[Role of FDG PET in the staging, recurrence and treatment response to imatinib (Glivec) in patients with gastrointestinal stromal tumors].
BACKGROUND
Gastrointestinal stromal tumors (GISTs) account for almost 4 % of all gastrointestinal neoplasms. Recently, a new type of tyrosine kinase inhibitor (Glivec), has been successfully used in patients with metastasic or unresectable disease. The aim of the study is to show the utility of PET in the staging, recurrence and treatment response to Glivec in GIST tumors.


METHODS
48 whole body FDG-PET studies in 27 patients with GIST (19 men/mean age = 56 y) were evaluated for initial staging (n = 13), recurrence (n = 15) or treatment response to Glivec (n = 20). Images were acquired in a whole body 2D mode using attenuation correction on an Advance Nxi G.E.MS camera and were evaluated visually and quantatively using SUV analysis. Results were compared with radiological findings, hystological confirmation or follow-up.


RESULTS
In the initial staging evaluation, FDG-PET shows a more extensive disease than suspected in 3/10 patients. In other 3 patients PET ruled out mesenteric or peritoneal disease. In the evaluation of treatment response to Glivec, FDG-PET showed a good response in eleven patients (complete response in seven and partial response in four). In this group a sixty percent decrease of the SUV max was assessed. Two patients showed no response to Glivec at doses of 400 mg or 800 mg, showing a stable SUV value and/or increased in some abdominal lesions. PET detected recurrence in one patient.


CONCLUSIONS
This study show how FDG-PET is accurate in the early treatment response to Glivec. PET could be helpful in the staging and recurrence of GIST tumors.
Simó Perdigó
M
M
CETIR Unitat PET, Esplugues de Llobregat, Barcelona. msimo@cetir.es
García Garzón
J R
JR
Soler Peter
M
M
Pérez Moure
G
G
López Gandul
S
S
Lomeña Caballero
F J
FJ
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D019008:Drug Resistance, Neoplasm; D005260:Female; D019788:Fluorodeoxyglucose F18; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D009367:Neoplasm Staging / Q000379:methods; D010879:Piperazines / Q000627:therapeutic use*; D049268:Positron-Emission Tomography; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011743:Pyrimidines / Q000627:therapeutic use*; D019275:Radiopharmaceuticals; D013274:Stomach Neoplasms
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000068877:Imatinib Mesylate