Positron emission tomography in surveillance of head and neck squamous cell carcinoma after definitive chemoradiotherapy

Post-treatment surveillance imaging in head and neck cancer: a systematic review

BACKGROUND

In patients treated for head and neck cancer, imaging studies are usually obtained within 3-6 months after treatment for assessment of treatment response. After 6 months, most guidelines advocate clinical follow-up, with imaging reserved for patients with clinically suspect or equivocal findings. However, some guidelines do recommend systematic imaging surveillance, and many clinicians tend to include some type of imaging in their follow-up schemes.

OBJECTIVES

This systematic review focuses on the usefulness of routine (systematic) post-treatment imaging surveillance of head and neck cancer beyond the first 3-6-month baseline imaging study.

METHODS

A systematic literature search was conducted using PubMed and Google Scholar. Additional studies were identified by reviewing reference lists. Only original studies and review papers were considered. Results obtained with systematic post-treatment surveillance imaging were compared to symptom-directed imaging and/or clinical finding-directed imaging.

RESULTS

Five hundred twenty-one records were identified through the database search, and 44 additional records were identified through other sources. Forty-eight articles were selected for the final review. Analysis of these records showed that almost half of cases of locoregional recurrences and/or metastases were only detected by imaging (40.9%), and the mean time of detection of recurrent or metastatic disease (11.5 months) was well beyond the period of the first post-treatment scan. Most authors reported superior results with PET-CT when compared to other imaging techniques.

CONCLUSION

Strong arguments were found in favor of systematic imaging surveillance in locoregional advanced head and neck cancer during at least one and preferably 2 years after treatment.

CRITICAL RELEVANCE STATEMENT

Analysis of the selected records showed that almost half of cases of locoregional recurrences and/or metastases were only detected by imaging. This systematic review suggests that imaging may currently be underused in the post-treatment surveillance of patients with head and neck cancer.

KEY POINTS

• This systematic review focuses on the usefulness of long-term systematic imaging surveillance in patients treated for head and neck cancer. • Analysis of 521 articles revealed that systematic imaging allowed the initial detection of locoregional recurrences and/or metastases in more than 40% of patients. • Imaging may currently be underused in the post-treatment surveillance of patients with advanced head and neck cancer.

Surgical site complications of isolated salvage neck dissection post-radiotherapy and post-chemoradiotherapy - A cohort analysis (1997-2017)

INTRODUCTION

This study aims to quantify surgical site complications (SSC) after isolated salvage neck dissection (ND) compared with primary ND.

PATIENTS AND METHODS

Between 1997 and 2017 in the Netherlands Cancer Institute - Antoni van Leeuwenhoek, a total of 323 isolated NDs were performed in 308 patients: primary ND (n = 144), post-radiotherapy (RT) ND (n = 53) and post-chemoradiotherapy (CRT) ND (n = 126). Patient, tumor and therapy characteristics were recorded. SSCs were scored according to the Clavien-Dindo Classification (CDC).

RESULTS

101 NDs (31%) were complicated by at least one SSC. In total, 189 different SSCs occurred. Translated to CDC, 45 complications were grade 2, 25 grade 3a and 31 grade 3b. No significant difference in occurrence of SSC (CDC >1) was found between all groups. However, post-CRT, selective (SND) and modified radical ND and radical ND (MRND/RND) (p = 0.005), resection of sternocleidomastoid muscle (SCM) (p = 0.039) and duration of super selective ND surgery (p = 0.048) were significantly associated with more SSC. SCM muscle removal was associated with more surgical site infection (p = 0.045) and necrosis (p = 0.036). From week 10 post-RT/CRT, no difference in complication frequency with primary ND was seen.

CONCLUSION

Post-CRT SND, MRND/RND and SCM muscle resection were associated with an increased incidence of SSCs. If oncologically possible, limit the extent of ND and when an MRND is inevitable, preserve the SCM muscle for optimal prevention of SSC. Concerning SSC, optimal timing of salvage ND is minimal 10 weeks after RT/CRT.

AHNS series: Do you know your guidelines? Guideline recommendations for recurrent and persistent head and neck cancer after primary treatment

Locoregional recurrent/persistent head and neck cancer following primary treatment is a significant challenge as it is usually difficult to treat and has worse outcomes compared to the primary setting. Surgical resection of a local or regional recurrence offers the best chance of cure when feasible. Local recurrence outcomes vary by subsite with laryngeal recurrences having the best prognoses and hypopharynx having the worst. Instances of persistent neck masses following primary nonsurgical treatment can be evaluated with positron emission tomography (PET) with CT (PET-CT) when there is no definitive diagnosis of a recurrence/persistence. Reirradiation with or without chemotherapy can be considered for primary treatment when surgery is not an option, for adjuvant treatment following salvage surgery, or for palliation. Immunotherapy represents a newer class of chemotherapeutic agents. Current guidelines recommend enrollment in clinical trials especially when surgery is not an option as outcomes remain universally poor in the recurrent/persistent setting.

Optimal timing for salvage surgery after definitive radiotherapy in hypopharyngeal cancer

Purpose

Use of radiotherapy combined with chemotherapy is increasing in hypopharyngeal cancer. However, many show residual tumor after radiotherapy. Timing for treatment evaluation and salvage therapy is essential. However, optimal timing for salvage surgery has not been suggested. In this study, we tried to evaluate optimal timing for salvage surgery.

Methods and Materials

Patients who were diagnosed with hypopharyngeal squamous cell carcinoma between 2006 and 2015 were retrospectively analyzed. All patients received definitive radiotherapy with or without chemotherapy. Response of all treated patients were analyzed at 1, 3, and 6 months after radiotherapy. Any patients with progression before 6 months were excluded.

Results

A total of 54 patients were analyzed. Complete remission (CR) rates at 1 month (CR₁), 3 months (CR₃) and 6 months (CR₆) were 66.7%, 81.5%, and 90.7%, respectively. Non-CR at 1 month (NCR₁), 3 months (NCR₃), and 6 months (NCR₆) showed poor locoregional recurrence-free survival rates (1-year rates of 63.7%, 66.7%, and 0.0%, respectively) compared to CR₁, CR₃, and CR₆ (1-year rates 94.3%, 88.0%, and 91.5%, respectively). Particularly significant differences were seen between CR₆ and NCR₆ (p < 0.001). Of 10 patients with NCR₃, 5 showed CR at 6 months (NCR₃/CR₆). There was no statistical difference in locoregional recurrence-free survival between CR₃ and NCR₃/CR₆ group (p = 0.990).

Conclusion

Our data suggest half of patients who did not show CR at 3 months eventually achieved CR at 6 months. Waiting until 6 months after radiotherapy may be appropriate for avoiding additional salvage therapy.

[PET-CT in head and neck cancer]

The importance of ¹⁸F-fluorodesoxyglucose positron-emission tomography (FDG-PET) for the diagnosis of malignant disease is increasing. On one hand, this is due to the high sensitivity of this method, on the other, because the entire body can be examined. FDG-PET can be particularly advantageous for the diagnosis of head and neck tumors, where tumor staging is an important prognostic parameter and essentially determines the therapeutic regimen. This article presents the different possibilities for combined evaluation with PET and computed tomography (CT) for the diagnosis of patients with head and neck cancer. Special focus is placed on primary staging and tumor follow-up, as well as on the role of PET-CT in the diagnosis of patients with cancer of unknown primary origin (CUP). The use of PET-CT for radiotherapy planning and new aspects of PET technology are also discussed.

Role of fluorine-18 fluorodeoxyglucose PET/CT in head and neck oncology: the point of view of the radiation oncologist

Squamous cell carcinoma is the most common malignant tumour of the head and neck. The initial TNM staging, the evaluation of the tumour response during treatment, and the long-term surveillance are crucial moments in the approach to head and neck squamous cell carcinoma (HNSCC). Thus, at each of these moments, the choice of the best diagnostic tool providing the more precise and larger information is crucial. Positron emission tomography with fluorine-18 fludeoxyglucose integrated with CT (¹⁸F-FDG-PET/CT) rapidly gained clinical acceptance, and it has become an important imaging tool in routine clinical oncology. However, controversial data are currently available, for example, on the role of ¹⁸F-FDG-PET/CT imaging during radiotherapy planning, the prognostic value or its real clinical impact on treatment decisions. In this article, the role of ¹⁸F-FDG-PET/CT imaging in HNSCC during pre-treatment staging, radiotherapy planning, treatment response assessment, prognosis and follow-up is reviewed focusing on current evidence and controversial issues. A proposal on how to integrate ¹⁸F-FDG-PET/CT in daily clinical practice is also described.

Detecting Residual/Recurrent Head Neck Squamous Cell Carcinomas Using PET or PET/CT: Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the diagnostic accuracy of positron emission tomography (PET) and PET/computed tomography (CT) for detecting residual and/or recurrent local and regional disease and distant metastases in patients with head and neck squamous cell carcinomas (HNSCCs) following radiotherapy with or without chemotherapy.

DATA SOURCES

A systematic review with no language restrictions was conducted using PREMEDLINE, MEDLINE, EMBASE, and Google Scholar.

REVIEW METHODS

Only prospective studies with histopathological and/or clinical follow-up that assessed the diagnostic accuracy of PET and PET/CT in detecting residual and/or recurrent disease following radiotherapy with or without chemotherapy in patients with HNSCCs were included.

RESULTS

Twenty-seven studies were identified. The pooled sensitivity and specificity of PET and PET/CT for detecting residual or recurrent disease at the primary site was 86.2% and 82.3%, respectively. For residual and recurrent neck disease, the sensitivity and specificity were 72.3% and 88.3%, while for distant metastases, the values were 84.6% and 94.9%.

CONCLUSIONS

PET and PET/CT are highly accurate in detecting residual and/or recurrent HNSCC. PET/CT is more specific than PET alone. Specificity is also greater for scans performed more than 12 weeks after radiotherapy with or without chemotherapy. The authors support the use of PET/CT after 12 weeks posttreatment for the assessment of residual or recurrent disease.

Early detection of recurrent disease by FDG-PET/CT leads to management changes in patients with squamous cell cancer of the head and neck

OBJECTIVE

The objective of this study was to compare the efficacy of surveillance high-resolution computed tomography (HRCT) and physical examination/endoscopy (PE/E) with the efficacy of fluorodeoxyglucose (FDG)-positron emission tomography (PET)/HRCT for the detection of relapse in head and neck squamous cell carcinoma (HNSCC) after primary treatment.

METHODS

This is a retrospective analysis of contemporaneously performed FDG-PET/HRCT, neck HRCT, and PE/E in 99 curatively treated patients with HNSCC during post-therapy surveillance to compare performance test characteristics in the detection of early recurrence or second primary cancer.

RESULTS

Relapse occurred in 19 of 99 patients (20%) during a median follow-up of 21 months (range: 9-52 months). Median time to first PET/HRCT was 3.5 months. The median time to radiological recurrence was 6 months (range: 2.3-32 months). FDG-PET/HRCT detected more disease recurrences or second primary cancers and did so earlier than HRCT or PE/E. The sensitivity, specificity, and positive and negative predictive values for detecting locoregional and distant recurrence or second primary cancer were 100%, 87.3%, 56.5%, and 100%, respectively, for PET/HRCT versus 61.5%, 94.9%, 66.7%, and 93.8%, respectively, for HRCT versus 23.1%, 98.7%, 75%, and 88.6%, respectively, for PE/E. In 19 patients with true positive PET/HRCT findings, a significant change in the management of disease occurred, prompting either salvage or systemic therapy. Of the 14 curatively treated patients, 11 were alive with without disease at a median follow-up of 31.5 months.

CONCLUSION

FDG-PET/HRCT has a high sensitivity in the early detection of relapse or second primary cancer in patients with HNSCC, with significant management implications. Given improvements in therapy and changes in HNSCC biology, appropriate modifications in current post-therapy surveillance may be required to determine effective salvage or definitive therapies.

Evidence-based guideline recommendations on the use of positron emission tomography imaging in head and neck cancer

AIMS

To provide evidence-based practice guideline recommendations on the use of fluoro-2-deoxy-D-glucose positron emission tomography (PET) for diagnosis, staging and assessing treatment response, restaging or recurrence of head and neck cancer.

MATERIALS AND METHODS

A systematic review by Facey et al. (Health Technology Assessment 2007;11(44):iii-iv, xi-267) was used as the evidence base for recommendation development. As the review was limited to August 2005, the evidence base was updated to July 2011 using the same search strategies for MEDLINE and EMBASE used in the original review. The authors of the current systematic review drafted recommendations, which were reviewed, adapted and accepted by consensus by the Ontario provincial Head and Neck Disease Site Group and a special meeting of clinical experts.

RESULTS

The results of the Facey et al. review for head and neck cancer included five other systematic reviews and 31 primary studies. The 2005 to 2011 update search included four additional systematic reviews and 53 primary studies. Recommendations were developed based on this evidence and accepted by consensus.

CONCLUSIONS

PET is recommended in the M and bilateral nodal staging of all patients with head and neck squamous cell carcinoma where conventional imaging is equivocal, or where treatment may be significantly modified. PET is recommended in all patients after conventional imaging and in addition to, or prior to, diagnostic panendoscopy where the primary site is unknown. PET is recommended for the staging and assessment of recurrence of patients with nasopharyngeal carcinoma if conventional imaging is equivocal. PET is recommended for restaging patients who are being considered for major salvage treatment, including neck dissection.

Aggressive inflammatory and neoplastic processes of the paranasal sinuses

Although uncommon, sinonasal malignancies and aggressive inflammatory processes are entities every radiologist will encounter during the evaluation of routine sinus imaging studies. A high index of suspicion is necessary for prompt diagnosis. It is important to consider aggressive inflammatory disease in all patients having routine sinus computed tomography because any delay in diagnosis can adversely affect the patients' care. Magnetic resonance (MR) will often provide a better assessment of the lesion extent, allowing for better surgical treatment. MR is crucial for the accurate assessment of neoplastic lesions. A proficient understanding of the complex anatomy of the region is essential.

Diagnostic performance of post-treatment FDG PET or FDG PET/CT imaging in head and neck cancer: a systematic review and meta-analysis

PURPOSE

Our objective was to conduct a systematic review and meta-analysis of studies assessing the diagnostic performance of (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) with or without computed tomography (CT) in post-treatment response assessment and/or surveillance imaging of head and neck squamous cell carcinoma (HNSCC).

METHODS

A systematic search of the indexed medical literature was done using appropriate keywords to identify relevant studies. Metrics of diagnostic test accuracy, viz. sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were extracted from individual studies and combined using a random effects model to yield weighted mean pooled estimates with 95% confidence intervals (95% CI). The impact of timing of post-treatment scan, study quality and advancements in PET technology was explored through meta-regression.

RESULTS

A total of 51 studies involving 2,335 patients were included in the meta-analysis. The weighted mean (95% CI) pooled sensitivity, specificity, PPV and NPV of post-treatment FDG PET(CT) for the primary site was 79.9% (73.7-85.2%), 87.5% (85.2-89.5%), 58.6% (52.6-64.5%) and 95.1% (93.5-96.5%), respectively. Similar estimates for the neck were 72.7% (66.6-78.2%), 87.6% (85.7-89.3%), 52.1% (46.6-57.6%) and 94.5% (93.1-95.7%), respectively. Scans done ≥ 12 weeks after completion of definitive therapy had moderately higher diagnostic accuracy on meta-regression analysis using time as a covariate.

CONCLUSION

The overall diagnostic performance of post-treatment FDG PET(CT) for response assessment and surveillance imaging of HNSCC is good, but its PPV is somewhat suboptimal. Its NPV remains exceptionally high and a negative post-treatment scan is highly suggestive of absence of viable disease that can guide therapeutic decision-making. Timing of post-treatment imaging has a significant, though moderate impact on diagnostic accuracy.

The value of (18)F-FDG PET/CT for the detection of distant metastases in high-risk patients with head and neck squamous cell carcinoma

The aims of this study were to assess a cohort of patients with head and neck squamous cell carcinoma (HNSCC) for: (1) the prevalence of synchronous distant metastases (DM) as detected by the initial staging by using (18)F-FDG PET/CT, (2) the prevalence of metachronous DM, and (3) the validity of published risk factors with special emphasis on the maximum standardized uptake value (SUV max) for the prediction of DM. Two hundred and ninety nine patients with advanced HNSCC were included. Following risk factors at the time of diagnosis and during follow-up were analyzed: advanced T/N stage, poor histological differentiation, level IV/Vb lymph nodes, primary site in the larynx/hypopharynx, and SUV max. The prevalence of DM at initial staging and during follow-up was 10% and 11%, respectively. At initial staging, primary site in the larynx/hypopharynx and neck nodes in level IV/Vb, and during follow-up only level IV/Vb nodes achieved statistical significance. The sensitivity for (18)F-FDG PET/CT with regard to the detection of DM was 96.8%, the specificity 95.4%, the positive predictive value (PV) 69.8%, and the negative PV 99.6%. Patients without DM showed a significantly better overall survival (OS) than patients developing DM (p<0.001). There was no significant difference in OS with regard to the time of diagnosis of DM. The prevalence for synchronous and metachronous DM in advanced HNSCC is considerable. (18)F-FDG PET/CT is highly accurate for initial staging and follow-up. DM carries a bad prognosis regardless of the time of diagnosis.

Utilizing computed tomography as a road map for designing selective and superselective neck dissection after chemoradiotherapy

OBJECTIVE

To determine whether computed tomography can distinguish low risk neck levels that can be omitted when neck dissection is undertaken after chemoradiotherapy.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

Head and neck squamous cell carcinoma patients undergoing neck dissection after chemoradiotherapy between January 1998 and June 2008. We compared computed tomography findings after chemoradiotherapy with neck dissection pathology results; used primary location and computed tomography findings to design selective or superselective neck dissection; and determined whether these surgeries would have contained all metastatic disease.

RESULTS

A total of 104 patients were identified, providing 110 heminecks, 531 neck levels, and 3009 lymph nodes for analysis. Neck dissections were positive in 20 (19%) of 104 patients, corresponding to 20 hemineck dissections, 31 neck levels, and 53 lymph nodes. The negative predictive value for computed tomography was 95 percent. The negative predictive value for computed tomography per neck level was as follows: I, 100 percent; II, 96 percent; III, 96 percent; IV, 97 percent; and V, 96 percent. A selective neck dissection or a superselective neck dissection, guided by level specific computed tomography findings and limited to necks with post treatment partial response in one level, would have captured all disease in 52 (95%) of 55 and 51 (93%) of 55 heminecks.

CONCLUSION

Negative computed tomography accurately predicts pathologic complete response at neck dissection. Neck dissection can be avoided in these patients. Additionally, computed tomography reliably identifies low risk neck levels that do not require dissection, permitting selective neck dissection or superselective neck dissection in partial response patients with limited residual disease.

Neck dissection after chemoradiation for carcinoma of the upper aerodigestive tract: indications and complications

PURPOSE OF REVIEW

Chemoradiation has become a common approach in the treatment of advanced head and neck cancer. Its effectiveness in eradicating associated nodal metastases has resulted in modifications in the traditional paradigms for managing this aspect.

RECENT FINDINGS

Regardless of the pretreatment neck staging, patients who have a complete response to chemoradiation are unlikely to have residual viable tumor in this region, thus putting in question the need for planned neck dissection. F-Fluorodeoxyglucose positron emission tomography/computed tomography has become a standard tool to assess disease response to chemoradiotherapy, including the associated nodal disease. However, there remains an ongoing debate about its timing. The extent of neck dissection is trending toward an approach for selective procedures in order to minimize the long-term sequelae of extensive neck fibrosis.

SUMMARY

Post-chemoradiotherapy neck dissection is an effective procedure for selected patients with advanced head and neck cancer but is becoming a less needed intervention.

Clinical Applications of FDG PET and PET/CT in Head and Neck Cancer

18F-FDG PET plays an increasing role in diagnosis and management planning of head and neck cancer. Hybrid PET/CT has promoted the field of molecular imaging in head and neck cancer. This modality is particular relevant in the head and neck region, given the complex anatomy and variable physiologic FDG uptake patterns. The vast majority of 18F-FDG PET and PET/CT applications in head and neck cancer related to head and neck squamous cell carcinoma. Clinical applications of 18F-FDG PET and PET/CT in head and neck cancer include diagnosis of distant metastases, identification of synchronous 2nd primaries, detection of carcinoma of unknown primary and detection of residual or recurrent disease. Emerging applications are precise delineation of the tumor volume for radiation treatment planning, monitoring treatment, and providing prognostic information. The clinical role of 18F-FDG PET/CT in N0 disease is limited which is in line with findings of other imaging modalities. MRI is usually used for T staging with an intense discussion concerning the preferable imaging modality for regional lymph node staging as PET/CT, MRI, and multi-slice spiral CT are all improving rapidly. Is this review, we summarize recent literature on 18F-FDG PET and PET/CT imaging of head and neck cancer.