Incremental (?) role of positron emission tomography/computed tomography in clinically unknown primary patients with neck metastasis

Diagnosis and Management of Squamous Cell Carcinoma of Unknown Primary in the Head and Neck: ASCO Guideline

PURPOSE

To provide evidence-based recommendations to practicing physicians and other health care providers on the diagnosis and management of squamous cell carcinoma of unknown primary in the head and neck (SCCUP).

METHODS

The American Society of Clinical Oncology convened an Expert Panel of medical oncology, surgery, radiation oncology, radiology, pathology, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2008 through 2019. Outcomes of interest included survival, local and regional disease control, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 100 relevant studies to inform the evidence base for this guideline. Four main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate pathology techniques, and adjuvant therapy.

RECOMMENDATIONS

Evidence-based recommendations were developed to address preoperative evaluation for patients with a neck mass, surgical diagnostic and therapeutic procedures, appropriate treatment options in unilateral versus bilateral SCCUP.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

A Nordic survey on the management of head and neck CUP

CONCLUSION

The management of Head and Neck Cancer of Unknown Primary (HNCUP) patients varies both between centres within and also between the Nordic countries. This study contributes to a continuing discussion of how to improve the accuracy of diagnosis and quality of treatment of HNCUP patients.

OBJECTIVES

The initiative for this study was based on the lack of common guidelines for diagnostic procedures and for treatment of HNCUP patients in the Nordic countries constituting a region having a rather homogeneous population.

METHOD

A structured questionnaire was sent to all university hospitals in the five Nordic countries.

RESULTS

Four of the five Nordic countries use either national guidelines or specific protocols when handling HNCUP. The main diagnostic tools are PET-CT, fine needle aspiration, endoscopic evaluation with biopsies, and most often bilateral tonsillectomy. At 21 of 22 university hospitals the treatment decision is made at a multidisciplinary conference. Three of seven Swedish centres use only radiotherapy or chemoradiotherapy to treat N+ HNCUP patients. Robotic surgery for biopsy of the tongue base is beginning to become an alternative to targeted biopsies in Sweden and Finland. Narrow Band Imaging is used only in Finland.

Role of 18-Fludeoxyglucose positron emission tomography-computed tomography and subsequent panendoscopy in head and neck squamous cell carcinoma of unknown primary

OBJECTIVES/HYPOTHESIS

Head and neck squamous cell carcinomas of unknown primary (HNSCCUP) accounts for up to 10% of presenting head and neck squamous cell carcinomas. Identification of the primary site allows for directed therapy. Where initial investigations have failed to locate the primary site, 18-fludeoxyglucose positron emission tomography-computed tomography (PET/CT) has emerged as a useful tool with improved sensitivity over positron emission tomography alone. Following PET/CT scan, the role of subsequent panendoscopy ± biopsy has not been fully assessed. We aim to evaluate and quantify the role of PET/CT and subsequent panendoscopy in HNSCCUP.

STUDY DESIGN

Retrospective cohort study.

METHODS

Patients with HNSCCUP presenting between January 2005 and December 2010 at a regional oncology referral center were studied. All patients who presented with a metastatic neck node and unknown primary who had undergone PET/CT prior to panendoscopy were included. The accuracy of PET/CT was calculated and compared with panendoscopy and histopathological findings.

RESULTS

Fifty-two patients were included. Twenty-seven PET/CT scans suggested a primary site. Calculated diagnostic parameters were 83% sensitivity, 87% specificity, positive predictive value 89%, and negative predictive value 80%. Three false-positive PET/CT scans were noted after panendoscopy and normal histology. Importantly, three confirmed tongue base tumors were found on panendoscopy, which were undetected on PET/CT.

CONCLUSIONS

PET/CT is a valuable resource for locating tumors in HNSCCUP. It helps direct biopsy and aids in the detection of local and distant metastases along with synchronous primary tumors. Importantly, due to both false-positive and false-negative PET/CT rates, panendoscopy and biopsy remains an essential adjunct investigation irrespective of PET/CT results.

LEVEL OF EVIDENCE

4 Laryngoscope, 126:1354-1358, 2016.

Use of PET in Head and Neck Cancers

Head and neck cancer imaging is especially necessary for staging. Computed tomography and magnetic resonance imaging are the techniques frequently used for this purpose. These methods are valuable for displaying detailed anatomical structures; however, they may be inadequate for making the distinction between recurrence, residual tumor, fibrosis, and normal tissues with an altered anatomy after treatments such as surgery, radiotherapy, and chemotherapy and for the detection of metastases. From this point, positron emission tomography may be a promising imaging method. Scanning the entire body with a single method is an important advantage of positron emission tomography. It may be useful in the detection of synchronous tumors, which are a serious problem in head and neck cancers. Positron emission tomography may provide additional contribution for neck metastases, where the primary site is unknown and is undetectable by other imaging techniques.