Chin et al. Mediastinal staging of non-small cell lung cancer with PET. American Journal of Respiratory and Critical Care Medicine. 152:2090-2096. 1995.
Clinical Bottom Lines:
1. PET offers the advantage of potentially identifying micrometastases in normal sized nodes on CT.
2. Further clinical trials have been completed to potentially discern if PET offers more prognostic inforamtion and identifies the limitations of PET scanning in NSCLC.
3. PET scans, though not appropriate for all patients, may prove to be a useful in adjunctive non-invasive tool in NSCLC.
Evidence:
30 patients with potentially respectable NSCLC tumors received PET and CT and results compared with pathologic tissue diagnosis at time of surgery.
PET CT sensitivity 78% 56% specificity 81% 86% PPV 64% 63% NPV 89% 82% +LR 4.1 4 -LR 3.7 2
Comments:
1. Although small number in inital study, a subsequent abstract with 112 patients (73 went to surgery) has been presented.
2. ln 2nd abstract, PET had 3 FN's and 4FP's with a sens. 95% and PPV 94%.
3. Several of the cancers that PET overstaged had recurrence.
4. Most of the cancers that PET understaged had chest wall invasion or were central tumors.
5. SUV's (standard uptake values) may take on more importance as objective evidence in reading PET scans.
6. Questions of interest that may be answered now that> 200 patients enrolled, include does a (+) or (-) PET have any prognostic implications? and what causes a FN or a FP?