Objectives: The aim of this study was to evaluate the prognostic value of pretreatment 18F-fluorodeoxyglucose PET/computed tomography (CT), particularly in the assessment of metabolic tumor burden markers such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), with respect to clinical outcomes in stage I non-small-cell lung cancer (NSCLC) patients undergoing stereotactic body radiation therapy (SBRT).
Methods: This retrospective study evaluated 50 patients who underwent SBRT for stage I NSCLC from May 2007 to December 2012. The maximum standardized uptake value (SUVmax), average SUV (SUVavg), MTV, and TLG were measured from the PET/CT scan. The study population was dichotomized at the median into high and low groups. Kaplan–Meier log-rank tests were then used to compare high with low PET/CT parameter groups, and univariate Cox proportional hazards regression analysis was carried out to identify predictors of overall survival.
Results: The 2-year local control rate was 93.7%. After a median follow-up of 25.1 months, the 2-year overall survival was 79.3%. Eight patients (16%) had disease recurrence. There were three local failures (6%), three mediastinal failures (6%), and six cases of distant metastases (12%). Both Kaplan–Meier actuarial analysis and Cox proportional hazards regression found no correlation between SUVmax, SUVavg, MTV, and TLG and overall survival.
Conclusion: Standard PET/CT measures, such as SUVmax, as well as newer measures of metabolic tumor burden, such as MTV and TLG, were not correlated with overall survival in our study population of stage I NSCLC patients undergoing SBRT. Larger studies with longer follow-up periods are needed to confirm these results.
Departments of aRadiology
cSurgery, Division of Cardiothoracic Surgery, Stony Brook University Medical Center, Stony Brook, New York, USA
Correspondence to Robert Matthews, MD, Health Sciences Center, L-4 Rm 120, Stony Brook, NY 11794-8460, USA Tel: +1 631 444 1298; fax: +1 631 444 8965; e-mail: firstname.lastname@example.org
Received April 27, 2013
Accepted June 25, 2013