EAST MELBOURNE, AustraliaTwo studies from the Peter MacCallum
Cancer Institute, East Melbourne, Australia, have shown the utility of
18F-FDG-PET for newly diagnosed and suspected recurrent non-small-cell lung
cancer (NSCLC). These studies evaluated the impact of PET in routine clinical
practice within a tertiary oncology facility, said Rodney J. Hicks, MD, lead
author of both studies.
For 153 consecutive patients with newly diagnosed NSCLC, the researchers
compared the treatment plan based on conventional staging methods with the
treatment plan based on incorporation of PET findings. The results showed that
10% of cases were downstaged and 33% were upstaged by inclusion of PET.
Among patients with assessable tumors, the PET stage was confirmed in 89%.
PET had a high impact on 54 patients (35%), including 34 whose treatment was
changed from curative to palliative (see Figure 1), 6 whose therapy was changed
from palliative to curative, and 14 whose treatment modality was changed but
not the treatment intent. For 39 patients (25%), a previously selected therapy
was changed because of the PET results (J Nucl Med 42:1596-1604, 2001).
"Staging that incorporated PET provided a more accurate prognostic
stratification than did staging based on conventional investigations," Dr.
Hicks and his colleagues concluded. "Further, the additional information
provided by PET significantly and appropriately changed management in the
majority of patients."
The second trial of F-18-FDG PET involved 63 consecutive NSCLC patients with
suspected relapse more than 6 months after definitive treatment. The
researchers compared the apparent extent of disease on conventional restaging
with that on FDG-PET. In order to validate diagnostic findings, serial imaging
and pathologic results were obtained during a median follow-up of 19 months.
PET was positive in 41 of 42 patients with confirmed relapse (98%
sensitivity). There was no evidence of disease during a minimum follow-up of 12
months in 14 of 15 patients with clinically suspected relapse but negative PET
findings (negative predictive value, 93%) (J Nucl Med 42:1605-1613, 2001).