The real additional value of FDG-PET in detecting the occult primary tumour in patients with cervical lymph node metastases of unknown primary tumour

Tumor control of cervical lymph node metastases of unknown primary origin: the impact of the radiotherapy target volume

PURPOSE

Debate on the extent of treatment of neck metastasis of cancer of unknown primary tumors (CUPs) is still ongoing. In two Dutch tertiary referral centers, the post-surgical radiation target volume changed from the bilateral neck including the pharyngeal axis to the unilateral neck only, in the course of the last decade. This study aims to investigate the outcome of patients with CUP before and after de-escalation of post-surgical radiotherapy.

METHODS

Data of two Dutch tertiary referral centers were merged. Disease-free survival (DFS), overall survival (OS), and regional control rate (RCR) of 80 patients diagnosed with CUP (squamous cell and undifferentiated carcinomas) between 1990 and 2009 were retrospectively analyzed.

RESULTS

Thirty patients received bilateral neck and pharyngeal axis radiotherapy and 42 patients ipsilateral radiotherapy only. In another eight patients, the postsurgical radiation target volume was expanded to the contralateral neck or to the pharyngeal axis, due to suspicious lesions on imaging. The 5-year DFS, OS and RCR were 60%, 51.2%, and 80%, respectively, in the total patient population. RCR did not differ in patients treated with ipsilateral as compared to bilateral radiotherapy nor did 5-year OS and DFS. No tumors occurred in the pharyngeal axis.

CONCLUSION

In this study, omitting elective treatment of the contralateral neck and pharyngeal axis did not lead to a decrease in locoregional control or survival rates when treating patients with CUP.

The impact of the patient's condition, diagnostic procedures and treatment on the survival of carcinoma of unknown primary site patients

Introduction

Carcinoma of unknown primary site (CUP) refers to 1–5% of all head and neck neoplasms. Very often, the primary site remains difficult to determine. Squamous cell carcinoma is the most frequent histopathological type diagnosed in the head and neck region. According to statistics, a primary site is usually located in the oropharynx.

Study objective

The study presents diagnostic difficulties and the methods of diagnosing and the therapy of CUP and primary sites in patients treated in the region of Lower Silesia and Silesia. The aim of the study was to show a retrospective analysis of 233 CUP patients to assess how clinical features, diagnosis and treatment affect the survival of patients.

Material and methods

The diagnostics of patients included panendoscopy with specimen collection (nasoendoscopy, laryngoscopy, esophagoscopy, brochoscopy), computed tomography examination of the neck, chest, abdomen and pelvis minor, as well as positron emission tomography examination. Tonsilletomy was performed in 37 patients. Neck dissection was carried out in 109 subjects and 165 patients were treated bt radiotherapy, and 135 by chemotherapy.

Conclusions

Tonsillectomy is required in CUP patients with the negative results of biopsy and imaging tests. It gives a possibility of detecting the primary site and improves the results of treatment and survival of CUP patients.Combination therapy, including surgical treatment and chemoradiotherapy, gives the best therapeutic results in CUP patients. The general condition of patient and younger age have an impact on prognosis and survival.

Head and neck carcinoma of unknown primary

In adult cervicofacial pathology, carcinoma of unknown primary is defined as lymph-node metastasis the anatomic origin of which is not known at the time of initial management. It constitutes up to 5% of head and neck cancers. Presentation may suggest benign pathology, delaying and confusing oncologic treatment. Diagnostic strategy in cervical lymph node with suspicion of neoplasia requires exhaustive work-up to diagnose malignancy and, in 45% to 80% of cases, depending on the series, to identify the primary site. Histologic types comprise squamous cell carcinoma, thyroid carcinoma, adenocarcinoma, neuroendocrine carcinoma and undifferentiated carcinoma. Association is sometimes found with human papilloma virus or Epstein Barr virus, guiding treatment. The objective of the present study was to provide clinicians with the necessary diagnostic tools, based on the current state of clinical, imaging and pathologic knowledge, and to detail treatment options.

Diagnostic and treatment modalities for patients with cervical lymph node metastases of unknown primary site - current status and challenges

Background and Purpose

This review aims to provide a comprehensive overview of the literature and elucidate open questions for future clinical trials concerning diagnostics and treatment modalities for cervical cancer of unknown primary (CUP).

Methods

A literature search for head and neck CUP was performed with focus on diagnostics and therapies as well as molecular markers.

Results

High level evidence on CUP is limited. However, it seems that a consensus exists regarding the optimal diagnostic procedures. The correct implementation of biomarkers for patient stratification and treatment remains unclear. An even greater dispute dominates about the ideal treatment with publications ranging from sole surgery to surgery with postoperative bilateral radiotherapy with inclusion of the mucosa and concomitant chemotherapy.

Conclusions

Cervical CUP represents a very heterogeneous malignant disease. On this account many aspects concerning treatment optimization remain unclear, despite a considerable number of publications in the past. Future research in form of prospective randomized trials is needed in order to better define patient stratification criteria and enable tailored treatment.

Extensive Regional Metastasis of High-Grade Mucoepidermoid Carcinoma of an Unknown Primary Tumor

PURPOSE

Mucoepidermoid carcinoma (MEC) is the most common salivary carcinoma. It arises most frequently in the major salivary glands, but can also arise in minor glands or intraosseous sites. MEC of an unknown primary occurs very rarely. The present report documents only the third case reported in medical studies.

METHODS

A 66-year-old man with previous carcinoma in situ (CIS) of the left posterior oral tongue that had been excised in 2004 and again in 2010 presented with a hard lymph node, 3 × 2 cm at level II of the right neck in July 2015. Positron emission tomography-computed tomography (PET-CT) revealed multiple, bilateral cervical lymphadenopathy, with no primary site identified. Fine needle aspiration biopsy and cytologic examination from the right neck was positive for malignancy, suggestive of metastatic squamous cell carcinoma. Panendoscopy and biopsy revealed CIS at the tongue bases and tonsils bilaterally (p16-negative). The patient's case was presented to a tumor board, and definitive concurrent cispl.atin-based chemoradiation was recommended for TisN2cM0, stage IVA oropharyngeal CIS, which was completed in November 2015. PET-CT in January 2015 showed complex interval changes, with some areas demonstrating improvement (ie, no uptake in the left neck) and worsening in others (ie, increased metabolic activity in the right neck), suggestive of residual disease. Repeat PET-CT in March 2016 showed increased nodal involvement and increasing standardized uptake value. Bilateral modified radical neck dissection was undertaken, and histologic examination showed high-grade MEC in 51 of 61 lymph nodes with extracapsular spread and soft tissue involvement.

RESULTS

The patient died in May 2016 at 2 months after surgery.

CONCLUSIONS

Metastatic MEC of an unknown primary is a diagnostic challenge. PET-CT might not be the most reliable diagnostic investigation to identify the primary or metastatic foci, such as was demonstrated in the present case.

Neck lymph node metastases from unknown primary

Metastatic cervical carcinoma from unknown primary is a metastatic disease in the lymph nodes of the neck without any evidence of a primary tumour after appropriate investigation. The condition is rare and definite evidence is lacking for both diagnosis and treatment. In this review of the literature, we tried to draw some clinical indications based on the few available studies. We ultimately came to the following conclusions: (1) a thorough and accurate diagnostic work-up should be systematically offered. It includes accurate inspection with fibroscopy, CT or MRI, fine needle aspiration, panendoscopy and positron emission tomography, (2) Patients with low-volume neck disease, N1 and N2a stage and without extracapsular extension on histopathological examination should receive single modality treatment. Radiotherapy and surgery may be similarly effective but, if possible, surgery (excisional biopsy, neck dissection and tonsillectomy) should be favoured because it consents a more precise staging, (3) patients with more advanced conditions require combined treatment in the form of either resection followed by adjuvant radiation (±chemotherapy) or primary chemoradiation (±post-therapy neck dissection).

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.

The role of PET-CT in radiotherapy planning of solid tumours

BACKGROUND

PET-CT is becoming more and more important in various aspects of oncology. Until recently it was used mainly as part of diagnostic procedures and for evaluation of treatment results. With development of personalized radiotherapy, volumetric and radiobiological characteristics of individual tumour have become integrated in the multistep radiotherapy (RT) planning process. Standard anatomical imaging used to select and delineate RT target volumes can be enriched by the information on tumour biology gained by PET-CT. In this review we explore the current and possible future role of PET-CT in radiotherapy treatment planning. After general explanation, we assess its role in radiotherapy of those solid tumours for which PET-CT is being used most.

CONCLUSIONS

In the nearby future PET-CT will be an integral part of the most radiotherapy treatment planning procedures in an every-day clinical practice. Apart from a clear role in radiation planning of lung cancer, with forthcoming clinical trials, we will get more evidence of the optimal use of PET-CT in radiotherapy planning of other solid tumours.

[Importance of nuclear medicine diagnostics in CUP syndrome]

CLINICAL/METHODICAL ISSUE

The diagnostic work-up in patients with carcinoma of unknown primary (CUP) syndrome is extensive, highly time-consuming and cost-intensive and ultimately often fails to detect a primary site.

STANDARD RADIOLOGICAL METHODS

In this context chest X-ray and computed tomography (CT) have been used as standard imaging modalities in CUP syndrome.

METHODOLOGICAL INNOVATIONS

Since the introduction of positron emission tomography (PET) evaluation of tumor vitality has become possible. Furthermore, PET-CT hybrid scanners allow the combination of functional and morphological imaging.

PERFORMANCE

Several meta-analyses have reported an additional overall detection rate between 24.5 % and 44 % by either PET or PET-CT. Metastatic localization (cervical versus extracervical) did not influence the performance. The sensitivity was usually high (> 80 %) but specificity was moderate ranging from 68 % to 88 % at best. If mentioned, the results obtained by fluorodeoxyglucose (FDG)-PET significantly changed the clinical management in approximately one third of the patients studied. In a direct comparison with PET alone, PET-CT did not depict significantly more primary tumors but was able to reduce false positive findings.

ACHIEVEMENTS

To determine the real additional value of PET-CT in the diagnosis of CUP syndrome large prospective studies with more uniform inclusion criteria are needed. Despite the capabilities of FDG-PET-CT there is as yet no evidence that a potentially improved diagnostic algorithm is translated into a better patient outcome.

PRACTICAL RECOMMENDATIONS

Nevertheless, FDG-PET-CT should be performed in all CUP patients where conventional imaging failed to detect a primary site or the results are equivocal. In CUP patients with cervical lymph node metastases PET-CT should be carried out prior to panendoscopy to reduce the number of false negative biopsies.

Submucosal small-cell neuroendocrine carcinoma of the larynx detected using 18F-fluorodeoxyglucose positron emission tomography/computed tomography: A case report and review of the literature

A 67-year-old male presented with a metastatic carcinoma in the right side of the neck from an unknown primary site. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography showed increased ¹⁸F-FDG uptake in the right larynx and right neck lymph nodes. A smooth lesion was identified in the submucosa of the right supraglottic region via a suspension laryngoscopy under general anaesthesia. A biopsy was performed and a frozen section revealed a small-cell (SC) carcinoma. A total laryngectomy and bilateral neck dissection were performed simultaneously, and the pathological results demonstrated a SC neuroendocrine carcinoma. The patient received chemo-radiotherapy postoperatively, however, succumbed due to distant metastasis one year following surgery.

18F-fluorodeoxyglucose positron emission tomography-computed tomography as a diagnostic tool in patients with cervical nodal metastases of unknown primary site: a meta-analysis

BACKGROUND

We performed a meta-analysis to evaluate the value of (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)FDG PET-CT) for the detection of primary sites in patients with cervical nodal metastases of unknown origin.

METHODS

Studies were systematically searched for relevant PET-CT original articles in the MEDLINE and EMBASE databases. We calculated the primary tumor detection rate, sensitivity, specificity, and likelihood ratios for (18)FDG PET-CT. We also constructed the hierarchic summary receiver operating characteristic curve for (18)FDG PET-CT.

RESULTS

This present study analyzed a total of 7 selected studies (246 patients). The primary tumor detection rate, sensitivity and specificity of PET-CT were 0.44 (95% confidence interval [CI] = 0.31-0.58), 0.97 (95% CI = 0.63-0.99), and 0.68 (95% CI = 0.49-0.83). Area under the curve was 0.83 (95% CI = 0.80-0.86).

CONCLUSIONS

(18)FDG PET-CT has high sensitivity and low specificity for the detection of primary sites in patients with cervical nodal metastases of unknown origin.

CUP-syndrome diagnostic procedure scheme

Patients with CUP-Syndrome represent a small percentage of patients treated by ENT doctor. Often, in spite of the implementation detailed diagnostics, detection of the primary tumor fails. Very important element is to follow the correct sequence of tests and taking into account conditions outside ENT. I our article, we would like to propose a diagnostic scheme including interview with patient, laryngological and imaging tests and multi-disciplinary consulting. We hope that this scheme will facilitate the treatment of patients with CUP-Syndrome and increase the efficiency of detection of primary tumor.

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography as an effective diagnostic workup in cervical metastasis of carcinoma from an unknown primary tumor

PURPOSE

The purpose of this study is to assess the potential of ¹⁸F-fluorodeoxyglucose (¹⁸FDG) positron emission tomography/computed tomography (PET/CT) imaging for the diagnosis of cervical metastasis of carcinoma of an unknown primary tumor (CUP) and to determine whether the maximum standardized uptake value (SUV(max)) is a prognostic factor.

METHODS

Twenty-five consecutive patients with cervical metastasis of CUP were retrospectively analyzed by PET/CT between July 2007 and July 2011.

RESULTS

FDG PET/CT suggested a primary tumor in 21 out of 25 patients (84.0%). The sensitivity of FDG PET/CT in detecting the primary tumor was 73.3% (11 of 15), and the positive predictive value was 52.4% (11 of 21). The median follow-up duration of survival patients was 10.4 months (range: 0-30 months). The estimated 2-year overall survival rate of all patients was 50.0%. Univariate analyses did not reveal a significant difference in overall survival between the group of 11 patients identified by pathology and the 14 patients not identified by pathology (overall survival was 57.1% and 49.1%, respectively; p=0.468). The median SUV(max) was 7.6. In the log-rank test, patients with a low SUV(max) (≤ 7.0) in cervical lymph nodes had a significantly higher survival rate at 2 years (87.5% vs. 21.2%; p=0.007) than patients with a high SUV(max) (>7.0).

CONCLUSIONS

Although our study was inconclusive due to the small sample size, our results suggest that FDG PET/CT may be an effective diagnostic workup in the cervical metastasis of carcinoma from an unknown primary tumor (UPT). In the present study, SUV(max) of PET/CT in the cervical lymph node may serve as a prognostic factor of cervical metastasis of carcinoma from a UPT based on the limited number of patients. Further studies are needed to confirm these findings.

Contemporary management of lymph node metastases from an unknown primary to the neck: I. A review of diagnostic approaches

In an era of advanced diagnostics, metastasis to cervical lymph nodes from an occult primary tumor is a rare clinical entity and accounts for approximately 3% of head and neck malignancies. Histologically, two thirds of cases are squamous cell carcinomas (SCCs), with other tissue types less common in the neck. With modern imaging and tissue examinations, a primary tumor initially undetected on physical examination is revealed in >50% of patients and the site of the index primary can be predicted with a high level of probability. In the present review, the range and limitations of diagnostic procedures are summarized and the optimal diagnostic workup is proposed. Initial preferred diagnostic procedures are a fine-needle aspiration biopsy (FNAB) and imaging. This allows directed surgical biopsy (such as tonsillectomy), based on the preliminary findings, and prevents misinterpretation of postsurgical images. When no primary lesion is suggested after imaging and panendoscopy, and for patients without a history of smoking and alcohol abuse, molecular profiling of an FNAB sample for human papillomavirus (HPV) and/or Epstein-Barr virus (EBV) is important.

[Usefulness of 18F-FDG PET/CT examination in the diagnosis of head and neck cancer--preliminary results]

OBJECTIVES

The aim of the study was to determine the usefulness of 18-FFDG PET/CT in oncological diagnostics in laryngology.

MATERIAL AND METHODS

45 PET/CT examinations were performed in 41 patients diagnosed with head and neck cancer in Department of Otolaryngology and Nuclear Medicine Department WUM from 2008 to 2011. In 3 patients PET/CT study was conducted several times.

RESULTS

In 18 patients the result of PET/CT examination was negative, in 27 – positive. Based on PET/CT imaging the recurrent disease was diagnosed in 9 patients, cervical lymph node metastases – in 12 patients, distant metastases – in 6 patients, possible primary tumour localization – in 3 patients. In 7 cases additional foci of increased FDG uptake were revealed outside the head and neck. Among 22 contrast enhanced CT scans performed earlier, in 18 cases results were confirmed. In 2 cases there was no increased FDG concentration in lesions considered suspicious due to CT, in 2 patients increased focal FDG uptake was observed despite no changes in CT scans. The mean SUVmax value in all the lesions in head and neck region was 3.0; for examinations revealing recurrent disease, nodal or distant metastases mean SUVmax was 7.9.

CONCLUSIONS

18F-FDG PET/CT is a useful diagnostic tool for staging of head and neck cancer, identifying residual and recurrent disease and detecting the occult primary tumour. It also allows the visualization of other lesions suspected for malignancy, localized outside the head and neck region.