Early changes in 2-deoxy-2-[18F]fluoro-D-glucose metabolism in squamous-cell carcinoma during chemotherapy in vivo and in vitro

CD47 Deficiency in Mice Exacerbates Chronic Fatty Diet-Induced Steatohepatitis Through Its Role in Regulating Hepatic Inflammation and Lipid Metabolism

Inflammation is one of the hallmarks of non-alcoholic steatohepatitis. CD47 is a widely expressed transmembrane protein that signals through inhibitory receptor signal regulatory protein α (SIRPα) to inhibit macrophage activation and phagocytosis. In this study, we sought to investigate the role of CD47 in hepatosteatosis and fibrosis induced by a chronic high-fat diet (HFD), by comparing disease development in wild-type (WT) and CD47KO mice fed HFD for 40 weeks. The HFD induced remarkably more severe hepatic steatosis and fibrosis but less body weight gain and less subcutaneous fat accumulation in CD47KO mice compared to WT mice. Liver tissues from HFD-fed CD47KO mice exhibited enhanced inflammation characterized by increased proinflammatory cytokine production and increased nuclear factor-κB (NF-κB) activation compared to similarly fed WT mice. Although higher expression of apolipoproteins was observed in CD47KO mice compared to WT mice under a low-fat diet (LFD), HFD-fed WT and CD47KO mice showed comparably prominent downregulation of these apolipoprotein genes, suggesting that the marked difference observed in lipid accumulation and hepatosteatosis between these mice cannot be explained by changes in apolipoproteins. Like apolipoproteins, sirtuin 1 (SIRT1) and peroxisome proliferator activated receptor alpha (PPARα), which are involved in regulation of both lipid metabolism and inflammation, were more highly expressed in CD47KO than WT mice under LFD but more severely suppressed in CD47KO than in WT mice under HFD. Taken together, our results indicate that CD47 plays a significant role in the pathogenesis of HFD-induced hepatosteatosis and fibrosis through its role in regulation of inflammation and lipid metabolism.

Very Early Response Evaluation by PET/MR in Patients with Lung Cancer-Timing and Feasibility

Purpose: With the increasing number of therapy options available for patients with lung cancer, early response evaluation is needed. We performed this pilot study to assess the feasibility of early, repeated Positron emission tomography-magnetic resonance (PET/MR), the impact of timing and the capability for response prediction in lung tumors during chemotherapy. Methods: Patients with stage IV non-small cell lung cancer referred for chemotherapy were prospectively recruited. Fluorine-18-Fluorodeoxyglucose(¹⁸F-FDG)-PET/MR scans were performed prior to, during and after the first or second cycle of chemotherapy. Primary tumors were defined on all scans and size, FDG-uptake and apparent diffusion coefficient (ADC) were measured. Early response was described over time and a Standard Linear Mixed Model was applied to analyze changes over time. Results: 45 FDG-PET/MR scans were performed in 11 patients. Whereas the overall changes measured by ADC did not change significantly, there was an overall significant decrease in FDG-uptake from pre to post treatment scans. There was no difference in the FDG-uptake measured 1 or 3 weeks after therapy, but uptake measured 2 weeks after therapy differed from measurements at week 3. Changes measured in patients scanned during the first treatment cycle appeared more pronounced than during the second cycle. Conclusions: This pilot study indicates that response evaluation shortly after initiation of chemotherapy appears concordant with later evaluation and probably more reliable than evaluation midway between cycles. Responses during or after the first cycle of chemotherapy rather than during subsequent cycles are likely to be more readily measured.

Functional imaging early during (chemo)radiotherapy for response prediction in head and neck squamous cell carcinoma; a systematic review

This systematic review gives an extensive overview of the current state of functional imaging during (chemo)radiotherapy to predict locoregional control (LRC) and overall survival (OS) for head and neck squamous cell carcinoma. MEDLINE and EMBASE were searched for literature until April 2018 assessing the predictive performance of functional imaging (computed tomography perfusion (CTp), MRI and positron-emission tomography (PET)) within 4 weeks after (chemo)radiotherapy initiation. Fifty-two studies (CTp: n = 4, MRI: n = 19, PET: n = 26, MRI/PET: n = 3) were included involving 1623 patients. Prognostic information was extracted according the PRISMA protocol. Pooled estimation and subgroup analyses were performed for comparable parameters and outcome. However, the heterogeneity of included studies limited the possibility for comparison. Early tumoral changes from (chemo)radiotherapy can be captured by functional MRI and ¹⁸F-FDG-PET and could allow for personalized treatment adaptation. Lesions showed potentially prognostic intratreatment changes in perfusion, diffusion and metabolic activity. Intratreatment ADC_mean increase (decrease of diffusion restriction) and low SUV_max (persistent low or decrease of ¹⁸F-FDG uptake) were most predictive of LRC. Intratreatment persistent high or increase of perfusion on CT/MRI (i.e. blood flow, volume, permeability) also predicted LRC. Low SUV_max and total lesion glycolysis (TLG) predicted favorable OS. The optimal timing to perform functional imaging to predict LRC or OS was 2-3 weeks after treatment initiation.

Chemotherapy with cisplatin: insights into intracellular pH and metabolic landscape of cancer cells in vitro and in vivo

Although cisplatin plays a central role in cancer chemotherapy, the mechanisms of cell response to this drug have been unexplored. The present study demonstrates the relationships between the intracellular pH (pHi), cell bioenergetics and the response of cervical cancer to cisplatin. pHi was measured using genetically encoded sensor SypHer2 and metabolic state was accessed by fluorescence intensities and lifetimes of endogenous cofactors NAD(P)H and FAD. Our data support the notion that cisplatin induces acidification of the cytoplasm early after the treatment. We revealed in vitro that a capacity of cells to recover and maintain alkaline pHi after the initial acidification is the crucial factor in mediating the cellular decision to survive and proliferate at a vastly reduced rate or to undergo cell death. Additionally, we showed for the first time that pHi acidification occurs after prolonged therapy in vitro and in vivo, and this, likely, favors metabolic reorganization of cells. A metabolic shift from glycolysis towards oxidative metabolism accompanied the cisplatin-induced inhibition of cancer cell growth in vitro and in vivo. Overall, these findings contribute to an understanding of the mechanisms underlying the responsiveness of an individual cell and tumor to therapy and are valuable for developing new therapeutic strategies.

Response assessment after induction chemotherapy for head and neck squamous cell carcinoma: From physical examination to modern imaging techniques and beyond

Significant correlations between the response to induction chemotherapy and success of subsequent radiotherapy have been reported and suggest that the response to induction chemotherapy is able to predict a response to radiotherapy. Therefore, induction chemotherapy may be used to tailor the treatment plan to the individual patient with head and neck cancer: following the planned subsequent (chemo)radiation schedule, planning a radiation dose boost, or reassessing the modality of treatment (eg, upfront surgery). Findings from reported trials suggest room for improvement in clinical response assessment after induction chemotherapy, but an optimal method has yet to be identified. Historically, indices of treatment efficacy in solid tumors have been based solely on systematic assessment of tumor size. However, functional imaging (eg, fluorodeoxyglucose‐positron emission tomography (FDG‐PET) potentially provides an earlier indication of response to treatment than conventional imaging techniques. More advanced imaging techniques are still in an exploratory phase and are not ready for use in clinical practice.

Effectiveness of FDG-PET/CT for evaluating early response to induction chemotherapy in head and neck squamous cell carcinoma: A systematic review

BACKGROUND

F-Fluoro-Deoxy-Glucose Positron Emission Tomography with Computed Tomography (F-FDG PET/CT) may be a powerful tool to predict treatment outcome. We aimed to review the effectiveness of F-FDG PET/CT in the assessment of early response to induction chemotherapy (IC) in patients with advanced Head and Neck Squamous Cell Cancer (HNSCC) without previous treatment.

METHODS

PubMed, Cochrane Library, Science Direct and Web of Science were searched to May 2016. Reference lists of the included articles and additional studies identified by one nuclear medicine expert were screened for potential relevant studies that investigated the effectiveness of F-FDG PET/CT performed before and after IC. Three authors independently screened all retrieved articles, selected studies that met inclusion criteria and extracted data. The methodology of the selected studies was evaluated by using the risk of bias checklist of the Agency for Healthcare Research and Quality (AHRQ).

RESULTS

Seven out of 170 eligible studies met our inclusion criteria. A total of 207 advanced HNSCC patients were evaluated with F-FDG PET/CT at baseline and after IC in the selected articles. Six from seven studies concluded that F-FDG PET/CT allowed early evaluation response to IC and predicted survival outcomes.

CONCLUSION

The present systematic review confirms the potential value of F-FDG PET/CT as a diagnostic tool for early IV response assessment in HNSCC patients. However, the lack of standard definitions for response criteria and heterogeneous IC protocols indicate the need to further studies in order to better define the role of F-FDG PET/CT in these patients.

FDG-based quantitative comparison of glucose metabolism in vitro, exemplified by a head-to-head comparison between a triple-negative breast cancer cell line and a non-malignant foetal cell line

BACKGROUND

Glucose metabolism can be studied in vitro by a variety of means, also by fluorodeoxyglucose (FDG). As an example of the potential use we have compared the high glucose consumption in cancer cells and in transformed non-malignant foetal cells. The high glucose metabolism in cancer cells is not primarily for the production of energy, a large proportion is transformed to lactate only, producing two instead of potentially 32 ATP equivalents. The secreted lactate reduces the pH in the local microenvironment and gives malignant cells, more apt to thrive in hypoxic and acid environments, a competitive advantage.

PURPOSE

To demonstrate the use of FDG in head-to-head comparison of glucose uptake and lactate production in a highly malignant and a highly proliferative non-malignant cell line.

MATERIALS AND METHODS

Cell cultures of a foetal kidney cell line and a triple negative breast cancer cell line were incubated with FDG for one hour, washed, harvested and the radioactivity content in the cells was measured in a well counter. The lactate concentration was measured in conditioned medium.

RESULTS

The FDG uptake was consistently higher in the non-malignant foetal cell line. The levels of lactate in the conditioned medium were similar.

CONCLUSION

Quantitative comparison of glucose metabolism by in vitro use of FDG is a practical, cheap and rapid method. Some foetal cells have higher glucose uptake and produce as much lactate as this highly malignant cell line. This is an argument against the high glucose consumption being related solely to malignancy.

[¹⁸F]FDG positron emission tomography within two weeks of starting erlotinib therapy can predict response in non-small cell lung cancer patients

Purpose

The aim of this prospective study was to evaluate whether [¹⁸F]FDG-PET/CT, performed within two weeks of starting erlotinib therapy can predict tumor response defined by RECIST 1.1 criteria after 8 weeks of treatment in patients with inoperable (stage IIIA to IV) non-small cell lung cancer patients.

Patients and Methods

Three [¹⁸F]FDG-PET/CT scans were acquired in 12 patients before (5±4 days) and after 9±3 days (early PET) and 60±6 days (late PET) of erlotinib therapy. Conventional evaluation, including at least chest CT (baseline versus after 8 weeks of treatment), was performed according to RECIST 1.1 criteria. Change in [¹⁸F]FDG uptake was compared with conventional response, progression-free survival (PFS), and overall survival (OS).

Results

By using ROC analysis, the Area Under the Curve for prediction of metabolic non-progressive disease (mNP) by early PET was 0.86 (95% CI, 0.62 to 1.1; P = 0.04) at a cut-off of 21.6% reduction in maximum Standardized Uptake Value (SUVmax). This correctly classified 11/12 patients (7 with true progressive disease; 4 with true non-progressive disease; 1 with false progressive disease). Non-progressive disease after 8 weeks of treatment according to RECIST 1.1 criteria was significantly more frequent in patients classified mNP (P = 0.01, Fisher's exact test). mNP patients showed prolonged PFS (HR = 0.27; 95% CI, 0.04 to 0.59; P<0.01) and OS (HR = 0.34; 95% CI, 0.06 to 0.84; P = 0.03). Late PET analysis provided concordant results.

Conclusion

Morphologic response, PFS and OS survival in non-small cell lung cancer patients can be predicted by [¹⁸F]FDG-PET/CT scan within 2 weeks after starting erlotinib therapy.

Integrin α(v)β₃ as a PET imaging biomarker for osteoclast number in mouse models of negative and positive osteoclast regulation

PURPOSE

The goal of this study was to determine the specificity of ⁶⁴Cu-CB-TE2A-c(RGDyK) (⁶⁴Cu-RGD) for osteoclast-related diseases, such as Paget's disease or rheumatoid arthritis.

PROCEDURES

C57BL/6 mice were treated systemically with osteoprotegerin (OPG) for 15 days or RANKL for 11 days to suppress and stimulate osteoclastogenesis, respectively. The mice were then imaged by positron emission tomography/computed tomography using ⁶⁴Cu-RGD, followed by determination of serum TRAP5b and bone histology. Standard uptake values were determined to quantify ⁶⁴Cu-RGD in bones and other tissues.

RESULTS

Mice treated with OPG showed decreased bone uptake of ⁶⁴Cu-RGD at 1, 2, and 24 h post-injection of the tracer (p < 0.01 for all time points) compared to vehicle controls, which correlated with a post-treatment decrease in serum TRAP5b. In contrast, mice treated with RANKL showed significantly increased bone uptake at 2 h post-injection of (⁶⁴Cu-RGD (p < 0.05) compared to the vehicle control group, corresponding to increased serum TRAP5b and OC numbers as determined by bone histology.

CONCLUSIONS

These data demonstrate that ⁶⁴Cu-RGD localizes to areas in bone with increased osteoclast numbers and support the use of ⁶⁴Cu-RGD as an imaging biomarker for osteoclast number that could be used to monitor osteoclast-related pathologies and their treatments.

Early prediction of survival following induction chemotherapy with DCF (docetaxel, cisplatin, 5-fluorouracil) using FDG PET/CT imaging in patients with locally advanced head and neck squamous cell carcinoma

PURPOSE

Locally advanced head and neck squamous cell carcinoma (HNSCC) has a high rate of recurrence. Induction chemotherapy with DCF (docetaxel, cisplatin, 5-fluorouracil) before chemoradiotherapy could lead to the best disease control of inoperable stage III/IV HNSCC but with an increased risk of acute toxicity. Early assessment of therapeutic efficacy is a key issue in considering the benefit of escalation in a poor prognosis population.

METHODS

Patients with stage III/IV HNSCC, in whom DCF induction chemotherapy followed by concurrent chemoradiotherapy had been validated by a multidisciplinary team, were prospectively included in the study. FDG PET/CT scans were performed in all patients before and after two of the three cycles of DCF. EORTC99 criteria were used to evaluate PET responses as follows: group 1 (metabolic responders) showing a complete response (CR) or partial response (PR), and subgroup 0 (metabolic nonresponders) showing stable disease (SD) or progressive disease (PD). The primary endpoint for monitoring patients was event-free survival (EFS). EFS probabilities between the two groups were estimated by the Kaplan-Meier method and statistically compared using the log-rank test.

RESULTS

Fifteen consecutive patients (14 men, 1 woman; age 57.5 ± 6.2 years, mean ± SD) were analysed. Therapeutic assessment by PET/CT demonstrated CR in four patients, PR in six, SD in four and PD in one. Among the ten patients with a metabolic response (group 1), none had relapsed at the time of this report, while four of five patients with no metabolic response (group 0) showed recurrence within an average of 9.0 ± 1.6 months. Median EFS was, respectively, 18.9 months (3.8-25.3 months) and 10.2 months (7.5-12.7 months) in group 1 and group 0. The corresponding 1-year EFS rates were 100 % and 20 %, respectively. The difference in EFS between the two groups was statistically significant (p = 0.0014).

CONCLUSION

Early therapeutic response demonstrated on FDG PET/CT after two cycles of induction chemotherapy with DCF in patients with inoperable stage III/IV HNSCC seems to be a predictive factor for EFS.

Optical imaging of breast cancer oxyhemoglobin flare correlates with neoadjuvant chemotherapy response one day after starting treatment

Approximately 8-20% of breast cancer patients receiving neoadjuvant chemotherapy fail to achieve a measurable response and endure toxic side effects without benefit. Most clinical and imaging measures of response are obtained several weeks after the start of therapy. Here, we report that functional hemodynamic and metabolic information acquired using a noninvasive optical imaging method on the first day after neoadjuvant chemotherapy treatment can discriminate nonresponding from responding patients. Diffuse optical spectroscopic imaging was used to measure absolute concentrations of oxyhemoglobin, deoxyhemoglobin, water, and lipid in tumor and normal breast tissue of 24 tumors in 23 patients with untreated primary breast cancer. Measurements were made before chemotherapy, on day 1 after the first infusion, and frequently during the first week of therapy. Various multidrug, multicycle regimens were used to treat patients. Diffuse optical spectroscopic imaging measurements were compared with final postsurgical pathologic response. A statistically significant increase, or flare, in oxyhemoglobin was observed in partial responding (n = 11) and pathologic complete responding tumors (n = 8) on day 1, whereas nonresponders (n = 5) showed no flare and a subsequent decrease in oxyhemoglobin on day 1. Oxyhemoglobin flare on day 1 was adequate to discriminate nonresponding tumors from responding tumors. Very early measures of chemotherapy response are clinically convenient and offer the potential to alter treatment strategies, resulting in improved patient outcomes.

Sequential FDG-PET/CT after neoadjuvant chemotherapy is a predictor of histopathologic response in patients with head and neck squamous cell carcinoma

PURPOSE

To evaluate whether 2-deoxy-2-[(18)F]fluoro-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) more accurately predicts the histopathologic response to neoadjuvant chemotherapy (NAC) than magnetic resonance imaging (MRI) in patients with head and neck squamous cell carcinoma (HNSCC).

PROCEDURES

Sixteen patients with HNSCC underwent FDG-PET/CT and MRI scans before and after one cycle of NAC, followed by surgical resection. The 26 surgically resected specimens of the 16 patients were analyzed. Decreases in maximum standardized uptake value (SUV(max)) or in tumor maximum size (diameter(max)) were calculated, and their accuracies for the prediction of histopathologic response were evaluated.

RESULTS

In histopathologic responders (n = 7), percent decreases in SUV(max) were significantly higher (P < 0.001) than in non-responders (n = 19). Applying a cut-off point of 55.5%, the histopathologic response could be predicted with a sensitivity and specificity of 86% and 95%, respectively.

CONCLUSION

FDG-PET/CT can predict histopathologic NAC responses with higher accuracy than MRI in HNSCC patients.

Early Metabolic Flare in Squamous Cell Carcinoma after Chemotherapy is a Marker of Treatment Sensitivity In Vitro

Purpose

Early metabolic response with a decrease in glucose demand after cytotoxic treatment has been reported to precede tumor volume shrinkage. However, preclinical studies report of a very early rise in metabolism, a flare, following treatment. To elucidate these observations, we performed an experimental study on early metabolic response with sequential analysis of metabolic changes.

Methods

Three squamous cell carcinoma cell lines and one nontumorigenic cell line were exposed to cisplatin. The uptake of the fluorescent glucose analogue 2-NBDG was examined at days 1–6 using fluorescence microscopy. The relation between 2-NBDG-uptake and cell survival was evaluated.

Results

The tumor cells exhibited a high uptake of 2-NBDG, whereas the uptake in the nonmalignant cells was low. The more cisplatin sensitive cell lines exhibited a more pronounced metabolic flare than the less sensitive cell line.

Conclusion

A metabolic flare was a very early sign of treatment response and potentially it could be used as an early marker of treatment sensitivity.