The role of PET/CT in the management of patients affected by head and neck tumors: a review of the literature

Identification of a metabolic reprogramming-related signature associated with prognosis and immune microenvironment of head and neck squamous cell carcinoma by in silico analysis

Background

Metabolic reprogramming is one of the essential features of tumorigenesis. Herein, this study aimed to develop a novel metabolism‐related gene signature for head and neck squamous cell carcinoma (HNSCC) patients.

Methods

The transcriptomic and clinical data of HNSCC samples were collected from The Cancer Genome Atlas (TCGA) and GSE65858 datasets. The metabolism‐related gene‐based prognostic signature (MRGPS) was constructed by the Least Absolute Shrinkage and Selection Operator (LASSO) regression model. The time‐dependent receiver operating characteristic (ROC) and Kaplan‐Meier (K‐M) survival curves were plotted for evaluating its predicting performance. At the same time, univariate along with multivariate analysis was carried out to explore its correlation with clinicopathologic factors. Furthermore, GSEA analysis was performed to explore the signaling pathways affected by MRGPS. We also analyzed the associations of MRGPS with the tumor immune microenvironment (TIME), as well as identified potential compounds via Connectivity Map (CMap) and molecular docking.

Results

A total of 12 differentially expressed metabolism‐related genes were identified and selected to construct the MRGPS. Notably, this signature performed well in predicting HNSCC patients’ survival and could serve as an independent prognostic factor in multiple datasets. In addition to the metabolism‐related pathway, this signature could also affect some immune‐related pathways. The results indicated that MRGPS is correlated with immune cells infiltration and anti‐cancer immune response. Furthermore, we identified cephaeline as a potential therapeutic compound for HNSCC.

Conclusion

Taken together, we established an MRGs‐based signature that has the potential to predict the clinical outcome and immune microenvironment, which help to search for potential combination immunotherapy compounds and provide a promising therapeutic strategy for treating HNSCC patients.

In vivo monitoring of the therapeutic efficacy of a CXCR1/2 inhibitor with 18F-FDG PET/CT imaging in experimental head and neck carcinoma: A feasibility study

The chemokine receptors CXCR1/2 play a key role in the aggressiveness of several types of cancers including head and neck squamous cell carcinomas (HNSCCs). In HNSCCs, CXCR1/2 signaling promotes cell proliferation and angiogenesis leading to tumor growth and metastasis. The competitive inhibitor of CXCR1/2, C29, inhibits the growth of experimental HNSCCs in mice. However, a non-invasive tool to monitor treatment response is essential to implement the use of C29 in clinical practices. ¹⁸F-FDG PET/CT is a gold-standard tool for the staging and the post-therapy follow-up of HNSCCs patients. Our study aimed to perform the first in vivo monitoring of C29 efficacy by non-invasive ¹⁸F-FDG PET/CT imaging. Mice bearing experimental HNSCCs (CAL33) were injected with ¹⁸F-FDG (T0) and thereafter treated (n = 7 mice, 9 tumors, 50 mg/kg by gavage) or not (n = 7 mice, 10 tumors) with C29 for 4 consecutive days. Final ¹⁸F-FDG-tumor uptake was determined at day 4 (TF). The average relative change (TF-T0) in ¹⁸F-FDG tumor uptake was +25.85 ± 10.93 % in the control group vs −5.72 ± 10.07 % in the C29-treated group (p < 0.01). These results were consistent with the decrease of the tumor burden and with the decrease of tumor proliferating Ki67+ cells. These results paved the way for the use of ¹⁸F-FDG to monitor tumor response following C29 treatment.

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CXCR1/2 inhibitors represent a new class of anti-cancer drugs.

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CXCR1/2 inhibition delays HNSCCs tumor growth.

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¹⁸F-FDG allows early monitoring of CXCR1/2 inhibitors efficacy.

PET/CT in Surgical Planning for Head and Neck Cancer

Fluorine-18 (¹⁸F)-fluorodeoxyglucose (FDG) positron emission tomography fused with computed tomography (PET/CT) is a valuable tool in surgical planning for head and neck squamous cell carcinoma (HNSCC). If performed prior to biopsy or other surgical intervention, FDG-PET/CT has high sensitivity for the detection of the primary site in patients with cervical lymph node metastases from unknown primary origin and can be used to direct the surgical workup. FDG-PET/CT is superior to CT alone for detection of nodal metastases outside the expected pattern or distant metastases or second primary cancers and can greatly affect determination of appropriate management including surgical eligibility. Prior to the advent of PET/CT, many patients undergoing (chemo)radiation-based therapy had planned post-treatment neck dissection; FDG-PET/CT now has a proven role in the evaluation of recurrent or persistent disease amenable to salvage surgery and enables safe avoidance of planned postradiation neck dissection with a high negative predictive value. Specifically for this important application, two standardized reporting metrics may be used in the head and neck anatomic region: the "Hopkins criteria" and the "Neck Imaging Reporting and Data System"; both systems produce a formalized evaluation and recommendation based on PET/CT findings. The role of PET/CT as a replacement for elective neck dissection or examination under anesthesia remains controversial but deserves further study. FDG-PET/CT has a wide-ranging impact on the surgical management of patients with HNSCC and should be used routinely in patients with unknown primary nodal disease and those presenting with advanced-stage cancers at initial staging and to assess treatment response.

Imaging in oral cancers: A comprehensive review

This review aims at simplifying the relevant imaging anatomy, guiding the optimal imaging method and highlighting the key imaging findings that influence prognosis and management of oral cavity squamous cell carcinoma (OSCC). Early OSCC can be treated with either surgery alone while advanced cancers are treated with a combination of surgery, radiotherapy and/or chemotherapy. Considering the complex anatomy of the oral cavity and its surrounding structures, imaging plays an indispensable role not only in locoregional staging but also in the distant metastatic work-up and post treatment follow-up. Knowledge of the anatomy with understanding of common routes of spread of cancer, allows the radiologist to accurately determine disease extent and augment clinical findings to plan appropriate therapy. This review aims at simplifying the relevant imaging anatomy, guiding the optimal imaging method and highlighting the key imaging findings that influence prognosis and management.

Positron emission tomography with computed tomography imaging (PET/CT) for the radiotherapy planning definition of the biological target volume: PART 1

AIM

Functional and molecular imaging, including positron emission tomography with computed tomography imaging (PET/CT) is increasing for radiotherapy (RT) definition of the target volume. This expert review summarizes existing data of functional imaging modalities and RT management, in terms of target volume delineation, for the following anatomical districts: brain (for primary and secondary tumors), head/neck and lung.

MATERIALS AND METHODS

A collection of available published data was made, by PubMed a search. Only original articles were carefully and critically revised.

RESULTS

For primary and secondary brain tumors, amino acid PET radiotracers could be useful to identify microscopic residual areas and to differ between recurrence and treatment-related alterations in case of re-irradiation. As for head and neck neoplasms may benefit from precise PET/CT-based target delineation, due to the major capability to identify high-risk RT areas. In primary and secondary lung cancer, PET/CT could be useful both to delimit a tumor and collapsed lungs and as a predictive parameter of treatment response.

CONCLUSION

Taken together, molecular and functional imaging approaches offer a major step to individualize radiotherapeutic care going forward. Nevertheless, several uncertainties remain on the standard method to properly assess the target volume definition including PET information for primary and secondary brain tumors.

The emerging role of trans-oral robotic surgery for the detection of the primary tumour site in patients with head-neck unknown primary cancers: A meta-analysis

The identification of the site in head neck unknown primary (HNUP) tumour is of utmost importance to help select best treatment while decreasing treatment-related morbidity and mortality. The primary purpose of this study is to demonstrate that TORS may be a valuable tool in detecting primary tumour. Studies were systematically searched in the PubMed, EMBASE, the Cochrane Library and CENTRAL electronic databases. A total of 12 selected studies (349 patients) were analyzed. The primary tumour detection and positive surgical margins rates were 70.8% and 19.4%, respectively. The rate of HPV-related tumour was 71.3%. The primary tumour was mainly in base of tongue (64%). In conclusion, TORS seems to be an effective surgical approach both in terms of detection of primary tumour site and in terms of therapeutic perspective for HNUP. In particular, a subset of HPV-related tumours might benefits all advantages from this surgical modality.

Beyond EGFR inhibition: multilateral combat strategies to stop the progression of head and neck cancer

Epidermal growth factor receptor (EGFR) overexpression is common in head and neck squamous cell carcinoma. Targeted therapy specifically directed towards EGFR has been an area of keen interest in head and neck cancer research, as EGFR is potentially an integration point for convergent signaling. Despite the latest advancements in cancer diagnostics and therapeutics against EGFR, the survival rates of patients with advanced head and neck cancer remain disappointing due to anti-EGFR resistance. This review article will discuss recent multilateral efforts to discover and validate actionable strategies that involve signaling pathways in heterogenous head and neck cancer and to overcome anti-EGFR resistance in the era of precision medicine. Particularly, this review will discuss in detail the issue of cancer metabolism, which has recently emerged as a novel mechanism by which head and neck cancer may be successfully controlled according to different perspectives.

South Korean researchers propose novel combination strategies for overcoming drug resistance and halting the progression of head and neck cancer (HNC). Although high levels of epidermal growth factor receptor (EGFR) protein in HNC correlate with reduced survival, patients’ response to the EGFR inhibitor cetuximab often declines rapidly after a short period of effectiveness. Hyung Kwon Byeon at Korea University College of Medicine in Seoul and colleagues review current knowledge of the mechanisms underlying cetuximab resistance. They suggest that evaluating a patient’s genetic profile and combining cetuximab with drugs that enhance the effects of inhibiting EGFR signaling pathways (with inhibitors of other EGFR family members or proteins that mediate EGFR entry to the cell nucleus, for example) as well as with agents that inhibit cancer cell metabolism could be a more effective approach for treating HNC.

Prognostic significance of pretreatment 18F-fluorodeoxyglucose positron emission tomography evaluation using metabolic tumor volume of the primary tumor and lymph nodes in advanced hypopharyngeal cancer

BACKGROUND

The purpose of this study was to retrospectively evaluate the usefulness of pretreatment positron emission tomography (PET) using metabolic tumor volume (MTV) of the primary tumor and lymph nodes in advanced hypopharyngeal cancer.

METHODS

From June 2007 to December 2015, consecutive patients with advanced hypopharyngeal cancer who underwent PET and were treated with definitive radiation therapy were retrospectively reviewed.

RESULTS

A total of 61 patients were eligible for this study. On multivariate analysis, MTV of the primary tumor (MTV-T) was significantly related to the local control rate and overall survival (OS) (P = .036 and .012, respectively). In patients with lower MTV-T, MTV of metastatic lymph nodes (MTV-N) was significantly related to disease-specific survival and OS (P = .012 and .017, respectively).

CONCLUSION

MTV-T is a significant predictor in patients with advanced hypopharyngeal cancer, and MTV-N is also significant in patients with lower MTV-T.

Utility of first positron emission tomography-computed tomography scan as a prognostic tool following treatment of sinonasal and skull base malignancies

BACKGROUND

The prognostic value of the first posttreatment whole body integrated positron emission tomography-computed tomography (PET/CT) scanning in patients with sinonasal/skull base malignancies is undetermined.

METHODS

We retrospectively reviewed the data of all patients that underwent surgery for sinonasal/skull base malignancies in 2000-2015. The results of the pretreatment and posttreatment PET/CT findings and the clinical course were retrieved.

RESULTS

Thirty-eight patients (average age 60.6 years, 20 males) were included. Sensitivity and specificity, positive predictive value, and negative predictive value of the first PET/CT scan for predicting persistent/recurrent disease were 85.7%, 87.5%, 80%, and 91.3%, respectively. Overall 5-year survival was significantly lower in the first posttreatment PET/CT-positive group (35%) compared to the PET/CT-negative group (93%) (P = .0008).

CONCLUSION

Posttreatment PET/CT findings are highly prognostic in patients with sinonasal/skull base malignancies. Negative findings on the first posttreatment PET/CT scan predict a significantly better overall survival.

Early metabolic 18F-FDG PET/CT response of locally advanced squamous-cell carcinoma of head and neck to induction chemotherapy: A prospective pilot study

Objective

The objective of this study was to assess the clinical value of 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) after the first cycle of induction chemotherapy (IC) in locally advanced squamous cell carcinoma of the head and neck (LASCCHN).

Methods and findings

A prospective, single-arm, single center study was performed, with patients enrolled between February 2010 and July 2013.Patients (n = 49) with stage III/IVA–B LASCCHN who underwent IC with taxanes, cisplatin, and fluorouracil were recruited. Staging procedures included loco-regional and chest imaging, endoscopic examination, and PET/CT scan. On day 14 of the first cycle, a second PET/CT scan was performed. Patients with no early increase in regional lymph node maximum ¹⁸F-FDG standard uptake value (SUV), detected using ¹⁸F-FDG PET/CT after first IC had better progression-free survival (hazard ratio (HR) = 0.18, 95%, confidence interval (CI) 0.056–0.585; p = 0.004) and overall survival (HR = 0.14, 95% CI 0.040–0.498; p = 0.002), and were considered responders. In this subgroup, patients who achieved a reduction of ≥ 45% maximum primary tumor SUV experienced improved progression-free (HR = 0.23, 95% CI 0.062–0.854; p = 0.028) and overall (HR = 0.11, 95% CI 0.013–0.96; p = 0.046) survival.

Conclusions

These results suggest a potential role for early response evaluation with PET/CT examination in patients with LASCCHN undergoing IC. Increased regional lymph node maximum SUV and insufficient decrease in primary tumor uptake predict poorer outcomes.

Targeting metabolic pathways for head and neck cancers therapeutics

Cancer cells have distinctive energy metabolism pathways that support their rapid cell division. The preference for anaerobic glycolysis under the normal oxygen condition is known as the Warburg effect and has been observed in head and neck cancers. These metabolic changes are controlled by cancer-related transcription factors, such as tumor suppressor gene and hypoxia inducible factor 1α. In addition, various metabolic enzymes also actively regulate cancer-specific metabolism including the switch between aerobic and anaerobic glycolysis. For a long time, these metabolic changes in cancer cells have been considered a consequence of transformation required to maintain the high rate of tumor cell replication. However, recent studies indicate that alteration of metabolism is sufficient to initiate tumor transformation. Indeed, oncogenic mutations in the metabolic enzymes, isocitrate dehydrogenase and succinate dehydrogenase, have been increasingly found in various cancers, including head and neck cancers. In the present review, we introduce recent findings regarding the cancer metabolism, including the molecular mechanisms of how they affect cancer pathogenesis and maintenance. We also discuss the current and future perspectives on therapeutics that target metabolic pathways, with an emphasis on head and neck cancer.

Preoperative 18F-FDG-PET/CT vs Contrast-Enhanced CT to Identify Regional Nodal Metastasis among Patients with Head and Neck Squamous Cell Carcinoma

Objective Our objective was to compare the accuracy of preoperative positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced CT (CECT) in detecting cervical nodal metastases in patients treated with neck dissection and to scrutinize the ability of each modality to determine nodal stage. Study Design Case series with chart review. Setting Montefiore Medical Center, Bronx, New York. Subjects and Methods Patients who underwent neck dissection at our institution for primary treatment of head and neck squamous cell carcinoma (HNSCC) and had received preoperative PET/CT and CECT were included in this study. Imaging studies were reinterpreted by 3 specialists within the field and compared for interreader agreement. Concordance between radiology and histopathology was measured using neck levels and sides, along with patient nodal stage. Sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and agreement coefficients were calculated. Results Seventy-three patients were included in the study. Sensitivity was 0.69 and 0.94 (level and side) for PET/CT vs 0.53 and 0.66 for CECT ( P = .056, P = .001). Specificity was 0.86 and 0.56 for PET/CT vs 0.91 and 0.76 for CECT ( P = .014, P = .024). No significant difference was found in overall accuracy ( P = .33, P = .88). The overall agreement percentages between N stage called by imaging modality and pathology were 52% and 55% for PET/CT and CECT, respectively. Conclusion No significant difference in sensitivity was found between PET/CT and CECT. CECT was found to have superior specificity compared with PET/CT. The information gleaned from each modality in the pretreatment evaluation of HNSCC appears to be complementary.

Recurrent oropharyngeal cancer after organ preserving treatment: pattern of failure and survival

The objectives is to thoroughly analyze the pattern of failure and oncologic outcome in recurrent oropharyngeal cancer (OPC) after (chemo)radiotherapy and correlate the site of failure to the planned radiation dose. Between January 2010 and April 2014, 57 patients with recurrent OPC after (chemo)radiotherapy were analyzed. Endpoints were pattern of failure and overall survival (OS). Local (LF) and regional failure (RF) were classified as in-field [>50% within gross tumor volume (GTV)], marginal [<50% within GTV but >50% within clinical target volume (CTV)], or out-of-field (>50% outside CTV) recurrences. In the whole group, 70 recurrences were reported. Of the 31 LF, 29 (93.5%) were in-field and 2 (6.5%) were marginal. No out-field LF was reported. Of the 21 RF, 13 RF (62%) were in-field, 6 (28.5%) marginal, and 2 (9.5%) out-of-field recurrences. Forty-three percent of RF was developed in an electively treated neck level, and 2 of them were contralateral. OS at 2 years in recurrent HPV positive, compared to HPV-negative OPC, were 66 and 18%, respectively (p = 0.011). OS was also significantly better in patients that were salvage treatment which was possible (70 vs. 6%, p < 0.001). Median survival after distant failure was 3.6 months. The great majority of LFs were located within the GTV and 43% of RFs developed in an electively treated neck level. The currently used margins and dose recipe and the indication for bilateral nodal irradiation need to be reevaluated. OS was significantly better in recurrent HPV-positive OPC and in patients, where salvage treatment was possible.

Impact of 3T multiparametric MRI and FDG-PET-CT in the evaluation of occult primary cancer with cervical node metastasis

Background

This study aimed to determine the ability of multimodal evaluation with multiparametric 3T-MRI (MPMRI) and positron emission tomography - computed tomography (PET/CT) to detect cancer of unknown primary origin (CUP) with neck lymph node (LN) metastasis.

Methods

The study group comprised 38 retrospectively analysed consecutive patients with LN metastasis in the head and neck (HN) region without known primary tumours (PTs). Statistical values of 3T-MRI and of FDG-PET/CT scans were evaluated.

Results

Of the 38 CUPs, conventional native T1-, T2-weighted and STIR sequences detected 6 PTs. Native sequences plus diffusion-weighted imaging (DWI) found 14-, and with fat suppression contrast-enhanced T1-weighted measurement as well as with the complex MPMRI found 15 primaries and with PET/CT 17 CUPs could be evaluated, respectively. The detection rates were 15.8, 36.8, 39.5, 39.5 and 44.7 % for conventional native MRI, native plus DWI, native with contrast-enhanced MRI (CE-MRI), for MPMRI, and for PET/CT, respectively. The overall detection rate proved by histology was 47.4 %. PET/CT provided the highest sensitivity (Sv: 94.4 %) but a lower specificity (Sp: 65.0 %), using MPMRI (Sv: 88.2 %) the specificity increased to 71.4 %. DWIincreased specificity of the native sequences (Sp: 76.2 %). Conventional native sequences plus DWI as well as 3T-MPMRI and PET/CT were same accurate (Acc: 79.0 %) and had similar likelihood ratio (LR: 3.42, 3.03 and 2.62) in detecting unknown PT sites.

Conclusions

The accuracy of FDG-PET/CT and MPMRI in case of CUP in finding the primary cancer in the neck regions is identical. While using PET/CT whole body information can be obtained in one examination. MPMRI shows the local soft tissue status more accurately. In cases of CUP PET/CT should be the first method of choice if it is available. MPMRI can clarify the exact primary tumor stage, and it can be advantageous in clarifying the prognostic factors, which is necessary in case of advanced tumor stage and when surgery is under consideration. In case low N stage is likely after the clinical examination and wait and see policy can be considered, MPMRI is recommended, and in this case the significance the of radiation free MPMRI is increasing.

Electronic supplementary material

The online version of this article (doi:10.1186/s40644-016-0097-x) contains supplementary material, which is available to authorized users.