Neither PET nor PET/CT has been proven to benefit patients with esophageal cancer, according to a report issued August 20 from the German Institute for Quality and Efficiency in Health Care (IQWiG).
The report adds that the potential advantage of PET and PET/CT — the ability to visualize metabolic activity — "remains unclear," compared with morphologic imaging techniques, such as CT alone or MRI, that display anatomical structures.
According to the team from the IQWiG, there is no strong evidence that PET, alone or in combination with CT, increases survival, improves quality of life, or results in fewer operations or diagnostic interventions. This conclusion stems from the fact that there are no studies that directly compare outcomes using these newer technologies with outcomes using older, standard methods.
The German investigators did find 48 studies related to the diagnostic and prognostic accuracy of PET and PET/CT. Most focused on the accuracy of primary staging or the classification of tumor stages pretreatment.
But again, the investigators say, "too few studies are so far available that directly compared PET or PET/CT with other diagnostic techniques and investigated treatment response (restaging) or diagnosis and prognosis of tumor recurrence." They conclude that this evidence is not strong enough to be reliable.
That particular conclusion about staging will likely surprise some people. "Many experts assume that an examination using PET or PET/CT, alone or in combination with other methods, is better able to evaluate how far a tumor has spread (staging) and whether it has responded to treatment (restaging)," a press statement from the IQWiG notes.
The IQWiG team reports that literature comparing PET with CT is lacking. Even though there were 19 studies directly comparing PET with CT, "conclusions in favor of 1 or the 2 techniques cannot be drawn," they write. The reason is that either no statistically significant difference was shown or the data could not be interpreted with sufficient certainty.
The report is currently only available in German. Those interested in the English translation, which will be issued soon, should email email@example.com.
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Cite this: PET Not Proven in Esophageal Cancer, Says German Report - Medscape - Sep 04, 2013.