose positron emission tomography and pathological risk factors to predict postoperative recurrence in stage I lung adenocarcinoma

OBJECTIVE

The aim of this study was to investigate the predictive value of qualitative assessment of tumor fluorine-18 fluorodeoxyglucose (F-FDG) uptake on PET and pathological risk factors for postoperative tumor recurrence in patients with stage I lung adenocarcinoma.

PATIENTS AND METHODS

Eighty-seven patients with stage I lung adenocarcinoma who had undergone F-FDG-PET and sequential surgical treatment without adjuvant chemotherapy were enrolled into this retrospective study. Qualitative assessment visually compared tumor F-FDG uptake with liver uptake. Tumors with one or more risk factors of tumor size of at least 4 cm, poorly differentiated, visceral pleural invasion, and lymphovascular invasion were defined as pathological high-risk tumors.

RESULTS

Patients with pathological high-risk tumors had a significantly (P=0.015) higher standardized uptake value. A multivariable Cox's proportional hazard analysis showed that tumor F-FDG uptake>liver uptake (adjusted hazard ratio: 3.54; 95% confidence interval: 1.36-9.21, P=0.010) and pathological high-risk tumors (adjusted hazard ratio: 2.34; 95% confidence interval: 1.13-4.87, P=0.023) were significant independent predictors of postoperative tumor recurrence. Patients with tumor F-FDG uptake>liver uptake and pathological high-risk tumors had significantly (P=0.001) worse 5-year disease-free survival (38.8%) and significantly (P=0.011) worse overall survival (68.5%).

CONCLUSION

Tumor F-FDG uptake>liver uptake and pathological high-risk tumors were significant independent predictors of postoperative tumor recurrence in stage I lung adenocarcinoma. Combining the two factors improves the prediction of disease-free and overall survivals, which could offer a feasible prediction model for clinically recommending adjuvant chemotherapy.

Metabolic positron emission tomography parameters predict failure patterns in early non-small-cell lung cancer treated with stereotactic body radiation therapy: a single institution experience

Objective

The prognostic value of metabolic parameters using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has not been established for early non-small cell lung cancer (NSCLC). Accordingly, the authors investigated the prognostic value of metabolic parameters in terms of failure patterns in patients with early NSCLC who underwent stereotactic body radiation therapy (SBRT).

Methods

Data from 35 patients with Stage I NSCLC who underwent SBRT using CyberKnife and received pretreatment FDG PET/CT between 2008 and 2016 were retrospectively reviewed. Maximum standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis were measured. The significance of these parameters with regard to failure patterns was assessed.

Results

The median follow-up was 23 months for all patients and 34 months for living patients. Ten patients experienced recurrence: three local failures, five regional failures (RF), and eight distant failures (DF). Three-year local, regional and distant control rates were 96.7%, 86.4% and 71.1%, respectively. High SUVmax (<9 vs. ≥9) was an independent predictive factor associated with increased RF (P = 0.027) and DF (P = 0.008). Furthermore, SUVmax was indicative of both progression-free (P = 0.015) and overall (P = 0.034) survival.

Conclusions

High SUVmax was a significant metabolic parameter associated with increased RF and DF in patients with early NSCLC who received SBRT, having a high propensity for dissemination. These results suggest that adjuvant treatment in conjunction with SBRT may be considered in patients with early NSCLC and high SUVmax.

Dynamic prognostication using conditional survival analysis for patients with operable lung adenocarcinoma

PURPOSE

To evaluate conditional survival among patients with surgically resected stage I-IIIa lung adenocarcinoma and identify changes in prognostic contributions for various prognostic factors over time.

PATIENTS AND METHODS

We performed conditional survival analysis at each t0 (=0, 1, 2, 3, 4, 5 years) for 723 consecutive patients who underwent surgical resection for lung adenocarcinoma, stratified by various clinico-demographic features, as well as pathologic and imaging (tumor-shadow disappearance ratio [TDR] on CT and maximum standardized uptake value [SUVmax] on PET) characteristics. Uni- and multivariableCox regression analyses were performed to evaluate relationships between those variables and conditional survival.

RESULTS

Three-year conditional overall survival (OS) and disease-free survival (DFS) were 92.12% and 75.51% at baseline, but improved steadily up to 98.33% and 95.95% at 5 years after surgery. In contrast to demographic factors, pathologic (stage, subtype, pathologic grade and differentiation) and radiologic factors (TDR and SUVmax) maintained a statistically significant association with subseqeunt 3-year OS until 3 years after surgery. According to the multivariableanalysis, high SUVmax and low TDR value were independent predictors of subsequent 3-year OS and DFS at baseline, 1 and 2 years after surgery, respectively.

CONCLUSION

Our findings based on CS provide theoretical background for clinicians to plan longer period of surveillance following lung adenocarcinoma resection in survivors with preoperatively high SUVmax and low TDR on PET-CT and chest CT, respectively.

The predictive value of 18F-FDG PET-CT for assessing the clinical outcomes in locally advanced NSCLC patients after a new induction treatment: low-dose fractionated radiotherapy with concurrent chemotherapy

Background

Patients with locally advanced non-small-cell lung cancer (LA-NSCLC) have poor prognosis despite several multimodal approaches. Recently, low-dose fractionated radiotherapy concurrent to the induction chemotherapy (IC-LDRT) has been proposed to further improve the effects of chemotherapy and prognosis. Until now, the predictive value of metabolic response after IC-LDRT has not yet been investigated. Aim: to evaluate whether the early metabolic response, assessed by ¹⁸F-fluoro-deoxyglucose positron emission-computed tomography (¹⁸F-FDG PET-CT), could predict the prognosis in LA-NSCLC patients treated with a multimodal approach, including IC-LDRT.

Methods

Forty-four consecutive patients (35males, mean age: 66 ± 7.8 years) with stage IIIA/IIIB NSCLC were retrospectively evaluated. Forty-four patients underwent IC-LDRT (2 cycles of chemotherapy, 40 cGy twice daily), 26/44 neo-adjuvant chemo-radiotherapy (CCRT: 50.4Gy), and 20/44 surgery. ¹⁸F-FDG PET-CT was performed before (baseline), after IC-LDRT (early) and after CCRT (final), applying PET response criteria in solid tumours (PERCIST). Patients with complete/partial metabolic response were classified as responders; patients with stable/progressive disease as non-responders. Progression free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meyer analysis; the relationship between clinical factors and survivals were assessed using uni-multivariate regression analysis.

Results

Forty-four out of 44, 42/44 and 23/42 patients underwent baseline, early and final PET-CT, respectively. SUL_peak of primary tumour and lymph-node significantly (p = 0.004, p = 0.0002, respectively) decreased after IC-LDRT with a further reduction after CCRT (p = 0.0006, p = 0.02, respectively). At early PET-CT, 20/42 (47.6%) patients were classified as responders, 22/42 (52.3%) as non-responders. At final PET-CT, 19/23 patients were classified as responders (12 responders and 7 non-responders at early PET-CT), and 4/23 as non-responders (all non-responders at early PET-CT). Early responders had better PFS and OS than early non-responders (p ≤ 0.01). Early metabolic response was predictive factor for loco-regional, distant and global PFS (p = 0.02, p = 0.01, p = 0.005, respectively); surgery for loco-regional and global PFS (p = 0.03, p = 0.009, respectively).

Conclusions

In LA-NSCLC patients, ¹⁸F-FDG metabolic response assessed after only two cycles of IC-LDRT predicts the prognosis. The early evaluation of metabolic changes could allow to personalize therapy. This multimodality approach, including both low-dose radiotherapy that increases the effects of induction chemotherapy, and surgery that removes the disease, improved clinical outcomes. Further prospective investigation of this new induction approach is warranted.

PET Imaging-Based Phenotyping as a Predictive Biomarker of Response to Tyrosine Kinase Inhibitor Therapy in Non-small Cell Lung Cancer: Are We There Yet?

The increased understanding of the molecular pathology of different malignancies, especially lung cancer, has directed investigational efforts to center on the identification of different molecular targets and on the development of targeted therapies against these targets. A good representative is the epidermal growth factor receptor (EGFR); a major driver of non-small cell lung cancer tumorigenesis. Today, tumor growth inhibition is possible after treating lung tumors expressing somatic mutations of the EGFR gene with tyrosine kinase inhibitors (TKI). This opened the doors to biomarker-directed precision or personalized treatments for lung cancer patients. The success of these targeted anticancer therapies depends in part on being able to identify biomarkers and their patho-molecular make-up in order to select patients that could respond to specific therapeutic agents. While the identification of reliable biomarkers is crucial to predict response to treatment before it begins, it is also essential to be able to monitor treatment early during therapy to avoid the toxicity and morbidity of futile treatment in non-responding patients. In this context, we share our perspective on the role of PET imaging-based phenotyping in the personalized care of lung cancer patients to non-invasively direct and monitor the treatment efficacy of TKIs in clinical practice.

Molecular Imaging and Precision Medicine in Lung Cancer

Precision medicine allows tailoring of preventive or therapeutic interventions to avoid the expense and toxicity of futile treatment given to those who will not respond. Lung cancer is a heterogeneous disease functionally and morphologically. PET is a sensitive molecular imaging technique with a major role in the precision medicine algorithm of patients with lung cancer. It contributes to the precision medicine of lung neoplasia by interrogating tumor heterogeneity throughout the body. It provides anatomofunctional insight during diagnosis, staging, and restaging of the disease. It is a biomarker of tumoral heterogeneity that helps direct selection of the most appropriate treatment, the prediction of early response to cytotoxic and cytostatic therapies, and is a prognostic biomarker in patients with lung cancer.

Prognostic Value of 18F-FDG PET/CT in Surgical Non-Small Cell Lung Cancer: A Meta-Analysis

Background

The identification of surgical non-small cell lung cancer (NSCLC) patients with poor prognosis is a priority in clinical oncology because of their high 5-year mortality. This meta-analysis explored the prognostic value of maximal standardized uptake value (SUV_max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on disease-free survival (DFS) and overall survival (OS) in surgical NSCLC patients.

Materials and Methods

MEDLINE, EMBASE and Cochrane Libraries were systematically searched until August 1, 2015. Prospective or retrospective studies that evaluated the prognostic roles of preoperative 18F-FDG PET/CT with complete DFS and OS data in surgical NSCLC patients were included. The impact of SUV_max, MTV or TLG on survival was measured using hazard ratios (HR). Sub-group analyses were performed based on disease stage, pathological classification, surgery only and cut-off values.

Results

Thirty-six studies comprised of 5807 patients were included. The combined HRs for DFS were 2.74 (95%CI 2.33–3.24, unadjusted) and 2.43 (95%CI: 1.76–3.36, adjusted) for SUV_max, 2.27 (95%CI 1.77–2.90, unadjusted) and 2.49 (95%CI 1.23–5.04, adjusted) for MTV, and 2.46 (95%CI 1.91–3.17, unadjusted) and 2.97 (95%CI 1.68–5.28, adjusted) for TLG. The pooled HRs for OS were 2.54 (95%CI 1.86–3.49, unadjusted) and 1.52 (95%CI 1.16–2.00, adjusted) for SUV_max, 2.07 (95%CI 1.16–3.69, unadjusted) and 1.91 (95%CI 1.13–3.22, adjusted) for MTV, and 2.47 (95%CI 1.38–4.43, unadjusted) and 1.94 (95%CI 1.12–3.33, adjusted) for TLG. Begg’s test detected publication bias, the trim and fill procedure was performed, and similar HRs were obtained. The prognostic role of SUV_max, MTV and TLG remained similar in the sub-group analyses.

Conclusions

High values of SUV_max, MTV and TLG predicted a higher risk of recurrence or death in patients with surgical NSCLC. We suggest the use of FDG PET/CT to select patients who are at high risk of disease recurrence or death and may benefit from aggressive treatments.

Correlation between FDG-PET/CT findings and solid type non-small cell cancer prognostic factors: are there differences between adenocarcinoma and squamous cell carcinoma?

OBJECTIVES

The maximum standardized uptake value (SUVmax) of FDG-PET/CT is commonly used as an indicator to evaluate the invasiveness and prognosis of non-small-cell lung cancers (NSCLC). We investigated the correlation between SUVmax and tumor invasiveness or postoperative recurrence of solid type NSCLC and compared squamous cell carcinoma (SCC)/adenosquamous carcinoma (ASC) to adenocarcinoma (AC).

METHODS

A retrospective review of preoperative PET/CT, thin-section CT, and postoperative pathological records obtained over a 5-year period was conducted. Solid type NSCLC tumors on thin-section CT with confirmed diagnosis from surgical resection (diameter ≤3 cm) were included. Multivariate logistic regression was used to evaluate the correlation between tumor characteristics and pathological prognostic factors or postoperative recurrence.

RESULTS

150 patients (111 males, 39 females; mean age 67 years; 106 cases of AC, 36 cases of SCC, and 8 cases of ASC) were included. SUVmax was significantly correlated with pleural involvement (p = 0.047), lymphatic permeation (p = 0.003), lymph node metastasis (p = 0.027), and tumor invasiveness (p < 0.001). Receiver operating characteristic analysis indicated an optimal SUVmax threshold of 5.0 for tumor invasiveness. Histopathological type was significantly correlated with pleural involvement (p = 0.042), but not with other types of invasiveness. Twenty-nine patients experienced postoperative recurrence. SUVmax was significantly correlated with tumor recurrence (p = 0.004), but size and histopathological type were not (p = 0.502 and p = 0.351, respectively).

CONCLUSION

SUVmax of the primary lesion in solid type NSCLC was significantly correlated with tumor invasiveness and postoperative recurrence. No differences in tumor invasiveness were observed between solid type AC and SCC/ASC. However, in solid type AC, SUVmax of the primary lesion was more significantly correlated with recurrence.

Preliminary comparison of diffusion-weighted MRI and PET/CT in predicting histological type and malignancy of lung cancer

INTRODUCTION

Emerging evidence shows that diffusion-weighted magnetic resonance imaging (DW MRI) and fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸ F-FDG PET/CT) might be useful in predicting histological type and malignancy of lung cancer, and even in specifically detecting the types of gene mutation.

OBJECTIVE

We assessed whether DW MRI is equivalent to PET/CT in lung cancer diagnosis and evaluation.

METHODS

The institutional review board approved this study, and written informed consent was obtained from all patients. DW MRI and FDG PET/CT were performed before therapy in 15 lung cancer patients diagnosed by pathological examination. Apparent diffusion coefficient (ADC), ratio of ADC (rADC = ADC in tumor/ADC in spinal cord) and maximal standardized uptake value (SUV_max ) were assessed.

RESULTS

ADC, rADC and SUV_max did not reveal significant differences among different types of lung cancer. Sensitivity, specificity and accuracy of ADC, rADC and SUV_max proved to be not significantly different in the detection of adenocarcinoma and squamous cell carcinoma. Difference in the abilities of the sensitivity, specificity and accuracy of ADC, rADC and SUV_max to detect adenocarcinoma and squamous cell carcinoma proved to be insignificant. Although Ki-67 score did not show correlation with ADC, rADC and SUV_max , significant positive correlation was found between ADC and rADC, and ADC and SUV_max .

CONCLUSIONS

Both DW MRI and FDG PET/CT had similar limited diagnostic capability of predicting different histological types and malignancy of lung cancer. This study may help provide a novel insight into diagnostic and therapeutic strategies of lung cancer based on DW MRI.

FDG-PET maximum standardized uptake value is prognostic for recurrence and survival after stereotactic body radiotherapy for non-small cell lung cancer

OBJECTIVES

Glucose metabolic activity measured by [(18)F]-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) has shown prognostic value in multiple malignancies, but results are often confounded by the inclusion of patients with various disease stages and undergoing various therapies. This study was designed to evaluate the prognostic value of tumor FDG uptake quantified by maximum standardized uptake value (SUVmax) in a large group of early-stage non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT) using consistent treatment techniques.

MATERIALS AND METHODS

Two hundred nineteen lesions in 211 patients treated with definitive SBRT for stage I NSCLC were analyzed after a median follow-up of 25.2 months. Cox regression was used to determine associations between SUVmax and overall survival (OS), disease-specific survival (DSS), and freedom from local recurrence (FFLR) or distant metastasis (FFDM).

RESULTS

SUVmax >3.0 was associated with worse OS (p<0.001), FFLR (p=0.003) and FFDM (p=0.003). On multivariate analysis, OS was associated with SUVmax (HR 1.89, p=0.03), gross tumor volume (GTV) (HR 1.94, p=0.005) and Karnofsky performance status (KPS) (HR 0.51, p=0.008). DSS was associated only with SUVmax (HR 2.58, p=0.04). Both LR (HR 11.47, p=0.02) and DM (HR 3.75, p=0.006) were also associated with higher SUVmax.

CONCLUSION

In a large patient population, SUVmax >3.0 was associated with worse survival and a greater propensity for local recurrence and distant metastasis after SBRT for NSCLC.

Diffusion-weighted magnetic resonance imaging in preoperative assessment of non-small cell lung cancer

BACKGROUND

Diffusion-weighted magnetic resonance imaging (DWI) frequently shows heterogeneity of signal intensity (SI) in non-small cell lung cancer (NSCLC). The purpose of our study was to examine the association of SI and DWI patterns with histology, tumor invasiveness, lymph node metastasis, and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) uptake in NSCLC.

METHODS

One hundred forty-five patients with NSCLC underwent preoperative DWI and FDG-PET. DWI patterns were visually classified as homogenous (HOM) (n = 81) or heterogeneous (HET) (n = 64). The former was further classified as faint (faint-HOM) (n = 27) or dark (dark-HOM) (n = 54) according to a cutoff value of SI. Associations of SI and DWI patterns with tumor histology, lymphatic or vascular invasion, pleural invasion, lymph node metastasis, and FDG uptake were evaluated.

RESULTS

All faint-HOM tumors were well-differentiated adenocarcinoma, whereas dark-HOM and HET tumors were less-differentiated adenocarcinoma or non adenocarcinoma. Although the dark areas in HET tumors showed a dense aggregation of tumor cells, their faint areas showed abundant fibrovascular stroma or necrosis, or a well-differentiated part of adenocarcinoma. Tumor size and the frequencies of lymphatic or vascular invasion, pleural invasion, and nodal metastasis were highest in HET tumors, followed by dark-HOM and faint-HOM (P = .1-P < .001) tumors. Sixty-five tumors having at least 1 of the invasions or metastasis showed significantly higher SI than the 81 tumors without (P < .001). HET tumors had the highest FDG uptake, followed by dark-HOM and faint-HOM tumors; differences between the groups were significant (P < .01 to P < .001).

CONCLUSIONS

The SI and heterogeneity of DWI reflect the histologic heterogeneity, tumor aggressiveness, and FDG-PET uptake in NSCLC.

Predictive value of 18F-FDG PET and CT morphologic features for recurrence in pathological stage IA non-small cell lung cancer

Patients with pathological stage IA non-small cell lung cancer (NSCLC) may relapse despite complete surgical resection without lymphovascular invasion. A method of selecting a high-risk group for adjuvant therapy is necessary. The aim of this study was to assess the predictive value of F-fluorodeoxyglucose (FDG) uptake and the morphologic features of computed tomography (CT) for recurrence in pathological stage IA NSCLC.One hundred forty-five patients with pathological stage IA NSCLC who underwent pretreatment with FDG positron emission tomography and CT evaluations were retrospectively enrolled. The associations among tumor recurrence and patient characteristics, maximal standard uptake value (SUVmax) of primary tumors, and CT imaging features were investigated using univariate and multivariate analyses. A receiver operating characteristic (ROC) curve analysis was performed to quantify the predictive value of these factors.Tumor recurrence developed in 21 (14.5%) of the 145 patients, and the 5-year recurrence-free survival rate was 77%. The univariate analysis demonstrated that SUVmax, the grade of histological differentiation, tumor size, and the presence of bronchovascular bundle thickening were significant predictive factors (P < 0.05). A higher SUVmax (≥2.5) (P = 0.021), a lower ground-glass opacity ratio (≤17%) (P = 0.014), and the presence of bronchovascular bundle thickening (P = 0.003) were independent predictive factors of tumor recurrence in the multivariate analysis. The use of this predictive model yielded a greater area under the ROC curve (0.877), which suggests good discrimination.The combined evaluation of FDG uptake and CT morphologic features may be helpful in the prediction of recurrence in patients with pathological stage IA NSCLC and in the stratification of a high-risk group for postoperative adjuvant therapy or prospective clinical trials.

Does early PET/CT assesment of response to chemotherapy predicts survival in patients with advanced stage non-small-cell lung cancer?

The aim of this study is to determine the prognostic role and the timing of metabolic response to chemotherapy, based on F-fluorodeoxyglucose positron emission tomography (F-FDG-PET), in patients with metastatic non-small-cell lung cancer (NSCLC). The study included 55 patients with metastatic NSCLC that were analyzed in terms of prognostic factors and survival. F-FDG-PET/CT findings were evaluated in patients separated into 3 groups, before and after 1st, 2nd, 3rd cycle of the first line chemotherapy. Metabolic response was assessed according to PET Response Criteria in Solid Tumors (PERCIST 1.0). Among the 55 patients, 34 (62%) died, and 21 (38%) remained alive during a mean follow-up of 13.5 months. Median overall survival (OS) was 11.69 months (range 2-26.80 months) and median progression-free survival (PFS) was 6.27 months (range 1.37-20.43 months). Univariate analysis showed that the only favorable prognostic factor for OS in all the patients was the achievement of metabolic response. Metabolic response according to PERCIST, and weight lose ≤ 5% were also independent favorable prognostic factors predictive of survival in all patients based on multivariet analysis (metabolic response: P=0.002, OR; 1.90, 95% CI 1.26-2.89, and weight lose ≤5%: P=0.022, OR; 2.24, 95% CI 1.12-4.47). Median OS in all patients with partial response (PR)-according to the PERCIST 1.0- was significantly longer than in those with progressive disease (PD) (16.36 months vs 8.14 months, P=0.008). Median OS in the patients with PR was significantly longer than in those with PD based on PET/CT performed after 2nd and 3rd cycles of chemotherapy (18.35 months vs 7.54 months, P=0.012 and 18.04 months vs 7.43 months, P<0.001, respectively), whereas, median OS did not differ significantly between patients with PR and those with PD based on PET/CT performed after the 1st cycle of chemotherapy (8.01 months vs 5.08 months, P=0.290). Metabolic response according to PERCIST and weight loss are independent factors predictive of OS. PET/CT performed after second cycle of chemotherapy may be the earliest predictor of treatment response in patients with advanced stage NSCLC.

18F-FDG PET/CT metabolic variability in functioning oncocytic parathyroid adenoma with brown tumors

A 29-year-old female patient exhibited a solitary neck mass, severe hypercalcemia, and multiple skeletal lytic lesions consistent with metastatic neoplastic disease. Fine-needle aspiration (FNA) cytology of the neck lesion indicated a follicular thyroid neoplasm. CT-guided bone biopsy was non-diagnostic. Subsequent 18F-FDG PET/CT examination demonstrated avid glucose uptake within the neck mass and diffuse bony lesions of variable metabolic activity. Repeat biopsy utilizing PET/CT guidance produced core tissue with classic histologic features of a brown tumor. Postoperative histology revealed an exclusively oncocytic parathyroid adenoma. Atypical radiotracer uptake of this rare functioning adenoma subtype is illustrated with discussion of improved procedural diagnostic yield utilizing PET/CT.

Prediction of pathologic prognostic factors in patients with lung adenocarcinomas: comparison of thin-section computed tomography and positron emission tomography/computed tomography

Background

The ratio of the maximum diameter of consolidation to the maximum tumor diameter (C/T ratio) on thin-section computed tomography (TSCT) and the maximum standardized uptake value (SUVmax) on ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) are often used as preoperative independent variables to evaluate the invasiveness of lung adenocarcinoma. We investigated the associations between these independent variables and pathologic invasiveness in pulmonary adenocarcinomas.

Methods

We selected patients with peripheral lung adenocarcinomas, definitively diagnosed by surgical resection, with diameters of ≤ 30 mm over a 4-year period ending in December 2010. The association between 3 independent variables (tumor size, SUVmax, and C/T ratio) and pathologic prognostic factors was evaluated using logistic analysis.

Results

We evaluated a total of 163 primary lung adenocarcinomas in 148 patients (93 males and 55 females; age range: 34 to 84 years). Using multivariate logistic regression analysis, SUVmax and the C/T ratio were significantly associated with tumor invasiveness (odds ratio [OR] = 1.227; p = 0.025 and OR = 1.019; p = 0.008, respectively). Tumor size was not associated with invasiveness (OR = 1.003; p = 0.925). For solid type adenocarcinomas, only SUVmax was significantly associated with invasiveness (OR = 1.558; p = 0.003). For subsolid type adenocarcinomas, only the C/T ratio was significantly associated with invasiveness (OR = 1.030; p = 0.009).

Conclusions

Both the C/T ratio and the SUVmax are significantly correlated with pathologic invasiveness in patients with small lung adenocarcinomas, while there was a difference between the 2 evaluations. Solid type adenocarcinomas with SUVmax values of ≥ 4.4 and subsolid type adenocarcinomas with C/T ratio ≥ 53% were so highly invasive.

Pretreatment [18F]-fluoro-2-deoxy-glucose positron emission tomography maximum standardized uptake value as predictor of distant metastasis in early-stage non-small cell lung cancer treated with definitive radiation therapy: rethinking the role of positron emission tomography in personalizing treatment based on risk status

PURPOSE

The aim of this study was to determine whether the preradiation maximum standardized uptake value (SUVmax) of the primary tumor for [(18)F]-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) has a prognostic significance in patients with Stage T1 or T2N0 non-small cell lung cancer (NSCLC) treated with curative radiation therapy, whether conventional or stereotactic body radiation therapy (SBRT).

METHODS AND MATERIALS

Between January 2007 and December 2011, a total of 163 patients (180 tumors) with medically inoperable histologically proven Stage T1 or T2N0 NSCLC and treated with radiation therapy (both conventional and SBRT) were entered in a research ethics board approved database. All patients received pretreatment FDG-PET / computed tomography (CT) at 1 institution with consistent acquisition technique. The medical records and radiologic images of these patients were analyzed.

RESULTS

The overall survival at 2 years and 3 years for the whole group was 76% and 67%, respectively. The mean and median SUVmax were 8.1 and 7, respectively. Progression-free survival at 2 years with SUVmax <7 was better than that of the patients with tumor SUVmax ≥7 (67% vs 51%; P=.0096). Tumors with SUVmax ≥7 were associated with a worse regional recurrence-free survival and distant metastasis-free survival. In the multivariate analysis, SUVmax ≥7 was an independent prognostic factor for distant metastasis-free survival.

CONCLUSION

In early-stage NSCLC managed with radiation alone, patients with SUVmax ≥7 on FDG-PET / CT scan have poorer outcomes and high risk of progression, possibly because of aggressive biology. There is a potential role for adjuvant therapies for these high-risk patients with intent to improve outcomes.

CT and PET-CT of a dog with multiple pulmonary adenocarcinoma

A 10-year-old, intact female Yorkshire terrier had multiple pulmonary nodules on thoracic radiography and ultrasonography with no lesions elsewhere. Computed tomography (CT) and positron emission tomography and computed tomography (PET-CT) using 18F-fluorodeoxyglucose (FDG) were performed to identify metastasis and undetected primary tumors. On CT examination, pulmonary nodules had a hypoattenuating center with thin peripheral enhancement, suggesting ischemic or necrotizing lesion. In PET-CT at 47 min after intravenous injection of 11.1 MBq/kg of FDG, the maximum standardized uptake value of each pulmonary nodule was about from 3.8 to 6.4. There were no abnormal lesions except for four pulmonary nodules on the CT and PET-CT. Primary lung tumor was tentatively diagnosed, and palliative therapy using 2 mg/kg tramadol and 2.2 mg/kg carprofen twice per day was applied. After the dog’s euthanasia due to deteriorated clinical signs and poor prognosis, undifferentiated pulmonary adenocarcinoma was diagnosed through histopathologic and immunochemistry examination. To the best of the authors’ knowledge, this is the first study of CT and PET-CT features of canine pulmonary adenocarcinoma. In this case, multiple pulmonary adenocarcinoma could be determined on the basis of FDG PET-CT through screening the obvious distant metastasis and/or lymph node invasions and excluding unknown primary tumors.

DW MRI at 3.0 T versus FDG PET/CT for detection of malignant pulmonary tumors

Emerging evidence suggests that diffusion-weighted magnetic resonance imaging (DW MRI) could be useful for tumor detection with N and M staging of lung cancer in place of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). DW MRI at 3.0 T and FDG PET/CT were performed before therapy in 113 patients with pulmonary nodules. Mean apparent diffusion coefficient (ADC), maximal standardized uptake value (SUVmax ) and Ki-67 scores were assessed. Quantitatively, specificity and accuracy of ADC (91.7 and 92.9%, respectively) were significantly higher than those of SUVmax (66.7 and 77.9% respectively, p < 0.05), although sensitivity was not significantly different between them (93.5 and 83.1%, p > 0.05). Qualitatively, sensitivity, specificity and accuracy of DW MRI (96.1, 83.3 and 92.0%, respectively) were also not significantly different from that of FDG PET/CT (88.3, 83.3 and 86.7%, respectively, p > 0.05). Significant negative correlation was found between Ki-67 score and ADC (r = -0.66, p < 0.05), ADC and SUVmax (r = -0.37, p < 0.05), but not between Ki-67 score and SUVmax (r = -0.11, p > 0.05). In conclusion, quantitative and qualitative assessments for detection of malignant pulmonary tumors with DW MRI at 3.0 T are superior to those with FDG PET/CT. Furthermore, ADC could predict the malignancy of lung cancer.

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.

Primary tumor PET/CT [¹⁸F]FDG uptake is an independent predictive factor for regional lymph node metastasis in patients with non-small cell lung cancer

Aim: To investigate the correlation between [¹⁸F]fluorodeoxyglucose (FDG) uptake in a primary tumor and pathologic N stages, and to further analyze the possible risk factors contributing to the regional lymph node metastasis. Patients and methods: Eighty patients with non-small cell lung cancer (NSCLC) who underwent positron emission tomography/computed tomography were enrolled in the study. The FDG uptake in the primary tumor was compared for the different N staging groups and further correlation was performed. The degree of FDG uptake in the primary tumor and other possible variables related to the incidence of lymph node metastasis were examined by univariate and logistic multivariate analysis. FDG uptake was quantitated using the maximum standardized uptake value (SUV_max). Results: Statistically significant differences were found in the SUV_max of the primary tumors among different N staging groups (F = 4.124, P = 0.023), and the correlation between them was also statistically significant (r = 0.438, P = 0.000). Univariate analysis showed that blood tumor markers, primary tumor size, histologic grade, and SUV_max of the primary tumor were significantly associated with lymph node involvement. Logistic multivariate analysis showed that blood tumor makers and SUV_max of primary tumor might be considered as significant predictive factors for lymph node metastasis in patients with NSCLC. Conclusion: Our results show that there is a significant relationship between the SUV_max of the primary tumor and the pathologic N stage of NSCLC. FDG uptake by the primary tumor may be an independent predictor of regional lymph node metastasis in patients with NSCLC.

FDG-PET SUVmax combined with IASLC/ATS/ERS histologic classification improves the prognostic stratification of patients with stage I lung adenocarcinoma

BACKGROUND

We investigated the association between the newly proposed International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification and (18)F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET), and whether the combination of these radiologic and pathologic factors can further prognostically stratify patients with stage I lung adenocarcinoma.

METHODS

We retrospectively evaluated 222 patients with pathologic stage I lung adenocarcinoma who underwent FDG-PET scanning before undergoing surgical resection between 1999 and 2005. Patients were classified by histologic grade according to the IASLC/ATS/ERS classification (low, intermediate, or high grade) and by maximum standard uptake value (SUVmax) (low <3.0, high ≥3.0). The cumulative incidence of recurrence (CIR) was used to estimate recurrence probabilities.

RESULTS

Patients with high-grade histology had higher risk of recurrence (5-year CIR, 29% [n = 25]) than those with intermediate-grade (13% [n = 181]) or low-grade (11% [n = 16]) histology (p = 0.046). High SUVmax was associated with high-grade histology (p < 0.001) and with increased risk of recurrence compared to low SUVmax (5-year CIR, 21% [n = 113] vs. 8% [n = 109]; p = 0.013). Among patients with intermediate-grade histology, those with high SUVmax had higher risk of recurrence than those with low SUVmax (5-year CIR, 19% [n = 87] vs. 7% [n = 94]; p = 0.033). SUVmax was associated with recurrence even after adjusting for pathologic stage (p = 0.037).

CONCLUSIONS

SUVmax on FDG-PET correlates with the IASLC/ATS/ERS classification and can be used to stratify patients with intermediate-grade histology, the predominant histologic subtype, into two prognostic subsets.

Clinical outcome and predictors of survival and pneumonitis after stereotactic ablative radiotherapy for stage I non-small cell lung cancer

Background

Stereotactic ablative radiotherapy (SABR) can achieve excellent local control rates in early-stage non-small cell lung cancer (NSCLC) and has emerged as a standard treatment option for patients who cannot undergo surgery or those with isolated recurrences. However, factors that may predict toxicity or survival are largely unknown. We sought here to identify predictors of survival and pneumonitis after SABR for NSCLC in a relatively large single-institution series.

Methods

Subjects were 130 patients with stage I NSCLC treated with four-dimensional computed tomography (4D CT) –planned, on-board volumetric image–guided SABR to 50 Gy in 4 fractions. Disease was staged by positron emission tomography/computed tomography (PET/CT) and scans were obtained again at the second follow-up after SABR.

Results

At a median follow-up time of 26 months, the 2-year local control rate was 98.5%. The median overall survival (OS) time was 60 months, and OS rates were 93.0% at 1 year, 78.2% at 2 years, and 65.3% at 3 years. No patient experienced grade 4–5 toxicity; 15 had radiation pneumonitis (12 [9.3%] grade 2 and 3 [2.3%] grade 3). Performance status, standardized uptake value (SUV)_max on staging PET/CT, tumor histology, and disease operability were associated with OS on univariate analysis, but only staging SUV_max was independently predictive on multivariate analysis (P = 0.034). Dosimetric factors were associated with radiation pneumonitis on univariate analysis, but only mean ipsilateral lung dose ≥9.14 Gy was significant on multivariate analysis (P = 0.005).

Conclusions

OS and radiation pneumonitis after SABR for stage I NSCLC can be predicted by staging PET SUV_max and ipsilateral mean lung dose, respectively.

Baseline SUVmax at PET-CT in stage IIIA non-small-cell lung cancer patients undergoing surgery after neoadjuvant therapy: prognostic implication focused on histopathologic subtypes

RATIONALE AND OBJECTIVES

To evaluate the prognostic significance of maximum standardized uptake value (SUVmax) at (18)F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography in patients with stage IIIA non-small-cell lung cancer (NSCLC) who underwent surgical resection after neoadjuvant chemoradiotherapy, focused on the relationship between SUVmax values and tumor histology.

MATERIALS AND METHODS

We retrospectively evaluated the initial SUVmax of 205 patients (112 adenocarcinomas, 82 squamous cell carcinomas [SCCs], and 11 of other histology) with a stage IIIA NSCLC who underwent surgical resection after neoadjuvant chemoradiotherapy, and who were followed for up to 6 years. Clinical data, including histologic type, pathologic response, and treatment, were reviewed, and the relationship between the SUVmax and patient overall survival was examined.

RESULTS

Overall, the 2-year survival rate was 68%. Between the two histologic subtypes of adenocarcinoma and SCC, we noted significant differences in all variables of gender (male predominance in SCC), initial SUVmax (greater in SCC), pathologic response (more complete remission in SCC), and overall survival (better in SCC) (all P values, < .05). SUVmax remained as a sole independent factor for survival in multivariate analysis in whole series (SUVmax cutoff, 13; median survival, 3.0 years vs. 4.0 years; P = .016) and in adenocarcinomas (SUVmax cutoff, 11.5; median survival, 2.6 years vs. 3.6 years; P = .045), but not in SCCs.

CONCLUSION

The initial SUVmax is a sole significant prognostic factor in patients with a surgically resected NSCLC after neoadjuvant chemoradiotherapy, particularly in patients with an adenocarcinoma.

Potential role of FDG PET imaging in predicting metastatic potential and assessment of therapeutic response to neoadjuvant chemotherapy in Ewing sarcoma family of tumors

AIMS AND OBJECTIVES

The aim of this study was to retrospectively correlate FDG uptake in primary Ewing sarcoma family of tumors (ESFT) with tumor behavior, and to evaluate whether FDG PET can be used to predict response to neoadjuvant chemotherapy (NACT) in this patient group.

METHODS

Out of the total 54 patients of recently diagnosed ESFT who underwent pretreatment FDG PET imaging, group I included patients without metastasis at presentation (n = 34) and group II included those with metastasis at presentation (n = 20). Fourteen of these patients had undergone FDG PET after 4 cycles of induction chemotherapy and surgical resection of primary tumor. In this subgroup of 14 patients, maximum standardized uptake value (SUVmax) of primary tumor was estimated before and after 4 cycles of induction chemotherapy and was correlated with the histopathological response in terms of necrosis in the tumor specimen.

RESULTS

Mean SUVmax in the primary tumor in group I patients was 6.84 and in group II patients, it was 11.31. The difference between mean SUVmax of these 2 groups was significant by Wilcoxon test analysis, with P < 0.01. In group II patients, SUVmax in metastasis with maximum FDG uptake was consistently lower as compared with that of primary tumor. In subgroup of 14 patients, Pearson correlation analysis showed that percentage change in SUVmax of primary tumor correlated well with percentage necrosis on histopathological examination (P < 0.01).

CONCLUSION

FDG uptake in primary ESFT reflected its metastatic potential and hence the aggressive behavior. The significant correlation between change in metabolic activity of the primary tumor and histopathological response after neoadjuvant chemotherapy suggests that FDG PET may be an ideal noninvasive method to assess tumor behavior and response to therapy in ESFT.

Standard uptake value of positron emission tomography in clinical stage I lung cancer: clinical application and pathological correlation

OBJECTIVES

The aim of this study was to assess the standard uptake value in clinical stage I non-small cell lung cancer (NSCLC) and its correlation with pathological status and prognosis.

METHODS

We retrospectively reviewed 674 patients diagnosed with NSCLC between January 2002 and June 2005. Patients with clinical stage I diseases undergone a preoperative positron emission tomography-computed tomography scan followed by anatomic resection. We reviewed the clinical features of 152 patients with an average follow-up of 87 months.

RESULTS

We analysed the clinical features of 108 patients with stage I NSCLC and 44 patients with non-stage I NSCLC. There were no statistical differences in age, histological type, location or tumour differentiation between the two groups. In the Stage I group, the patients had lower maximum standard uptake value (SUVmax; 3.80 ± 3.17 vs 5.73 ± 3.65, P = 0.001), lower carcinoembryonic antigen (CEA) levels (2.86 ± 4.80 vs 9.11 ± 17.21 ng/ml, P = 0.027) and smaller tumour size (2.39 ± 0.98 vs 3.73 ± 2.04 cm, P < 0.001). The patients with higher SUVmax had a more advanced pathological stage, poorer tumour differentiation and larger tumour size. A higher SUVmax was an independent factor predicting an advanced pathological stage (SUVmax ≥ 3.3, odds ratio 3.246). The median survival of patients with SUVmax ≥ 3.3 and SUVmax <3.3 were 64.32 and 53.08 months, respectively (P = 0.654).

CONCLUSIONS

Higher preoperative 18-fluorodeoxyglucose uptake by a tumour was significantly associated with an advanced pathological stage but not correlated with a poorer prognosis. An aggressive preoperative work-up for occult N2 disease should be emphasized, avoiding inappropriate thoracotomy.

Value of dual time point F-18 FDG-PET/CT imaging for the evaluation of prognosis and risk factors for recurrence in patients with stage I non-small cell lung cancer treated with stereotactic body radiation therapy

PURPOSE

To investigate prognostic and risk factors for recurrence after stereotactic body radiation therapy (SBRT) in patients with stage I non-small cell lung carcinoma (NSCLC), focusing on dual time point [18]F-fluorodeoxyglucose positron emission tomography (FDG PET).

MATERIALS AND METHODS

We prospectively evaluated 57 patients with stage I NSCLC (45 T1N0M0 and 12 T2N0M0) who had undergone pretreatment FDG-PET/CT and were subsequently treated with SBRT. All patients received a whole-body PET/CT scan at 60 min and a whole-lung at 120 min after the injection. The maximum standardized uptake value (SUV) and retention index (RI) of the lesions were calculated. Local recurrence, regional lymph node metastasis, distant metastasis, and the recurrence pattern were evaluated. Cox proportional hazard regression analyses were performed to evaluate prognostic factors or risk factors of recurrence.

RESULTS

During the median follow-up period of 27 months, local recurrence, regional lymph node metastasis, and distant metastasis were seen in 17 (30%), 12 (21%), and 17 (30%) of the 57 patients, respectively. The 3-year overall survival rate was 63.4%. SUVmax did not affect any recurrence, DFS, OS, or CSS. RI significantly predicted higher distant metastasis (HR 47.546, p=0.026). In contrast, RI tended to predict lower local recurrence (HR 0.175, p=0.246) and regional lymph node metastasis (HR 0.109, p=0.115).

CONCLUSIONS

SUVmax at staging FDG-PET does not predict any recurrence, DFS, OS or CSS. In contrast, higher RI predicts higher distant metastasis and tended to predict lower local or regional lymph node metastasis.

18F-FDG uptake in primary lung cancer as a predictor of intratumoral vessel invasion

OBJECTIVE

This study investigated how fluorodeoxyglucose (FDG) uptake on PET in the primary tumor may predict intratumoral vessel invasion (IVI) in it.

METHODS

A total of 512 patients with lung neoplasms determined by a surgical procedure and histopathological diagnosis had undergone FDG-PET scanning.

RESULTS

Among the 440 cases confirmed to be malignant, the maximum standardized uptake value (SUV(max)) was significantly lower in IVI-negative cases than IVI-positive cases (P < 0.001). In the substudy on adenocarcinoma (AC), SUV(max) was significantly lower in IVI-negative cases too (P < 0.001), but SUV(max) in squamous cell carcinoma was without significant difference. In addition, IVI was associated with a significantly higher probability of lymph node metastasis (P < 0.001).

CONCLUSIONS

This study indicates that a malignant lung tumor with higher SUV(max) has a significantly higher probability of IVI and lymph node metastasis, particularly if the malignancy is an AC.

Positron emission tomography/computed tomography and lymphovascular invasion predict recurrence in stage I lung cancers

BACKGROUND

Although pathologic stage I lung cancers generally have a favorable prognosis, approximately 20% of patients experience recurrence after surgery. Therefore, a method of selecting patients who need adjuvant therapy is necessary. The goal of this study was to evaluate the significance of positron emission tomography (PET)/computed tomography (CT) results after lung cancer surgery and to identify the predictive factors for recurrence in cases of pathologic stage I lung cancer.

METHODS

From January 2004 to December 2008, 356 patients with lung cancer underwent surgery at our institution. Of these, 282 patients received F-18 fluorodeoxyglucose PET/CT, and the maximum standardized uptake value (max SUV) was measured. There were 201 patients with pathologic stages IA and IB evaluated. The associations between disease-free survival (DFS) and the following clinicopathological factors were analyzed: age, gender, smoking history, carcinoembryonic antigen level, tumor size, max SUV values, histology, and lymphovascular and pleural invasion.

RESULTS

The 4-year DFS rate was 86.3%. Multivariate analysis revealed lymphovascular invasion (LVI; p < 0.01) and max SUV ≥4.7 (p < 0.01) to be independent predictive factors. Patients with a max SUV more than 4.7 had a significantly high risk of recurrence. DFS of patients with high max SUVs and LVI (n = 18) was significantly reduced compared with other patients (n = 183, p < 0.01).

CONCLUSIONS

The PET-CT results significantly correlated with recurrence in pathologic stage I lung cancers. Patients with high max SUVs and LVI were more likely to have recurrence and should be candidates for adjuvant chemotherapy.

International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma

INTRODUCTION

Adenocarcinoma is the most common histologic type of lung cancer. To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small nonresection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies.

METHODS

An international core panel of experts representing all three societies was formed with oncologists/pulmonologists, pathologists, radiologists, molecular biologists, and thoracic surgeons. A systematic review was performed under the guidance of the American Thoracic Society Documents Development and Implementation Committee. The search strategy identified 11,368 citations of which 312 articles met specified eligibility criteria and were retrieved for full text review. A series of meetings were held to discuss the development of the new classification, to develop the recommendations, and to write the current document. Recommendations for key questions were graded by strength and quality of the evidence according to the Grades of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

The classification addresses both resection specimens, and small biopsies and cytology. The terms BAC and mixed subtype adenocarcinoma are no longer used. For resection specimens, new concepts are introduced such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure lepidic growth (AIS) or predominant lepidic growth with ≤ 5 mm invasion (MIA) to define patients who, if they undergo complete resection, will have 100% or near 100% disease-specific survival, respectively. AIS and MIA are usually nonmucinous but rarely may be mucinous. Invasive adenocarcinomas are classified by predominant pattern after using comprehensive histologic subtyping with lepidic (formerly most mixed subtype tumors with nonmucinous BAC), acinar, papillary, and solid patterns; micropapillary is added as a new histologic subtype. Variants include invasive mucinous adenocarcinoma (formerly mucinous BAC), colloid, fetal, and enteric adenocarcinoma. This classification provides guidance for small biopsies and cytology specimens, as approximately 70% of lung cancers are diagnosed in such samples. Non-small cell lung carcinomas (NSCLCs), in patients with advanced-stage disease, are to be classified into more specific types such as adenocarcinoma or squamous cell carcinoma, whenever possible for several reasons: (1) adenocarcinoma or NSCLC not otherwise specified should be tested for epidermal growth factor receptor (EGFR) mutations as the presence of these mutations is predictive of responsiveness to EGFR tyrosine kinase inhibitors, (2) adenocarcinoma histology is a strong predictor for improved outcome with pemetrexed therapy compared with squamous cell carcinoma, and (3) potential life-threatening hemorrhage may occur in patients with squamous cell carcinoma who receive bevacizumab. If the tumor cannot be classified based on light microscopy alone, special studies such as immunohistochemistry and/or mucin stains should be applied to classify the tumor further. Use of the term NSCLC not otherwise specified should be minimized.

CONCLUSIONS

This new classification strategy is based on a multidisciplinary approach to diagnosis of lung adenocarcinoma that incorporates clinical, molecular, radiologic, and surgical issues, but it is primarily based on histology. This classification is intended to support clinical practice, and research investigation and clinical trials. As EGFR mutation is a validated predictive marker for response and progression-free survival with EGFR tyrosine kinase inhibitors in advanced lung adenocarcinoma, we recommend that patients with advanced adenocarcinomas be tested for EGFR mutation. This has implications for strategic management of tissue, particularly for small biopsies and cytology samples, to maximize high-quality tissue available for molecular studies. Potential impact for tumor, node, and metastasis staging include adjustment of the size T factor according to only the invasive component (1) pathologically in invasive tumors with lepidic areas or (2) radiologically by measuring the solid component of part-solid nodules.