Clinical value of PET/CT's SUV max at baseline, early follow-up, and end of treatment reevaluation as a prognostic factor in small cell lung cancer patients with extended disease.

Abstract

e18558 Background: Patients with Small Cell Lung Cancer (SCLC) have been staged by the two-stage system. This system defines limited disease (LD) when is confined to ipsilateral hemithorax that can be encompassed within tolerable radiation field; extended disease (ED) is defined as the disease extending outside the hemithorax. The IASLC recommended that TNM staging should be used in SCLC including clinical trials. However these systems have shown poor correlation between clinical findings and the pathological results. Objectives: Evaluate prognostic factors as age, ECOG and PET CT’s SUV max at base line, early follow up and end of treatment reevaluation; and their correlation with Overall survival (OS) and Progression free survival (PFS). Methods: Prospectively were recruited patients with histologically confirmed SCLC and ED and were evaluated with basal PET CT, early follow up (PET CT after 2 cycles of Platinum based chemotherapy) and end of treatment assessment with a PET CT after 6 cycles. Comprehensive database including clinical data were collected as age, ECOG, site of metastases, type of treatment and outcome. 23 patients were recruited from January 2010 to June 2012 and the follow up made until January 15th 2013. The Cox correlation test was used. Results: Median age 66,5 years (range 52-80) the OS was 7,9 months (CI 95% 6.7-9.1) and the PFS was 5,3 months (CI 95% 4,5-6,2). The baseline ECOG was an independent prognostic factor for OS (p= <0,0001) and PSF (p= 0,008). Age was not prognostic in our data. SUV max at baseline was an independent prognostic factor for OS (p= 0,001) and PFS (p= 0,009). For early follow up were evaluated 14 patients and for end of treatment reevaluation were assessed 9 patients. Differences between SUV max at baseline and early follow up or with end of treatment reevaluation were not predictive for PFS or OS. Conclusions: In our study the ECOG and basal PET CT SUV max are independent prognosis factors with consistent correlation with OS and PFS. The early follow up and end of treatment reevaluation with PET CT did not predict outcome in our patients. Further studies should be considered to test the value of follow up with PET CT.