FDG-PET. A possible prognostic factor in head and neck cancer

Prognostic significance of standardized uptake value and metabolic tumour volume on ¹⁸F-FDG PET/CT in oropharyngeal squamous cell carcinoma

PURPOSE

Standardized uptake value (SUV) and metabolic tumour volume (MTV) measured by (18)F-FDG PET/CT are emerging prognostic biomarkers in human solid cancers. However, their prognostic significance in oropharyngeal squamous cell carcinoma (OPSCC) has been investigated in only a few studies and with small cohorts. In the present study we evaluated the ability of SUV, MTV, and total lesion glycolysis (TLG) measured on pretreatment (18)F-FDG PET/CT to predict recurrence and survival outcomes in OPSCC.

METHODS

The study included 221 patients with OPSCC who underwent pretreatment (18)F-FDG PET/CT imaging and received definitive treatment at our tertiary referral centre. The PET imaging parameters SUVmax, SUVpeak, MTV and TLG were measured in primary tumours with focal (18)F-FDG uptake. Clinical and imaging variables significantly associated with overall survival (OS) and disease-free survival (DFS) were identified by univariate and multivariate analyses using the Cox proportional hazards model.

RESULTS

Overall 5-year OS and DFS rates were 72.0 % and 79.5 %, respectively, during a median follow-up of 61 months (range 18 - 122 months). The cut-off values of tumour SUVmax, SUVpeak, MTV and TLG for prediction of DFS were 7.55, 6.80, 11.06 mL and 78.56 g, respectively. Univariate analyses showed that age >60 years, advanced tumour stage, and high tumour SUVmax, SUVpeak, MTV and TLG were significantly associated with decreased OS and DFS (P < 0.05 each). Age, tumour SUVmax and MTV remained independent variables for OS and DFS (P < 0.05 each) in the multivariate analyses.

CONCLUSION

SUVmax and MTV measured on pretreatment (18)F-FDG PET/CT may be useful in predicting the clinical outcomes in OPSCC patients. This study investigated the clinical prognostic value of imaging parameters from pretreatment (18)F-FDG PET/CT in 221 patients who underwent definitive treatment for oropharyngeal squamous cell carcinoma. High maximum standardized uptake value and metabolic tumour volume were independently associated with decreased disease-free and overall survival outcomes.

Molecular Connections between Cancer Cell Metabolism and the Tumor Microenvironment

Cancer cells preferentially utilize glycolysis, instead of oxidative phosphorylation, for metabolism even in the presence of oxygen. This phenomenon of aerobic glycolysis, referred to as the “Warburg effect”, commonly exists in a variety of tumors. Recent studies further demonstrate that both genetic factors such as oncogenes and tumor suppressors and microenvironmental factors such as spatial hypoxia and acidosis can regulate the glycolytic metabolism of cancer cells. Reciprocally, altered cancer cell metabolism can modulate the tumor microenvironment which plays important roles in cancer cell somatic evolution, metastasis, and therapeutic response. In this article, we review the progression of current understandings on the molecular interaction between cancer cell metabolism and the tumor microenvironment. In addition, we discuss the implications of these interactions in cancer therapy and chemoprevention.

Chicken or the egg: Warburg effect and mitochondrial dysfunction

Compared with normal cells, cancer cells show alterations in many cellular processes, including energy metabolism. Studies on cancer metabolism started with Otto Warburg's observation at the beginning of the last century. According to Warburg, cancer cells rely on glycolysis more than mitochondrial respiration for energy production. Considering that glycolysis yields much less energy compared with mitochondrial respiration, Warburg hypothesized that mitochondria must be dysfunctional and this is the initiating factor for cancer formation. However, this hypothesis did not convince every scientist in the field. Some believed the opposite: the reduction in mitochondrial activity is a result of increased glycolysis. This discrepancy of opinions is ongoing. In this review, we will discuss the alterations in glycolysis, pyruvate metabolism, and the Krebs cycle in cancer cells and focus on cause and consequence.

Metabolic tumor volume as a prognostic imaging-based biomarker for head-and-neck cancer: pilot results from Radiation Therapy Oncology Group protocol 0522

PURPOSE

To evaluate candidate fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging biomarkers for head-and-neck chemoradiotherapy outcomes in the cooperative group trial setting.

METHODS AND MATERIALS

Radiation Therapy Oncology Group (RTOG) protocol 0522 patients consenting to a secondary FDG-PET/CT substudy were serially imaged at baseline and 8 weeks after radiation. Maximum standardized uptake value (SUVmax), SUV peak (mean SUV within a 1-cm sphere centered on SUVmax), and metabolic tumor volume (MTV) using 40% of SUVmax as threshold were obtained from primary tumor and involved nodes.

RESULTS

Of 940 patients entered onto RTOG 0522, 74 were analyzable for this substudy. Neither high baseline SUVmax nor SUVpeak from primary or nodal disease were associated with poor treatment outcomes. However, primary tumor MTV above the cohort median was associated with worse local-regional control (hazard ratio 4.01, 95% confidence interval 1.28-12.52, P=.02) and progression-free survival (hazard ratio 2.34, 95% confidence interval 1.02-5.37, P=.05). Although MTV and T stage seemed to correlate (mean MTV 6.4, 13.2, and 26.8 for T2, T3, and T4 tumors, respectively), MTV remained a strong independent prognostic factor for progression-free survival in bivariate analysis that included T stage. Primary MTV remained prognostic in p16-associated oropharyngeal cancer cases, although sample size was limited.

CONCLUSION

High baseline primary tumor MTV was associated with worse treatment outcomes in this limited patient subset of RTOG 0522. Additional confirmatory work will be required to validate primary tumor MTV as a prognostic imaging biomarker for patient stratification in future trials.

18FDG SUV in the primary tumor and lymph node metastases is not predictive for development of distant metastases in high risk head and neck cancer patients

BACKGROUND

Pretreatment screening on distant metastases is particularly useful in head and neck squamous cell carcinoma (HNSCC) patients with high risk factors.

METHODS

In a retrospective study of 88 patients with previously identified clinical high risk factors the predictive value of standardized uptake value (SUV) of 18F-fluorodeoxyglucose (FDG) in the primary tumor and in the lymph node metastases for the development of distant metastases was examined. Different SUVs corrected for plasma glucose levels and body mass index were calculated and analysed in different patient groups: all patients (n=88), patients with a follow up >6months (n=73), not previously treated patients (n=51) and not previously treated patients with a follow up >6months (n=40).

RESULTS

Twenty-four of the 88 (27%) high risk HNSCC patients were diagnosed with distant metastases during screening and follow up. No correlation was found between different SUVs of the primary tumor and lymph nodes metastases and the development of distant metastases.

CONCLUSION

SUVs of primary tumor and lymph node on FDG-PET are not predictive for distant metastases in a (selected) group of patients with already high risk factors for distant metastases.

Primary tumor standardized uptake value predicts survival in head and neck squamous cell carcinoma

BACKGROUND

The purpose of this study was to determine whether the pretreatment primary tumor standardized uptake value (SUV), as measured by positron emission tomography (PET), can add prognostic information for predicting survival in patients with head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

7 articles were identified by searching electronic databases. Statistical analysis was performed with RevMan 4.2.2. SUV measurement and SUV threshold for defining high SUV were studied dependently. For each publication, we first obtained an estimate of the relative risk (RR) for comparing patients with a low or a high SUV. Subsequently, we aggregated the individual RRs into a combined RR, using a fixed-effect model. Publication bias was assessed using a funnel plot.

RESULTS

The study included 7 clinical trials dedicated to HNSCC, involving 674 patients who underwent fluoro-2-deoxy-D-glucose-PET scanning before treatment. The combined RR from the 7 reports for the survival was 0.53 (95% confidence interval: 0.46-0.62). The funnel plot showed symmetrical distribution, indicating no evidence of any substantial publication bias.

CONCLUSION

Our meta-analysis indicates that patients with HNSCC who have a primary tumor with a high SUV have poor survival; this should be further confirmed in a meta-analysis based on individual patient data.

Clinical utility of multimodality imaging with dynamic contrast-enhanced MRI, diffusion-weighted MRI, and 18F-FDG PET/CT for the prediction of neck control in oropharyngeal or hypopharyngeal squamous cell carcinoma treated with chemoradiation

The clinical usefulness of pretreatment imaging techniques for predicting neck control in patients with oropharyngeal or hypopharyngeal squamous cell carcinoma (OHSCC) treated with chemoradiation remains unclear. In this prospective study, we investigated the role of pretreatment dynamic contrast-enhanced perfusion MR imaging (DCE-PWI), diffusion-weighted MR imaging (DWI), and [¹⁸F]fluorodeoxyglucose-positron emission tomography (¹⁸F-FDG PET)/CT derived imaging markers for the prediction of neck control in OHSCC patients treated with chemoradiation. Patients with untreated OHSCC scheduled for chemoradiation between August, 2010 and July, 2012 were eligible for the study. Clinical variables and the following imaging parameters of metastatic neck lymph nodes were examined in relation to neck control: transfer constant, volume of blood plasma, and volume of extracellular extravascular space (V_e) on DCE-PWI; apparent diffusion coefficient (ADC) on DWI; maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis on ¹⁸F-FDG PET/CT. There were 69 patients (37 with oropharynx SCC and 32 with hypopharynx SCC) with successful pretreatment DCE-PWI and DWI available for analysis. After a median follow-up of 31 months, 25 (36.2%) participants had neck failure. Multivariate analysis identified hemoglobin level <14.3 g/dL (P = 0.019), V_e <0.23 (P = 0.040), and ADC >1.14×10⁻³ mm²/s (P = 0.003) as independent prognostic factors for 3-year neck control. A prognostic scoring system was formulated by summing up the three significant predictors of neck control. Patients with scores of 2–3 had significantly poorer neck control and overall survival rates than patients with scores of 0–1. We conclude that hemoglobin levels, V_e, and ADC are independent pretreatment prognostic factors for neck control in OHSCC treated with chemoradiation. Their combination may identify a subgroup of patients at high risk of developing neck failure.

Prognostic value of metabolic tumor volume as measured by fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in nasopharyngeal carcinoma

BACKGROUND

The prognostic value of the tumor burden characterized by the metabolic tumor volume (MTV) remains under investigation in nasopharyngeal carcinoma (NPC). The purpose of this study was to evaluate the prognostic value of the maximum standardized uptake value (SUVmax ) and MTV according to metabolic volume threshold as measured by positron emission tomography (PET)/computed tomography (CT), and other clinical factors, in patients with NPC.

METHODS

This study was a retrospective chart review. We evaluated the association of SUVmax , MTV2.5 , MTV3.0 , and other clinical factors with overall survival (OS) using Kaplan-Meier and Cox regression models. (MTV2.5 and MTV3.0 are the volume of hypermetabolic tissue within the regions of gross tumor volumes with a SUV value greater than the threshold values of 2.5 and 3.0, respectively.)

RESULTS

Higher MTV2.5 of 31.45 cm(3) and MTV3.0 of 23.01 cm(3) were associated with an increased risk of death (hazard ratio [HR] = 5.028; p = 0.029), although no significant relationship was found between SUVmax and OS. Interestingly, MTV3.0 was associated with OS in both the differentiated and undifferentiated groups, although MTV2.5 was only associated with OS in the undifferentiated group. Among the clinical parameters, only radiotherapy was associated with longer OS (HR = 12.124; p < 0.001).

CONCLUSION

The MTV and radiotherapy could be prognostic values associated with OS. Particularly, MTV2.5 and MTV3.0 might be valuable metabolic parameters for predicting long-term survival in patients with NPC. Furthermore, MTV3.0 may be more useful because it can be applied irrespective of pathologic subtype.

The Anatomical Biological Value on Pretreatment (18)F-fluorodeoxyglucose Positron Emission Tomography Computed Tomography Predicts Response and Survival in Locally Advanced Head and Neck Cancer

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has become increasingly relevant in the staging of head and neck cancers, but its prognostic value is controversial. The objective of this study was to evaluate different PET/CT parameters for their ability to predict response to therapy and survival in patients treated for head and neck cancer. A total of 28 consecutive patients with a variety of newly diagnosed head and neck cancers underwent PET/CT scanning at our institution before initiating definitive radiation therapy. All underwent a posttreatment PET/CT to gauge tumor response. Pretreatment PET/CT parameters calculated include the standardized uptake value (SUV) and the anatomical biological value (ABV), which is the product of SUV and greatest tumor diameter. Maximum and mean values were studied for both SUV and ABV, and correlated with response rate and survival. The mean pretreatment tumor ABV_max decreased from 35.5 to 7.9 (P = 0.0001). Of the parameters tested, only pretreatment ABV_max was significantly different among those patients with a complete response (CR) and incomplete response (22.8 vs. 65, respectively, P = 0.021). This difference was maximized at a cut-off ABV_max of 30 and those patients with ABV_max < 30 were significantly more likely to have a CR compared to those with ABV_max of ≥ 30 (93.8% vs. 50%, respectively, P = 0.023). The 5-year overall survival was 80% compared to 36%, respectively, (P = 0.028). Multivariate analysis confirmed that ABV_max was an independent prognostic factor. Our data supports the use of PET/CT, and specifically ABV_max, as a prognostic factor in head and neck cancer. Patients who have an ABV_max ≥ 30 were more likely to have a poor outcome with chemoradiation alone, and a more aggressive trimodality approach may be indicated in these patients.

Estimate of the impact of FDG-avidity on the dose required for head and neck radiotherapy local control

Background and purpose

Although FDG-avid tumors are recognized as a potential target for dose escalation, there is no clear basis for selecting a boost dose to counter this apparent radioresistance. Using a novel analysis method, based on the new concept of an outcome-equivalent dose, we estimate the extra dose required to equalize local control between FDG-avid and non-avid head and neck tumors.

Materials and methods

Based on a literature review, five reports of head and neck cancer (423 patients in total), along with an internal validation dataset from our institution (135 oropharynx patients), were used in this analysis. To compensate for the heterogeneity among multi-institutional patient cohorts and corresponding treatment techniques, local control data of the cohorts were fit to a single dose–response curve with a clinically representative steepness (γ₅₀ = 2), thereby defining an ‘outcome-equivalent dose’ (OED) for each institutional cohort. Separate dose–response curves were then determined for the FDG-avid and FDG-non-avid patient cohorts, and the ratio of TD₅₀ (tumor dose required for 50% of control) values between the high- and low-FDG-uptake groups (TD_50,high/TD_50,low) was estimated, resulting in an estimated metabolic dose-modifying factor (mDMF) due to FDG-avidity.

Results

For individual datasets, the estimated mDMFs were found to be in the range of 1.07–1.62, decreasing if the assumed slope (γ₅₀) increased. Weighted logistic regression for the six datasets resulted in a mDMF of 1.19 [95% CI: 1.04–1.34] for a γ₅₀ value of 2, which translates to a needed dose increase of about 1.5 Gy per unit increase in the maximum standardized uptake value (SUV_m) of FDG-PET [95% CI: 0.3–2.7]. Assumptions of lower or higher γ₅₀ values (1.5 or 2.5) resulted in slightly different mDMFs: 1.26 or 1.15, respectively. A validation analysis with seven additional datasets, based on relaxed criteria, was consistent with the estimated mDMF.

Conclusions

We introduced a novel outcome-equivalent dose analysis method to estimate the dose– response modifying effect of FDG uptake variation. To reach equal response rates, FDG-avid tumors are likely to require 10% to 30% more dose than FDG-non-avid tumors. These estimates provide a rational starting point for selecting IMRT boosts for FDG-avid tumors. However, independent tests and refinements of the estimated dose-modifying effect, using high-quality prospective clinical trial data, are needed.

Prognostic value of dual-time-point 18F-FDG PET-CT imaging in patients with head and neck squamous cell carcinoma

OBJECTIVE

The objective of this study was to investigate the independent prognostic value of dual-time-point (18)F-fluorodeoxyglucose ((18)F-FDG) PET-CT imaging in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS

Patients referred to our department to undergo (18)F-FDG PET-CT for staging of HNSCC were prospectively included. Each patient was scanned using a Philips Gemini PET-CT system 1 h (early acquisition) and 2 h (delayed acquisition) after injection. An intratumoral retention index (RI) of (18)F-FDG was measured for each examination by the dual-time-point method. Event-free survival (EFS) and overall survival (OS) were determined by the Kaplan-Meier method and compared with the conventional maximum standardized uptake value (SUV(max)) at 60 min, SUV(max) at 120 min, and RI in univariate and multivariate analyses including the usual prognostic factors such as age, sex, primary site, SCC histologic grade, and American Joint Committee on Cancer stage (I, II, III, and IV).

RESULTS

Sixty-six consecutive patients (60 men and six women; mean age=61 ± 9 years) were included in the study. In univariate analysis, besides age and stage, RI was predictive of EFS (P=0.01) but not of OS (P=0.1), whereas SUV(max) at 60 min was not predictive of EFS (P=0.18) or OS (P=0.08) and SUV(max) at 120 min was predictive of OS (P=0.02) but not of EFS (P=0.05). In multivariate analysis, RI persisted as an independent predictive factor for EFS (P=0.02) but not SUV(max) at 120 min for OS (P=0.12).

CONCLUSION

Our results suggest an additional prognostic interest of RI measured by dual-time-point (18)F-FDG PET-CT, independent of usual prognostic factors, in patients with HNSCC.

The feasibility of 18F-fluorodeoxyglucose-positron emission tomography uptake as a prognostic factor for paranasal sinus malignancy

BACKGROUND

There is a correlation between (18)F-fluorodeoxyglucose (FDG) uptake and the level of intracellular metabolic tumor activity, which in turn may be associated with active proliferation, invasion, and prognosis as well as distant metastases in head and neck cancer. This study was designed to assess whether tumor uptake of FDG positron emission tomography (PET) expressed as the maximum standardized uptake value (SUVmax) can be used to predict survival in subjects with paranasal sinus malignancy.

METHODS

We enrolled 42 consecutive subjects with a histological diagnosis of squamous cell carcinoma in paranasal sinus malignancy, into a retrospective institutional imaging trial. Thirty-eight subjects (90.5%) underwent a baseline FDG-PET scan before curative treatment and were eligible for analysis.

RESULTS

A total of 38 subjects with paranasal sinus malignancy undergoing PET/computed tomography imaging in the initial stages were assessed separately for a potential correlation between SUVmax and T staging, histological grading, and overall survival. Log-rank testing revealed a significant correlation between overall survival and histological grading (p = 0.046); and there was some correlation between SUVmax and histological grading, but not significantly different. The receiver operation characteristic curve was identified for cutoff value of SUVmax as a prognostic factor. We compared the low tumor of the SUVmax group with the high tumor of the SUVmax group divided by the cutoff value of SUVmax. We did find a significant correlation between SUVmax and disease control and mortality (p = 0.003, p < 0.001).

CONCLUSION

In our study, we concluded that subjects with higher tumor FDG uptakes should be considered for a more aggressive disease.

Predictive value of pre-therapy (18)F-FDG PET/CT for the outcome of (18)F-FDG PET-guided radiotherapy in patients with head and neck cancer

PURPOSE

The aim of this study was to evaluate the predictive role of pre-therapy fluorodeoxyglucose (FDG) uptake parameters of primary tumour in head and neck cancer (HNC) patients undergoing intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) on FDG-positive volume-positron emission tomography (PET) gross tumour volume (PET-GTV).

METHODS

This retrospective study included 19 patients (15 men and 4 women, mean age 59.2 years, range 23-81 years) diagnosed with HNC between 2005 and 2011. Of 19 patients, 15 (79 %) had stage III-IV. All patients underwent FDG PET/CT before treatment. Metabolic indexes of primary tumour, including metabolic tumour volume (MTV), maximum and mean standardized uptake value (SUVmax, SUVmean) and total lesion glycolysis (TLG) were considered. Partial volume effect correction (PVC) was performed for SUVmean and TLG estimation. Correlations between PET/CT parameters and 2-year disease-free survival (DFS), local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) were assessed. Median patient follow-up was 19.2 months (range 4-24 months).

RESULTS

MTV, TLG and PVC-TLG predicting patients' outcome with respect to all the considered local and distant disease control endpoints (LRFS, DMFS and DFS) were 32.4 cc, 469.8 g and 547.3 g, respectively. SUVmean and PVC-SUVmean cut-off values predictive of LRFS and DFS were 10.8 and 13.3, respectively. PVC was able to compensate errors up to 25 % in the primary HNC tumour uptake. Moreover, PVC enhanced the statistical significance of the results.

CONCLUSION

FDG PET/CT uptake parameters are predictors of patients' outcome and can potentially identify patients with higher risk of treatment failure that could benefit from more aggressive approaches. Application of PVC is recommended for accurate measurement of PET parameters.

18-FDG-PET in the initial staging of sinonasal malignancy

OBJECTIVES/HYPOTHESIS

The utility of fluorine-18 fluorodeoxyglucose-positron emission tomography (PET) has been gradually defined for most head and neck cancers, However, its utility in the initial diagnosis of sinonasal malignancy has not been extensively studied. The aim of this study was to determine if PET scanning accurately diagnoses and stages malignant sinonasal lesions and if maximum standard uptake value (SUV max) correlates with clinically advanced disease.

STUDY DESIGN

Retrospective chart review.

METHODS

There were 51 patients with sinonasal malignancy who underwent diagnostic whole body PET or PET-computed tomography scans that were analyzed for patient and disease characteristics, SUV max, and staging.

RESULTS

Of the 51 patients, 48 scans were positive at the primary site, with a sensitivity of 94%. Four patients were found to have intensely avid uptake, in which the numerical SUV max was not documented, and three patients did not have any uptake in the region of their tumor. Mean SUV max at the primary site was 16.1 (range, 3.1-59). Metastasis was detected in 31% (16/51) of the patients. There was a potential positive correlation between SUV max at the primary site and detection of metastasis on univariate analysis (r = 0.19, P = .09), but on multivariate analysis, SUV max was not found to correlate with T staging or metastasis.

CONCLUSIONS

For diagnosis of sinonasal malignancy, PET scans have a high sensitivity, although false negatives occurred in 6% of cases. PET scanning detected metastasis in 31% of patients, but SUV max did not function as a marker for clinically advanced disease. The role of diagnostic PET for sinonasal malignancy is currently limited to cases with a high suspicion of metastatic disease.

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

BACKGROUND

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Variety and complexity of fluorine-18-labelled fluoro-2-deoxy-D-glucose accumulations in the oral cavity of patients with oral cancers

OBJECTIVES

To elucidate the points that require attention when interpreting fluorine-18-labelled fluoro-2-deoxy-d-glucose ((18)F-FDG)/positron emission tomography (PET) images by demonstration of (18)F-FDG accumulation in various areas of the oral cavity other than primary lesions in patients with oral cancers.

METHODS

(18)F-FDG accumulations with a maximal standardized uptake value of over 2.5 in various areas of the oral cavity other than primary lesions were identified in 82 patients with oral cancers.

RESULTS

(18)F-FDG/PET-positive areas, excluding primary tumours, included the front intrinsic muscles of the tongue (89.0%), upper and lower marginal parts of the orbicularis oris muscle (64.6%), sublingual glands, palatine tonsil, pharyngeal tonsil, and lingual tonsil. In addition, some areas in the jaws also showed accumulation.

CONCLUSIONS

In patients with oral cancers, areas of (18)F-FDG accumulation in the oral cavity should be precisely identified and appropriately diagnosed, because accumulations can be seen in areas other than the primary tumour.

Cancer metabolism, stemness and tumor recurrence: MCT1 and MCT4 are functional biomarkers of metabolic symbiosis in head and neck cancer

Here, we interrogated head and neck cancer (HNSCC) specimens (n = 12) to examine if different metabolic compartments (oxidative vs. glycolytic) co-exist in human tumors. A large panel of well-established biomarkers was employed to determine the metabolic state of proliferative cancer cells. Interestingly, cell proliferation in cancer cells, as marked by Ki-67 immunostaining, was strictly correlated with oxidative mitochondrial metabolism (OXPHOS) and the uptake of mitochondrial fuels, as detected via MCT1 expression (p < 0.001). More specifically, three metabolic tumor compartments were delineated: (1) proliferative and mitochondrial-rich cancer cells (Ki-67+/TOMM20+/COX+/MCT1+); (2) non-proliferative and mitochondrial-poor cancer cells (Ki-67−/TOMM20−/COX−/MCT1−); and (3) non-proliferative and mitochondrial-poor stromal cells (Ki-67−/TOMM20−/COX−/MCT1−). In addition, high oxidative stress (MCT4+) was very specific for cancer tissues. Thus, we next evaluated the prognostic value of MCT4 in a second independent patient cohort (n = 40). Most importantly, oxidative stress (MCT4+) in non-proliferating epithelial cancer cells predicted poor clinical outcome (tumor recurrence; p < 0.0001; log-rank test), and was functionally associated with FDG-PET avidity (p < 0.04). Similarly, oxidative stress (MCT4+) in tumor stromal cells was specifically associated with higher tumor stage (p < 0.03), and was a highly specific marker for cancer-associated fibroblasts (p < 0.001). We propose that oxidative stress is a key hallmark of tumor tissues that drives high-energy metabolism in adjacent proliferating mitochondrial-rich cancer cells, via the paracrine transfer of mitochondrial fuels (such as L-lactate and ketone bodies). New antioxidants and MCT4 inhibitors should be developed to metabolically target “three-compartment tumor metabolism” in head and neck cancers. It is remarkable that two “non-proliferating” populations of cells (Ki-67−/MCT4+) within the tumor can actually determine clinical outcome, likely by providing high-energy mitochondrial “fuels” for proliferative cancer cells to burn. Finally, we also show that in normal mucosal tissue, the basal epithelial “stem cell” layer is hyper-proliferative (Ki-67+), mitochondrial-rich (TOMM20+/COX+) and is metabolically programmed to use mitochondrial fuels (MCT1+), such as ketone bodies and L-lactate. Thus, oxidative mitochondrial metabolism (OXPHOS) is a common feature of both (1) normal stem cells and (2) proliferating cancer cells. As such, we should consider metabolically treating cancer patients with mitochondrial inhibitors (such as Metformin), and/or with a combination of MCT1 and MCT4 inhibitors, to target “metabolic symbiosis.”

Prognostic value of (18)F-fluorodeoxyglucose positron emission tomography, computed tomography and magnetic resonance imaging in oral cavity squamous cell carcinoma with pathologically positive neck lymph node

Purpose

To evaluate the prognostic value of preoperative neck lymph node (LN) assessment with ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET), computed tomography (CT), and magnetic resonance imaging (MRI) in oral cavity squamous cell carcinoma (OSCC) patients with pathologically positive LN.

Materials and Methods

In total, 47 OSCC patients with pathologically positive LN were retrospectively reviewed with preoperative ¹⁸F-FDG PET and CT/MRI. All patients underwent surgical resection, neck dissection and postoperative adjuvant radiotherapy and/or chemotherapy between March 2002 and October 2010. Histologic correlation was performed for findings of ¹⁸F-FDG PET and CT/MRI.

Results

Thirty-six (76.6%) of 47 cases were correctly diagnosed with neck LN metastasis by ¹⁸F-FDG PET and 32 (68.1%) of 47 cases were correctly diagnosed by CT/MRI. Follow-up ranged from 20 to 114 months (median, 56 months). Clinically negative nodal status evaluated by ¹⁸F-FDG PET or CT/MRI revealed a trend toward better clinical outcomes in terms of overall survival, disease-free survival, local recurrence-free survival, regional nodal recurrence-free survival, and distant metastasis-free survival rates even though the trends were not statistically significant. However, there was no impact of neck node standardized uptake value (SUV_max) on clinical outcomes. Notably, SUV_max showed significant correlation with tumor size in LN (p < 0.01, R² = 0.62). PET and CT/MRI status of LN also had significant correlation with the size of intranodal tumor deposit (p < 0.05, R² = 0.37 and p < 0.01, R² = 0.48, respectively).

Conclusion

¹⁸F-FDG PET and CT/MRI at the neck LNs might improve risk stratification in OSCC patients with pathologically positive neck LN in this study, even without significant prognostic value of SUV_max.

FDG-PET/CT imaging biomarkers in head and neck squamous cell carcinoma

This article discusses the value of ¹⁸F-fluoro-2-deoxyglucose PET/CT imaging biomarkers in head and neck squamous cell carcinoma. ¹⁸F-fluoro-2-deoxyglucose PET/CT is valuable at baseline staging, radiotherapy planning, therapy response assessment and in the follow-up of patients with head and neck squamous cell carcinoma. Maximum and peak standardized uptake value (SUV_max and SUV_peak), metabolic tumor volume and total lesion glycolysis are the common ¹⁸F-fluoro-2-deoxyglucose quantitative parameters that have been studied, along with qualitative assessments. These parameters will be evaluated with respect to their established or potential role as noninvasive biomarkers for patient risk stratification, treatment response and survival outcome.

The role of 18F-FDG PET/CT metabolic tumour volume in predicting survival in patients with metastatic nasopharyngeal carcinoma

OBJECTIVES

To investigate the role of PET-derived imaging markers in predicting metastatic nasopharyngeal carcinoma (NPC) outcomes.

MATERIALS AND METHODS

A total of 56 patients with metastatic NPC were enrolled. Before treatment, all of the participants underwent (18)F-FDG PET/CT. The following (18)F-FDG PET parameters were assessed: standardised uptake value, metabolic tumour volume (MTV), and total lesion glycolysis. Multivariate Cox proportional hazards models were used to identify the independent predictors of survival.

RESULTS

The multivariate analysis showed that performance status>1 (P=0.007), Epstein-Barr virus (EBV) DNA titre>5000 copies/mL (P=0.001), and MTV>110 mL (P=0.013) were independent risk factors for progression-free survival (PFS). Male sex (P=0.004), performance status>1 (P<0.0001), EBV DNA level>5000 copies/mL (P<0.0001), and MTV>110 mL (P=0.003) independently predicted overall survival (OS). The 2-year PFS and OS rates of the patients with MTV≤110 mL were 23.2% and 43%, respectively, compared with 0% and 9.1%, respectively, for those with MTV>110 mL. Combining the MTV with the EBV DNA titre allowed further survival stratification by dividing the patients into three groups with distinct PFS (2-year rates=30.8%, 7.1%, and 0%, P<0.0001) and OS (2-year rates=68.4%, 40%, and 0%, P<0.0001) rates.

CONCLUSION

The MTV appears to be an independent risk factor in metastatic NPC patients. This factor is complementary to the EBV DNA titre for predicting survival in metastatic NPC.

The Application of FDG-PET as Prognostic Indicators in Head and Neck Squamous Cell Carcinoma

This article discusses the role of FDG-PETederived parameters as prognostic indicators in patients with squamous cell carcinoma of the head and neck. The basic underlying biology of FDG-PET scans and the quantitative information that can be derived are discussed. A review of the literature is performed. Potential applications in the management of head and neck cancer and future directions in clinical trials are discussed.

18F-FDG PET/CT metabolic tumor volume and total lesion glycolysis predict outcome in oropharyngeal squamous cell carcinoma

Treatment of oropharyngeal squamous cell carcinoma with chemoradiotherapy can now accomplish excellent locoregional disease control, but patient overall survival (OS) remains limited by development of distant metastases (DM). We investigated the prognostic value of staging (18)F-FDG PET/CT, beyond clinical risk factors, for predicting DM and OS in 176 patients after definitive chemoradiotherapy.

METHODS

The PET parameters maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were recorded. Univariate Cox regression was used to examine the prognostic value of these variables and clinical prognosticators for local treatment failure (LTF), OS, and DM. Multivariate analysis examined the effect of SUVmax, TLG, and MTV in the presence of other covariates. Kaplan-Meier curves were used to evaluate prognostic values of PET/CT parameters.

RESULTS

Primary tumors were distributed across all stages. Most patients underwent chemoradiotherapy only, and 11 also underwent tonsillectomy. On univariate analysis, primary tumor MTV was predictive of LTF (P = 0.005, hazard ratio [HR] = 2.4 for a doubling of MTV), DM and OS (P < 0.001 for both, HR = 1.9 and 1.8, respectively). The primary tumor TLG was associated with DM and OS (P < 0.001, HR = 1.6 and 1.7, respectively, for a doubling of TLG). The primary tumor SUVmax was associated with death (P = 0.029, HR = 1.1 for a 1-unit increase in standardized uptake value) but had no relationship with LTF or DM. In multivariate analysis, TLG and MTV remained associated with death after correcting for T stage (P = 0.0125 and 0.0324, respectively) whereas no relationship was seen between standardized uptake value and death after adjusting for T stage (P = 0.158).

CONCLUSION

Parameters capturing the volume of (18)F-FDG-positive disease (MTV or TLG) provide important prognostic information in oropharyngeal squamous cell carcinoma treated with chemoradiotherapy and should be considered for risk stratification in this disease.

FDG PET/CT and diffusion-weighted imaging of head and neck squamous cell carcinoma: comparison of prognostic significance between primary tumor standardized uptake value and apparent diffusion coefficient

PURPOSE

To compare primary tumor (18)F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUV(max)) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) obtained in the same patients with head and neck squamous cell carcinoma (HNSCC) to clarify the prognostic significance of both indexes.

MATERIALS AND METHODS

The study population comprised 26 patients with HNSCC visible on both pretreatment FDG PET/CT and DWI. Correlation between SUV(max) and ADC (b values; 0 and 800 seconds/mm(2)) was analyzed by the Spearman's rank test. Disease-free survival (DFS) was calculated by the Kaplan-Meier method. Prognostic significance was assessed by the long-rank test and Cox proportional hazards analysis.

RESULTS

SUV(max) and ADC correlated significantly and negatively (ρ = -0.566, P = 0.005). High (>12.1) SUV(max) (P < 0.001), low (≤ 0.88) ADC (P = 0.009), high (T3-4) T stage (P = 0.030), and high (N2-3) N stage (P = 0.007) were significant in predicting poor 2-year DFS. The accuracy for predicting disease events was 81% (21/26) for SUV(max) (>12.1) and 73% (19/26) for ADC(≤ 0.88) without significant difference between them (P = 0.52). Disease event hazards ratios for significant unadjusted SUV(max) (P = 0.015) and ADC (P = 0.039) remained significant when adjusted for other dichotomized clinical covariates (SUV(max); P = 0.009-0.039, ADC; P = 0.017-0.037) except SUV(max) for ADC and ADC for SUV(max) and T stage.

CONCLUSION

These results suggest that pretreatment primary tumor SUV(max) and ADC correlate significantly and negatively and both may have similar potential to predict DFS or disease events of HNSCC.

Comparison of PET/CT with conventional imaging modalities (USG, CECT) in evaluation of N0 neck in head and neck squamous cell carcinoma

BACKGROUND

Evaluation of a clinically N0 neck is mandatory in cases of squamous cell carcinoma of head and neck region in order to determine the need to address the neck. The study was designed to compare the accuracy of PET/CT scan with that of USG and CECT Neck in assessing clinically N0 neck in cases of squamous cell carcinoma of upper aerodigestive tract.

METHODS

Single center, prospective, study over a 2 year period. All Cases of squamous cell carcinoma of upper aerodigestive tract with no palpable neck lymphadenopathy and who were scheduled for surgery were evaluated with USG, CECT and 18F-FDG PET/CT, of the neck. Post operative histopathology was correlated with pre-operative nodal status. Statistical analysis was done using the chi square test.

RESULTS

In the 49 patients enrolled, 51 neck sides underwent dissections. Sensitivity of USG, CECT and PET-CT was 4.76%, 23.80% and 71.43% respectively while the specificity was 93.33%, 93.33% and 96.67% respectively. The positive predictive value (PPV) calculated for USG, CECT and PET-CT was 33.33%, 71%, 93.5% respectively while the negative predictive value (NPV) 58.33%, 63.63% and 82.85% respectively.

CONCLUSIONS

In N0 neck in head and neck squamous cell carcinoma, though FDG-PET-CT is more accurate than either USG or CECT in staging of the neck, it is not accurate enough to alter the current treatment paradigm.

Biological response of nasopharyngeal carcinoma to radiation therapy: a pilot study using serial 18F-FDG PET/CT scans

We used serial (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) to evaluate tumors' maximum standardized uptake value (SUV(max)) before, during, and after radiotherapy to explore the biological behavior of and response to radiation therapy in various subtypes of nasopharyngeal carcinoma (NPC). Sixty-one patients with pathologically diagnosed NPC were prospectively enrolled into the study. WHO type II(B) disease had a higher initial SUV(max) and more significant biological response at the primary site as compared with type II(A) subtype. The two subtypes of WHO type II NPC may significantly differ in their biological behavior and response to radiotherapy.

Expression of human protein S100A7 (psoriasin), preparation of antibody and application to human larynx squamous cell carcinoma

BACKGROUND

Up-regulation of S100A7 (Psoriasin), a small calcium-binding protein, is associated with the development of several types of carcinomas, but its function and possibility to serve as a diagnostic or prognostic marker have not been fully defined. In order to prepare antibodies to the protein for immunohistochemical studies we produced the recombinant S100A7 protein in E. coli. mRNA extracted from human tracheal tumor tissue which was amplified by RT-PCR to provide the region coding for the S100A7 gene. The amplified fragment was cloned in the vector pCR2.1-TOPO and sub-cloned in the expression vector pAE. The protein rS100A7 (His-tag) was expressed in E. coli BL21::DE3, purified by affinity chromatography on an Ni-NTA column, recovered in the 2.0 to 3.5 mg/mL range in culture medium, and used to produce a rabbit polyclonal antibody anti-rS100A7 protein. The profile of this polyclonal antibody was evaluated in a tissue microarray.

RESULTS

The rS100A7 (His-tag) protein was homogeneous by SDS-PAGE and mass spectrometry and was used to produce an anti-recombinant S100A7 (His-tag) rabbit serum (polyclonal antibody anti-rS100A7). The molecular weight of rS100A7 (His-tag) protein determined by linear MALDI-TOF-MS was 12,655.91 Da. The theoretical mass calculated for the nonapeptide attached to the amino terminus is 12,653.26 Da (delta 2.65 Da). Immunostaining with the polyclonal anti-rS100A7 protein generated showed reactivity with little or no background staining in head and neck squamous cell carcinoma cells, detecting S100A7 both in nucleus and cytoplasm. Lower levels of S100A7 were detected in non-neoplastic tissue.

CONCLUSIONS

The polyclonal anti-rS100A7 antibody generated here yielded a good signal-to-noise contrast and should be useful for immunohistochemical detection of S100A7 protein. Its potential use for other epithelial lesions besides human larynx squamous cell carcinoma and non-neoplastic larynx should be explored in future.

The role of preoperative [18F]fluorodeoxyglucose positron emission tomography in predicting early recurrence after curative resection of hepatocellular carcinomas

PURPOSE

(18)F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) scan reflects tumor differentiation and predicts clinical outcome in patients with hepatocellular carcinoma (HCC). We investigated the correlation of PET scans with tumor differentiation and early tumor recurrence (time-to-recurrence <1 year).

METHODS

We reviewed the medical records of 93 patients with HCC who underwent curative resection at our hospital from August 2004 through December 2008. PET scans were performed preoperatively, and the maximum standardized uptake value of the tumor (SUV(tumor)) and the tumor-to-non-tumor SUV ratio (TNR) were calculated from FDG uptake.

RESULTS

Twenty-six (27.9%) had recurrences and 12 of them (46.2%) had early recurrences. SUV(tumor) and TNR correlated strongly with tumor differentiation (p < 0.001). Early recurrence-free and the overall survival rates in the low TNR group (TNR <2.0) were higher than in the high TNR group (TNR ≥2.0) (p = 0.015, p = 0.013). According to univariate analysis, predictors of early tumor recurrence were large tumor size (≥5 cm), high TNR (≥2), high SUV(tumor) (≥4), and high Edmoson-Steiner grade. However, on multivariate analysis, none of the examined factors were statistically significant independent predictor.

CONCLUSION

PET scans reflect tumor differentiation in HCCs. Because high TNR (TNR ≥2) and SUV(tumor) (SUV ≥4) were these cutoff point significant predictors in univariate analysis, future studies with more statistical power are needed to assess the significance.

Efficacy of fluoro-2-deoxy-D-glucose positron emission tomography to evaluate responses to concurrent chemoradiotherapy for head and neck squamous cell carcinoma

OBJECTIVE

This study evaluates the utility of fluorodeoxyglucose-positron emission tomography (FDG-PET) in patients with head and neck squamous cell carcinoma (HNSCC) who received concurrent chemoradiotherapy (CCRT).

METHODS

Sixty-five patients were recruited for this study between November 2002 and April 2007. The FDG-PET scan was performed before treatment and 4-6 weeks after treatment.

RESULTS

The mean of maximum standardized uptake value (SUVmax) before treatment at the primary tumor site was 8.1 (range, 2-22). The sensitivity of FDG-PET for the diagnosis of primary tumor site was 98%. The mean of SUVmax after treatment was 2.6 (range, 2-5). The sensitivity, specificity, and accuracy of FDG-PET for the diagnosis of primary tumor site after treatment were 100%, 40%, and 46%, respectively. The mean of SUVmax before treatment at the nodal site was 4.7 (range, 2-16). The mean of SUVmax after treatment was 2.0 (range, 2-6.7). The pre-treatment SUVmax of T2, T3, and T4 stages were significantly higher than that of the T1 stage. The N stage had no correlation in terms of the pre-treatment nodal site SUVmax.

CONCLUSION

Our results indicate that FDG-PET is a useful imaging method for evaluating the response of CCRT in patients with HNSCC. However, performing FDG-PET 4-6 weeks after treatment may be too early as it may give false-positive results due to fibrosis and scarring.

Metabolic tumour volume. Prognostic value in locally advanced squamous cell carcinoma of the head and neck

PURPOSE

Evaluate the predictive and prognostic value of semi-quantitative FDG-PET variables derived from pretreatment FDG-PET images in patients suffering from locally advanced squamous cell carcinoma of the head and neck (SCCHN), treated by means of concomitant radiochemotherapy.

PATIENTS, METHODS

40 patients with newly diagnosed SCCHN that were treated with concomitant radiochemotherapy underwent FDG-PET/CT for treatment planning; 18 patients had neck dissection prior to their baseline scan and to receiving radiochemotherapy. FDG-PET images were used to calculate metabolic tumour volumes using region growing and a threshold of 50% (MTV50) of primary lesions and involved lymph nodes as well as the mean and maximum standard uptake value (SUVmean and SUVmax) of the primary tumours.

RESULTS

Neither SUVmean nor SUVmax values of the primary tumour were significantly different between responders and non-responders whereas MTV50 values of the primary tumour proved significantly higher in non-responders. SUVmean, SUVmax and MTV50 of the primary tumour were not predictive for overall or disease free survival. Contrariwise, dichotomized summed MTV50 values (cut-off≥31 cm3) of the primary tumour and involved lymph nodes in patients that didn't have neck dissection prior to radiochemotherapy were predictive for disease free and overall survival in both univariate and multivariate analysis (p≤0.05).

CONCLUSION

Summed MTV50 values of both the primary tumour and involved lymph nodes provided independent prognostic information on disease free and overall survival.

Can FDG PET predict radiation treatment outcome in head and neck cancer? Results of a prospective study

Purpose

In head and neck cancer (HNC) various treatment strategies have been developed to improve outcome, but selecting patients for these intensified treatments remains difficult. Therefore, identification of novel pretreatment assays to predict outcome is of interest. In HNC there are indications that pretreatment tumour ¹⁸F-fluorodeoxyglucose (FDG) uptake may be an independent prognostic factor. The aim of this study was to assess the prognostic value of FDG uptake and CT-based and FDG PET-based primary tumour volume measurements in patients with HNC treated with (chemo)radiotherapy.

Methods

A total of 77 patients with stage II–IV HNC who were eligible for definitive (chemo)radiotherapy underwent coregistered pretreatment CT and FDG PET. The gross tumour volume of the primary tumour was determined on the CT (GTV_CT) and FDG PET scans. Five PET segmentation methods were applied: interpreting FDG PET visually (PET_VIS), applying an isocontour at a standardized uptake value (SUV) of 2.5 (PET_2.5), using fixed thresholds of 40% and 50% (PET_40%, PET_50%) of the maximum intratumoral FDG activity (SUV_MAX) and applying an adaptive threshold based on the signal-to-background (PET_SBR). Mean FDG uptake for each PET-based volume was recorded (SUV_mean). Subsequently, to determine the metabolic volume, the integrated SUV was calculated as the product of PET-based volume and SUV_mean. All these variables were analysed as potential predictors of local control (LC), regional recurrence-free survival (RRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS).

Results

In oral cavity/oropharynx tumours PET_VIS was the only volume-based method able to predict LC. Both PET_VIS and GTV_CT were able to predict DMFS, DFS and OS in these subsites. Integrated SUVs were associated with LC, DMFS, DFS and OS, while SUV_mean and SUV_MAX were not. In hypopharyngeal/laryngeal tumours none of the variables was associated with outcome.

Conclusion

There is no role yet for pretreatment FDG PET as a predictor of (chemo)radiotherapy outcome in HNC in daily routine. However, this potential application needs further exploration, focusing both on FDG PET-based primary tumour volume, integrated SUV and SUV_MAX of the primary tumour.

Analysis of pretreatment FDG-PET SUV parameters in head-and-neck cancer: tumor SUVmean has superior prognostic value

PURPOSE

To evaluate the prognostic significance of different descriptive parameters in head-and-neck cancer patients undergoing pretreatment [F-18] fluoro-D-glucose-positron emission tomography (FDG-PET) imaging.

PATIENTS AND METHODS

Head-and-neck cancer patients who underwent FDG-PET before a course of curative intent radiotherapy were retrospectively analyzed. FDG-PET imaging parameters included maximum (SUV(max)), and mean (SUV(mean)) standard uptake values, and total lesion glycolysis (TLG). Tumors and lymph nodes were defined on co-registered axial computed tomography (CT) slices. SUV(max) and SUV(mean) were measured within these anatomic regions. The relationships between pretreatment SUV(max), SUV(mean), and TLG for the primary site and lymph nodes were assessed using a univariate analysis for disease-free survival (DFS), locoregional control (LRC), and distant metastasis-free survival (DMFS). Kaplan-Meier survival curves were generated and compared via the log-rank method. SUV data were analyzed as continuous variables.

RESULTS

A total of 88 patients was assessed. Two-year OS, LRC, DMFS, and DFS for the entire cohort were 85%, 78%, 81%, and 70%, respectively. Median SUV(max) for the primary tumor and lymph nodes was 15.4 and 12.2, respectively. Median SUV(mean) for the primary tumor and lymph nodes was 7 and 5.2, respectively. Median TLG was 770. Increasing pretreatment SUV(mean) of the primary tumor was associated with decreased disease-free survival (p = 0.01). Neither SUV(max) in the primary tumor or lymph nodes nor TLG was prognostic for any of the clinical endpoints. Patients with pretreatment tumor SUV(mean) that exceeded the median value (7) of the cohort demonstrated inferior 2-year DFS relative to patients with SUV(mean) ≤ the median value of the cohort, 58% vs. 82%, respectively, p = 0.03.

CONCLUSION

Increasing SUV(mean) in the primary tumor was associated with inferior DFS. Although not routinely reported, pretreatment SUV(mean) may be a useful prognostic FDG-PET parameter and should be further evaluated prospectively.

18F-FDG PET or PET-CT to evaluate prognosis for head and neck cancer: a meta-analysis

PURPOSE

The purpose of this meta-analysis was to evaluate the prognostic value of standard uptake value (SUV) from serial Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in patients with head and neck cancer.

METHODS

We searched for articles limited to head and neck cancer, dealt with the impact of SUV on survival and published in English. The endpoints were disease-free survival (DFS), overall survival (OS), and local control (LC). Two reviewers extracted data independently.

RESULTS

Thirty-five studies were identified; of which, 26 studies involving 1,415 patients met the inclusion criteria. Pooled survival data suggested better DFS, OS, and LC in patients with low SUV of pre-treatment, and the odds ratio (OR) was 0.23, 0.24, and 0.27, respectively. Patients having tumors with low SUV of post-treatment also had significantly better DFS (OR = 0.17) and OS (OR = 0.28) than those with high SUV.

CONCLUSIONS

The present meta-analysis showed that (18)F-FDG uptake, as measured by the SUV before treatment and metabolic response after treatment, are valuable for predicting long-term survival in head and neck cancer. High (18)F-FDG uptake may be useful for identifying patients requiring more aggressive treatment.

Is there a correlation between 18F-FDG-PET standardized uptake value, T-classification, histological grading and the anatomic subsites in newly diagnosed squamous cell carcinoma of the head and neck?

(18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET)/CT imaging of squamous cell carcinoma of the head and neck (HNSCC) renders the possibility to study metabolic tumor activity by measuring FDG-uptake expressed as maximum standardized uptake value (SUV(max)). A correlation between SUV(max) and several factors including T-classification, histological tumor differentiation or different anatomic subsites is of potential interest in HNSCC. The aim of this study was to evaluate how metabolic tumor activity derived from FDG-PET correlates with prognostic clinical and pathological parameters including these factors. 262 patients with HNSCC undergoing PET/CT for initial staging were assessed separately for a potential correlation between SUV(max) and T-classification, histological grading, and anatomical subsites of the primary tumor. Nonparametric testing showed a significant correlation between SUV(max) and T-classification (P < 0.001). On the contrary, no statistically significant correlation was found between SUV(max) and histological tumor grading. Furthermore, no statistical significant correlation between the different anatomical subsites and SUV(max) were found. There was no significant correlation of SUV(max) and tumor grading after adjustment for T-stage and anatomical localization of the tumor, neither.

CONCLUSION

Metabolic tumor activity correlates with T-stage of HNSCC. However, histological tumor grading does not correlate with SUV(max). The role of primary tumor SUV(max) as a predictor of outcome or survival remains unclear. Clinicians should therefore exercise caution in attributing any clinical importance to SUV(max) obtained from a single PET/CT exam.

FDG-PET staging and importance of lymph node SUV in head and neck cancer

Objectives

The role of positron emission tomography (PET) with fluoro-deoxy-glucose (FDG) in the staging of head and neck cancer (HNC) is unclear. The NCCN guidelines do not recommend FDG-PET as a part of standard workup. The purpose of this report is to examine the role of FDG-PET imaging in altering management and providing prognostic information for HNC.

Methods

Retrospective review of HNC patients who had a staging FDG-PET scan performed at either Thomas Jefferson University or University of Kansas Medical Center between the years 2001 and 2007. A total of 212 PET scans were performed in patients who went on to receive radiotherapy.

Results

The median follow-up time for all patients was 469 days. The PPV and NPV of PET imaging to correctly identify lymph node status was 94% and 89% respectively. Lymph nodes with extracapsular extension (ECE) had higher SUVs than nodes without ECE, 11.0 vs. 5.0 (p < 0.0007). Maximum SUV for the primary tumor > 8.0 was predictive of worse overall survival (p < 0.045), while the SUV of the lymph nodes was predictive for distant recurrence at one year--with a mean SUV value of 10.4 for patients with distant failure vs. 7.0 without (p < 0.05).

Conclusions

FDG-PET staging in head and neck cancer has good positive and negative predictive values in determining lymph node status. The maximum SUV of the primary tumor is predictive of overall survival. This is the first report to find that the SUV of a lymph node is predictive for ECE and also for distant recurrence.

Standardized uptake value is of prognostic value for outcome in head and neck squamous cell carcinoma

CONCLUSIONS

The literature-based meta-analysis confirmed that increased standardized uptake value (SUV) of the primary tumor is a poor prognostic factor in patients with head and neck squamous cell carcinoma (HNSCC), which should be further confirmed in a meta-analysis based on individual patient data.

OBJECTIVES

Primary tumor SUV, as measured by positron emission tomography (PET), has been studied as a potential prognostic factor for local control, disease-free survival, and overall survival. However, the limited sample sizes of the studies in the past led us to conduct a meta-analysis to improve the precision in estimating the effect of SUV on the prognosis of HNSCC.

METHODS

Eight articles were identified by searching electronic databases. Statistical analysis was performed with RevMan 4.2.2. SUV measurement and SUV threshold for defining high SUV were studied dependently. For each publication, we first obtained an estimate of the relative risk (RR) for comparing patients with a low and a high SUV. Subsequently, we aggregated the individual RRs into a combined RR, using a fixed-effects model. Publication bias was assessed with funnel plot.

RESULTS

We identified eight clinical trials dedicated to HNSCC. The combined RR from five reports for the local control was 0.71 (95% confidence interval [CI]: 0.63-0.81). The combined RR of the disease-free survival from six reports was 0.63 (95% CI: 0.54-0.73). Meanwhile, the combined RR of the overall survival from three reports was 0.57 (95% CI: 0.44-0.74). The funnel plot showed symmetrical distribution, indicating no evidence of substantial publication bias.

Prognostic value of (18)F-fluorodeoxyglucose positron emission tomography in patients with extrahepatic bile duct cancer

BACKGROUND

(18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) is used in the differential diagnosis and staging of extrahepatic bile duct cancer (EBDC), but its prognostic value has not been fully elucidated. In this study, we investigated the prognostic value of FDG-PET in EBDC patients.

METHODS

The study included 73 consecutive patients with EBDC, of whom 48 underwent surgical resection for EBDC. The effects of clinicopathological factors including the standardized uptake value (SUV) of the primary lesion and lymph node metastasis detected by FDG-PET (PET-N) on overall survival were evaluated.

RESULTS

In all 73 patients, multivariate analysis showed that surgical resection (risk ratio 2.5, 95% confidence interval [CI] 1.17-5.35, P = 0.018) and the SUV (2.0, 1.07-3.91, P = 0.030) were independent predictors of survival. In the 48 patients who underwent surgical resection, multivariate analysis revealed that perineural invasion (risk ratio 3.2, 95% CI 1.28-7.93, P = 0.012), pathologic lymph node metastasis (3.4, 1.27-9.17, P = 0.015), and PET-N (4.0, 1.10-15.25, P = 0.036) were independent predictors of overall survival. In the 25 patients without surgical resection, the SUV showed a significant relationship with overall survival (P = 0.014).

CONCLUSION

Our data suggest that the SUV of the primary lesion is a useful prognostic factor in patients with EBDC, and the prognosis for patients with PET-N remains very poor despite surgical resection.