PT  - JOURNAL ARTICLE
AU  - Edet-Sanson, Agathe
AU  - Doyeux, Kaya
AU  - Dubray, Bernard
AU  - Hapdey, Sebastien
AU  - Hitzel, Anne
AU  - Guernou, Mohamed
AU  - Modezelewski, Romain
AU  - Gensanne, David
AU  - Gardin, Isabelle
AU  - Vera, Pierre
TI  - Variation of FDG-PET tumor metabolism during external radiotherapy (ERT) in patients with non small cell lung cancer (NSCLC)
DP  - 2009 May 01
TA  - Journal of Nuclear Medicine
PG  - 279--279
VI  - 50
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/50/supplement_2/279.short
4100  - http://jnm.snmjournals.org/content/50/supplement_2/279.full
SO  - J Nucl Med2009 May 01; 50
AB  - 279 Objectives To assess the feasibility of serial FDG-PET imaging during ERT and to determine when the variation of FDG uptake is maximal. Methods 9 NSCLC patients with a significant FDG-PET tumor activity (versus background level), candidate for curative ERT alone (RT; n=3) (60 to 70 Gy, 2 Gy per fraction, 5 fractions per week) or ERT associated to chemotherapy (CRT; n=6) were prospectively investigated. 5 or 6 PET/CT (PETn, n=1-6) per patient were performed on Siemens Biograph. For each exam, a 15min thoracic respiratory gated (RG) acquisition was started 60±5mn after the injection of 3.5 MBq/kg of FDG followed by a standard 5min ungated (STD) thoracic acquisition. PET2-6 were performed during RT every 14 Gy. Tumor metabolism was assessed by the variation of SUVmax,PETn compared to SUVmax,PET1. We also compared the tumor volumes on RG and STD acquisitions applying a 40% threshold of SUVmax. Results Tumor volumes were not different between STD or RG acquisitions because the tumor localizations were slightly influenced by respiratory movements. At 14 Gy, SUVmax increased in 4/9 patients (2/3 RT and 2/6 CRT). At 28 and 42 Gy, mean decrease of SUVmax was 42±20% and 39±21%. An increase of SUVmax was observed in a single CRT patient. Conclusions FDG-PET images can be analyzed during thoracic RT, either alone or associated to chemotherapy. A single FDG-PET acquisition after 42 Gy appears to be able to separate the patients according to FDG-PET response during RT. A longer follow-up is necessary to assess the potential predictive value of FDG-PET response during RT.