F-18 fluorodeoxyglucose positron emission tomography staging in radical radiotherapy candidates with nonsmall cell lung carcinoma - Powerful correlation with survival and high impact on treatment

BACKGROUND. Successful treatment of nonsmall cell lung carcinoma (NSCLC) wi th radical radiotherapy (RT) requires accurate delineation of tumor extent. Conventional computed tomography-based noninvasive staging often estimates intrathoracic thoracic tumor extent incorrectly and fails to detect distan t metastasis. High sensitivity and specificity are reported for F-18 fluoro deoxyglucose (FDG) positron emission tomography (PET) staging in potentiall y resectable NSCLC. The authors investigated FDG-PET staging in radical RT candidates with unresectable NSCLC. METHODS. The authors prospectively studied 153 consecutive patients with un resectable NSCLC who were candidates for radical RT after conventional stag ing and had PET scans. Patients were allocated both "before PET" and "after PET" stages. Subsequent management was recorded. Survival analysis was use d to compare validity of pre-PET and post-PET staging. RESULTS. After PET, 107 patients (70%) actually received radical therapies (radical RT with or without concurrent chemotherapy, n = 102; radical surge ry, n = 5); 46 patients (30%a) received palliative treatment because of PET -detected distant metastasis (n = 28; 18%) or extensive locoregional diseas e (n = 18; 12%). Palliative therapies were RT (n = 33), chemotherapy (n = 1 2), or supportive care (n = 1). All five surgically treated patients underw ent potentially curative resections after downstaging by PET. For radically treated patients, post-PET stage (P = 0.0041) but not pre-PET stage (P = 0 .19) was strongly associated with survival. Radically treated patients surv ived longer than those treated palliatively (P = 0.02; 1-year survival, 69% and 44%, respectively; 2-year survival, 44% radical; no palliative patient s had 2-yr follow-up). CONCLUSIONS. Positron emission tomography-assisted staging detected unsuspe cted metastasis in 20%, strongly influenced choice of treatment strategy, f requently impacted RT planning, and was a powerful predictor of survival. P otential impact of FDG-PET is even greater in radical RT candidates with NS CLC than in surgical candidates. (C) 2001 American Cancer Society.