External ultrasonography of the neck does not add diagnostic value to integrated positron emission tomography-computed tomography (PET-CT) scanning in the diagnosis of cervical lymph node metastases in patients with esophageal carcinoma

Abstract

One of the objectives of preoperative imaging in esophageal cancer patients is the detection of cervical lymph node metastases. Traditionally, external ultrasonography of the neck has been combined with computed tomography (CT) in order to improve the detection of cervical metastases. In general, integrated positron emission tomography-computed tomography (PET-CT) has been shown to be superior to CT or PET regarding staging and therefore may limit the role of external ultrasonography of the neck. The objective of this study was to determine the additional value of external ultrasonography of the neck to PET-CT. This study included all patients referred our center for treatment of esophageal carcinoma. Diagnostic staging was performed to determine treatment plan. Cervical lymph nodes were evaluated by external ultrasonography of the neck and PET-CT. In case of suspect lymph nodes on external ultrasonography or PET-CT, fine needle aspiration (FNA) was performed. Between 2008 and 2010, 170 out of 195 referred patients underwent both external ultrasonography of the neck and PET-CT. Of all patients, 84% were diagnosed with a tumor at or below the distal esophagus. In 140 of 170 patients, the cervical region was not suspect; no FNA was performed. Seven out of 170 patients had suspect nodes on both PET-CT and external ultrasonography. Five out of seven patients had cytologically confirmed malignant lymph nodes, one of seven had benign nodes, in one patient FNA was not performed; exclusion from esophagectomy was based on intra-abdominal metastases. In one out of 170 patients, PET-CT showed suspect nodes combined with a negative external ultrasonography; cytology of these nodes was benign. Twenty-two out of 170 patients had a negative PET-CT with suspect nodes on external ultrasonography. In 18 of 22 patients, cervical lymph nodes were cytologically confirmed benign; in four patients, FNA was not possible or inconclusive. At a median postoperative follow-up of 15 months, only 1% of patients developed cervical lymph node metastases. This study shows no additional value of external ultrasonography to a negative PET-CT. According to our results, it can be omitted in the primary workup. However, suspect lymph nodes on PET-CT should be confirmed by FNA to exclude false positives if it would change treatment plan.

Cervical ultrasonography has no additional value over negative 18F-FDG PET/CT scans for diagnosing cervical lymph node metastases in patients with oesophageal cancer

“…Our results are consistent with two articles in the literature that reported no additional value of cervical ultrasonography to integrated 18 F-FDG PET/CT scanning (or standalone PET combined with CT) for detecting cervical lymph node metastases ( n = 170 and n = 136, respectively) [ 14 , 15 ]. One study found an additional value of 4% (3/74) of cervical ultrasonography over standalone PET and CT imaging ( n = 109) [ 16 ].…”

“…Therefore, the use of integrated 18 F-FDG PET/CT is currently highly recommended in initial oesophageal cancer staging [ 13 ]. Owing to the improvement in oesophageal cancer staging by 18 F-FDG PET/CT scanning, it has been suggested that the additional role of cervical ultrasonography for the detection of cervical lymph node metastasis may be limited [ 14 ]. This hypothesis was confirmed in the current cohort of patients in which no additional value of cervical ultrasonography was found to integrated 18 F-FDG PET/CT scanning for the detection of cervical metastasis.…”

“…This may have led to an underestimation of the diagnostic value of PET/CT, as standalone PET and CT may result in lower diagnostic accuracies compared to integrated 18 F-FDG PET/CT scanning. To this regard, the only study so far that used integrated 18 F-FDG PET/CT scanning demonstrated no additional value of cervical ultrasonography for the detection of cervical lymph node metastases [ 14 ]. The current study was able to confirm these results in an independent set of patients, which suggests external generalizability to other patient populations.…”

Stage‐directed individualized therapy in esophageal cancer

“…However, since the introduction of PET/CT, the additional role of external ultrasonography to detect cervical lymph node metastases in esophageal cancer staging may be limited. This is suggested by two large series that found no additional value of external ultrasonography over PET/CT with regard to the detection of cervical lymph node metastases . Only one study has shown an additional value of 4% (3/74) of external ultrasonography over CT and PET imaging .…”

“…This is suggested by two large series that found no additional value of external ultrasonography over PET/CT with regard to the detection of cervical lymph node metastases. 29,30 Only one study has shown an additional value of 4% (3/74) of external ultrasonography over CT and PET imaging. 31 However, in the latter study, the CT and PET scans were performed separately, which may yield lower diagnostic accuracy compared with integrated PET/CT scanning.…”