Thallium and FDG uptake by atelectasis with bronchogenic carcinoma

Abstract

We report a case of bronchogenic carcinoma with atelectasis studied by T1-SPECT and FDG-PET. In the carcinoma, abnormally high uptake of T1 and FDG were detected, but in the region of atelectasis, an abnormally high uptake of T1 with a relatively low uptake of FDG were observed. On quantitative analyses, the T1 retention indexes of the tumor and atelectasis were 29.7 and 42.0. The mean SUVs of FDG of the tumor and the atelectasis were 8.92 and 1.28. T1-SPECT could not distinguish the atelectasis from the carcinoma. FDG-PET was superior to T1-SPECT in this case in detecting malignancy and distinguishing it from atelectasis.

Imaging with F‐18 FDG PET is superior to Tl‐201 SPECT in the staging of non‐small cell lung cancer for radical radiation therapy*

“…In the case described by Kawabe et al, FDG-PET was superior to thallium scanning in distinguishing between atelectasis and tumour. 26 Flores et al…”

“…Although wash‐out of activity is typical of inflammatory atelectasis, Tl‐201 retention in atelectatic lung may be prolonged, giving a false positive result for tumour involvement in some cases. In the case described by Kawabe et al , FDG‐PET was superior to thallium scanning in distinguishing between atelectasis and tumour 26 . Flores et al reported that thallium‐201 was less sensitive and specific than CT in the imaging of lung tumours 13 .…”

“…In combination these factors make this a relatively expensive imaging protocol, which may be appropriate only if the scan provides useful information that appropriately guides management. There is now evidence to suggest that Tl‐201 SPECT may be unreliable in distinguishing tumour from atelectasis 25,26 . Although wash‐out of activity is typical of inflammatory atelectasis, Tl‐201 retention in atelectatic lung may be prolonged, giving a false positive result for tumour involvement in some cases.…”

“…There is now evidence to suggest that Tl-201 SPECT may be unreliable in distinguishing tumour from atelectasis. 25,26 Although wash-out of activity is typical of inflammatory atelectasis, Tl-201 retention in atelectatic lung may be prolonged, giving a false positive result for tumour involvement in some cases. In the case described by Kawabe et al, FDG-PET was superior to thallium scanning in distinguishing between atelectasis and tumour.…”

A Multimodality Imaging Review of Malignant Pleural Mesothelioma Response Assessment

“…[43][44][45] In addition to its diagnostic value, the accurate differentiation between tumor and atelectasis achieved by PET has proved beneficial for the creation of appropriate size portals during radiation therapy planning, to minimize radiation dose to normal tissue, 46 and could potentially be useful in ensuring that selection of sites for response assessment avoids atelectatic areas. McAdams and colleagues 44 reported their results on 9 patients with rounded atelectasis who underwent dedicated FDG-PET imaging.…”