18F-fluorodeoxyglucose positron emission tomography to evaluate cervical node metastases in patients with head and neck squamous cell carcinoma: a meta-analysis

Prognostic value of metabolic tumor volume and total lesion glycolysis in head and neck cancer: a systematic review and meta-analysis

We conducted a comprehensive systematic review of the literature on volumetric parameters and a meta-analysis of the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) in patients with head and neck cancer (HNC).

METHODS

A systematic search of MEDLINE and EMBASE was performed using the key words PET, head and neck, and volume. Inclusion criteria were (18)F-FDG PET used as an initial imaging tool; studies limited to HNC; patients who had not undergone surgery, chemotherapy, or radiotherapy before PET scans; and studies reporting survival data. Event-free survival and overall survival were considered markers of outcome. The impact of MTV or TLG on survival was measured by the effect size hazard ratio (HR). Data from each study were analyzed using Review Manager.

RESULTS

Thirteen studies comprising 1,180 patients were included in this study. The combined HR for adverse events was 3.06 (2.33-4.01, P < 0.00001) with MTV and 3.10 (2.27-4.24, P < 0.00001) with TLG, meaning that tumors with high volumetric parameters were associated with progression or recurrence. Regarding overall survival, the pooled HR was 3.51 (2.62-4.72, P < 0.00001) with MTV and 3.14 (2.24-4.40, P < 0.00001) with TLG. There was no evidence of significant statistical heterogeneity at an I(2) of 0%.

CONCLUSION

MTV and TLG are prognostic predictors of outcome in patients with HNC. Despite clinically heterogeneous HNC and the various methods adopted between studies, we can confirm that patients with a high MTV or TLG have a higher risk of adverse events or death.

Can contrast-enhanced ultrasound distinguish malignant from reactive lymph nodes in patients with head and neck cancers?

The purpose of this study was to investigate the utility of contrast-enhanced ultrasound in differentiating benign from malignant cervical lymph nodes in patients with squamous cell carcinoma of the head and neck. A consecutive series of 17 patients with known head and neck malignancy scheduled for neck surgery and lymph node clearance were recruited for contrast-enhanced ultrasound evaluation. Sonographic signal intensity as a function of time, comparing features of time to peak, time to arrival and time to wash-out, was quantified. The selected node was removed surgically and submitted for histology. Contrast-enhanced ultrasound examination had 100% sensitivity and 85.7% specificity for lymph node involvement. Functional analysis revealed contrast peaks significantly earlier in the malignant nodes (mean ± standard deviation) of 24.14 ± 2.7 s compared with 29.33 ± 3.4 s (p = 0.0128). Contrast-enhanced ultrasound holds promise in the detection and characterization of metastatic nodes that would not be diagnosed as abnormal on the basis of conventional ultrasound criteria.

MRI and PET-CT: Comparison in post-treatment evaluation of head and neck squamous cell carcinomas

BACKGROUND

Treatment of patients with head and neck cancers includes surgery, radiation therapy and chemotherapy due to which the complex anatomy in this region is further complicated by post surgical or radiation changes making the distinction between post therapy changes and recurrence or residual tumor challenging. We decided to compare the diagnostic performance of FDG-PET/CT and MRI scans in the response assessment of patients with Head and Neck Squamous Cell Carcinomas (HNSCC).

METHODS

Fifty consecutive patients with carcinoma of the head and neck region undergoing treatment at our center were enrolled in the study and evaluated with both MRI scan and PET-CT scan at presentation, at 12 weeks after treatment and at 24 weeks post-treatment.

RESULTS

Post treatment evaluation at 24 weeks revealed a sensitivity, specificity, PPV, NPV of 95.83%, 82.37%, 78.91%, 96.3% for MRI respectively while corresponding values for PET-CT scans were 95.83%, 91.97%, 85.45% and 96.3%. Evaluation by treatment modality showed a concurrence rate of positive biopsies of 71.33% and 74.54% respectively for MRI and PET-CT scans in surgical patients, 93.33% and 91.25% respectively for the chemo-radiotherapy and 71.43% and 85.71% respectively for patients treated with surgery and radiotherapy.

CONCLUSION

In our study, both modalities were useful for evaluation at 12 weeks, however by 24 weeks PET-CT was superior. Both the modalities suffer from high negative predictive values and relatively low positive predictive values. These persisted irrespective of the treatment modality with MRI being slightly better for patients on chemo-radiotherapy while PET-CT scans were better if surgery was one of the modalities of treatment.

Functional imaging in radiation therapy planning for head and neck cancer

Functional imaging and its application to radiotherapy (RT) is a rapidly expanding field with new modalities and techniques constantly developing and evolving. As technologies improve, it will be important to pay attention to their implementation. This review describes the main achievements in the field of head and neck cancer (HNC) with particular remarks on the unsolved problems.

Application of clinical PET imaging to human laryngeal squamous cell carcinoma xenografts

Positron emission tomography (PET) imaging with [F-18]-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) is extensively applied in clinical practice. However, in animal experiments, the application of clinical PET is difficult, due to limitations in sensitivity and spatial resolution. This study aimed to determine the potential of ¹⁸F-FDG PET with regard to the imaging of human laryngeal squamous cell carcinoma (LSCC) xenografts. Twenty-seven LSCC tumor-bearing nude mice were divided randomly into seven groups which were each handled differently; the anesthetization, fasting, warming and the time point at which scanning was initiated were varied. The size of each xenograft was measured prior to conducting the scan. Using the RAMLA 3D image reconstruction method, images were acquired. The region of interest (ROI) technology was adopted to calculate target and non-target (T/N) ratios. The results were subsequently analyzed by semiquantitative analysis. The analysis showed that there was no significant correlation between tumor size and PET image quality (r=0.381, P>0.05); however, the handling conditions of the mice had a greater influence on the tumor image quality. Fasting increased ¹⁸F-FDG uptake (T/N, 1.153±0.008) to a certain degree, although the effect was unstable. By contrast, combining warming and fasting increased ¹⁸F-FDG uptake significantly (T/N, 2.0±0.29; P<0.05). The acquisition time had no impact on the tumor image quality. The study demonstrated that the application of clinical PET scanning has potential in the study of human LSCC xenografts in nude mice, and that the quality of the image of the tumor is greatly influenced by the handling conditions of the animals.

Molecular PET imaging for biology-guided adaptive radiotherapy of head and neck cancer

Integration of molecular imaging PET techniques into therapy selection strategies and radiation treatment planning for head and neck squamous cell carcinoma (HNSCC) can serve several purposes. First, pre-treatment assessments can steer decisions about radiotherapy modifications or combinations with other modalities. Second, biology-based objective functions can be introduced to the radiation treatment planning process by co-registration of molecular imaging with planning computed tomography (CT) scans. Thus, customized heterogeneous dose distributions can be generated with escalated doses to tumor areas where radiotherapy resistance mechanisms are most prevalent. Third, monitoring of temporal and spatial variations in these radiotherapy resistance mechanisms early during the course of treatment can discriminate responders from non-responders. With such information available shortly after the start of treatment, modifications can be implemented or the radiation treatment plan can be adapted tailing the biological response pattern. Currently, these strategies are in various phases of clinical testing, mostly in single-center studies. Further validation in multicenter set-up is needed. Ultimately, this should result in availability for routine clinical practice requiring stable production and accessibility of tracers, reproducibility and standardization of imaging and analysis methods, as well as general availability of knowledge and expertise. Small studies employing adaptive radiotherapy based on functional dynamics and early response mechanisms demonstrate promising results. In this context, we focus this review on the widely used PET tracer (18)F-FDG and PET tracers depicting hypoxia and proliferation; two well-known radiation resistance mechanisms.

Role of positron emission tomography/computed tomography (PET/CT) in head and neck cancer

Positron emission tomography/computed tomography (PET/CT) has an important role in the diagnosis and treatment of head and neck cancer. The technique can aid in the detection of an unknown primary tumor, assist in locoregional staging, evaluate for distant metastases or second primary tumors, and be a component of restaging and tumor surveillance. This article reviews the basic principles, pitfalls, and uses of PET/CT in head and neck cancer, as well as potential future applications.

18FDG-PET/CT for the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment: a meta-analysis

BACKGROUND

We performed a meta-analysis to evaluate the role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG-PET/CT) in the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment.

MATERIALS AND METHODS

Studies about (18)FDG-PET/CT for the detection of regional nodal metastasis in patients with primary HNC were systematically searched in the MEDLINE, EMBASE, and EBM Review databases from January 1, 2000 to July 25, 2012. A software called "Stata 12.0" was used to obtain pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for PET/CT. We also calculated hierarchic summary receiver operating characteristic (HSROC) curves and area under the curves.

RESULTS

14 articles (742 patients) fulfilled all inclusion criteria. The pooled sensitivity, and specificity with 95% confidence interval for PET/CT on a per-neck-side analysis were 0.84 (0.77-0.89) and 0.84 (0.78-0.89). The corresponding values for PET/CT on a per-nodal-level analysis 0.84 (0.78-0.88) and 0.96 (0.94-0.98).

CONCLUSIONS

(18)FDG-PET/CT had good diagnostic performance for the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment.

Novel diagnostic modalities for assessment of the clinically node-negative neck in oral squamous-cell carcinoma

Oral squamous-cell carcinomas arise in mucosal linings of the oral cavity and frequently metastasise to regional lymph nodes in the neck. The presence of nodal metastases is a determinant of prognosis and clinical management. The neck is staged by palpation and imaging, but accuracy of these techniques to detect small metastases is low. In general, 30-40% of patients will have occult nodal disease and will develop clinically detectable lymph-node metastases when the neck is left untreated. The choice at present is either elective treatment or careful observation followed by treatment of the neck in patients who develop manifest metastases. These unsatisfying therapeutic options have been the subject of debate for decades. Recent developments in staging of the neck, including expression profiling and sentinel lymph-node biopsy, will allow more personalised management of the neck.

Initial staging of squamous cell carcinoma of the oral cavity, larynx and pharynx (excluding nasopharynx). Part I: Locoregional extension assessment: 2012 SFORL guidelines

OBJECTIVES

To set out good practice guidelines for locoregional extension assessment of squamous cell carcinoma of the head and neck (excluding nasopharynx, nasal cavities and sinuses).

MATERIALS AND METHODS

A critical multidisciplinary review of the literature on locoregional extension assessment of squamous cell carcinoma of the head and neck was conducted, applying levels of evidence in line with the French health authority's (HAS) literature analysis guide of January 2000.

CONCLUSION

Based on the levels of evidence of the selected articles and on work-group consensus, graded guidelines are set out for clinical, endoscopic and imaging locoregional extension assessment of head and neck cancer.

Evaluation of 18F-FDG PET/CT and CT/MRI with histopathologic correlation in patients undergoing central compartment neck dissection for squamous cell carcinoma of the larynx, hypopharynx, and esophagus

OBJECTIVES

Central compartment lymph node metastasis (CLNM) in patients with laryngeal, hypopharyngeal, or cervical esophageal squamous cell carcinoma is associated with unfavorable clinical outcomes, but cannot be reliably detected using computed tomography (CT)/magnetic resonance imaging (MRI). Therefore, we assessed the clinical utility of using (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT to identify CLNM in these patients.

PATIENTS AND METHODS

A total of 62 patients were preoperatively evaluated using (18)F-FDG PET/CT and CT/MRI. Histopathologic analysis of the dissected neck tissues was used as the gold standard for assessing these imaging techniques. The diagnostic value of (18)F-FDG PET/CT for detecting CLNM was calculated and compared with CT/MRI. Univariate and multivariate analyses were utilized to determine the factors predictive of CLNM.

RESULTS

Of the 62 patients in the study cohort, 12 (19%) had CLNM. Compared with histology, both (18)F-FDG PET/CT and CT/MRI demonstrated low sensitivity for detecting CLNM (58% vs 42%, respectively, P = 0.625). The specificities of (18)F-FDG PET/CT and CT/MRI for the detection of CLNM were 88% and 90%, respectively (P = 1.000). Univariate and multivariate analyses showed that clinical metastasis to any cervical lymph node was significantly associated with CLNM (P = 0.018).

CONCLUSIONS

Neither (18)F-FDG PET/CT nor CT/MRI is a sensitive diagnostic imaging modality for detecting CLNM. Routine elective central compartment dissection or radiotherapy should be advocated for the treatment of these patients.

Changes in functional imaging parameters following induction chemotherapy have important implications for individualised patient-based treatment regimens for advanced head and neck cancer

BACKGROUND

When induction chemotherapy (IC) is used prior to chemoradiotherapy (CRT) in head and neck cancer (HNC), functional imaging (FI) may inform adaptation of treatment plans with the aim of optimising outcomes. Understanding the impact of IC on FI parameters is, therefore, essential.

PURPOSE

To prospectively evaluate the feasibility of acquiring serial FI ((18)F-FDG-PET, diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI) and its role in defining individualised treatment regimens following IC in HNC.

METHODS AND MATERIALS

Ten patients with stage III and IV HNC underwent conventional (CT and MRI) and functional (DW, DCE-MRI and (18)F-FDG-PET/CT) imaging at baseline and following two cycles of IC prior to definitive CRT.

RESULTS

One patient withdrew due to claustrophobia. Seven out of nine patients had a complete metabolic response to IC on (18)F-FDG-PET imaging. DCE-MRI showed a significant fall in transfer constant (K(trans)) (0.209 vs 0.129 min(-1)P<0.01) and integrated area under gadolinium curve at 60s (IAUGC6O) (18.4 vs 11.9 mmol/min, P<0.01) and DW-MRI a rise in ADC (0.89 vs 1.06 × 10(-3) mm(2)/s, P<0.01) following IC.

CONCLUSIONS

Acquiring FI sequences is feasible in HNC. There are marked changes in FI parameters following IC which may guide adaptation of individualised treatment regimens.

Current advances in diagnosis and surgical treatment of lymph node metastasis in head and neck cancer

Still today, the status of the cervical lymph nodes is the most important prognostic factor for head and neck cancer. So the individual treatment concept of the lymphatic drainage depends on the treatment of the primary tumor as well as on the presence or absence of suspect lymph nodes in the imaging diagnosis. Neck dissection may have either a therapeutic objective or a diagnostic one. The selective neck dissection is currently the method of choice for the treatment of patients with advanced head and neck cancers and clinical N0 neck. For oncologic reasons, this procedure is generally recommended with acceptable functional and aesthetic results, especially under the aspect of the mentioned staging procedure. In this review article, current aspects on pre- and posttherapeutic staging of the cervical lymph nodes are described and the indication and the necessary extent of neck dissection for head and neck cancer is discussed. Additionally the critical question is discussed if the lymph node metastasis bears an intrinsic risk of metastatic development and thus its removal in a most possible early stage plays an important role.

Transoral resection of pharyngeal cancer: summary of a National Cancer Institute Head and Neck Cancer Steering Committee Clinical Trials Planning Meeting, November 6-7, 2011, Arlington, Virginia

Recent advances now permit resection of many pharyngeal tumors through the open mouth, an approach that can greatly reduce the morbidity of surgical exposure. These transoral techniques are being rapidly adopted by the surgical community and hold considerable promise. On November 6-7, 2011, the National Cancer Institute sponsored a Clinical Trials Planning Meeting to address how to further investigate the use of transoral surgery, both in the good prognosis human papillomavirus (HPV)-initiated oropharyngeal cancers, and in those with HPV-unrelated disease. The proceedings of this meeting are summarized.

The diagnosis and treatment of oral cavity cancer

BACKGROUND

About 10,000 persons are diagnosed as having carcinoma of the oral cavity or the throat in Germany every year. Squamous-cell carcinoma accounts for 95% of cases.

METHODS

We systematically reviewed the pertinent literature on predefined key questions about these tumors (which were agreed upon by a consensus of the investigators), concerning imaging, the removal of cervical lymph nodes, and resection of the primary tumor.

RESULTS

246 clinical trials were selected for review on the basis of 3014 abstracts. There was only one randomized, controlled trial (evidence level 1-); the remaining trials reached evidence levels 2++ to 3. Patients with mucosal changes of an unclear nature persisting for more than two weeks should be examined by a specialist without delay. The diagnosis is made by computed tomography or magnetic resonance imaging along with biopsy and a standardized histopathological examination. Occult metastases are present in 20% to 40% of cases. Advanced disease (stages T3 and T4) should be treated by surgery followed by radiotherapy, with or without chemotherapy. 20% of the patients overall go on to have a recurrence, usually within 2 to 3 years of the initial treatment. The 5-year survival rate is somewhat above 50%. Depending on the radicality of surgery and radiotherapy, there may be functional deficits, osteoradionecrosis, and xerostomia. The rate of loss of implants in irradiated bone is about 10% in 3 years.

CONCLUSION

The interdisciplinary planning and implementation of treatment, based on the patient's individual constellation of findings and personal wishes, are prerequisites for therapeutic success. Reconstructive measures, particularly microsurgical ones, have proven their usefulness and are an established component of surgical treatment.

Recommendations of the Spanish Societies of Radiation Oncology (SEOR), Nuclear Medicine & Molecular Imaging (SEMNiM), and Medical Physics (SEFM) on (18)F-FDG PET-CT for radiotherapy treatment planning

Positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) is a valuable tool for diagnosing and staging malignant lesions. The fusion of PET and computed tomography (CT) yields images that contain both metabolic and morphological information, which, taken together, have improved the diagnostic precision of PET in oncology. The main imaging modality for planning radiotherapy treatment is CT. However, PET-CT is an emerging modality for use in planning treatments because it allows for more accurate treatment volume definition. The use of PET-CT for treatment planning is highly complex, and protocols and standards for its use are still being developed. It seems probable that PET-CT will eventually replace current CT-based planning methods, but this will require a full understanding of the relevant technical aspects of PET-CT planning. The aim of the present document is to review these technical aspects and to provide recommendations for clinical use of this imaging modality in the radiotherapy planning process.

A novel PET scanner with semiconductor detectors may improve diagnostic accuracy in the metastatic survey of head and neck cancer patients

OBJECTIVES

Our research group developed new PET scanner with semiconductor detectors for high spatial resolution with low scatter noise. On head and neck cancer (HNC) surgery, FDG-PET may often provide false-positive findings in cervical node involvements. Accordingly, we assessed diagnostic accuracy using this new scanner in the HNC patients as compared with the conventional lutetium oxyorthosilicate (LSO) PET.

METHODS

We prospectively studied FDG imaging in 35 HNC patients by both semiconductor PET and LSO-PET. At 60 min after (18)F-FDG injection, two PET scans were obtained using both scanners consecutively and in random order. Two nuclear medicine specialists scored FDG abnormalities using 5 point scale system for receiver operating characteristic (ROC) curve analysis.

RESULTS

63 suspected of metastatic or recurrent lesions were evaluated and correlated by the final confirmation by pathological findings or clinical courses (malignant 26/benign 37). Semiconductor PET showed sensitivity of 92.3 % (24/26), specificity of 51.4 % (19/37), and accuracy of 68.2 % (43/63), while LSO-PET showed sensitivity of 84.6 % (22/26), specificity of 16.2 %(6/37), and accuracy of 44.4 % (28/63), respectively. Especially, semiconductor PET accurately diagnosed as true negative in the 13 of 14 lesions only detected by LSO-PET. ROC analyses revealed the diagnostic superiority of semiconductor PET from location of- and area under curve particularly in the study of small (≤10 mm) lesions.

CONCLUSION

A new novel semiconductor PET scanner can increase diagnostic accuracy with reduction in false positive findings in the HNC patients mainly due to higher spatial resolution and lower noise than the LSO-PET. This new technology can lead to more accurate diagnosis and the more optimal therapeutic tactics in head and neck surgery.

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

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

METHODS

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

RESULTS

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

CONCLUSION

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

Radiotherapy for head and neck tumours in 2012 and beyond: conformal, tailored, and adaptive?

Intensity-modulated radiation therapy (IMRT) is a conformal irradiation technique that enables steep dose gradients. In head and neck tumours this approach spares parotid-gland function without compromise to treatment efficacy. Anatomical and molecular imaging modalities may be used to tailor treatment by enabling proper selection and delineation of target volumes and organs at risk, which in turn lead to dose prescriptions that take into account the underlying tumour biology (eg, human papillomavirus status). Therefore, adaptations can be made throughout the course of radiotherapy, as required. Planned dose increases to parts of the target volumes may also be used to match the radiosensitivity of tumours (so-called dose-painting), assessed by molecular imaging. For swift implementation of tailored and adaptive IMRT, tools and procedures, such as accurate image acquisition and reconstruction, automatic segmentation of target volumes and organs at risk, non-rigid image and dose registration, and dose summation methods, need to be developed and properly validated.

Detection of cervical lymph node metastasis in head and neck cancer patients with clinically N0 neck-a meta-analysis comparing different imaging modalities

BACKGROUND

How to properly manage clinically negative neck of head and neck cancer patients is a controversial topic. Research is now directed toward finding a method sensitive enough to bring the risk of occult metastases below 20%. The aim of this review was to compare the diagnostic accuracy of different imaging modalities, including CT, MRI, PET and US, in clinically N0 head and neck cancer patients.

METHODS

For this systematic review and meta-analysis, PubMed and the Cochrane Database were searched for relevant original articles published up to May 2011. Inclusion criteria were as follows: articles were reported in English; CT, MRI, PET or US were performed to identify cervical metastases in clinically N0 head and neck squamous cell carcinoma; and data were sufficient for the calculation of true-positive or false-negative values. A bivariate random effect model was used to obtain pooled sensitivity and specificity. The positive and negative test probability of neck metastasis was generated based on Bayesian theory and collected data for different pre-test possibilities.

RESULTS

Of the 168 identified relevant articles, 7 studies fulfilled all inclusion criteria for CT, 6 studies for MRI, 11 studies for PET and 8 studies for US. There was no difference in sensitivity and specificity among these imaging modalities, except CT was superior to US in specificity. The pooled estimates for sensitivity were 52% (95% confidence interval [CI], 39% ~ 65%), 65% (34 ~ 87%) 66% (47 ~ 80%), and 66% (45 ~ 77%), on a per-neck basis for CT, MRI, PET and US, respectively. The pooled estimates for specificity were 93% (87% ~ 97%), 81% (64 ~ 91%), 87% (77 ~ 93%), and 78% (71 ~ 83%) for CT, MRI, PET and US, respectively. With pre-examination nodal metastasis probabilities set at 10%, 20% and 30%, the post-exam probabilities of positive nodal metastasis rates were 47%, 66% and 77% for CT; 27%, 46% and 59% for MRI; 36%, 56% and 69% for PET; and 25%, 42% and 56% for US, respectively. Negative nodal metastasis probabilities were 95%, 89% and 82% for CT; 95%, 90% and 84% for MRI; 96%, 91% and 86% for PET; and 95%, 90% and 84% for US, respectively.

CONCLUSIONS

Modern imaging modalities offer similar diagnostic accuracy to define and diagnose clinically N0 neck. Minimizing morbidity and avoiding elective neck dissection is acceptable in some select cases.

Clinical significance of combined assessment of the maximum standardized uptake value of F-18 FDG PET with nodal size in the diagnosis of cervical lymph node metastasis of oral squamous cell carcinoma

RATIONALE AND OBJECTIVES

This study aimed to elucidate the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for nodal involvement in oral squamous cell carcinoma (OSCC), and to reveal clinically useful factors to distinguish between true-positive (TP) and false-positive (FP) nodes.

MATERIALS AND METHODS

Thirty-eight patients with primary OSCC who underwent neck dissection were assessed. The diagnostic accuracy of F-18 FDG PET/CT was evaluated, and then compared with that of CT/ultrasonography (US). Furthermore, the association of the maximum standardized uptake value (SUVmax) and nodal size with the histopathologic findings was examined.

RESULTS

Sensitivity and specificity using F-18 FDG PET/CT were 77.1% and 97.3%, and those using CT/US were 72.9% and 98.9%, respectively. The SUVmax of TP nodes was significantly higher than that of FP nodes. Nodes with SUVmax >4.5 were pathologically confirmed as metastasis. Nodes with SUVmax ≤4.5 were further discriminated between TP and FP nodes by using the long axis diameters or the ratios of long to short axis diameter as clinical parameters. Positive correlation between the SUVmax and the short-axis diameter was found in TP nodes. The AUC obtained from the ROC curves of the SUVmax alone (AUC, 0.804) was improved by combination with the long-axis diameter (AUC, 0.867) or the short-axis diameter (AUC, 0.846), although no significant difference was found.

CONCLUSIONS

These results indicated that F-18 FDG PET/CT was potentially useful in diagnosing preoperative nodal state. Furthermore, combined assessment of SUVmax with nodal size could be significant in the identification of metastatic lymph nodes in OSCC patients.

Delayed response assessment with FDG-PET-CT following (chemo) radiotherapy for locally advanced head and neck squamous cell carcinoma

AIMS

To analyse the diagnostic accuracy of delayed response assessment 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography-computed tomography (PET-CT) following (chemo)radiation for locally advanced head and neck squamous cell carcinoma (HNSCC).

MATERIAL AND METHODS

Forty-four consecutive patients who underwent a baseline and response assessment using FDG PET-CT for HNSCC following (chemo)radiation between August 2008 and April 2011 were identified retrospectively. Clinicopathological findings and serial clinical follow-up provided the reference standard.

RESULTS

Median follow-up was 14 months (range 5-43 months). Response assessment FDG PET-CT was performed at 16.8 weeks (inter-quartile range 15.8-18.6 weeks). Thirty-one out of 44 (70%) response assessment examinations showed a complete metabolic response. Seven out of 40 (18%) assessable primary tumours were positive. Eight out of 41 (20%) patients with pre-treatment nodal disease had equivocal or positive FDG uptake at response assessment. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for primary disease and nodal disease were 100, 89, 43, 100, and 100%, and 92, 63, and 100%, respectively. Seven patients had residual FDG-negative soft tissue detectable on the unenhanced CT component of the response assessment images; all remained disease free after clinical observation. Distant metastases were detected on response assessment FDG PET-CT in four out of the 44 patients (10%).

CONCLUSION

The diagnostic accuracy of response assessment with FDG PET-CT performed at approximately 16 weeks post-(chemo)radiotherapy is good. The very high NPV of a complete metabolic response can be used to guide management decisions. Although the PPV is limited for local residual disease, FDG PET-CT is a powerful screening tool for the detection of interim metastatic disease.

Improving target definition for head and neck radiotherapy: a place for magnetic resonance imaging and 18-fluoride fluorodeoxyglucose positron emission tomography?

Defining the target for head and neck radiotherapy is a critical issue with the introduction of steep dose gradients associated with intensity-modulated radiotherapy. Tumour delineation inaccuracies are a major source of error in radiotherapy planning. The integration of 18-fluoride fluorodeoxyglucose positron emission tomography ((18)FDG-PET) and magnetic resonance imaging directly into the radiotherapy planning process has the potential to greatly improve target identification/selection and delineation. This raises a range of new issues surrounding image co-registration, delineation methodology and the use of functional data and treatment adaptation. This overview will discuss the practical aspects of integrating (18)FDG-PET and magnetic resonance imaging into head and neck radiotherapy planning.

The Impact of (18)F-FDG PET CT Prior to Chemoradiotherapy for Stage III/IV Head and Neck Squamous Cell Carcinoma

Introduction. To determine the value of a FDG-PET-CT scan in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) prior to chemoradiotherapy. Materials and Methods. Consecutive patients with stage III or IV HNSCC who had undergone a staging FDG-PET-CT scan prior to chemoradiotherapy between August 2008 and April 2011 were included. Clinical details and conventional imaging (CT and/or MRI) were, retrospectively, reviewed, a TNM stage was assigned, and levels of cervical lymph node involvement were documented. This process was repeated with the addition of FDG-PET-CT. Radiotherapy plans were reviewed for patients with an alteration identified on TNM staging and/or nodal level identification with FDG-PET-CT and potential alterations in radiotherapy planning were documented. Results. 55 patients were included in the analysis. FDG-PET-CT altered the TNM stage in 17/55 (31%) of patients, upstaging disease in 11 (20%) and downstaging in 6 (11%); distant metastases were identified by FDG-PET-CT in 1 (2%) patient. FDG-PET-CT altered the lymph node levels identified in 22 patients (40%), upclassifying disease in 16 (29%) and downclassifying in 6 (11%). Radiotherapy plans were judged retrospectively to have been altered by FDG-PET-CT in 10 patients (18%). Conclusions. The use of FDG-PET-CT potentially impacts upon both treatment decisions and radiotherapy planning.

Patterns of regional lymph node metastasis of nasopharyngeal carcinoma: a meta-analysis of clinical evidence

BACKGROUND

The characteristics of cervical lymphatic metastasis in nasopharyngeal carcinoma (NPC) are not completely understood. As such, radiotherapy to the entire lymphatic of the neck bilaterally has been empirically practiced even in early stage disease, although not supported by clinical evidence. We studied the pattern and probability of nodal metastasis through a meta-analysis of published evidences, with an aim to establish an evidence-based guideline for selecting and delineation of clinical target volume of neck lymphatics for conformation radiation for NPC.

METHODS

A literature search yielded an initial 411 original articles, and 13 studies with 2920 NPC cases staged via MRI were included in this analysis. The occurrence of nodal metastasis was calculated and analyzed according to the respective regional nodal levels.

RESULTS

85% of NPC cases presented with lymphadenopathy. The most commonly involved regions include retropharyngeal (69%) and level II lymph nodes (70%). The overall probability of levels III, IV, and V nodal involvement are 45%, 11%, and 27%, respectively. Low-risk node groups included the supraclavicular, levels IA/IB and VI nodes, and parotid nodes with involvement rates at 3%, 0%, 3%, 0%, and 1%, respectively. Nodal metastases followed an orderly pattern and the probability of "skip" metastasis between levels varied between 0.5-7.9%.

CONCLUSIONS

Lymph node metastasis in NPC follows a predictable and orderly pattern. The rarity of metastasis in certain nodal groups and "skip" metastasis suggest that reduced treatment volume is feasible in conformal radiotherapy for NPC.

Opportunities and challenges facing biomarker development for personalized head and neck cancer treatment

Head and neck oncologists have traditionally relied on clinical tumor features and patient characteristics to guide care of individual patients. As surgical, radiotherapeutic, and systemic treatments have evolved to become more anatomically precise and mechanistically specific, the opportunity for improved cure and functional patient recovery has never been more promising for this historically debilitating cancer. However, personalized treatment must be accompanied by sophisticated patient selection to triage the application of advanced therapies toward ideal patient candidates. In this monograph, we review current progress, investigative themes, and key challenges facing head and neck cancer biomarker development intended to make personalized head and neck cancer treatment a clinical reality.

Preoperative predictive model of cervical lymph node metastasis combining fluorine-18 fluorodeoxyglucose positron-emission tomography/computerized tomography findings and clinical factors in patients with oral or oropharyngeal squamous cell carcinoma

OBJECTIVE

This study aimed to construct a preoperative predictive model of cervical lymph node metastasis using fluorine-18 fluorodeoxyglucose positron-emission tomography/computerized tomography ((18)F-FDG PET/CT) findings in patients with oral or oropharyngeal squamous cell carcinoma (SCC).

STUDY DESIGN

Forty-nine such patients undergoing preoperative (18)F-FDG PET/CT and neck dissection or lymph node biopsy were enrolled. Retrospective comparisons with spatial correlation between PET/CT and the anatomical sites based on histopathological examinations of surgical specimens were performed. We calculated a logistic regression model, including the SUVmax-related variable.

RESULTS

When using the optimal cutoff point criterion of probabilities calculated from the model that included either clinical factors and delayed-phase SUVmax ≥0.087 or clinical factors and maximum standardized uptake (SUV) increasing rate (SUV-IR) ≥ 0.100, it significantly increased the sensitivity, specificity, and accuracy (87.5%, 65.7%, and 75.2%, respectively).

CONCLUSIONS

The use of predictive models that include clinical factors and delayed-phase SUVmax and SUV-IR improve preoperative nodal diagnosis.

Predictive value of positron emission tomography-computed tomography image fusion in the diagnosis of head and neck cancer: does it really improve staging and management?

AIMS

To determine (1) the accuracy of positron emission tomography - computed tomography in the diagnosis of head and neck cancer, (2) the learning curve involved, and (3) whether its use alters patient management.

MATERIALS AND METHODS

A retrospective study including 80 patients with head and neck cancer who underwent positron emission tomography - computed tomography image fusion at Blackpool Victoria Hospital.

RESULTS

Fifty-three patients underwent positron emission tomography - computed tomography for staging (32 for detection of a primary tumour and 21 for detection of distant metastasis) and 27 for detection of loco-regional recurrence. Ten primary tumours and 20 recurrences were accurately diagnosed by this method. Eighteen patients had their tumour stage and management modified as a result of this method of imaging. The effect of the learning curve resulted in better true positive detection rates, one year after introduction (81 versus 61 per cent). The sensitivity and specificity of this method in detecting head and neck cancer were 70 and 42 per cent, respectively, whereas those of conventional imaging were 73 and 51 per cent, respectively.

CONCLUSION

Compared with magnetic resonance imaging, the benefits of positron emission tomography - computed tomography may be limited to diagnosis of recurrence, as it is less hindered by tissue fibrosis, radiotherapy-related oedema, scarring and inflammation.

Tumor markers in fine-needle aspiration washout for cervical lymphadenopathy in patients with known malignancy: preliminary study

OBJECTIVE

The purposes of our study were to assess whether tumor marker concentration in fine-needle aspiration (FNA) washout from cervical lymph nodes (LNs) differs between metastatic and nonmetastatic LNs and whether tumor marker concentrations in FNA washout can contribute to the diagnosis of metastatic LNs.

SUBJECTS AND METHODS

Ultrasound-guided FNA was performed for 157 neck nodes in 157 patients, including 136 patients with known malignancy (28 breast, 34 lung, 41 head and neck, seven esophagus, nine cervix, 10 gastrointestinal [GI] tract, and seven ovary cancers) and 21 patients without known malignancy (control group). Immediately after an FNA cytology specimen was obtained, the needle was rinsed with 1 mL of normal saline solution, and variable tumor marker concentrations were measured in the washout: carcinoembryonic antigen (CEA) and cancer antigen (CA) 15-3 for breast; CEA and cytokeratin 19 fragment for lung; squamous cell antigen for head and neck, esophagus, and cervix; CEA and CA 19-9 for GI; CA 125 for ovarian cancer; and all the tumor marker concentrations for the control group. The tumor marker concentration was compared between the metastatic and nonmetastatic LNs in the control group and between the metastatic and nonmetastatic LNs in the known malignancy group, according to the known malignancy.

RESULTS

At final diagnosis, 104 LNs were metastatic and 53 were nonmetastatic (including 21 LNs in the control group). The tumor marker concentrations of cases with negative or nondiagnostic cytologic results were evaluated. The sensitivity of FNA cytology alone was compared with the combined sensitivity of FNA cytology and tumor marker concentration. Metastatic LNs had higher corresponding FNA tumor marker concentrations than did nonmetastatic LNs in both the control and known malignancy groups (p < 0.05), except for CA 19-9 in GI cancer. Eight of 10 cases (80%) with negative or nondiagnostic cytologic results but metastatic LNs at final diagnosis showed elevated tumor marker concentrations. The sensitivity of FNA cytology (90.4%) increased to 98.1% when combined with tumor marker concentration (p < 0.05). Tumor marker concentrations in FNA washout with cervical metastatic LNs were elevated in comparison with those of nonmetastatic LNs.

CONCLUSION

Evaluation of tumor marker concentrations in FNA washout could improve the detection of metastatic LNs in patients with known malignancy.