Follow-up or Surveillance (18)F-FDG PET/CT and Survival Outcome in Lung Cancer Patients

Consistency and prognostic value of preoperative staging and postoperative pathological staging using 18F-FDG PET/MRI in patients with non-small cell lung cancer

OBJECTIVE

In recent years, positron emission tomography/magnetic resonance imaging (PET/MRI) has been clinically used as a method to diagnose non-small cell lung cancer (NSCLC). This study aimed to evaluate the concordance of staging and prognostic ability of NSCLC patients using thin-slice computed tomography (CT) and ¹⁸F-fluorodeoxyglucose (FDG) PET/MRI.

METHODS

This retrospective study was performed on consecutive NSCLC patients who underwent both diagnostic CT and ¹⁸F-FDG PET/MRI before surgery between November 2015 and May 2019. The cTNM staging yielded from PET/MRI was compared with CT and pathological staging, and concordance was investigated, defining pathological findings as reference. To assess the prognostic value of disease-free survival (DFS) and overall survival (OS), we dichotomized the typical prognostic factors and TNM classification staging (Stage I vs. Stage II or higher). Kaplan-Meier curves derived by the log-rank test were generated, and univariate and multivariate analyses were performed to identify the factors associated with DFS and OS.

RESULTS

A total of 82 subjects were included; PET/MRI staging was more consistent (59 of 82) with pathological staging than with CT staging. There was a total of 21 cases of CT and 11 cases of PET/MRI that were judged as cStage I, but were actually pStage II or pStage III. CT tended to judge pN1 or pN2 as cN0 compared to PET/MRI. There was a significant difference between NSCLC patients with Stage I and Stage II or higher by PET/MRI staging as well as prognosis prediction of DFS by pathological staging (P < 0.001). In univariate analysis, PET/MRI, CT, and pathological staging (Stage I or lower vs. Stage II or higher) all showed significant differences as prognostic factors of recurrence or metastases. In multivariate analysis, pathological staging was the only independent factor for recurrence (P = 0.009), and preoperative PET/MRI staging was a predictor of patient survival (P = 0.013).

CONCLUSIONS

In NSCLC, pathologic staging was better at predicting recurrence, and preoperative PET/MRI staging was better at predicting survival. Preoperative staging by PET/MRI was superior to CT in diagnosing hilar and mediastinal lymph-node metastases, which contributed to the high concordance with pathologic staging.

The usefulness of 18F-FDG PET/CT in follow-up and recurrence detection for patients with lung carcinoma and its impact on the survival outcome

Background

We assess the usefulness of 18F-FDG PET/CT for detection of recurrent or residual tumor in post treatment patients with NSCLC and comparing the results with CECT, and we evaluate its impact to the clinical assessment and overall survival of lung cancer patients.

Results

A prospective study of 63 patients with potentially resectable NSCLC, were divided into 2 groups according to the initial staging of the disease and the early response to treatment.

Group A (n=29) patients were treated by curative treatment, and group B (n=34) patients were treated by palliative treatment.

Evaluation of patients was done during the follow-up period clinically every 3 months and by 18F-FDG PET/CT and CECT imaging at 6 months intervals.

In group A, 18F-FDG PET/CT correctly diagnosed all recurrent or residual tumors (n=7) whereas CECT diagnosed only 5 with 2 false negative cases.

In group B, 18F-FDG PET/CT correctly diagnosed all recurrent or residual tumors (n=23) whereas CECT diagnosed 16 patients with 7 false negative cases.

By comparison of 18F-FDG PET/CT and CECT in detection of residual or recurrent lung cancer (n=30), the sensitivity, specificity, PPV, NPV, and accuracy of 18F-FDG PET/CT were 100%, 92%, 92%, 100%, and 96% respectively, while of CECT were 72%, 95%, 94%, 79%, and 84% respectively in correlation with reference standard data. The calculated SUV max ranged from 2.1 to 4.9.

There was a significant difference in overall survival between patients in routine scan who had positive 18F FDG PET/CT result (median survival 18 months) and those who had negative result (median survival 45 months) (P<0.0001).

Conclusion

18 F-FDG PET/CT plays an important role in distinguishing post treatment changes from tumor recurrence in patients with lung cancer. Follow-up or surveillance 18 F-FDG PET/CT is a prognostic indicator for overall survival of patients.

Thoracic positron emission tomography: 18F-fluorodeoxyglucose and beyond

Ongoing technologic and therapeutic advancements in medicine are now testing the limits of conventional anatomic imaging techniques. The ability to image physiology, rather than simply anatomy, is critical in the management of multiple disease processes, especially in oncology. Nuclear medicine has assumed a leading role in detecting, diagnosing, staging and assessing treatment response of various pathologic entities, and appears well positioned to do so into the future. When combined with computed tomography (CT) or magnetic resonance imaging (MRI), positron emission tomography (PET) has become the sine quo non technique of evaluating most solid tumors especially in the thorax. PET/CT serves as a key imaging modality in the initial evaluation of pulmonary nodules, often obviating the need for more invasive testing. PET/CT is essential to staging and restaging in bronchogenic carcinoma and offers key physiologic information with regard to treatment response. A more recent development, PET/MRI, shows promise in several specific lung cancer applications as well. Additional recent advancements in the field have allowed PET to expand beyond imaging with ¹⁸F-flurodeoxyglucose (FDG) alone, now with the ability to specifically image certain types of cell surface receptors. In the thorax this predominantly includes ⁶⁸Ga-DOTATATE which targets the somatostatin receptors abundantly expressed in neuroendocrine tumors, including bronchial carcinoid. This receptor targeted imaging technique permits targeting these tumors with therapeutic analogues such as ¹⁷⁷Lu labeled DOTATATE. Overall, the proper utilization of PET in the thorax has the ability to directly impact and improve patient care.

Adenine Nucleotide Translocase 2 as an Enzyme Related to [18F] FDG Accumulation in Various Cancers

PURPOSE

Although glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) are known as major proteins involved in the molecular mechanisms for accumulating 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) in cancer cells, sometimes, [¹⁸F] FDG accumulation cannot be explained by the expression of these two proteins. We investigated the involvement of adenine nucleotide translocase 2 (ANT2), which catalyzes ADP/ATP exchange at the mitochondrial inner membrane, in [¹⁸F] FDG accumulation.

PROCEDURES

ANT2 expression was evaluated in various cancer cell lines and human cancer tissues (microarrays) using western blot and immunohistochemical (IHC) staining, respectively. The expression levels of ANT2 were compared to [¹⁸F] FDG accumulation and pathologic findings, including differentiation grade. Additionally, we modulated ANT2 expression levels using ANT2 siRNA and an ANT2 expression vector in cancer cells and murine xenografted tumors.

RESULTS

[¹⁸F] FDG accumulation correlated with ANT2 expression in various cancer cell lines; this was not explained by GLUT1 and/or HK2 expression. At both the cell and tissue levels, ANT2 expression was high in less-differentiated or more malignant type of cancers. [¹⁸F] FDG accumulation changed according to the modulation of the ANT2 expression level.

CONCLUSION

In various cancer cells and tissues, the expression levels of ANT2 explained [¹⁸F] FDG accumulation better than those of GLUT1 and HK2. ANT2 can be used as a marker of dedifferentiated pathology and aggressiveness of cancer.

Association of Receipt of Positron Emission Tomography-Computed Tomography With Non-Small Cell Lung Cancer Mortality in the Veterans Affairs Health Care System

IMPORTANCE

Positron emission tomography-computed tomography (PET-CT) has been increasingly used in the management of lung cancer, but its association with survival has not been convincingly documented.

OBJECTIVE

To examine the association of the use of PET-CT with non-small cell lung cancer (NSCLC) mortality in the US Department of Veterans Affairs (VA) health care system from 2000 to 2013.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 64 103 veterans receiving care in the VA health care system who were diagnosed with incident NSCLC between September 2000 and December 2013. Data analysis took place in October 2018.

EXPOSURE

Use of PET-CT before and/or after diagnosis.

MAIN OUTCOMES AND MEASURES

All-cause and NSCLC-specific 5-year mortality; secondary outcome was receipt of stage-appropriate treatment.

RESULTS

A total of 64 103 veterans with the diagnosis of NSCLC were evaluated; 62 838 (98.0%) were men, and 50 584 (78.9%) were white individuals. Among these, 51 844 (80.9%) had a PET-CT performed: 25 735 (40.1%) in the 12 months before diagnosis and 41 242 (64.3%) in the 5 years after diagnosis. Increased PET-CT use (597 of 978 veterans [59.2%] in 2000 vs 3649 of 3915 [93.2%] in 2013) and decreased NSCLC-specific 5-year mortality (879 of 978 veterans [89.9%] in 2000 vs 3226 of 3915 veterans [82.4%] in 2013) were found over time. Increased use of stage-appropriate therapy was also seen over time, from 346 of 978 veterans (35.4%) in 2000 to 2062 of 3915 (52.7%) in 2013 (P < .001). Increased PET-CT use was associated with higher-complexity level VA facilities (26 127 veterans [82.3%] at level 1a vs 1289 [75.2%] at level 3 facilities; P < .001) and facilities with on-site PET-CT compared with facilities without on-site PET-CT (33 081 [82.2%] vs 17 443 [80.3%]; P < .001). Use of PET-CT before diagnosis was associated with increased likelihood of stage-appropriate treatment for all stages of NSCLC (eg, veterans with stage 1 disease: 4837 of 7870 veterans [61.5%] who received PET-CT underwent surgical resection vs 4042 of 7938 veterans [50.9%] who did not receive PET-CT; P < .001) and decreased mortality in a risk-adjusted model among all participants and among veterans undergoing stage-appropriate treatment (all-cause mortality: hazard ratio [HR], 0.78; 95% CI, 0.77-0.79; NSCLC-specific mortality: HR, 0.78; 95% CI, 0.76-0.80). Facilities with on-site PET-CT and higher-complexity level facilities were associated with a mortality benefit, with 16% decreased mortality at level 1a vs level 3 facilities (HR, 0.84; 95% CI, 0.80-0.89) and a 3% decrease in all-cause mortality in facilities with on-site PET-CT (HR, 0.97; 95% CI, 0.96-0.99).

CONCLUSIONS

In this study, the use of PET-CT among veterans with NSCLC significantly increased from 2000 to 2013, coinciding with decreased 5-year mortality and an increase in stage-appropriate treatment. Variation in use of PET-CT was found, with the highest use at higher-complexity level facilities and those with PET-CT on-site. These facilities were associated with reduced all-cause and NSCLC-specific mortality.

Quantitative PET/CT in clinical practice: assessing the agreement of PET tumor indices using different clinical reading platforms

OBJECTIVE

The aim of this study was to determine whether various fluorine-18-fluorodeoxyglucose PET/CT-derived parameters used in oncology vary significantly depending on the interpretation software systems used in clinical practice for multiple human solid tumors.

PATIENTS AND METHODS

A total of 120 fluorine-18-fluorodeoxyglucose PET/CT studies carried out in patients with pancreatic, lung, colorectal, and head and neck cancers were evaluated retrospectively on two different vendor software platforms including Mirada and MIMVista. Regions of interest were placed on the liver to determine the liver mean standardized uptake value at lean body mass (SUL) and on each tumor to determine the SULmax, SULpeak. Total lesion glycolysis (TLG) and metabolic tumor volume (MTV) were determined using fixed thresholds of 50% of SULmax and SULpeak. Inter-reader, intersystem intraclass correlations, systematic bias, and variability reflected by the 95% limits of agreement, and precision were determined.

RESULTS

There was excellent inter-reader reliability between the readers and the two software systems, with intraclass correlations more than 0.9 for all PET metrics, with P values less than 0.0001. The bias and SD on Bland-Altman analysis between the two software platforms for tumor SULmax, SULpeak, Max50MTV, and Peak50MTV, respectively, for Reader 1 were -1.52±2.24, 0.80±3.67, -0.80±13.01, and -4.49±20.6. For Reader 2, the biases were -1.62±1.95, 0.18±3.60, -0.27±4.64, and -3.13±8.30. The precision between the two systems was better for SULmax and SULpeak, with less variance observed, than for volume-based metrics such as Max50MTV and Peak50MTV or TLG.

CONCLUSION

Excellent correlation has been found between two tested software reading platforms for all PET-derived metrics in a dual-reader analysis. Overall, the SULmax and SULpeak values had less bias and better precision compared with the MTV and TLG.

Cost Analysis of PET/CT Versus CT as Surveillance for Stage III Non-Small-Cell Lung Cancer After Definitive Radiation Therapy

INTRODUCTION

A previous study showed that use of positron emission tomography (PET)/computed tomography (CT) for surveillance after treatment of non-small-cell lung cancer (NSCLC) does not yield a detection or survival benefit over the use of chest CT. However, PET/CT remains a common method of follow-up imaging. Here we estimated and compared the costs of PET/CT versus CT for surveillance of patients with stage III NSCLC and identified patient and provider demographic characteristics associated with preference for use of PET/CT.

PATIENTS AND METHODS

We reviewed 178 patients with stage III NSCLC who had received ≥ 1 PET/CT scan within 6 months of completing radiotherapy (n = 89) or had received CT after radiotherapy (n = 89) from 2000 to 2011. Costs were measured according to Medicare payments converted from institutional billing records. Total and imaging costs were analyzed at 6, 12, 18, and 24 months after the end of treatment. Patient and provider demographic characteristics were also evaluated for potential associations with PET/CT use.

RESULTS

Total costs in the PET/CT group were higher during the first 18 months after treatment (P = .002 at 6 months, P = .019 at 12 months, and P = .018 at 18 months) but was marginally significant (P = .05) at 24 months. In univariate analysis of demographic variables, patients who lived in a state different from the treatment center might have been more likely to receive PET/CT (odds ratio [OR], 1.76; P = .051). In multivariate analysis, patients treated in 2007 to 2010 (OR, 29.9; P < .001) or 2003 to 2006 (OR, 11.6; P = .002) were more likely to receive PET/CT than patients treated in 1999 to 2002. In addition, radiation oncologists with > 10 years of experience were more likely to use PET/CT than those with less experience, although this result might be confounded by the small number of providers.

CONCLUSION

Use of PET/CT was associated with higher costs for 18 months after treatment, but the difference was at the borderline of statistical significance at 24 months.

18FDG-PET metabolic response of non-small-cell lung cancer to chemoradiotherapy with long-term follow-up

Aim

18Fluorodeoxyglucose-positron emission tomography (FDG-PET) can indicate the presence or absence of non-small-cell lung cancer (NSCLC) after treatment. We present a description of the FDG-PET results following the contemporary management of locally advanced NSCLC including long-term outcomes.

Methodology

The study participants were eight long-term survivors with metabolic tumour response (MTR) shown on FDG-PET following chemoradiotherapy for locally advanced stage NSCLC between June 2005 and April 2009.

Results

After therapy, MTR was complete in five patients; four subjects were free of cancer, and one patient experienced progression of disease at the time of last follow-up. Of the three individuals with incomplete MTRs, distant metastases developed in two patients, and one subject remained disease-free. Long-term survival ranged from 37 to 75 months.

Conclusion

Although the number of cases is small, our observations confirm the diagnostic role of FDG-PET as well as its value for predicting prognosis in the clinical practice of oncology.

Value of fourth and subsequent post-therapy follow-up 18F-FDG PET/CT scans in patients with breast cancer

OBJECTIVE

To evaluate the accuracy and value of the fourth and subsequent post-therapy follow-up fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) scans in the clinical assessment of breast cancer patients.

MATERIALS AND METHODS

Ninety-two female patients, with a total of 426 fourth and subsequent follow-up PET/CT scans, were retrospectively included. Patients were followed for a median of 23.7 months (range, 0.7-124.4) from the fourth follow-up PET/CT. The diagnostic accuracy of PET/CT, its impact on clinical assessment, patients' management, and survival outcome were established.

RESULT

Of the 426 follow-up PET/CT scans, 264 (62%) were interpreted as positive and 162 (38%) were interpreted as negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the fourth and subsequent follow-up PET/CT scans were 97.7, 98.1, 98.8, 96.3, and 97.9%, respectively. Fourth and subsequent follow-up PET/CT were useful in excluding a tumor in 13.4% (39/292) of patients with a clinical suspicion of recurrence and identifying suspected recurrence in 10.5% (14/134) of patients without previous clinical suspicion. A change in management was noted in 6.7% (9/134) of scan times when the scans were performed without previous clinical suspicion of recurrence or therapy response and was 27.7% (81/292) when the scans were performed with clinical suspicion. Overall survival differed significantly between patients with all negative follow-up scans (n=23) and those who had at least one positive follow-up scan (n=69) (hazard ratio of 4.65, P<0.001).

CONCLUSION

The fourth and subsequent PET/CT scans performed after the completion of primary treatment led to a change in management in 27.7% of patients when the scans were performed with clinical suspicion and only in 6.7% of patients when performed without clinical suspicion or context.

JOURNAL CLUB: Value of Quantitative FDG PET/CT Volumetric Biomarkers in Recurrent Colorectal Cancer Patient Survival

OBJECTIVE

The purpose of this study was to evaluate the impact of quantitative PET parameters in the overall survival of patients with recurrent colorectal cancer.

MATERIALS AND METHODS

A total of 105 patients with a biopsy-proven recurrence of colorectal cancer who underwent PET/CT were included in the study. A gradient segmentation method was used to calculate maximum and peak standardized uptake values (SUVmax, SUVpeak), total lesion glycolysis (TLGtotal), and metabolic tumor volume (MTVtotal). These parameters were measured for each recurrent lesion at the primary, locoregional, and distant sites. The median follow-up time was 31.3 months. Overall survival (OS) was the primary outcome and was calculated using Kaplan-Meier survival plots and Cox regression analyses.

RESULTS

The mean ± SD for SUVmax, SUVpeak, TLGtotal, and MTVtotal of the included patients was 7.3 ± 5.3, 5.3 ± 3.3, 280.8 ± 1181 g, and 79.8 ± 294 mL, respectively. The median OS for patients who were alive was 50 months in comparison with 23.4 months among patients who died. Age (p = 0.041), tumor grade (p = 0.010), median TLG (p = 0.031), and median MTV (p = 0.009) remained significantly associated with OS in the multivariate Cox regression analysis. Kaplan-Meier survival analysis performed on the basis of the median PET/CT parametric values showed that SUVmax (threshold, 5.63; hazard ratio [HR] = 1.7; 95% CI, 1-2.8; p = 0.02), MTVtotal (threshold, 13.85 mL; HR = 2.2; 95% CI, 1.3-3.9; p = 0.003), and TLGtotal (threshold, 36.14 g; HR = 1.9; 95% CI, 1.1-3.3; p = 0.01) were significant predictors of OS during follow-up. An integrated risk stratification model with SUVmax and MTVtotal into three subgroups predicted patient survival outcomes (HR = 1.8; 95% CI, 1.25-2.65; log-rank p = 0.003).

CONCLUSION

SUVmax, MTVtotal, TLGtotal, and integrated score with FDG avidity and total tumor burden provide survival information for patients with biopsy-proven recurrent colorectal cancer.

Estimation of Recurrence Risk After Normal (18)F-FDG PET/CT in Nonsmall-Cell Lung Cancer

The authors aimed to assess the risk of recurrence in patients with nonsmall-cell lung cancer after surgery with no evidence of disease (NED) demonstrated on (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). A total of 140 subjects with adenocarcinoma or squamous cell carcinoma of the lung were included in this study. Patients had FDG PET/CT scans within a year after surgery between January 2007 and December 2014. Patients with PET/CT scans with NED were included. Following an NED PET/CT scan, recurrence or metastasis was found in 14 patients (10.0%), and deaths in 4 (2.9%) during a median follow-up of 636 days. Although the rates of recurrence or metastasis were very low, the risk for recurrence continuously increased after 600 days up to 0.03%. The risk was higher in patients with positive margin at surgery, lymphovascular invasion, N2 stage, and TNM stage III/IV. In conclusion, according to the smoothed hazard functions, there was a very low risk of recurrence until 600 days after normal (18)F-FDG PET scans. The risk was higher in patients with positive margin at surgery, lymphovascular invasion, N2 stage, and TNM stage III/IV.

The Value of FDG PET/CT in Treatment Response Assessment, Follow-Up, and Surveillance of Lung Cancer

OBJECTIVE

The purpose of this article is to summarize the evidence regarding the role of FDG PET/CT in treatment response assessment and surveillance of lung cancer and to provide suggested best practices.

CONCLUSION

FDG PET/CT is a valuable imaging tool for assessing treatment response for patients with lung cancer, though evidence for its comparative effectiveness with chest CT is still evolving. FDG PET/CT is most useful when there is clinical suspicion or other evidence for disease recurrence or metastases. The sequencing, cost analysis, and comparative effectiveness of FDG PET/CT and conventional imaging modalities in the follow-up setting need to be investigated.

Influence of Surveillance PET/CT on Detection of Early Recurrence After Definitive Radiation in Stage III Non-small-cell Lung Cancer

BACKGROUND

There are few data to support the use of varying imaging modalities in evaluating recurrence in non-small-cell lung cancer (NSCLC). We compared the efficacy of surveillance positron emission tomography (PET)/computed tomography (CT) versus CT scans of the chest in detecting recurrences after definitive radiation for NSCLC.

MATERIALS AND METHODS

We retrospectively analyzed 200 patients treated between 2000 and 2011 who met the inclusion criteria of stage III NSCLC, completion of definitive radiation treatment, and absence of recurrence within the initial 6 months. These patients were then grouped on the basis of the use of PET/CT imaging during postradiation surveillance. Patients who received ≥ 1 PET/CT scans within 6 months of the end of radiation treatment were placed in the PET group whereas all others were placed in the CT group. We compared survival times from the end of treatment to the date of death or last follow-up using log rank tests. Multivariate analysis was conducted to identify factors associated with decreased survival.

RESULTS

In the entire cohort, median event-free survival (EFS) was 26.7 months, and median overall survival (OS) was 41.2 months. The CT group had a median EFS of 21.4 months versus 29.4 months for the PET group (P = .59). There was no difference in OS between the CT and PET groups (median OS of 41.2 and 41.3 months, respectively; P = .59). There was also no difference in local recurrence-free survival or distant metastases-free survival between the CT-only and PET/CT groups (P = .92 and P = .30, respectively). Similarly, in multivariate analysis, stratification into the PET group was not associated with improved EFS (hazard ratio [HR], 0.90; 95% confidence interval [CI], 0.61-1.34; P = .60) or OS (HR, 1.2; 95% CI, 0.83-1.7; P = .34).

CONCLUSIONS

In stage III NSCLC patients treated with definitive radiation and without early recurrence, PET/CT scan surveillance did not result in decreased time to detection of locoregional or distant recurrence or improved survival.

Trends in the Use of (18)F-Fluorodeoxyglucose PET Imaging in Surveillance of Non-Small-Cell Lung and Colorectal Cancer

PURPOSE

Surveillance PET after curative-intent treatment of non-small-cell lung cancer (NSCLC) or colorectal cancer (CRC) is not clearly supported by available evidence or the Choosing Wisely campaign. However, the frequency of PET imaging during the surveillance period is relatively unknown.

METHODS

Using Surveillance, Epidemiology, and End Results-Medicare data, 65,748 patients aged 66 years or older who were diagnosed with stage I to IIIA NSCLC or stage I to III CRC from 2001 through 2009 and who underwent surgical resection were identified. Trends in "any PET" or "PET-only" use 6 to 18 months postoperatively were assessed.

RESULTS

Any PET use more than doubled over the study period. Eleven percent of patients with NSCLC and 4% of those with CRC diagnosed in 2001 received any PET, compared with 25% of patients with NSCLC and 13% of those with CRC in 2009 (P < .001 for both). Higher stage disease was correlated with higher PET utilization and faster growth in use over the study period. PET-only use also increased over the study period, especially in higher stage disease. Fewer than 2% of patients diagnosed with stage IIIA NSCLC in 2001 received PET only, compared with 15% of patients diagnosed in 2009 (P = .014). Similarly, 1% of patients diagnosed with stage III CRC in 2001 received PET only, compared with 8% of patients diagnosed in 2009 (P < .001).

CONCLUSIONS

PET utilization during the surveillance period increased between 2001 and 2009. Further research is needed to determine the factors driving use of surveillance PET and to examine relationships between PET and patient outcomes.

Present and future roles of FDG-PET/CT imaging in the management of lung cancer

Integrated positron emission tomography/computed tomography (PET/CT) using 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) has emerged as a powerful tool for combined metabolic and anatomic evaluation in clinical oncologic imaging. This review discusses the utility of (18)F-FDG PET/CT as a tool for managing patients with lung cancer. We discuss different patient management stages, including diagnosis, initial staging, therapy planning, early treatment response assessment, re-staging, and prognosis.

FDG PET/CT in Patients With Head and Neck Squamous Cell Carcinoma After Primary Surgical Resection With or Without Chemoradiation Therapy

OBJECTIVE

The purpose of this study was to assess the value of posttreatment FDG PET/CT in patients with squamous cell carcinoma of the head and neck (HNSCC) treated with primary surgical resection with or without adjuvant concurrent chemoradiotherapy.

MATERIALS AND METHODS

A total of 98 HNSCC patients were treated with primary surgical resection and had undergone PET/CT within 6 months of treatment completion. The accuracy of the scans and the added value to clinical assessment and impact on management were established based on the clinical information before and after each scan. Overall survival of patients was estimated with Kaplan-Meier curves.

RESULTS

Of the total 98 scans, 25 (25.5%) were interpreted as positive and 73 (74.5%) as negative. The sensitivity of posttreatment PET/CT was 80.0%; specificity, 89.5%; positive predictive value, 66.7%; negative predictive value, 94.4%; and accuracy, 87.5%. These scans were helpful in excluding tumor in 31.8% of patients with clinical suspicion of residual disease and identifying suspected residual disease in 13.2% of patients with no prior clinical suspicion. Multivariate regression analysis showed that tumor size, grade (p = 0.041), scan type (p = 0.002), and scan result (p = 0.005) were independent covariates associated with overall survival. Kaplan-Meier analysis showed a significant difference and association in overall survival between patients with a positive versus a negative posttherapy PET/CT scan result (hazard ratio, 5.65; 95% CI, 2.48-12.83; log rank Mantel-Cox p < 0.001).

CONCLUSION

Posttreatment FDG PET/CT results had a high negative predictive value, added value to clinical assessment of 35% of patients, influenced subsequent management, and were associated with survival outcome of HNSCC patients treated with primary surgical resection.

Update on F-18-fluoro-deoxy-glucose-PET/computed tomography in nonsmall cell lung cancer

PURPOSE OF REVIEW

The aim of this review is to provide an outline of current evidence for the use of F-18-fluoro-deoxy-glucose PET computed tomography (FDG-PET/CT) in nonsmall cell lung cancer (NSCLC) for diagnosis, staging, radiotherapy planning, response assessment and response monitoring.

RECENT FINDINGS

Management of patients with NSCLC requires a multimodality approach to accurately diagnose and stage patients. In this approach, FDG-PET/CT has become a standard staging instrument in lung cancer. FDG-PET/CT is, in addition to staging, also valuable for the characterization of the solitary pulmonary nodule. An increased uptake in the nodule as compared with mediastinal blood pool is suspected for malignancy. In radiotherapy planning, FDG-PET/CT can assist the radiation oncologist for optimal dose delivery to the tumour, while sparing healthy tissues. Evidence of the prognostic and predictive implications of FDG-PET/CT is accumulating. Volumetric parameters of PET, such as metabolic active tumour volume and total lesion glycolysis, are promising predictive and prognostic biomarkers. However, for implementation of metabolic response parameters in clinical practice, more randomized, PET-based, multicentre trials are necessary. The introduction of integrated PET and MRI scanners did not change the pivotal role of standard FDG-PET/CT yet, as with current technology, PET/MRI did not show superior performance in thoracic staging.

SUMMARY

The role of PET is described for diagnosis, staging and response assessment.

Value of FDG PET/CT in Patient Management and Outcome of Skeletal and Soft Tissue Sarcomas

Fluorodeoxyglucose (FDG)-PET/computed tomography (CT) has been increasingly used in bone and soft tissue sarcomas and provides advantages in the initial tumor staging, tumor grading, therapy assessment, and recurrence detection. FDG-PET/CT metabolic parameters are reliable predictors of survival in sarcomas and could be implemented in risk stratification models along with other prognostic factors in these patients.

FDG PET/CT in Pancreatic and Hepatobiliary Carcinomas: Value to Patient Management and Patient Outcomes

Fludeoxyglucose F 18 ((18)F-FDG) PET/CT has not been shown to offer additional benefit in the initial diagnosis of pancreatic cancer, but studies show benefit of (18)F-FDG PET/CT in initial staging and patient prognosis. There is evidence for (18)F-FDG PET and (18)F-FDG PET/CT in staging and prognosis of cholangiocarcinoma and gallbladder cancer. (18)F-FDG PET/CT has shown promise in staging liver malignancies by detecting extrahepatic metastasis. There is evidence supporting the ability of PET/CT in predicting prognosis in patients with hepatocellular carcinoma. Evidence is evolving for the role of (18)F-FDGPET/CT in predicting prognosis and survival in patients with colorectal liver metastasis.

Fluorodeoxyglucose positron emission tomography/computerized tomography in differentiated thyroid cancer management: Importance of clinical justification and value in predicting survival

INTRODUCTION

The purpose of this study was to evaluate the added value of follow-up fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to clinical assessment and predicting survival outcome in patients with differentiated thyroid cancers.

METHODS

This is an institutional review board approved, retrospective study of 202 biopsy-proven thyroid cancer patients at a single tertiary centre. A total of 327 follow-up or surveillance PET/CT scans done 6 or more months from initial treatment completion were included in this study. Median follow-up from completion of primary treatment was 94 months (range, 6.17-534.1 months). Overall survival benefit was measured using Kaplan-Meier plots with a Mantel-Cox log-rank test. Multivariate Cox regression model is provided with clinical covariates.

RESULTS

Of the 327 PET/CT scans from 202 patients, 161 were positive and 166 as negative for recurrence or metastasis. A total of 23 patients died during the study period. Patients with a positive PET/CT scan had shorter overall survival than those who had a negative scan (P < 0.0001, hazard ratio 6.1 (3.0-14.3) ). In the context of clinical assessment, PET/CT identified recurrence in 50% (25/50) of scans without prior clinical suspicion and ruled out recurrence in 36.8% (102/277) of scans with prior clinical suspicion. In a multivariate Cox regression model, factors associated with overall survival were stage (P < 0.0001), time to scan (P = 0.0005) and PET/CT result (P < 0.0001).

CONCLUSION

FDG PET/CT performed in follow-up more than 6 months from primary treatment completion adds value to clinical judgment and a prognostic marker of overall survival in thyroid cancer patients.

Relationship between 18F-FDG accumulation and lactate dehydrogenase A expression in lung adenocarcinomas

(18)F-FDG PET has been widely used in the management of malignant tumors. Lactate dehydrogenase A (LDHA) plays an important role in the development, invasion, and metastasis of malignancies. However, the relationship between (18)F-FDG accumulation and LDHA expression has not been investigated.

METHODS

Retrospective analysis was conducted for 51 patients with lung adenocarcinomas who underwent (18)F-FDG PET. The relationship between maximum standardized uptake value and the expression of LDHA, glucose transporter 1 (GLUT1), and hexokinase 2 (HK2) were examined. RNA interference was used to analyze the role of LDHA in tumor metabolism and growth in A549 cells. The AKT, also known as protein kinase B, pathway was also investigated to evaluate the molecular mechanisms of the relationship between LDHA expression and (18)F-FDG uptake.

RESULTS

Maximum standardized uptake value was significantly higher in the LDHA high-expression group than the LDHA low-expression group (P = 0.018). GLUT1 expression in lung adenocarcinomas was positively correlated with (18)F-FDG accumulation and LDHA expression whereas HK2 expression was not. Knockdown of LDHA led to a significant decrease in GLUT1 expression, (18)F-FDG uptake, and cell proliferation. The activated form of AKT was also decreased after LDHA knockdown.

CONCLUSION

LDHA increases (18)F-FDG accumulation into non-small cell lung cancer, possibly by upregulation of GLUT1 expression but not HK2 expression. LDHA may modulate (18)F-FDG uptake in lung adenocarcinomas via the AKT-GLUT1 pathway. These results indicate that (18)F-FDG PET/CT may predict LDHA expression levels and response to anti-LDHA therapy in lung adenocarcinomas.