Factors causing inaccurate staging of mediastinal nodal involvement in non-small cell lung cancer patients staged by positron emission tomography

Abstract

Despite documented superiority of positron emission tomography over other investigative modalities in the preoperative staging of non-small cell lung cancer, a proportion of patients will have an inaccurate staging of their mediastinal nodes. The aim of this retrospective review is to analyse the clinicopathological factors responsible for inaccurate nodal staging by integrated PET-CT. A total of 100 consecutive patients with histologically proven non-small cell lung cancer underwent staging with PET-CT prior to lung resection. Thirty-three patients, inaccurately staged by PET-CT, were analysed. Univariate analysis identified the following as significant in causing inaccurate nodal staging: history of tuberculosis (P=0.039) and non-insulin dependant diabetes (P=0.014). In multivariate analysis, we have identified the following as independent factors in causing inaccurate staging of mediastinal lymph nodes: rheumatoid arthritis, non-insulin dependent diabetes, history of tuberculosis, presence of atypical adenomatous hyperplasia and pneumonia (P<0.05). The highest rate of inaccuracy in mediastinal nodal staging was in nodal station 4 (11%, P=0.01) followed by station 7 (10%, P=0.02) and station 9 (3.5%, P=0.01). Interpretation of PET-CT staging of the mediastinum in patients with a history of the above should be with caution, as the incidence of false upstaging and down staging in these subgroups is high. Vigilance of such factors may improve the accuracy of PET-CT in staging mediastinal lymph nodes. Histological confirmation should always be sought.

Accuracy of PET/CT with FDG in mediastinal lymph node staging of patients with NSCLC

“…In fact, we had 10.5% of false negative and 8.5% of false positive cases. A high rate of false negative patients for N2 disease in the adenocarcinoma group was identified, as with other authors [35].…”

“…In conclusion he stressed the necessity to identify the subset of patients with a negative PET/CT, that could benefit from a mediastinoscopy [25][26][27][28][29][30][31][32][33][34][35][36][37].…”

“…Therefore, in patient cohorts with a higher likelihood of mediastinal lymph node involvement, a negative PET scan does not obviate the need of invasive staging procedures [31][32][33][34][35]. New randomized trials will be necessary to identify these cohorts of patients.…”

The Effectiveness of 18F-FDG PET/CT Combined with STIR MRI for Diagnosing Nodal Involvement in the Thorax

“…18 F-FDG PET can reflect physiologic and biochemical functions and is useful for differential diagnosis of benign and malignant lesions (14)(15)(16). However, there are numerous causes of 18 F-FDG uptake in benign processes, which lead to false-positive results (1,(17)(18)(19) even when PET/CT is also used (20,21). Some investigators have reported that short-t inversion-recovery (STIR) MRI has utility for the detection of metastases in mediastinal and hilar lymph nodes in lung cancer patients (22)(23)(24).…”

Nodal upstaging: effects of instrumentation and three-dimensional view in clinical stage I lung cancer

“…They concluded that early-stage NSCLC located in the lower lobes was associated with upstaging after surgery. Another study investigating nodal upstaging was reported by AlSarraf et al (5). This is study evaluated the risk factors of inaccuracy in N staging (both downstaging and upstaging), and concluded that inaccurate nodal staging was common in patients with history of tuberculosis, rheumatoid arthritis, and diabetes mellitus.…”