Abstract
ObjectiveThe maximal standardized uptake value (SUVmax) of pulmonary lesions on dual-time-point (DTP) fluorodeoxyglucose positron emission tomography (FDG-PET) has been shown to be useful for differentiation between malignant and non-malignant pulmonary lesions, and also to be of value for intrathoracic nodal staging of non-small cell lung cancer (NSCLC). However, a few NSCLC lesions have been found to show decreased FDG uptake on delayed images, and the significance of this finding remains unknown.Patients and methodsWe conducted a retrospective review of the data of 284 patients with NSCLC who underwent DTP FDG-PET before surgery. Cases of adenocarcinoma in situ and minimally invasive adenocarcinoma were excluded, because these lesions show little FDG uptake. Each patient was scanned at 60 min (early acquisition; SUV-E) and 115 min (delayed acquisition; SUV-D) after the radiopharmaceutical injection. The intratumoral retention index (RI) of 18F-FDG was measured for each examination by the DTP method. Recurrence-free survival (RFS) was determined by the Kaplan–Meier method and compared in relation to the SUV-E, SUV-D, and RI by univariate and multivariate analysis using models including the clinico-pathological prognostic factors.ResultsOf the 284 cases, the RI ≤ 0 was in 49 cases (17.3 %). This group of patients showed lower values of SUV-E and SUV-D, a smaller tumor size, and a lower rate of lymphatic invasion or vascular invasion. It was particularly noteworthy that lymph node metastasis was not histopathologically confirmed in any of these patients. Univariate analysis identified the RI, SUV-E and SUV-D, besides age, tumor size, lymph node metastasis, and tumor differentiation grade as predictors of the RFS. On the other hand, multivariate analysis identified the RI and lymph node metastasis, but not the SUV-E and SUV-D, as independent predictors of the RFS.ConclusionsThis study demonstrated that DTP FDG-PET of the primary tumor in NSCLC can be useful to predict the RFS of the patients. In addition, this method may also be useful to predict the presence/absence of intrathoracic lymph node metastasis in these patients.
Highlights
Fluorodeoxyglucose positron emission tomography (FDGPET) has become an important tool for the diagnosis and staging of non-small cell lung cancer (NSCLC) [1]
This study demonstrated that DTP fluorodeoxyglucose positron emission tomography (FDGPET) of the primary tumor in NSCLC can be useful to predict the Recurrence-free survival (RFS) of the patients
Several investigators have shown that determination of the SUVmax of the lymph nodes on DTP FDG-PET improved the diagnostic ability of this imaging modality for intrathoracic nodal staging in NSCLC patients [11,12,13]
Summary
Fluorodeoxyglucose positron emission tomography (FDGPET) has become an important tool for the diagnosis and staging of non-small cell lung cancer (NSCLC) [1]. In NSCLC patients, the SUVmax values of the primary tumors have been known to be correlated with the disease stage, nodal status, histological type, tumor differentiation grade, and rate of progression of the tumors [3,4,5]. Several studies have reported that determination of the SUVmax of pulmonary lesions on dual-time-point (DTP) FDG-PET is useful for differentiation between malignant and non-malignant pulmonary lesions [8,9,10]. Several investigators have shown that determination of the SUVmax of the lymph nodes on DTP FDG-PET improved the diagnostic ability of this imaging modality for intrathoracic nodal staging in NSCLC patients [11,12,13]. Most malignant lesions, including primary tumors and lymph nodes, show increased FDG uptake on the delayed-phase images
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
