http://www.ncbi.nlm.nih.gov/pubmed/22417800

Int J Radiat Oncol Biol Phys. 2012 Mar 13. [Epub ahead of print]

Residual (18)F-FDG-PET Uptake 12 Weeks after Stereotactic Ablative Radiotherapy for Stage I Non-Small-Cell Lung Cancer Predicts Local Control.

Bollineni VR, Widder J, Pruim J, Langendijk JA, Wiegman EM.

Source

Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Abstract

PURPOSE:

To investigate the prognostic value of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) uptake at 12 weeks after stereotactic ablative radiotherapy (SABR) for stage I non-small-cell lung cancer (NSCLC).

METHODS AND MATERIALS:

From November 2006 to February 2010, 132 medically inoperable patients with proven Stage I NSCLC or FDG-PET-positive primary lung tumors were analyzed retrospectively. SABR consisted of 60 Gy delivered in 3 to 8 fractions. Maximum standardized uptake value (SUV(max)) of the treated lesion was assessed 12 weeks after SABR, using FDG-PET. Patients were subsequently followed at regular intervals using computed tomography (CT) scans. Association between post-SABR SUV(max) and local control (LC), mediastinal failure, distant failure, overall survival (OS), and disease-specific survival (DSS) was examined.

RESULTS:

Median follow-up time was 17 months (range, 3-40 months). Median lesion size was 25 mm (range, 9-70 mm). There were 6 local failures: 15 mediastinal failures, 15 distant failures, 13 disease-related deaths, and 16 deaths from intercurrent diseases. Glucose corrected post-SABR median SUV(max) was 3.0 (range, 0.55-14.50). Using SUV(max) 5.0 as a cutoff, the 2-year LC was 80% versus 97.7% for high versus low SUV(max), yielding an adjusted subhazard ratio (SHR) for high post-SABR SUV(max) of 7.3 (95% confidence interval [CI], 1.4-38.5; p = 0.019). Two-year DSS rates were 74% versus 91%, respectively, for high and low SUV(max) values (SHR, 2.2; 95% CI, 0.8-6.3; p = 0.113). Two-year OS was 62% versus 81% (hazard ratio [HR], 1.6; 95% CI, 0.7-3.7; p = 0.268).

CONCLUSIONS:

Residual FDG uptake (SUV(max) ≥5.0) 12 weeks after SABR signifies increased risk of local failure. A single FDG-PET scan at 12 weeks could be used to tailor further follow-up according to the risk of failure, especially in patients potentially eligible for salvage surgery.