The maximum uptake of (18)F-deoxyglucose on positron emission tomography scan correlates with survival, hypoxia inducible factor-1alpha and GLUT-1 in non-small cell lung cancer

Robust PET-guided intensity-modulated radiation therapy

PURPOSE

Functional image guided intensity-modulated radiation therapy has the potential to improve cancer treatment quality by basing treatment parameters such as heterogeneous dose distributions information derived from imaging. However, such heterogeneous dose distributions are subject to imaging uncertainty. In this paper, the authors develop a robust optimization model to design plans that are desensitized to imaging uncertainty.

METHODS

Starting from the pretreatment fluorodeoxyglucose-positron emission tomography scans, the authors use the raw voxel standard uptake values (SUVs) as input into a series of intermediate functions to transform the SUV into a desired dose. The calculated desired doses were used as an input into a robust optimization model to generate beamlet intensities. For each voxel, the authors assume that the true SUV cannot be observed but instead resides in an interval centered on the nominal (i.e., observed) SUV. Then the authors evaluated the nominal and robust solutions through a simulation study. The simulation considered the effect of the true SUV being different from the nominal SUV on the quality of the treatment plan. Treatment plans were compared on the metrics of objective function value and tumor control probability (TCP).

RESULTS

Computational results demonstrate the potential for improvements in tumor control probability and deviation from the desired dose distribution compared to a nonrobust model while maintaining acceptable tissue dose.

CONCLUSIONS

Robust optimization can help design treatment plans that are more stable in the presence of image value uncertainties.

Potent anti-proliferative actions of a non-diuretic glucosamine derivative of ethacrynic acid

Ethacrynic acid (EA), a known inhibitor of the neoplastic marker glutathione S-transferase P1 and other GSTs, exerts a weak antiproliferative activity against human cancer cells. The clinical use of EA (Edecrin) as an anticancer drug is limited by its potent loop diuretic activity. In this study, we developed a non-diuretic 2-amino-2-deoxy-d-glucose conjugated EA (EAG) to target tumors cells via the highly expressed glucose transporter 1 (GLUT1). Cell survival assays revealed that EAG had little effect on normal cells, but was cytotoxic 3 to 4.5-fold greater than EA. Mechanistically, the EAG induced selective cell death in cancer cells by inhibiting GSTP1 and generating abundant reactive oxygen species. Furthermore, EAG induced p21(cip1) expression and a G2/M cell cycle block irrespective of the p53 gene status in tumor cells. These data encourage the development of new EA analogs.

Prognostic value of fluorine-18 fludeoxyglucose positron emission tomography parameters differs according to primary tumour location in small-cell lung cancer

OBJECTIVE

To investigate the prognostic value of fluorine-18 fludeoxyglucose (FDG) positron emission tomography (PET) parameters for small-cell lung cancer (SCLC), according to the primary tumour location, adjusted by conventional prognostic factors.

METHODS

From 2008 to 2013, we enrolled consecutive patients with histologically proven SCLC, who had undergone FDG-PET/CT prior to initial therapy. The primary tumour location was categorized into central or peripheral types. PET parameters and clinical variables were evaluated using univariate and multivariate analysis.

RESULTS

A total of 69 patients were enrolled in this study; 28 of these patients were categorized as having the central type and 41 patients as having the peripheral type. In univariate analysis, stage, serum neuron-specific enolase, whole-body metabolic tumour volume (WB-MTV) and whole-body total lesion glycolysis (WB-TLG) were found to be significant in both types of patients. In multivariate analysis, the independent prognostic factor was found to be stage in the central type, but WB-MTV and WB-TLG in the peripheral type. Kaplan-Meier analysis demonstrated that patients with peripheral type with limited disease and low WB-MTV or WB-TLG showed significantly better overall survival than all of the other groups (p < 0.0083).

CONCLUSION

The FDG-PET volumetric parameters were demonstrated to be significant and independent prognostic factors in patients with peripheral type of SCLC, while stage was the only independent prognostic factor in patients with central type of SCLC.

ADVANCES IN KNOWLEDGE

FDG-PET is a non-invasive method that could potentially be used to estimate the prognosis of patients, especially those with peripheral-type SCLC.

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

Background

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

Materials and Methods

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

Results

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

Conclusions

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

FMISO as a Biomarker for Clinical Radiation Oncology

Tumour hypoxia is a well-known negative prognostic marker in almost all solid tumours. [18F]Fluoromisonidazole (FMISO)-positron emission tomography (PET) is a non-invasive method to detect tumour hypoxia. Compared to other methods of hypoxia assessment it possesses some considerable advantages: It is non-invasive, it delivers spatial information on the hypoxia distribution within the entire tumour volume, and it can be repeated during the course of radio(chemo)therapy. This chapter briefly describes different methods of hypoxia evaluation and focuses on hypoxia PET imaging, with the most commonly used tracer being FMISO. The preclinical rationale and clinical studies to use FMISO-PET for patient stratification in radiation therapy are discussed as well as possible agents or radiation-dose modifications to overcome hypoxia.

FDG and Beyond

Although many PET tracers are in use, FDG still is the most widely used in clinical oncology practice. FDG therefore deserves an in-depth discussion, which is even more interesting because of the huge increase in the molecular biology of glucose metabolism. Obviously, other tracers are of increasing importance as well, and these will be discussed in short.

Lymph node density predicts lung metastases in oral squamous cell carcinoma

The association between lymph node density and survival free of lung metastases in oral squamous cell carcinoma (SCC), has not been investigated so far to our knowledge. Lymph node density ≧ 0.07 has been reported by a multicentre international study to be a significant predictor of shorter survival in patients with oral SCC who have invaded nodes. We investigated whether a lymph node density of ≧ 0.07 correlates with shorter overall survival, survival free of distant metastases, and survival free of lung metastases, in patients with oral SCC and invaded lymph nodes. Thirty-five patients with histologically-confirmed invaded lymph nodes werestudied. Their density was calculated as the ratio of the number of invaded lymph nodes:total number of nodes. A density of ≧ 0.07 correlated significantly with shorter overall survival (p<0.02), survival free of distant metastases (p<0.01), and survival free of lung metastases (p<0.01) on log rank testing. On testing by Cox's proportional hazards model of multivariate survival analysis with adjustment for the pathological stage (pstage IV/pstage III), and invaded surgical margins or extracapsular spread, or both, we found that lymph node density ≧ 0.07 was associated with significantly shorter survival (p<0.02). We conclude that lymph node density predicts lung metastases in patients with oral SCC.

Lymph node density is a prognostic factor in patients with major salivary gland carcinoma

Lymph node density (LND) has been reported to be a significant predictor of survival in patients with oral and other carcinomas exhibiting positive lymph nodes. The present study investigated whether the LND is associated with overall survival in subjects with major salivary gland carcinoma. A total of 78 patients newly diagnosed with major salivary gland carcinoma underwent primary tumor resection and neck dissection without preoperative treatment. Of these 78 patients, 32 with pathologically positive lymph nodes were enrolled in the present study. The LND was calculated as the ratio of the number of positive lymph nodes to the number of total lymph nodes. The survival rate was analyzed according to the Kaplan-Meier method. A univariate survival analysis was performed using the log-rank test, and a multivariate survival analysis was performed using the Cox proportional hazards model. An LND of ≥0.38 was found to significantly correlate with a shorter overall survival time in univariate analysis (P=0.017). In multivariate survival analysis, after adjusting for anatomical location (parotid gland/others), an LND of ≥0.38 was identified to be associated with a significantly shorter overall survival time. These results suggest that the LND functions as a prognostic factor in cases of major salivary gland carcinoma.

Random Walk and Graph Cut for Co-Segmentation of Lung Tumor on PET-CT Images

Accurate lung tumor delineation plays an important role in radiotherapy treatment planning. Since the lung tumor has poor boundary in positron emission tomography (PET) images and low contrast in computed tomography (CT) images, segmentation of tumor in the PET and CT images is a challenging task. In this paper, we effectively integrate the two modalities by making fully use of the superior contrast of PET images and superior spatial resolution of CT images. Random walk and graph cut method is integrated to solve the segmentation problem, in which random walk is utilized as an initialization tool to provide object seeds for graph cut segmentation on the PET and CT images. The co-segmentation problem is formulated as an energy minimization problem which is solved by max-flow/min-cut method. A graph, including two sub-graphs and a special link, is constructed, in which one sub-graph is for the PET and another is for CT, and the special link encodes a context term which penalizes the difference of the tumor segmentation on the two modalities. To fully utilize the characteristics of PET and CT images, a novel energy representation is devised. For the PET, a downhill cost and a 3D derivative cost are proposed. For the CT, a shape penalty cost is integrated into the energy function which helps to constrain the tumor region during the segmentation. We validate our algorithm on a data set which consists of 18 PET-CT images. The experimental results indicate that the proposed method is superior to the graph cut method solely using the PET or CT is more accurate compared with the random walk method, random walk co-segmentation method, and non-improved graph cut method.

Primary tumour standardised uptake value is prognostic in nonsmall cell lung cancer: a multivariate pooled analysis of individual data

(18)F-fluoro-2-deoxy-d-glucose positron emission tomography (PET) complements conventional imaging for diagnosing and staging lung cancer. Two literature-based meta-analyses suggest that maximum standardised uptake value (SUVmax) on PET has univariate prognostic value in nonsmall cell lung cancer (NSCLC). We analysed individual data pooled from 12 studies to assess the independent prognostic value of binary SUVmax for overall survival.After searching the published literature and identifying unpublished data, study coordinators were contacted and requested to provide data on individual patients. Cox regression models stratified for study were used.Data were collected for 1526 patients (median age 64 years, 60% male, 34% squamous cell carcinoma, 47% adenocarcinoma, 58% stage I-II). The combined univariate hazard ratio for SUVmax was 1.43 (95% CI 1.22-1.66) and nearly identical if the SUV threshold was calculated stratifying for histology. Multivariate analysis of patients with stage I-III disease identified age, stage, tumour size and receipt of surgery as independent prognostic factors; adding SUV (HR 1.58, 95% CI 1.27-1.96) improved the model significantly. The only detected interaction was between SUV and stage IV disease.SUV seems to have independent prognostic value in stage I-III NSCLC, for squamous cell carcinoma and for adenocarcinoma.

Association Between (18)F-FDG Avidity and the BRAF Mutation in Papillary Thyroid Carcinoma

PURPOSE

The BRAF mutation, a potential prognostic factor in papillary thyroid carcinoma (PTC), is associated with a high expression of the glucose transporter gene. We investigated which clinicopathologic factors, including BRAF mutation status, influence (18)F-fluoro-2-deoxyglucose ((18)F-FDG) avidity.

METHODS

We retrospectively reviewed 55 patients who underwent BRAF analysis from biopsy-confirmed PTC and (18)F-FDG positron emission tomography/computed tomography within 6 months before undergoing thyroid surgery from September 2008 to August 2014. Tumors were considered to be (18)F-FDG avid if the uptake was greater than that of the liver. (18)F-FDG uptake of PTCs was also analyzed semiquantitatively using SUVmax. The association between (18)F-FDG avidity and clinicopathologic variables (age, tumor size, perithyroidal extension, cervical lymph node status, and BRAF mutation status) was investigated.

RESULTS

Twenty-nine (52.7 %) of 55 patients had (18)F-FDG-avid PTCs. PTCs with the BRAF mutation showed higher (18)F-FDG avidity (24/38, 63.2 %) than those without (5/17, 29.4 %). The BRAF mutation (p = 0.025) and tumor size (p = 0.003) were significantly associated with (18)F-FDG avidity in univariate analysis, and the BRAF mutation status remained significant after adjusting for tumor size in multivariate analysis (p = 0.015). In the subgroup of tumor size ≥ 1 cm, the BRAF mutation was the only factor significantly associated with (18)F-FDG avidity (p = 0.021). The mean SUVmax of PTCs with the BRAF mutation was significantly higher than that of those without (4.89 ± 6.12 vs. 1.96 ± 1.10, p = 0.039).

CONCLUSIONS

The BRAF mutation must be one of the most important factors influencing (18)F-FDG avidity in PTCs, especially in those with a tumor size ≥ 1 cm.

Molecular Imaging to Plan Radiotherapy and Evaluate Its Efficacy

Molecular imaging plays a central role in the management of radiation oncology patients. Specific uses of imaging, particularly to plan radiotherapy and assess its efficacy, require an additional level of reproducibility and image quality beyond what is required for diagnostic imaging. Specific requirements include proper patient preparation, adequate technologist training, careful imaging protocol design, reliable scanner technology, reproducible software algorithms, and reliable data analysis methods. As uncertainty in target definition is arguably the greatest challenge facing radiation oncology, the greatest impact that molecular imaging can have may be in the reduction of interobserver variability in target volume delineation and in providing greater conformity between target volume boundaries and true tumor boundaries. Several automatic and semiautomatic contouring methods based on molecular imaging are available but still need sufficient validation to be widely adopted. Biologically conformal radiotherapy (dose painting) based on molecular imaging-assessed tumor heterogeneity is being investigated, but many challenges remain to fully exploring its potential. Molecular imaging also plays increasingly important roles in both early (during treatment) and late (after treatment) response assessment as both a predictive and a prognostic tool. Because of potentially confounding effects of radiation-induced inflammation, treatment response assessment requires careful interpretation. Although molecular imaging is already strongly embedded in radiotherapy, the path to widespread and all-inclusive use is still long. The lack of solid clinical evidence is the main impediment to broader use. Recommendations for practicing physicians are still rather scarce. (18)F-FDG PET/CT remains the main molecular imaging modality in radiation oncology applications. Although other molecular imaging options (e.g., proliferation imaging) are becoming more common, their widespread use is limited by lack of tracer availability and inadequate reimbursement models. With the increasing presence of molecular imaging in radiation oncology, special emphasis should be placed on adequate training of radiation oncology personnel to understand the potential, and particularly the limitations, of quantitative molecular imaging applications. Similarly, radiologists and nuclear medicine specialists should be sensitized to the special need of the radiation oncologist in terms of quantification and reproducibility. Furthermore, strong collaboration between radiation oncology, nuclear medicine/radiology, and medical physics teams is necessary, as optimal and safe use of molecular imaging can be ensured only within appropriate interdisciplinary teams.

Noninvasive Evaluation of Metabolic Tumor Volume in Lewis Lung Carcinoma Tumor-Bearing C57BL/6 Mice with Micro-PET and the Radiotracers 18F-Alfatide and 18F-FDG: A Comparative Analysis

Purpose

To explore the value of a new simple lyophilized kit for labeling PRGD₂ peptide (¹⁸F-ALF-NOTA-PRGD₂, denoted as ¹⁸F-alfatide) in the determination of metabolic tumor volume (MTV) with micro-PET in lewis lung carcinoma (LLC) tumor-bearing C57BL/6 mice verified by pathologic examination and compared with those using ¹⁸F-fluorodeoxyglucose (FDG) PET.

Methods

All LLC tumor-bearing C57BL/6 mice underwent two attenuation-corrected whole-body micro-PET scans with the radiotracers ¹⁸F-alfatide and ¹⁸F-FDG within two days. ¹⁸F-alfatide metabolic tumor volume (V_RGD) and ¹⁸F-FDG metabolic tumor volume (V_FDG) were manually delineated slice by slice on PET images. Pathologic tumor volume (V_Path) was measured in vitro after the xenografts were removed.

Results

A total of 37 mice with NSCLC xenografts were enrolled and 33 of them underwent ¹⁸F-alfatide PET, and 35 of them underwent ¹⁸F-FDG PET and all underwent pathological examination. The mean ± standard deviation of V_Path, V_RGD, and V_FDG were 0.59±0.32 cm³ (range,0.13~1.64 cm³), 0.61±0.37 cm³ (range,0.15~1.86 cm³), and 1.24±0.53 cm³ (range,0.17~2.20 cm³), respectively. V_Path vs. V_RGD, V_Path vs. V_FDG, and V_RGD vs. V_FDG comparisons were t = -0.145, P = 0.885, t = -6.239, P<0.001, and t = -5.661, P<0.001, respectively. No significant difference was found between V_Path and V_RGD. V_FDG was much larger than V_RGD and V_Path. V_RGD seemed more approximate to the pathologic gross tumor volume. Furthermore, V_Path was more strongly correlated with V_RGD (R = 0.964,P<0.001) than with V_FDG (R = 0.584,P<0.001).

Conclusions

¹⁸F-alfatide PET provided a better estimation of gross tumor volume than ¹⁸F-FDG PET in LLC tumor-bearing C57BL/6 mice.

Clinical Correlation Between Tumor Maximal Standardized Uptake Value in Metabolic Imaging and Metastatic Tumor Characteristics in Advanced Non-small Cell Lung Cancer

This study aimed to elucidate whether the maximal standardized uptake value (SUVmax) of primary tumors in metabolic imaging correlated with pathological or metastatic characteristics and whether it was prognostic in stage IV nonsmall cell lung cancer (NSCLC).We retrospectively reviewed the medical records of 412 eligible patients between June 2007 and January 2013. All enrolled patients fulfilled the following criteria: they were newly diagnosed with stage IV NSCLC without any previous treatment and had undergone a systemic evaluation, including 18(F)-Fluoro-2-deoxyglucose positron emission tomography/computed tomography, to assess synchronous metastatic sites. Patient and tumor characteristics were analyzed, and clinical correlations between SUVmax and metastatic features were investigated.The median age of the study population was 65 years (range, 30-94), and 259 (62.9%) patients were male. The median SUVmax was statistically higher in males, in tumors with squamous cell histology, and in poorly differentiated tumors. Multivariate logistic regression analysis revealed that SUVmax ≥ 11.4 (top 30 percentiles) were significantly correlated with positive lymph node status (odds ratio [OR] 3.473), abdomen/pelvis metastasis (OR 1.949), and the absence of bone metastasis (OR 0.399) in the subgroup of nonsquamous NSCLC (n = 343). In Kaplan-Meier survival analysis, overall survival was significantly lower among cohorts with high SUVmax (≥11.4) than with low SUVmax (<11.4) (P < 0.001, median 7.4 months vs 12.1 months).The tumors with different SUVmax have distinctive metastatic and biological features in stage IV NSCLC. The underlying mechanisms of this unique metabolic biology need to be resolved in future studies.

Metabolic Characteristics of Advanced Biliary Tract Cancer Using 18F-Fluorodeoxyglucose Positron Emission Tomography and Their Clinical Implications

BACKGROUND

In advanced biliary tract cancer (BTC), the metabolic landscape has not been evaluated by (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) yet. Furthermore, reports of the clinical implications of these metabolic features are limited. We aimed to evaluate the metabolic features and their clinical relevance in advanced BTC using (18)F-FDG PET.

PATIENTS AND METHODS

We consecutively enrolled patients with advanced BTC who underwent (18)F-FDG PET prior to palliative chemotherapy between 2003 and 2013. We evaluated the findings of PET, such as SUV(max), the number of lesions and organs with FDG uptake, pathologic findings, and clinical outcomes.

RESULTS

A total of 106 patients were enrolled: (53 intrahepatic cholangiocarcinoma [ICC], 7 extrahepatic BTC, 30 gallbladder cancer [GB Ca], and 16 ampulla of Vater cancer [AoV Ca]). The median SUV(max) differed according to the primary origin (ICC, 9.10; extrahepatic BTC, 5.90; GB Ca, 9.10; and AoV Ca, 6.37; p = .008) and histologic differentiation (well differentiated, 4.95; moderately differentiated, 6.60; poorly differentiated, 14.50; p = .004). Patients in the high metabolic group (SUV(max) of ≥7.5) had more poorly differentiated histology and more organs and lesions with FDG uptake than did those in the low metabolic group (SUV(max) of <7.5). The low metabolic group had a significantly longer OS (11.4 vs. 7.4 months, p = .007) and PFS (6.6 vs. 4.3 months, p = .024) than high metabolic group. In multivariate analysis, SUV(max) was a significant prognostic factor for overall survival (OS; p = .047) and progression-free survival (PFS; p = .039).

CONCLUSION

Metabolic characteristics of advanced BTC differ according to primary origin and histology. These metabolic features could be prognostic factors for OS and PFS in advanced BTC.

Therapeutic approaches to gastroesophageal junction adenocarcinomas

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the distinction between adenocarcinomas above, below, or within the gastroesophageal junction; combined modality therapy; tumor markers for use in personalized medicine; PET-CT and endoscopic biopsies in the evaluation of response to neoadjuvant chemoradiation therapy; a standardized grading system for tumor regression in squamous cell cancer and adenocarcinoma; the experimental basis for new approaches to medical treatment; the criteria measuring response in esophageal cancer; and the impact of novel imaging on staging and response assessment.

High FDG uptake areas on pre-radiotherapy PET/CT identify preferential sites of local relapse after chemoradiotherapy for locally advanced oesophageal cancer

PURPOSE

The high failure rates in the radiotherapy (RT) target volume suggest that patients with locally advanced oesophageal cancer (LAOC) would benefit from increased total RT doses. High 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) uptake (hotspot) on pre-RT FDG positron emission tomography (PET)/CT has been reported to identify intra-tumour sites at increased risk of relapse after RT in non-small cell lung cancer and in rectal cancer. Our aim was to confirm these observations in patients with LAOC and to determine the optimal maximum standardized uptake value (SUVmax) threshold to delineate smaller RT target volumes that would facilitate RT dose escalation without impaired tolerance.

METHODS

The study included 98 consecutive patients with LAOC treated by chemoradiotherapy (CRT). All patients underwent FDG PET/CT at initial staging and during systematic follow-up in a single institution. FDG PET/CT acquisitions were coregistered on the initial CT scan. Various subvolumes within the initial tumour (30, 40, 50, 60, 70, 80 and 90% SUVmax thresholds) and in the subsequent local recurrence (LR, 40 and 90% SUVmax thresholds) were pasted on the initial CT scan and compared[Dice, Jaccard, overlap fraction (OF), common volume/baseline volume, common volume/recurrent volume].

RESULTS

Thirty-five patients had LR. The initial metabolic tumour volume was significantly higher in LR tumours than in the locally controlled tumours (mean 25.4 vs 14.2 cc; p = 0.002). The subvolumes delineated on initial PET/CT with a 30-60% SUVmax threshold were in good agreement with the recurrent volume at 40% SUVmax (OF = 0.60-0.80). The subvolumes delineated on initial PET/CT with a 30-60% SUVmax threshold were in good to excellent agreement with the core volume (90% SUVmax) of the relapse (common volume/recurrent volume and OF indices 0.61-0.89).

CONCLUSION

High FDG uptake on pretreatment PET/CT identifies tumour subvolumes that are at greater risk of recurrence after CRT in patients with LAOC. We propose a 60% SUVmax threshold to delineate high FDG uptake areas on initial PET/CT as reduced target volumes for RT dose escalation.

Nitroimidazole derivatives: a patent review of US 2014/0141084 A1

Nitroimidazoles and their derivatives have drawn continuing interest over the years because of their varied biological activities and their recently found applications in drug development for antimicrobial chemotherapeutics and antiangiogenic hypoxic cell radiosensitizers. The electron-deficient nitroaromatic compounds have been investigated for use in cancer treatment as chemical modifiers. In this patent (US 2014/0141084 A1), amphiphilic polymers were designed and prepared based on nitroimidazole derivatives and carboxymethyl dextran, which can be used for the hypoxia-selective release of diagnostics or drugs.

Areas of high 18F-FDG uptake on preradiotherapy PET/CT identify preferential sites of local relapse after chemoradiotherapy for non-small cell lung cancer

The high rates of failure in the radiotherapy target volume suggest that patients with stage II or III non-small cell lung cancer (NSCLC) should receive an increased total dose of radiotherapy. Areas of high (18)F-FDG uptake on preradiotherapy (18)F-FDG PET/CT have been reported to identify intratumor subvolumes at high risk of relapse after radiotherapy. We wanted to confirm these observations on a cohort of patients included in 3 sequential prospective studies. Our aim was to assess an appropriate threshold (percentage of maximum standardized uptake value [SUVmax]) to delineate subvolumes on staging (18)F-FDG PET/CT scans assuming that a smaller target volume would facilitate isotoxic radiotherapy dose escalation.

METHODS

Thirty-nine patients with inoperable stage II or III NSCLC, treated with chemoradiation or with radiotherapy alone, were extracted from 3 prospective studies (ClinicalTrials.gov identifiers NCT01261585, NCT01261598, and RECF0645). All patients underwent (18)F-FDG PET/CT at initial staging, before radiotherapy, during radiotherapy, and during systematic follow-up in a single institution. All (18)F-FDG PET/CT acquisitions were coregistered on the initial scan. Various subvolumes in the initial acquisition (30%, 40%, 50%, 60%, 70%, 80%, and 90% SUVmax thresholds) and in the 3 subsequent acquisitions (40% and 90% SUVmax thresholds) were pasted on the initial scan and compared.

RESULTS

Seventeen patients had a local relapse. The SUVmax measured during radiotherapy was significantly higher in locally relapsed tumors than in locally controlled tumors (mean, 6.8 vs. 4.6; P = 0.02). The subvolumes delineated on initial PET/CT scans with 70%-90% SUVmax thresholds were in good agreement with the recurrent volume at a 40% SUVmax threshold (common volume/baseline volume, 0.60-0.80). The subvolumes delineated on initial PET/CT scans with 30%-60% SUVmax thresholds were in good to excellent agreement with the core volume of the relapse (90% SUVmax threshold) (common volume/recurrent volume and overlap fraction indices, 0.60-0.93). The agreement was moderate (>0.51) when a 70% SUVmax threshold was used to delineate on initial PET/CT scans.

CONCLUSION

High (18)F-FDG uptake areas on pretreatment PET/CT scans identify tumor subvolumes at greater risk of relapse in patients with NSCLC treated by concomitant chemoradiation. We propose a 70% SUVmax threshold to delineate areas of high (18)F-FDG uptake on initial PET/CT scans as the target volumes for potential radiotherapy dose escalation.

In vivo quantification of hypoxic and metabolic status of NSCLC tumors using [18F]HX4 and [18F]FDG-PET/CT imaging

PURPOSE

Increased tumor metabolism and hypoxia are related to poor prognosis in solid tumors, including non-small cell lung cancer (NSCLC). PET imaging is a noninvasive technique that is frequently used to visualize and quantify tumor metabolism and hypoxia. The aim of this study was to perform an extensive comparison of tumor metabolism using 2[(18)F]fluoro-2-deoxy-d-glucose (FDG)-PET and hypoxia using HX4-PET imaging.

EXPERIMENTAL DESIGN

FDG- and HX4-PET/CT images of 25 patients with NSCLC were coregistered. At a global tumor level, HX4 and FDG parameters were extracted from the gross tumor volume (GTV). The HX4 high-fraction (HX4-HF) and HX4 high-volume (HX4-HV) were defined using a tumor-to-blood ratio > 1.4. For FDG high-fraction (FDG-HF) and FDG high-volume (FDG-HV), a standardized uptake value (SUV) > 50% of SUVmax was used. We evaluated the spatial correlation between HX4 and FDG uptake within the tumor, to quantify the (mis)match between volumes with a high FDG and high HX4 uptake.

RESULTS

At a tumor level, significant correlations were observed between FDG and HX4 parameters. For the primary GTV, the HX4-HF was three times smaller compared with the FDG-HF. In 53% of the primary lesions, less than 1 cm(3) of the HX4-HV was outside the FDG-HV; for 37%, this volume was 1.9 to 12 cm(3). Remarkably, a distinct uptake pattern was observed in 11%, with large hypoxic volumes localized outside the FDG-HV.

CONCLUSION

Hypoxic tumor volumes are smaller than metabolic active volumes. Approximately half of the lesions showed a good spatial correlation between the PET tracers. In the other cases, a (partial) mismatch was observed. The addition of HX4-PET imaging has the potential to individualize patient treatment.

Maximum standardized uptake value on 18F-fluoro-2-deoxy-glucose positron emission tomography/computed tomography and glucose transporter-1 expression correlates with survival in invasive ductal carcinoma of the pancreas

OBJECTIVES

The purpose of this study was to assess the correlations among the maximum standardized uptake value (SUVmax) on 18F-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT); the expressions of glucose transporter 1 (GLUT-1), glucose transporter 3, and epidermal growth factor receptor (EGFR); as well as prognosis in patients with invasive ductal carcinoma of the pancreas.

METHODS

A total of 41 patients with surgically resected and histologically proven invasive ductal carcinoma of the pancreas who underwent preoperative FDG-PET/CT were assessed. The SUVmax at the primary tumor site was measured by FDG-PET/CT, and immunohistochemical staining of tumor sections was performed for GLUT-1, glucose transporter 3, and EGFR.

RESULTS

Higher FDG uptake (SUVmax, >3.40) and GLUT-1 expression were significantly associated with shorter overall survival (P < 0.05). The SUVmax was not found to be significantly correlated with clinicopathological characteristics such as TNM classification, lymph node metastasis, and tumor differentiation. The EGFR expression was significantly correlated with the SUVmax (P = 0.024).

CONCLUSIONS

Higher FDG uptake and GLUT-1 expression in invasive ductal carcinoma of the pancreas seems to be an important prognostic factor. In addition, the EGFR expression was significantly correlated with the SUVmax.

Fluorine 18 fluorodeoxyglucose PET/CT volume-based indices in locally advanced non-small cell lung cancer: prediction of residual viable tumor after induction chemotherapy

PURPOSE

To study whether volume-based indices of fluorine 18 fluorodeoxyglucose positron emission tomographic (PET)/computed tomographic (CT) imaging is an accurate tool to predict the amount of residual viable tumor after induction chemotherapy in patients with locally advanced non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

This study was approved by institutional review board with waivers of informed consent. Twenty-two patients with locally advanced NSCLC underwent surgery after induction chemotherapy. All had pre- and posttreatment FDG PET/CT scans. CT largest diameter, CT volume, maximum standardized uptake value (SUVmax), mean SUV (SUVmean), metabolic tumor volume (TV), and total lesion glycolysis of primary tumor were calculated. Changes in tumor measurements were determined by dividing follow-up by baseline measurement (ratio index). Amounts of residual viable tumor, necrosis, fibrous tissue, inflammatory infiltrate, and Ki-67 proliferative index were estimated on resected tumor. Correlations between imaging indices and histologic parameters were estimated by using Spearman correlation coefficients or Mann-Whitney tests.

RESULTS

No baseline or posttreatment indices correlated with percentage of residual viable tumor. TV ratio was the only index that correlated with percentage of residual viable tumor (r = 0.61 [95% confidence interval: 0.24, 0.81]; P = .003). Conversely, SUVmax and SUVmean ratios were only indices correlated with Ki-67 (r = 0.62 [95% confidence interval: 0.24, 0.82]; P = .003; and r = 0.60 [95% confidence interval: 0.21, 0.81]; P = .004, respectively). Total lesion glycolysis ratio was moderately correlated with residual viable tumor (r = 0.53 [95% confidence interval: 0.13, 0.78]; P = .01) and with Ki-67 (r = 0.57 [95% confidence interval: 0.18, 0.80]; P = .006). No ratios were correlated with presence of inflammatory infiltrate or foamy macrophages.

CONCLUSION

TV and total lesion glycolysis ratios were the only indices correlated with residual viable tumor after induction chemotherapy in locally advanced NSCLC.

Systematic analysis of 18F-FDG PET and metabolism, proliferation and hypoxia markers for classification of head and neck tumors

Background

Quantification of molecular cell processes is important for prognostication and treatment individualization of head and neck cancer (HNC). However, individual tumor comparison can show discord in upregulation similarities when analyzing multiple biological mechanisms. Elaborate tumor characterization, integrating multiple pathways reflecting intrinsic and microenvironmental properties, may be beneficial to group most uniform tumors for treatment modification schemes. The goal of this study was to systematically analyze if immunohistochemical (IHC) assessment of molecular markers, involved in treatment resistance, and ¹⁸F-FDG PET parameters could accurately distinguish separate HNC tumors.

Methods

Several imaging parameters and texture features for ¹⁸F-FDG small-animal PET and immunohistochemical markers related to metabolism, hypoxia, proliferation and tumor blood perfusion were assessed within groups of BALB/c nu/nu mice xenografted with 14 human HNC models. Classification methods were used to predict tumor line based on sets of parameters.

Results

We found that ¹⁸F-FDG PET could not differentiate between the tumor lines. On the contrary, combined IHC parameters could accurately allocate individual tumors to the correct model. From 9 analyzed IHC parameters, a cluster of 6 random parameters already classified 70.3% correctly. Combining all PET/IHC characteristics resulted in the highest tumor line classification accuracy (81.0%; cross validation 82.0%), which was just 2.2% higher (p = 5.2×10^-32) than the performance of the IHC parameter/feature based model.

Conclusions

With a select set of IHC markers representing cellular processes of metabolism, proliferation, hypoxia and perfusion, one can reliably distinguish between HNC tumor lines. Addition of ¹⁸F-FDG PET improves classification accuracy of IHC to a significant yet minor degree. These results may form a basis for development of tumor characterization models for treatment allocation purposes.

Hypoxia imaging with 18F-fluoroerythronitroimidazole integrated PET/CT and immunohistochemical studies in non-small cell lung cancer

PURPOSE

(18)F-fluoroerythronitroimidazole ((18)F-FETNIM) PET/CT allows a noninvasive assessment of tumor hypoxia. The purpose of this study was to evaluate a noninvasive and simplicity parameter for quantization of (18)F-FETNIM uptake with expectations to predict survival in non-small cell lung cancer surgical patients and investigate the relationship between (18)F-FETNIM uptake and molecular markers related to hypoxia, glucose metabolism, and angiogenesis.

PATIENTS AND METHODS

Thirty-two patients with biopsy-proven non-small cell lung cancer for surgical treatment were enrolled from March 2007 to February 2011. All patients had PET/CT studies with (18)F-FETNIM and subsequently underwent surgery. Twenty-five patients had stage II disease of surgical staging only for statistical analysis. The tumor-to-mediastinum (T/Me) ratio was calculated and correlated with survival and immunohistochemical staining of hypoxia inducible factor 1α (HIF-1α), glucose transporter 1 (GLUT-1), and vascular endothelial growth factor (VEGF).

RESULTS

The actuarial survival was worse for patients showing a high T/Me ratio, the best discriminative cutoff value being 1.9. A statistically significant worse survival was noted in patients having a tumor with a T/Me ratio of 1.9 or greater, compared with patients showing a tumor with a T/Me ratio of less than 1.9, a 3-year survival of 43.8% and 88.9%, respectively (P = 0.034). There was a positive correlation between T/Me ratio and HIF-1α (P = 0.023), GLUT-1 (P = 0.035), and VEGF (P = 0.042).

CONCLUSIONS

T/Me ratio provides a noninvasive parameter for quantization of (18)F-FETNIM uptake on PET/CT. T/Me ratio is correlated with a worse outcome and with the expression of HIF-1α, GLUT-1, and VEGF, all up-regulated under hypoxic conditions.

18[F]FDG-PET/CT is a useful molecular marker in evaluating tumour aggressiveness: a revised understanding of an in-vivo FDG-PET imaging that alludes the alteration of cancer biology

Molecular imaging employing (18)[F]FDG-PET/CT enables in-vivo visualization, characterisation and measurement of biological process in tumour at the molecular and cellular level. In oncology, this approach can be directly applied as translational biomarkers of disease progression. In this article, the improved roles of FDG as an in-vivo glycolytic marker which reflect biological changes across in-vitro cellular environment are discussed. New understanding in how altered metabolism via glycolytic downstream drivers of malignant transformation as reviewed below offers unique promise as to monitor tumour aggressiveness and hence optimize the therapeutic management.

Biological significance of 18F-FDG uptake on PET in patients with non-small-cell lung cancer

BACKGROUND

The aim of this study is to investigate the underlying biologic mechanisms of 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) uptake on positron emission tomography (PET) in non-small cell lung cancer (NSCLC).

METHODS

One-hundred forty patients with NSCLC who underwent 18F-FDG PET were included in the study. Tumor sections were stained by immunohistochemistry for glucose transporter 1 (GLUT1), GLUT3, hypoxia-inducible factor-1 alpha (HIF-1α), hexokinase I, vascular endothelial growth factor (VEGF), microvessels (CD34), epidermal growth factor receptor (EGFR), and molecules relevant to PI3K/Akt/mTOR signaling pathway (PTEN, p-Akt, p-mTOR and p-S6). We also conducted in vitro studies of 18F-FDG uptake and mTOR inhibition in NSCLC cells.

RESULTS

High 18F-FDG uptake was significantly associated with poor prognosis in NSCLC patients. 18F-FDG uptake was significantly correlated with GLUT1, hexokinase I, HIF-1α, VEGF, CD34, p-Akt, p-mTOR and EGFR. PTEN expression showed inverse correlation with 18F-FDG uptake. In in vitro study, 18F-FDG uptake was markedly decreased by the inhibition of GLUT1 and GLUT1 upregulation by the induction of HIF-1α increased the 18F-FDG uptake. Inhibition of both mTOR complex1 (mTORC1) and mTORC2 suppressed cell growth, but activity of mTORC1 regulated the 18F-FDG uptake. NCI-H1650 cells with PTEN loss showed the highest 18F-FDG uptake and the least sensitivity to mTOR inhibitors.

CONCLUSION

The amount of 18F-FDG accumulation is associated with molecules relevant to glucose metabolism, hypoxia, angiogenesis and mTOR signaling pathway. Especially, PTEN status may affect not only 18F-FDG uptake but also effect of mTOR inhibitors on the growth of NSCLC.

Non-FDG-avid primary papillary thyroid carcinoma may not differ from FDG-avid papillary thyroid carcinoma

BACKGROUND

FDG (2-[(18)F]Fluoro-2-D-deoxyglucose-positron emission tomography (PET)/computed tomography (CT), which can detect a change in glucose metabolism in cancer cells, has been introduced as a diagnostic and prognostic tool in papillary thyroid carcinoma (PTC). However, differences in the clinicopathological and biological characteristics between primary PTCs with FDG uptake and those without FDG uptake are not well established.

METHODS

A total of 188 patients with PTC who had preoperative PET/CT scans were enrolled to compare the differences of clinicopathological parameters between FDG-avid (F-PTC; n = 150) and non-FDG-avid tumors (FN-PTC; n = 38). Immunohistochemical staining for glucose transporter (GLUT)-1 and hypoxia-inducible factor-1 alpha (HIF-1α) was performed.

RESULTS

FN-PTCs were smaller; had a lower incidence of lymphatic invasion, vascular invasion, multifocality, and central lymph node metastasis; and had a lower maximum standardized uptake value than F-PTCs. After exclusion of high-risk patients for recurrence, FN-PTCs remained smaller (p < 0.001) and had less lymphatic invasion (p = 0.061). Among tumors larger than the spatial resolution of the PET/CT scan, macrocalcification was more frequent in FN-PTC than in F-PTC (p = 0.043). While FN-PTC and F-PTC showed no difference in GLUT-1 expression (50% vs. 75%, p = 0.363), FN-PTC showed lower HIF-1α immunoreactivity than F-PTC (25.0% vs. 75.0%, p = 0.032).

CONCLUSION

Tumor size and macrocalcification are clinicopathological differences between FN-PTC and F-PTC. Biologically, HIF-1α may be responsible for increased FDG uptake in PTC.

Hypoxia imaging with [¹⁸F]HX4 PET in NSCLC patients: defining optimal imaging parameters

BACKGROUND AND PURPOSE

[(18)F]HX4 is a promising hypoxia PET-tracer. Uptake, spatio-temporal stability and optimal acquisition parameters for [(18)F]HX4 PET imaging were evaluated in non-small cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

[(18)F]HX4 PET/CT images of 15 NSCLC patients were acquired 2h and 4h after injection (p.i.). Maximum standardized-uptake-value (SUV(max)), tumor-to-blood-ratio (TBR(max)), hypoxic fraction (HF) and contrast-to-noise-ratio (CNR) were determined for all lesions. To evaluate spatio-temporal stability, DICE-similarity and Pearson correlation coefficients were calculated. Optimal acquisition-duration was assessed by comparing 30, 20, 10 and 5 min acquisitions.

RESULTS

Considerable uptake (TBR >1.4) was observed in 18/25 target lesions. TBR(max) increased significantly from 2 h (1.6 ± 0.3) to 4 h p.i. (2.0 ± 0.6). Uptake patterns at 2 h and 4 h p.i. showed a strong correlation (R=0.77 ± 0.10) with a DICE similarity coefficient of 0.69 ± 0.08 for the 30% highest uptake volume. Reducing acquisition-time resulted in significant changes in SUV(max) and CNR. TBR(max) and HF were only affected for scan-times of 5 min.

CONCLUSIONS

The majority of NSCLC lesions showed considerable [(18)F]HX4 uptake. The heterogeneous uptake pattern was stable between 2 h and 4 h p.i. [(18)F]HX4 PET imaging at 4 h p.i. is superior to 2 h p.i. to reach highest contrast. Acquisition time may be reduced to 10 min without significant effects on TBR(max) and HF.

Characterization of tumor heterogeneity using dynamic contrast enhanced CT and FDG-PET in non-small cell lung cancer

PURPOSE

Dynamic contrast-enhanced CT (DCE-CT) quantifies vasculature properties of tumors, whereas static FDG-PET/CT defines metabolic activity. Both imaging modalities are capable of showing intra-tumor heterogeneity. We investigated differences in vasculature properties within primary non-small cell lung cancer (NSCLC) tumors measured by DCE-CT and metabolic activity from FDG-PET/CT.

METHODS

Thirty three NSCLC patients were analyzed prior to treatment. FDG-PET/CT and DCE-CT were co-registered. The tumor was delineated and metabolic activity was segmented on the FDG-PET/CT in two regions: low (<50% maximum SUV) and high (≥50% maximum SUV) metabolic uptake. Blood flow, blood volume and permeability were calculated using a maximum slope, deconvolution algorithm and a Patlak model. Correlations were assessed between perfusion parameters for the regions of interest.

RESULTS

DCE-CT provided additional information on vasculature and tumor heterogeneity that was not correlated to metabolic tumor activity. There was no significant difference between low and high metabolic active regions for any of the DCE-CT parameters. Furthermore, only moderate correlations between maximum SUV and DCE-CT parameters were observed.

CONCLUSIONS

No direct correlation was observed between FDG-uptake and parameters extracted from DCE-CT. DCE-CT may provide complementary information to the characterization of primary NSCLC tumors over FDG-PET/CT imaging.

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.

Targeted cancer therapy with a 2-deoxyglucose-based adriamycin complex

Adriamycin (ADM) has been effective against many types of solid tumors in clinical applications. However, its use is limited because of systemic toxicities, primarily cardiotoxicity, and multidrug resistance. In this study, a new active receptor-mediated complex, ADM conjugated with 2-amino-2-deoxy-d-glucose and succinic acid (2DG-SUC-ADM), was designed to target tumor cells through glucose transporter 1 (GLUT1). MTT assay and confocal images showed that the complex had better inhibition rate to tumor cells and low toxicity to normal cells. Most importantly, the complex displayed a potential to reverse overcome multidrug resistance in cancer cells, with more complex transported into the nucleus of tumor cells. Our in vivo experiments also showed that this new complex could significantly decrease organ toxicity and enhance the antitumor efficacy compared with free ADM, indicating a promising drug of 2DG-SUC-ADM for targeted cancer therapy.

Non-small cell lung cancer evaluated with quantitative contrast-enhanced CT and PET-CT: net enhancement and standardized uptake values are related to tumour size and histology

Background

Personalized cancer therapy remains a challenge. In this context, we attempted to identify correlations between tumour angiogenesis, tumour metabolism and tumour cell type. To this aim, we used single=phase multidetector computed tomography (MDCT) and hybrid positron emission tomography-computed tomography (PET/CT) to determine whether net enhancement and standardized uptake value (SUVmax) were correlated with tumour size and cytology in patients affected by non-small cell lung cancer (NSCLC).

Material/Methods

Our study included 38 patients (30 men, 8 women, mean age 70) with a NSCLC measuring between 3 cm and 7 cm, using a 16-slice multidetector CT (Brilliance Philips) and with PET-CT (Biograph 16 Siemens Medical Solutions). The following lesion parameters were evaluated: maximum diameter, medium density before contrast injection (CT_pre), medium density after contrast injection (CT_{post average}), density in the most enhanced part of the lesion after contrast (CT_{post max}), net enhancement, SUVmax, age, and cytology. Correlation coefficient and p-value were computed for each pair of variables. In addition, correlations were computed for each pair of variables, and for all combinations of tumour types. We focused on subsets of data with more than 10 observations, and with correlation r>0.500 and p<0.05.

Results

A weak correlation (r=0.32; p=0.048) was found between SUVmax and tumour size; the correlation was stronger for masses larger than 31 mm (r=0.4515; p=0.0268). No other correlations were found among the variables examined.

Conclusions

Our data may have prognostic significance, and could lead to more appropriate surgical treatment and better treatment outcome.

18F-FDG-PET/CT predicts survival in hypopharyngeal squamous cell carcinoma

OBJECTIVES

We investigated the relationship between overall survival of patients and pretreatment [(18)F]-2-fluorodeoxyglucose ((18)F-FDG) uptake, assessed by positron emission tomography combined with computed tomography (PET/CT) in hypopharyngeal squamous cell carcinoma.

METHODS

Thirty-one patients who were newly diagnosed as resectable hypopharyngeal squamous cell carcinoma underwent pretreatment (18)F-FDG-PET/CT. We used the maximum standardized uptake value (SUVmax) as (18)F-FDG uptake. Overall survival rate was calculated by the Kaplan-Meier method.

RESULTS

The median SUVmax was 11.53 (range 2.49-22.33). Patients with SUVmax ≥ 13 significantly exhibited shorter overall survival in univariate analysis (p < 0.01). Moreover, by Cox proportional hazards model of multivariate analysis, SUVmax ≥ 13 was a significant prognostic factor independent of clinical T and N classification, and treatment group (p < 0.02).

CONCLUSIONS

These results suggested that SUVmax obtained by pretreatment (18)F-FDG PET/CT assessment is an important prognostic factor in patients with hypopharyngeal squamous cell carcinoma.

Prediction of 2 years-survival in patients with stage I and II non-small cell lung cancer utilizing (18)F-FDG PET/CT SUV quantification

BACKGROUND

The purpose of the study was to evaluate the correlation between the maximum standardized uptake value (SUVmax), size of primary lung lesion, disease-free survival (DFS) and overall survival (OS) in patients with stage I and II non-small cell lung cancer (NSCLC) in 2 years follow-up.

PATIENTS AND METHODS

Forty-nine patients with stage I-II NSCLC were included in this study. Pre-surgical 2-deoxy-2-[18F]fluoro-D-glucose positron-emission tomography ((18)F-FDG PET/CT) study was performed for all patients. The relationship between SUVmax, tumour size and clinical outcome was measured. The cut-off value for SUVmax and tumour size with the best prognostic significance, probability of DFS and the correlation between SUVmax and the response to therapy were calculated.

RESULTS

There was a statistically significant correlation between SUVmax and DFS (p = 0.029). The optimal cut-offs were 9.00 for SUVmax (p = 0.0013) and 30mm for tumour size (p = 0.0028). Patients with SUVmax > 9 and primary lesion size > 30 mm had an expected 2years-DFS of 37.5%, while this rose to 90% if the tumour was <30 mm and/or SUVmax was <9.

CONCLUSIONS

In stage I-II, SUVmax and tumour size might be helpful to identify the subgroup of patients with high chance for recurrence.

Prognostic value of metabolic tumor burden from (18)F-FDG PET in surgical patients with non-small-cell lung cancer

OBJECTIVE

To assess the prognostic value of metabolic tumor burden as measured with metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on 2-deoxy-2-((18)F)fluoro-D-glucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT), independent of current Union Internacional Contra la Cancrum/American Joint Committee on Cancer tumor, node, and metastasis (TNM) stage; in comparison with that of standardized uptake value (SUV) in surgical patients with non-small-cell lung cancer (NSCLC).

MATERIAL AND METHODS

This study retrospectively reviewed 104 consecutive surgical patients (47 males, 57 females, median age at PET/CT scan of 67.92 years) with diagnosed stage I to IV NSCLC who had baseline (18)F-FDG PET/CT scans. The (18)F-FDG PET/CT scans were performed in accordance with National Cancer Institute guidelines. The MTV of tumors in the whole body (MTV(WB)), TLG of tumors in the whole body (TLG(WB)), the maximum standardized uptake value of tumors in the whole body (SUV(maxWB)) as well as the mean standardized uptake value of tumor in the whole body (SUV(meanWB)) were measured. The median follow-up among 67 survivors was 42.07 months from the PET/CT (range 2.82-80.95 months). Statistical methods included Kaplan-Meier curves, Cox regression, and C-statistics. The interobserver variability of SUV(maxWB), SUV(meanWB), MTV(WB), and TLG(WB) between two observers was analyzed using concordance correlation coefficients (CCCs).

RESULTS

The interobserver variability of SUV(maxWB), SUV(meanWB), MTV(WB) and TLG(WB) was very low with CCCs greater than 0.882. There was a statistically significant association of stage with overall survival (OS). The hazard ratio (HR) of stage III and stage IV as compared with stage I was 3.60 (P = .001) and 4.00 (P = .013), respectively. The MTV(WB) was significantly associated with OS with a HR for 1-unit increase of ln(MTV(WB)) of 1.40/1.32 (P = .004/.039), before/after adjusting for stage and other prognostic factors including chemoradiation therapy, and surgical procedure, respectively. TLG(WB) had a statistically significant association with OS before and after adjusting for stage and the other prognostic factors. The HR for 1-unit increase in ln(TLG(WB)) was 1.26 (P = .011) and 1.25 (P = .031), before and after the adjustment, respectively. Subjects with conditions that led to pneumonectomy (HR = 2.82, P = .035) or segmental resection (HR = 3.44, P = .044) had significantly worse survival than those needing lobectomy. There was no statistically significant association between OS and age, gender, tumor histology, ln(SUV(maxWB)), and ln(SUV(meanWB)) (all P > .05). There were 37 deaths during follow-up.

CONCLUSION

Baseline whole-body metabolic tumor burden as measured with MTV(WB) and TLG(WB) on FDG PET is a prognostic measure independent of clinical stage and other prognostic factors including chemoradiation therapy and surgical procedure with low interobserver variability and may be used to further risk stratify surgical patients with NSCLC. This study also suggests that MTV and TLG are better prognostic measures than SUV(max) and SUV(mean). These results will need to be validated in larger cohorts in a prospective study.

Is %ΔSUVmax a useful indicator of survival in patients with advanced nonsmall-cell lung cancer?

PURPOSE

To investigate the impact of the maximum standardized uptake value (SUVmax), size of primary lung lesion, and %ΔSUVmax on outcome (overall survival (OS) and 2-year disease-free survival (2-year DFS)) of patients with advanced nonsmall-cell lung cancer (NSCLC).

MATERIALS AND METHODS

86 stage III-IV NSCLC patients underwent 18 F-FDGPET/CT, before and after chemotherapy, and were classified into subgroups according to the response criteria of the European Organization for Research and Treatment of Cancer. SUVmax values and tumor size with the best prognostic significance were searched. Correlation between the SUVmax value and the initial response to therapy (best response) and the relationship between %ΔSUVmax and OS were assessed.

RESULTS

In patients in PD (20/86), the average pretreatment SUVmax was 11.8 ± 5.23, and the mean size of the primary lesion was 43.35 mm ± 16.63. In SD, PR, and CR patients (66/86), the average pretreatment SUVmax was 12.7 ± 8.05, and the mean size of the primary lesion was 41.6 mm ± 21.15. Correlation was identified only for %ΔSUVmax; patients with PD (ΔSUVmax > +25%) showed a worse OS than patients with ΔSUVmax < +25% (CR, PR, and SD) (P = 0.0235).

CONCLUSIONS

In stage III-IV NSCLC, among the assessed factors, only %ΔSUVmax may be considered as a useful prognostic factor.

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.

Comparison of near-infrared fluorescent deoxyglucose probes with different dyes for tumor diagnosis in vivo

Glucose plays a central role in the cellular energy metabolism. Malignant tumors exhibit an elevated rate of glycolysis over normal tissues. In this study, two near-infrared fluorescent dyes, Cypate and ICG-Der-02, with different water solubility, were conjugated to 2-amino-2-deoxy-D-glucose (2DG) to form Cypate-2DG and ICG-Der-02-2DG, respectively, for NIR fluorescent imaging of tumors in nude mice. The clear routes and tumor targeting abilities of the two NIR fluorescent 2DG probes were compared. Results showed that ICG-Der-02-2DG with higher hydrophilicity was cleared faster by kidneys than the more lipophilic Cypate-2DG. Cypate-2DG had slower but stronger tumor targeting ability compared with ICG-Der-02-2DG. To investigate the correlation between the targeting ability of the probe and the glucose transporter (GLUT1) expression levels of cancer cells, the accumulation of Cypate-2DG in tumors was assessed in MCF-7/estradiol, U87MG, MCF-7 and MDA-MB-435 tumor xenografts, which express different levels of GLUT1. The results show that both Cypate-2DG and ICG-Der-02-2DG possess tumor targeting ability on all the tumors examined, with a proportional correlation to GLUT1 expression. The findings demonstrate the broad applicability of these molecular probes for optical imaging of tumors and glucose-related pathologies.

Differences in growth properties of endometrial cancer in three dimensional (3D) culture and 2D cell monolayer

Three-dimensional (3D) in vitro models have an invaluable role in understanding the behaviour of tumour cells in a well defined microenvironment. This is because some aspects of tumour characteristics cannot be fully recapitulated in a cell monolayer (2D). In the present study, we compared growth patterns, expression of signalling molecules, and metabolism-associated proteins of endometrial cancer cell lines in 3D and 2D cell cultures. Cancer cells formed spherical structures in 3D reconstituted basement membrane (3D rBM), and the morphological appearance was cell line dependent. Cell differentiation was observed after 8 days in the 3D rBM. There was reduced proliferation, detected by less expression of PCNA in 3D rBM than in 2D cell monolayers. The addition of exogenous epidermal growth factor (EGF) to cancer cells induced phosphorylation of EGFR and Akt in both cell culture conditions. The uptake of glucose was selectively altered in the 3D rBM, but there was a lack of association with Glut-1 expression. The secretion of vascular endothelial growth factor (VEGF) and prostaglandin E(2) (PGE(2)) was selectively altered in 3D rBM, and it was cell line dependent. Our data demonstrated that 3D rBM as an in vitro model can influence proliferation and metabolism of endometrial cancer cell behaviour compared to 2D cell monolayer. Changes are specific to individual cell types. The use of 3D rBM is, therefore, important in the in vitro study of targeted anticancer therapies.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hypoxia imaging using Positron Emission Tomography in non-small cell lung cancer: implications for radiotherapy

Tumour hypoxia is an important contributor to radioresistance. Thus, increasing the radiation dose to hypoxic areas may result in improved locoregional tumour control. However, this strategy requires accurate detection of the hypoxic sub-volume using PET imaging. Secondly, hypoxia imaging may also provide prognostic information and may be of help to monitor treatment response. Therefore, a systematic review of the scientific literature was carried out on the use of Positron Emission Tomography (PET) to image Tumour hypoxia in non-small cell lung cancer (NSCLC). More specifically, the purpose of this review was (1) to summarize the different hypoxia tracers used, (2) to investigate whether Tumour hypoxia can be detected in NSCLC and finally (3) whether the presence of hypoxia can be used to predict outcome.